mojoshader_opengl.c

/**
 * MojoShader; generate shader programs from bytecode of compiled
 *  Direct3D shaders.
 *
 * Please see the file LICENSE.txt in the source's root directory.
 *
 *  This file written by Ryan C. Gordon.
 */

// !!! FIXME: preshaders shouldn't be handled in here at all. This should
// !!! FIXME:  be in the Effects API, once that's actually written.

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <assert.h>

// !!! FIXME: most of these _MSC_VER should probably be _WINDOWS?
#ifdef _MSC_VER
#define WIN32_LEAN_AND_MEAN 1
#include <windows.h>  // GL headers need this for WINGDIAPI definition.
#endif

#if (defined(__APPLE__) && defined(__MACH__))
#define PLATFORM_MACOSX 1
#endif

#if PLATFORM_MACOSX
#include <Carbon/Carbon.h>
#endif

#define __MOJOSHADER_INTERNAL__ 1
#include "mojoshader_internal.h"

#define GL_GLEXT_LEGACY 1
#include "GL/gl.h"
#include "GL/glext.h"

#ifndef GL_HALF_FLOAT_NV
#define GL_HALF_FLOAT_NV 0x140B
#endif

#ifndef GL_HALF_FLOAT_ARB
#define GL_HALF_FLOAT_ARB 0x140B
#endif

#ifndef GL_HALF_FLOAT_OES
#define GL_HALF_FLOAT_OES 0x8D61
#endif

// this happens to be the same value for ARB1 and GLSL.
#ifndef GL_PROGRAM_POINT_SIZE
#define GL_PROGRAM_POINT_SIZE 0x8642
#endif

struct MOJOSHADER_glShader
{
    const MOJOSHADER_parseData *parseData;
    GLuint handle;
    uint32 refcount;
};

typedef struct
{
    MOJOSHADER_shaderType shader_type;
    const MOJOSHADER_uniform *uniform;
    GLint location;
} UniformMap;

typedef struct
{
    const MOJOSHADER_attribute *attribute;
    GLint location;
} AttributeMap;

struct MOJOSHADER_glProgram
{
    MOJOSHADER_glShader *vertex;
    MOJOSHADER_glShader *fragment;
    GLuint handle;
    uint32 generation;
    uint32 uniform_count;
    uint32 texbem_count;
    UniformMap *uniforms;
    uint32 attribute_count;
    AttributeMap *attributes;
    size_t vs_uniforms_float4_count;
    GLfloat *vs_uniforms_float4;
    size_t vs_uniforms_int4_count;
    GLint *vs_uniforms_int4;
    size_t vs_uniforms_bool_count;
    GLint *vs_uniforms_bool;
    size_t ps_uniforms_float4_count;
    GLfloat *ps_uniforms_float4;
    size_t ps_uniforms_int4_count;
    GLint *ps_uniforms_int4;
    size_t ps_uniforms_bool_count;
    GLint *ps_uniforms_bool;

    size_t vs_preshader_reg_count;
    GLfloat *vs_preshader_regs;
    size_t ps_preshader_reg_count;
    GLfloat *ps_preshader_regs;

    uint32 refcount;

    int uses_pointsize;

    // GLSL uses these...location of uniform arrays.
    GLint vs_float4_loc;
    GLint vs_int4_loc;
    GLint vs_bool_loc;
    GLint ps_float4_loc;
    GLint ps_int4_loc;
    GLint ps_bool_loc;
};

typedef struct
{ 
    uint32 vs_index;
    uint32 ps_index;
    uint32 program_index;
    // TODO: state information.
} MOJOSHADER_glPass;

typedef struct
{ 
    uint32 pass_count;
    MOJOSHADER_glPass *passes;
} MOJOSHADER_glTechnique;

typedef struct
{
    GLvoid *data;
    uint32 data_size;
    GLboolean isset;

    uint32 shader_symbol_count;
    MOJOSHADER_symbol** shader_symbols;
    MOJOSHADER_symbol** preshader_symbols;
} glEffectParam;

struct MOJOSHADER_glEffect
{
    const MOJOSHADER_effect *effect;

    uint32 shader_count;
    MOJOSHADER_glShader **shaders;

    uint32 program_count;
    MOJOSHADER_glProgram **programs;

    uint32 technique_count;
    MOJOSHADER_glTechnique *techniques;

    uint32 param_count;
    glEffectParam *param_cache;

	uint32 refcount;

    uint32 bound_technique_index;
    uint32 bound_pass_index;
};

#ifndef WINGDIAPI
#define WINGDIAPI
#endif

// Entry points in base OpenGL that lack function pointer prototypes...
typedef WINGDIAPI void (APIENTRYP PFNGLGETINTEGERVPROC) (GLenum pname, GLint *params);
typedef WINGDIAPI const GLubyte * (APIENTRYP PFNGLGETSTRINGPROC) (GLenum name);
typedef WINGDIAPI GLenum (APIENTRYP PFNGLGETERRORPROC) (void);
typedef WINGDIAPI void (APIENTRYP PFNGLENABLEPROC) (GLenum cap);
typedef WINGDIAPI void (APIENTRYP PFNGLDISABLEPROC) (GLenum cap);
typedef WINGDIAPI void (APIENTRYP PFNGLBINDTEXTUREPROC) (GLenum target, GLuint texture);

// Max entries for each register file type...
#define MAX_REG_FILE_F 8192
#define MAX_REG_FILE_I 2047
#define MAX_REG_FILE_B 2047
#define MAX_TEXBEMS 3  // ps_1_1 allows 4 texture stages, texbem can't use t0.

struct MOJOSHADER_glContext
{
    // Allocators...
    MOJOSHADER_malloc malloc_fn;
    MOJOSHADER_free free_fn;
    void *malloc_data;

    // The constant register files...
    // !!! FIXME: Man, it kills me how much memory this takes...
    // !!! FIXME:  ... make this dynamically allocated on demand.
    GLfloat vs_reg_file_f[MAX_REG_FILE_F * 4];
    GLint vs_reg_file_i[MAX_REG_FILE_I * 4];
    uint8 vs_reg_file_b[MAX_REG_FILE_B];
    GLfloat ps_reg_file_f[MAX_REG_FILE_F * 4];
    GLint ps_reg_file_i[MAX_REG_FILE_I * 4];
    uint8 ps_reg_file_b[MAX_REG_FILE_B];
    GLuint sampler_reg_file[16];
    GLfloat texbem_state[MAX_TEXBEMS * 6];

    // This increments every time we change the register files.
    uint32 generation;

    // This keeps track of implicitly linked programs.
    HashTable *linker_cache;

    // This tells us which vertex attribute arrays we have enabled.
    GLint max_attrs;
    uint8 want_attr[32];
    uint8 have_attr[32];

    // rarely used, so we don't touch when we don't have to.
    int pointsize_enabled;

    // GL stuff...
    int opengl_major;
    int opengl_minor;
    int glsl_major;
    int glsl_minor;
    MOJOSHADER_glProgram *bound_program;
    char profile[16];

    // Effect stuff
    MOJOSHADER_glEffect *bound_effect;

    // Extensions...
    int have_core_opengl;
    int have_opengl_2;  // different entry points than ARB extensions.
    int have_opengl_3;  // different extension query.
    int have_GL_ARB_vertex_program;
    int have_GL_ARB_fragment_program;
    int have_GL_NV_vertex_program2_option;
    int have_GL_NV_fragment_program2;
    int have_GL_NV_vertex_program3;
    int have_GL_NV_gpu_program4;
    int have_GL_ARB_shader_objects;
    int have_GL_ARB_vertex_shader;
    int have_GL_ARB_fragment_shader;
    int have_GL_ARB_shading_language_100;
    int have_GL_NV_half_float;
    int have_GL_ARB_half_float_vertex;
    int have_GL_OES_vertex_half_float;
    int have_GL_ARB_instanced_arrays;

    // Entry points...
    PFNGLGETSTRINGPROC glGetString;
    PFNGLGETSTRINGIPROC glGetStringi;
    PFNGLGETERRORPROC glGetError;
    PFNGLGETINTEGERVPROC glGetIntegerv;
    PFNGLENABLEPROC glEnable;
    PFNGLDISABLEPROC glDisable;
    PFNGLBINDTEXTUREPROC glBindTexture;
    PFNGLDELETESHADERPROC glDeleteShader;
    PFNGLDELETEPROGRAMPROC glDeleteProgram;
    PFNGLATTACHSHADERPROC glAttachShader;
    PFNGLCOMPILESHADERPROC glCompileShader;
    PFNGLCREATESHADERPROC glCreateShader;
    PFNGLCREATEPROGRAMPROC glCreateProgram;
    PFNGLDISABLEVERTEXATTRIBARRAYPROC glDisableVertexAttribArray;
    PFNGLENABLEVERTEXATTRIBARRAYPROC glEnableVertexAttribArray;
    PFNGLGETATTRIBLOCATIONPROC glGetAttribLocation;
    PFNGLGETPROGRAMINFOLOGPROC glGetProgramInfoLog;
    PFNGLGETSHADERINFOLOGPROC glGetShaderInfoLog;
    PFNGLGETSHADERIVPROC glGetShaderiv;
    PFNGLGETPROGRAMIVPROC glGetProgramiv;
    PFNGLGETUNIFORMLOCATIONPROC glGetUniformLocation;
    PFNGLLINKPROGRAMPROC glLinkProgram;
    PFNGLSHADERSOURCEPROC glShaderSource;
    PFNGLUNIFORM1IPROC glUniform1i;
    PFNGLUNIFORM1IVPROC glUniform1iv;
    PFNGLUNIFORM4FVPROC glUniform4fv;
    PFNGLUNIFORM4IVPROC glUniform4iv;
    PFNGLUSEPROGRAMPROC glUseProgram;
    PFNGLVERTEXATTRIBPOINTERPROC glVertexAttribPointer;
    PFNGLACTIVETEXTUREPROC glActiveTexture;
    PFNGLBLENDEQUATIONPROC glBlendEquation;
    PFNGLBLENDFUNCSEPARATEPROC glBlendFuncSeparate;
    PFNGLDELETEOBJECTARBPROC glDeleteObjectARB;
    PFNGLATTACHOBJECTARBPROC glAttachObjectARB;
    PFNGLCOMPILESHADERARBPROC glCompileShaderARB;
    PFNGLCREATEPROGRAMOBJECTARBPROC glCreateProgramObjectARB;
    PFNGLCREATESHADEROBJECTARBPROC glCreateShaderObjectARB;
    PFNGLDISABLEVERTEXATTRIBARRAYARBPROC glDisableVertexAttribArrayARB;
    PFNGLENABLEVERTEXATTRIBARRAYARBPROC glEnableVertexAttribArrayARB;
    PFNGLGETATTRIBLOCATIONARBPROC glGetAttribLocationARB;
    PFNGLGETINFOLOGARBPROC glGetInfoLogARB;
    PFNGLGETOBJECTPARAMETERIVARBPROC glGetObjectParameterivARB;
    PFNGLGETUNIFORMLOCATIONARBPROC glGetUniformLocationARB;
    PFNGLLINKPROGRAMARBPROC glLinkProgramARB;
    PFNGLSHADERSOURCEARBPROC glShaderSourceARB;
    PFNGLUNIFORM1IARBPROC glUniform1iARB;
    PFNGLUNIFORM1IVARBPROC glUniform1ivARB;
    PFNGLUNIFORM4FVARBPROC glUniform4fvARB;
    PFNGLUNIFORM4IVARBPROC glUniform4ivARB;
    PFNGLUSEPROGRAMOBJECTARBPROC glUseProgramObjectARB;
    PFNGLVERTEXATTRIBPOINTERARBPROC glVertexAttribPointerARB;
    PFNGLGETPROGRAMIVARBPROC glGetProgramivARB;
    PFNGLPROGRAMLOCALPARAMETER4FVARBPROC glProgramLocalParameter4fvARB;
    PFNGLPROGRAMLOCALPARAMETERI4IVNVPROC glProgramLocalParameterI4ivNV;
    PFNGLVERTEXATTRIBDIVISORPROC glVertexAttribDivisorARB;
    PFNGLDELETEPROGRAMSARBPROC glDeleteProgramsARB;
    PFNGLGENPROGRAMSARBPROC glGenProgramsARB;
    PFNGLBINDPROGRAMARBPROC glBindProgramARB;
    PFNGLPROGRAMSTRINGARBPROC glProgramStringARB;

    // interface for profile-specific things.
    int (*profileMaxUniforms)(MOJOSHADER_shaderType shader_type);
    int (*profileCompileShader)(const MOJOSHADER_parseData *pd, GLuint *s);
    void (*profileDeleteShader)(const GLuint shader);
    void (*profileDeleteProgram)(const GLuint program);
    GLint (*profileGetAttribLocation)(MOJOSHADER_glProgram *program, int idx);
    GLint (*profileGetUniformLocation)(MOJOSHADER_glProgram *program, MOJOSHADER_glShader *shader, int idx);
    GLint (*profileGetSamplerLocation)(MOJOSHADER_glProgram *, MOJOSHADER_glShader *, int);
    GLuint (*profileLinkProgram)(MOJOSHADER_glShader *, MOJOSHADER_glShader *);
    void (*profileFinalInitProgram)(MOJOSHADER_glProgram *program);
    void (*profileUseProgram)(MOJOSHADER_glProgram *program);
    void (*profilePushConstantArray)(MOJOSHADER_glProgram *, const MOJOSHADER_uniform *, const GLfloat *);
    void (*profilePushUniforms)(void);
    void (*profilePushSampler)(GLint loc, GLuint sampler);
    int (*profileMustPushConstantArrays)(void);
    int (*profileMustPushSamplers)(void);
};


static MOJOSHADER_glContext *ctx = NULL;

// Error state...
static char error_buffer[1024] = { '\0' };

static void set_error(const char *str)
{
    snprintf(error_buffer, sizeof (error_buffer), "%s", str);
} // set_error

#if PLATFORM_MACOSX
static inline int macosx_version_atleast(int x, int y, int z)
{
    static int checked = 0;
    static int combined = 0;

    if (!checked)
    {
        SInt32 ver = 0;
        SInt32 major = 0;
        SInt32 minor = 0;
        SInt32 patch = 0;
        int convert = 0;

        if (Gestalt(gestaltSystemVersion, &ver) != noErr)
        {
            ver = 0x1000;  // oh well.
            convert = 1;  // split (ver) into (major),(minor),(patch).
        }
        else if (ver < 0x1030)
        {
            convert = 1;  // split (ver) into (major),(minor),(patch).
        }
        else
        {
            // presumably this won't fail. But if it does, we'll just use the
            //  original version value. This might cut the value--10.12.11 will
            //  come out to 10.9.9, for example--but it's better than nothing.
            if (Gestalt(gestaltSystemVersionMajor, &major) != noErr)
                convert = 1;
            else if (Gestalt(gestaltSystemVersionMinor, &minor) != noErr)
                convert = 1;
            else if (Gestalt(gestaltSystemVersionBugFix, &patch) != noErr)
                convert = 1;
        } // else

        if (convert)
        {
            major = ((ver & 0xFF00) >> 8);
            major = (((major / 16) * 10) + (major % 16));
            minor = ((ver & 0xF0) >> 4);
            patch = (ver & 0xF);
        } // if

        combined = (major << 16) | (minor << 8) | patch;
        checked = 1;
    } // if

    return (combined >= ((x << 16) | (y << 8) | z));
} // macosx_version_atleast
#endif

static inline void out_of_memory(void)
{
    set_error("out of memory");
} // out_of_memory

static inline void *Malloc(const size_t len)
{
    void *retval = ctx->malloc_fn((int) len, ctx->malloc_data);
    if (retval == NULL)
        out_of_memory();
    return retval;
} // Malloc

static inline void Free(void *ptr)
{
    if (ptr != NULL)
        ctx->free_fn(ptr, ctx->malloc_data);
} // Free


static inline void toggle_gl_state(GLenum state, int val)
{
    if (val)
        ctx->glEnable(state);
    else
        ctx->glDisable(state);
} // toggle_gl_state


// profile-specific implementations...

#if SUPPORT_PROFILE_GLSL
static inline GLenum glsl_shader_type(const MOJOSHADER_shaderType t)
{
    // these enums match between core 2.0 and the ARB extensions.
    if (t == MOJOSHADER_TYPE_VERTEX)
        return GL_VERTEX_SHADER;
    else if (t == MOJOSHADER_TYPE_PIXEL)
        return GL_FRAGMENT_SHADER;

    // !!! FIXME: geometry shaders?
    return GL_NONE;
} // glsl_shader_type


static int impl_GLSL_MustPushConstantArrays(void) { return 1; }
static int impl_GLSL_MustPushSamplers(void) { return 1; }

static int impl_GLSL_MaxUniforms(MOJOSHADER_shaderType shader_type)
{
    // these enums match between core 2.0 and the ARB extensions.
    GLenum pname = GL_NONE;
    GLint val = 0;
    if (shader_type == MOJOSHADER_TYPE_VERTEX)
        pname = GL_MAX_VERTEX_UNIFORM_COMPONENTS;
    else if (shader_type == MOJOSHADER_TYPE_PIXEL)
        pname = GL_MAX_FRAGMENT_UNIFORM_COMPONENTS;
    else
        return -1;

    ctx->glGetIntegerv(pname, &val);
    return (int) val;
} // impl_GLSL_MaxUniforms


static int impl_GLSL_CompileShader(const MOJOSHADER_parseData *pd, GLuint *s)
{
    GLint ok = 0;
    const GLint codelen = (GLint) pd->output_len;
    const GLenum shader_type = glsl_shader_type(pd->shader_type);

    if (ctx->have_opengl_2)
    {
        const GLuint shader = ctx->glCreateShader(shader_type);
        ctx->glShaderSource(shader, 1, (const GLchar**) &pd->output, &codelen);
        ctx->glCompileShader(shader);
        ctx->glGetShaderiv(shader, GL_COMPILE_STATUS, &ok);
        if (!ok)
        {
            GLsizei len = 0;
            ctx->glGetShaderInfoLog(shader, sizeof (error_buffer), &len,
                                 (GLchar *) error_buffer);
            ctx->glDeleteShader(shader);
            *s = 0;
            return 0;
        } // if

        *s = shader;
    } // if
    else
    {
        const GLhandleARB shader = ctx->glCreateShaderObjectARB(shader_type);
        assert(sizeof (shader) == sizeof (*s));  // not always true on OS X!
        ctx->glShaderSourceARB(shader, 1,
                              (const GLcharARB **) &pd->output, &codelen);
        ctx->glCompileShaderARB(shader);
        ctx->glGetObjectParameterivARB(shader,GL_OBJECT_COMPILE_STATUS_ARB,&ok);
        if (!ok)
        {
            GLsizei len = 0;
            ctx->glGetInfoLogARB(shader, sizeof (error_buffer), &len,
                                 (GLcharARB *) error_buffer);
            ctx->glDeleteObjectARB(shader);
            *s = 0;
            return 0;
        } // if

        *s = (GLuint) shader;
    } // else

    return 1;
} // impl_GLSL_CompileShader


static void impl_GLSL_DeleteShader(const GLuint shader)
{
    if (ctx->have_opengl_2)
        ctx->glDeleteShader(shader);
    else
        ctx->glDeleteObjectARB((GLhandleARB) shader);
} // impl_GLSL_DeleteShader


static void impl_GLSL_DeleteProgram(const GLuint program)
{
    if (ctx->have_opengl_2)
        ctx->glDeleteProgram(program);
    else
        ctx->glDeleteObjectARB((GLhandleARB) program);
} // impl_GLSL_DeleteProgram


static GLint impl_GLSL_GetUniformLocation(MOJOSHADER_glProgram *program,
                                          MOJOSHADER_glShader *shader, int idx)
{
    return 0;  // no-op, we push this as one big-ass array now.
} // impl_GLSL_GetUniformLocation


static inline GLint glsl_uniform_loc(MOJOSHADER_glProgram *program,
                                          const char *name)
{
    return ctx->have_opengl_2 ?
        ctx->glGetUniformLocation(program->handle, name) :
        ctx->glGetUniformLocationARB((GLhandleARB) program->handle, name);
} // glsl_uniform_loc


static GLint impl_GLSL_GetSamplerLocation(MOJOSHADER_glProgram *program,
                                          MOJOSHADER_glShader *shader, int idx)
{
    return glsl_uniform_loc(program, shader->parseData->samplers[idx].name);
} // impl_GLSL_GetSamplerLocation


static GLint impl_GLSL_GetAttribLocation(MOJOSHADER_glProgram *program, int idx)
{
    const MOJOSHADER_parseData *pd = program->vertex->parseData;
    const MOJOSHADER_attribute *a = pd->attributes;

    if (ctx->have_opengl_2)
    {
        return ctx->glGetAttribLocation(program->handle,
                                        (const GLchar *) a[idx].name);
    } // if

    return ctx->glGetAttribLocationARB((GLhandleARB) program->handle,
                                        (const GLcharARB *) a[idx].name);
} // impl_GLSL_GetAttribLocation


static GLuint impl_GLSL_LinkProgram(MOJOSHADER_glShader *vshader,
                                    MOJOSHADER_glShader *pshader)
{
    GLint ok = 0;

    if (ctx->have_opengl_2)
    {
        const GLuint program = ctx->glCreateProgram();

        if (vshader != NULL) ctx->glAttachShader(program, vshader->handle);
        if (pshader != NULL) ctx->glAttachShader(program, pshader->handle);

        ctx->glLinkProgram(program);

        ctx->glGetProgramiv(program, GL_LINK_STATUS, &ok);
        if (!ok)
        {
            GLsizei len = 0;
            ctx->glGetProgramInfoLog(program, sizeof (error_buffer),
                                     &len, (GLchar *) error_buffer);
            ctx->glDeleteProgram(program);
            return 0;
        } // if

        return program;
    } // if
    else
    {
        const GLhandleARB program = ctx->glCreateProgramObjectARB();
        assert(sizeof(program) == sizeof(GLuint));  // not always true on OS X!

        if (vshader != NULL)
            ctx->glAttachObjectARB(program, (GLhandleARB) vshader->handle);

        if (pshader != NULL)
            ctx->glAttachObjectARB(program, (GLhandleARB) pshader->handle);

        ctx->glLinkProgramARB(program);

        ctx->glGetObjectParameterivARB(program, GL_OBJECT_LINK_STATUS_ARB, &ok);
        if (!ok)
        {
            GLsizei len = 0;
            ctx->glGetInfoLogARB(program, sizeof (error_buffer),
                                 &len, (GLcharARB *) error_buffer);
            ctx->glDeleteObjectARB(program);
            return 0;
        } // if

        return (GLuint) program;
    } // else
} // impl_GLSL_LinkProgram

static void impl_GLSL_FinalInitProgram(MOJOSHADER_glProgram *program)
{
    
    program->vs_float4_loc = glsl_uniform_loc(program, "vs_uniforms_vec4");
    program->vs_int4_loc = glsl_uniform_loc(program, "vs_uniforms_ivec4");
    program->vs_bool_loc = glsl_uniform_loc(program, "vs_uniforms_bool");
    program->ps_float4_loc = glsl_uniform_loc(program, "ps_uniforms_vec4");
    program->ps_int4_loc = glsl_uniform_loc(program, "ps_uniforms_ivec4");
    program->ps_bool_loc = glsl_uniform_loc(program, "ps_uniforms_bool");
} // impl_GLSL_FinalInitProgram


static void impl_GLSL_UseProgram(MOJOSHADER_glProgram *program)
{
    if (ctx->have_opengl_2)
        ctx->glUseProgram(program ? program->handle : 0);
    else
        ctx->glUseProgramObjectARB((GLhandleARB) (program ? program->handle : 0));
} // impl_GLSL_UseProgram


static void impl_GLSL_PushConstantArray(MOJOSHADER_glProgram *program,
                                        const MOJOSHADER_uniform *u,
                                        const GLfloat *f)
{
    const GLint loc = glsl_uniform_loc(program, u->name);
    if (loc >= 0)   // not optimized out?
        ctx->glUniform4fv(loc, u->array_count, f);
} // impl_GLSL_PushConstantArray


static void impl_GLSL_PushUniforms(void)
{
    const MOJOSHADER_glProgram *program = ctx->bound_program;

    assert(program->uniform_count > 0);  // don't call with nothing to do!

    if (program->vs_float4_loc != -1)
    {
        ctx->glUniform4fv(program->vs_float4_loc,
                          program->vs_uniforms_float4_count,
                          program->vs_uniforms_float4);
    } // if

    if (program->vs_int4_loc != -1)
    {
        ctx->glUniform4iv(program->vs_int4_loc,
                          program->vs_uniforms_int4_count,
                          program->vs_uniforms_int4);
    } // if

    if (program->vs_bool_loc != -1)
    {
        ctx->glUniform1iv(program->vs_bool_loc,
                          program->vs_uniforms_bool_count,
                          program->vs_uniforms_bool);
    } // if

    if (program->ps_float4_loc != -1)
    {
        ctx->glUniform4fv(program->ps_float4_loc,
                          program->ps_uniforms_float4_count,
                          program->ps_uniforms_float4);
    } // if

    if (program->ps_int4_loc != -1)
    {
        ctx->glUniform4iv(program->ps_int4_loc,
                          program->ps_uniforms_int4_count,
                          program->ps_uniforms_int4);
    } // if

    if (program->ps_bool_loc != -1)
    {
        ctx->glUniform1iv(program->ps_bool_loc,
                          program->ps_uniforms_bool_count,
                          program->ps_uniforms_bool);
    } // if
} // impl_GLSL_PushUniforms


static void impl_GLSL_PushSampler(GLint loc, GLuint sampler)
{
    ctx->glUniform1i(loc, sampler);
} // impl_GLSL_PushSampler

#endif  // SUPPORT_PROFILE_GLSL


#if SUPPORT_PROFILE_ARB1
static inline GLenum arb1_shader_type(const MOJOSHADER_shaderType t)
{
    if (t == MOJOSHADER_TYPE_VERTEX)
        return GL_VERTEX_PROGRAM_ARB;
    else if (t == MOJOSHADER_TYPE_PIXEL)
        return GL_FRAGMENT_PROGRAM_ARB;

    // !!! FIXME: geometry shaders?
    return GL_NONE;
} // arb1_shader_type

static int impl_ARB1_MustPushConstantArrays(void) { return 0; }
static int impl_ARB1_MustPushSamplers(void) { return 0; }

static int impl_ARB1_MaxUniforms(MOJOSHADER_shaderType shader_type)
{
    GLint retval = 0;
    const GLenum program_type = arb1_shader_type(shader_type);
    if (program_type == GL_NONE)
        return -1;

    ctx->glGetProgramivARB(program_type, GL_MAX_PROGRAM_PARAMETERS_ARB, &retval);
    return (int) retval;  // !!! FIXME: times four?
} // impl_ARB1_MaxUniforms


static int impl_ARB1_CompileShader(const MOJOSHADER_parseData *pd, GLuint *s)
{
    GLint shaderlen = (GLint) pd->output_len;
    const GLenum shader_type = arb1_shader_type(pd->shader_type);
    GLuint shader = 0;
    ctx->glGenProgramsARB(1, &shader);

    ctx->glGetError();  // flush any existing error state.
    ctx->glBindProgramARB(shader_type, shader);
    ctx->glProgramStringARB(shader_type, GL_PROGRAM_FORMAT_ASCII_ARB,
                                shaderlen, pd->output);

    if (ctx->glGetError() == GL_INVALID_OPERATION)
    { 
        GLint pos = 0;
        ctx->glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &pos);
        const GLubyte *errstr = ctx->glGetString(GL_PROGRAM_ERROR_STRING_ARB);
        snprintf(error_buffer, sizeof (error_buffer),
                  "ARB1 compile error at position %d: %s",
                  (int) pos, (const char *) errstr);
        ctx->glBindProgramARB(shader_type, 0);
        ctx->glDeleteProgramsARB(1, &shader);
        *s = 0;
        return 0;
    } // if

    *s = shader;
    return 1;
} // impl_ARB1_CompileShader


static void impl_ARB1_DeleteShader(const GLuint _shader)
{
    GLuint shader = _shader;  // const removal.
    ctx->glDeleteProgramsARB(1, &shader);
} // impl_ARB1_DeleteShader


static void impl_ARB1_DeleteProgram(const GLuint program)
{
    // no-op. ARB1 doesn't have real linked programs.
} // impl_GLSL_DeleteProgram

static GLint impl_ARB1_GetUniformLocation(MOJOSHADER_glProgram *program,
                                          MOJOSHADER_glShader *shader, int idx)
{
    return 0;  // no-op, we push this as one big-ass array now.
} // impl_ARB1_GetUniformLocation

static GLint impl_ARB1_GetSamplerLocation(MOJOSHADER_glProgram *program,
                                          MOJOSHADER_glShader *shader, int idx)
{
    return shader->parseData->samplers[idx].index;
} // impl_ARB1_GetSamplerLocation


static GLint impl_ARB1_GetAttribLocation(MOJOSHADER_glProgram *program, int idx)
{
    return idx;  // map to vertex arrays in the same order as the parseData.
} // impl_ARB1_GetAttribLocation


static GLuint impl_ARB1_LinkProgram(MOJOSHADER_glShader *vshader,
                                    MOJOSHADER_glShader *pshader)
{
    // there is no formal linking in ARB1...just return a unique value.
    static GLuint retval = 1;
    return retval++;
} // impl_ARB1_LinkProgram


static void impl_ARB1_FinalInitProgram(MOJOSHADER_glProgram *program)
{
    // no-op.
} // impl_ARB1_FinalInitProgram


static void impl_ARB1_UseProgram(MOJOSHADER_glProgram *program)
{
    GLuint vhandle = 0;
    GLuint phandle = 0;
    if (program != NULL)
    {
        if (program->vertex != NULL)
            vhandle = program->vertex->handle;
        if (program->fragment != NULL)
            phandle = program->fragment->handle;
    } // if

    toggle_gl_state(GL_VERTEX_PROGRAM_ARB, vhandle != 0);
    toggle_gl_state(GL_FRAGMENT_PROGRAM_ARB, phandle != 0);

    ctx->glBindProgramARB(GL_VERTEX_PROGRAM_ARB, vhandle);
    ctx->glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, phandle);
} // impl_ARB1_UseProgram


static void impl_ARB1_PushConstantArray(MOJOSHADER_glProgram *program,
                                        const MOJOSHADER_uniform *u,
                                        const GLfloat *f)
{
    // no-op. Constant arrays are defined in source code for arb1.
} // impl_ARB1_PushConstantArray


static void impl_ARB1_PushUniforms(void)
{
    // vertex shader uniforms come first in program->uniforms array.
    MOJOSHADER_shaderType shader_type = MOJOSHADER_TYPE_VERTEX;
    GLenum arb_shader_type = arb1_shader_type(shader_type);
    const MOJOSHADER_glProgram *program = ctx->bound_program;
    const uint32 count = program->uniform_count;
    const GLfloat *srcf = program->vs_uniforms_float4;
    const GLint *srci = program->vs_uniforms_int4;
    const GLint *srcb = program->vs_uniforms_bool;
    GLint loc = 0;
    GLint texbem_loc = 0;
    uint32 i;

    assert(count > 0);  // shouldn't call this with nothing to do!

    for (i = 0; i < count; i++)
    {
        UniformMap *map = &program->uniforms[i];
        const MOJOSHADER_shaderType uniform_shader_type = map->shader_type;
        const MOJOSHADER_uniform *u = map->uniform;
        const MOJOSHADER_uniformType type = u->type;
        const int size = u->array_count ? u->array_count : 1;

        assert(!u->constant);

        // Did we switch from vertex to pixel (to geometry, etc)?
        if (shader_type != uniform_shader_type)
        {
            if (shader_type == MOJOSHADER_TYPE_PIXEL)
                texbem_loc = loc;

            // we start with vertex, move to pixel, then to geometry, etc.
            //  The array should always be sorted as such.
            if (uniform_shader_type == MOJOSHADER_TYPE_PIXEL)
            {
                assert(shader_type == MOJOSHADER_TYPE_VERTEX);
                srcf = program->ps_uniforms_float4;
                srci = program->ps_uniforms_int4;
                srcb = program->ps_uniforms_bool;
                loc = 0;
            } // if
            else
            {
                // These should be ordered vertex, then pixel, then geometry.
                assert(0 && "Unexpected shader type");
            } // else

            shader_type = uniform_shader_type;
            arb_shader_type = arb1_shader_type(uniform_shader_type);
        } // if

        if (type == MOJOSHADER_UNIFORM_FLOAT)
        {
            int i;
            for (i = 0; i < size; i++, srcf += 4, loc++)
                ctx->glProgramLocalParameter4fvARB(arb_shader_type, loc, srcf);
        } // if
        else if (type == MOJOSHADER_UNIFORM_INT)
        {
            int i;
            if (ctx->have_GL_NV_gpu_program4)
            {
                // GL_NV_gpu_program4 has integer uniform loading support.
                for (i = 0; i < size; i++, srci += 4, loc++)
                    ctx->glProgramLocalParameterI4ivNV(arb_shader_type, loc, srci);
            } // if
            else
            {
                for (i = 0; i < size; i++, srci += 4, loc++)
                {
                    const GLfloat fv[4] = {
                        (GLfloat) srci[0], (GLfloat) srci[1],
                        (GLfloat) srci[2], (GLfloat) srci[3]
                    };
                    ctx->glProgramLocalParameter4fvARB(arb_shader_type, loc, fv);
                } // for
            } // else
        } // else if
        else if (type == MOJOSHADER_UNIFORM_BOOL)
        {
            int i;
            if (ctx->have_GL_NV_gpu_program4)
            {
                // GL_NV_gpu_program4 has integer uniform loading support.
                for (i = 0; i < size; i++, srcb++, loc++)
                {
                    const GLint ib = (GLint) ((*srcb) ? 1 : 0);
                    const GLint iv[4] = { ib, ib, ib, ib };
                    ctx->glProgramLocalParameterI4ivNV(arb_shader_type, loc, iv);
                } // for
            } // if
            else
            {
                for (i = 0; i < size; i++, srcb++, loc++)
                {
                    const GLfloat fb = (GLfloat) ((*srcb) ? 1.0f : 0.0f);
                    const GLfloat fv[4] = { fb, fb, fb, fb };
                    ctx->glProgramLocalParameter4fvARB(arb_shader_type, loc, fv);
                } // for
            } // else
        } // else if
    } // for

    if (program->texbem_count)
    {
        const GLenum target = GL_FRAGMENT_PROGRAM_ARB;
        GLfloat *srcf = program->ps_uniforms_float4;
        srcf += (program->ps_uniforms_float4_count * 4) -
                (program->texbem_count * 8);
        loc = texbem_loc;
        for (i = 0; i < program->texbem_count; i++, srcf += 8)
        {
            ctx->glProgramLocalParameter4fvARB(target, loc++, srcf);
            ctx->glProgramLocalParameter4fvARB(target, loc++, srcf + 4);
        } // for
    } // if
} // impl_ARB1_PushUniforms

static void impl_ARB1_PushSampler(GLint loc, GLuint sampler)
{
    // no-op in this profile...arb1 uses the texture units as-is.
    assert(loc == (GLint) sampler);
} // impl_ARB1_PushSampler

#endif  // SUPPORT_PROFILE_ARB1


const char *MOJOSHADER_glGetError(void)
{
    return error_buffer;
} // MOJOSHADER_glGetError


static void *loadsym(MOJOSHADER_glGetProcAddress lookup, void *d,
                     const char *fn, int *ext)
{
    void *retval = NULL;
    if (lookup != NULL)
        retval = lookup(fn, d);

    if (retval == NULL)
        *ext = 0;

    return retval;
} // loadsym

static void lookup_entry_points(MOJOSHADER_glGetProcAddress lookup, void *d)
{
    #define DO_LOOKUP(ext, typ, fn) { \
        ctx->fn = (typ) loadsym(lookup, d, #fn, &ctx->have_##ext); \
    }

    DO_LOOKUP(core_opengl, PFNGLGETSTRINGPROC, glGetString);
    DO_LOOKUP(core_opengl, PFNGLGETERRORPROC, glGetError);
    DO_LOOKUP(core_opengl, PFNGLGETINTEGERVPROC, glGetIntegerv);
    DO_LOOKUP(core_opengl, PFNGLENABLEPROC, glEnable);
    DO_LOOKUP(core_opengl, PFNGLDISABLEPROC, glDisable);
    DO_LOOKUP(core_opengl, PFNGLBINDTEXTUREPROC, glBindTexture);
    DO_LOOKUP(opengl_3, PFNGLGETSTRINGIPROC, glGetStringi);
    DO_LOOKUP(opengl_2, PFNGLDELETESHADERPROC, glDeleteShader);
    DO_LOOKUP(opengl_2, PFNGLDELETEPROGRAMPROC, glDeleteProgram);
    DO_LOOKUP(opengl_2, PFNGLATTACHSHADERPROC, glAttachShader);
    DO_LOOKUP(opengl_2, PFNGLCOMPILESHADERPROC, glCompileShader);
    DO_LOOKUP(opengl_2, PFNGLCREATESHADERPROC, glCreateShader);
    DO_LOOKUP(opengl_2, PFNGLCREATEPROGRAMPROC, glCreateProgram);
    DO_LOOKUP(opengl_2, PFNGLDISABLEVERTEXATTRIBARRAYPROC, glDisableVertexAttribArray);
    DO_LOOKUP(opengl_2, PFNGLENABLEVERTEXATTRIBARRAYPROC, glEnableVertexAttribArray);
    DO_LOOKUP(opengl_2, PFNGLGETATTRIBLOCATIONPROC, glGetAttribLocation);
    DO_LOOKUP(opengl_2, PFNGLGETPROGRAMINFOLOGPROC, glGetProgramInfoLog);
    DO_LOOKUP(opengl_2, PFNGLGETSHADERINFOLOGPROC, glGetShaderInfoLog);
    DO_LOOKUP(opengl_2, PFNGLGETSHADERIVPROC, glGetShaderiv);
    DO_LOOKUP(opengl_2, PFNGLGETPROGRAMIVPROC, glGetProgramiv);
    DO_LOOKUP(opengl_2, PFNGLGETUNIFORMLOCATIONPROC, glGetUniformLocation);
    DO_LOOKUP(opengl_2, PFNGLLINKPROGRAMPROC, glLinkProgram);
    DO_LOOKUP(opengl_2, PFNGLSHADERSOURCEPROC, glShaderSource);
    DO_LOOKUP(opengl_2, PFNGLUNIFORM1IPROC, glUniform1i);
    DO_LOOKUP(opengl_2, PFNGLUNIFORM1IVPROC, glUniform1iv);
    DO_LOOKUP(opengl_2, PFNGLUNIFORM4FVPROC, glUniform4fv);
    DO_LOOKUP(opengl_2, PFNGLUNIFORM4IVPROC, glUniform4iv);
    DO_LOOKUP(opengl_2, PFNGLUSEPROGRAMPROC, glUseProgram);
    DO_LOOKUP(opengl_2, PFNGLVERTEXATTRIBPOINTERPROC, glVertexAttribPointer);
    DO_LOOKUP(opengl_2, PFNGLACTIVETEXTUREPROC, glActiveTexture);
    DO_LOOKUP(opengl_2, PFNGLBLENDEQUATIONPROC, glBlendEquation);
    DO_LOOKUP(opengl_2, PFNGLBLENDFUNCSEPARATEPROC, glBlendFuncSeparate);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLDELETEOBJECTARBPROC, glDeleteObjectARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLATTACHOBJECTARBPROC, glAttachObjectARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLCOMPILESHADERARBPROC, glCompileShaderARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLCREATEPROGRAMOBJECTARBPROC, glCreateProgramObjectARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLCREATESHADEROBJECTARBPROC, glCreateShaderObjectARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLGETINFOLOGARBPROC, glGetInfoLogARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLGETOBJECTPARAMETERIVARBPROC, glGetObjectParameterivARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLGETUNIFORMLOCATIONARBPROC, glGetUniformLocationARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLLINKPROGRAMARBPROC, glLinkProgramARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLSHADERSOURCEARBPROC, glShaderSourceARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLUNIFORM1IARBPROC, glUniform1iARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLUNIFORM1IVARBPROC, glUniform1ivARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLUNIFORM4FVARBPROC, glUniform4fvARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLUNIFORM4IVARBPROC, glUniform4ivARB);
    DO_LOOKUP(GL_ARB_shader_objects, PFNGLUSEPROGRAMOBJECTARBPROC, glUseProgramObjectARB);
    DO_LOOKUP(GL_ARB_vertex_shader, PFNGLDISABLEVERTEXATTRIBARRAYARBPROC, glDisableVertexAttribArrayARB);
    DO_LOOKUP(GL_ARB_vertex_shader, PFNGLENABLEVERTEXATTRIBARRAYARBPROC, glEnableVertexAttribArrayARB);
    DO_LOOKUP(GL_ARB_vertex_shader, PFNGLGETATTRIBLOCATIONARBPROC, glGetAttribLocationARB);
    DO_LOOKUP(GL_ARB_vertex_shader, PFNGLVERTEXATTRIBPOINTERARBPROC, glVertexAttribPointerARB);
    DO_LOOKUP(GL_ARB_vertex_program, PFNGLVERTEXATTRIBPOINTERARBPROC, glVertexAttribPointerARB);
    DO_LOOKUP(GL_ARB_vertex_program, PFNGLGETPROGRAMIVARBPROC, glGetProgramivARB);
    DO_LOOKUP(GL_ARB_vertex_program, PFNGLPROGRAMLOCALPARAMETER4FVARBPROC, glProgramLocalParameter4fvARB);
    DO_LOOKUP(GL_ARB_vertex_program, PFNGLDELETEPROGRAMSARBPROC, glDeleteProgramsARB);
    DO_LOOKUP(GL_ARB_vertex_program, PFNGLGENPROGRAMSARBPROC, glGenProgramsARB);
    DO_LOOKUP(GL_ARB_vertex_program, PFNGLBINDPROGRAMARBPROC, glBindProgramARB);
    DO_LOOKUP(GL_ARB_vertex_program, PFNGLPROGRAMSTRINGARBPROC, glProgramStringARB);
    DO_LOOKUP(GL_NV_gpu_program4, PFNGLPROGRAMLOCALPARAMETERI4IVNVPROC, glProgramLocalParameterI4ivNV);
    DO_LOOKUP(GL_ARB_instanced_arrays, PFNGLVERTEXATTRIBDIVISORPROC, glVertexAttribDivisorARB);

    #undef DO_LOOKUP
} // lookup_entry_points

static inline int opengl_version_atleast(const int major, const int minor)
{
    return ( ((ctx->opengl_major << 16) | (ctx->opengl_minor & 0xFFFF)) >=
             ((major << 16) | (minor & 0xFFFF)) );
} // opengl_version_atleast

static int verify_extension(const char *ext, int have, StringCache *exts,
                            int major, int minor)
{
    if (have == 0)
        return 0;  // don't bother checking, we're missing an entry point.

    else if (!ctx->have_core_opengl)
        return 0;  // don't bother checking, we're missing basic functionality.

    // See if it's in the spec for this GL implementation's version.
    if ((major > 0) && (opengl_version_atleast(major, minor)))
        return 1;

    // Not available in the GL version, check the extension list.
    return stringcache_iscached(exts, ext);
} // verify_extension


static void parse_opengl_version_str(const char *verstr, int *maj, int *min)
{
    if (verstr == NULL)
        *maj = *min = 0;
    else
        sscanf(verstr, "%d.%d", maj, min);
} // parse_opengl_version_str


#if SUPPORT_PROFILE_GLSL
static inline int glsl_version_atleast(const int major, const int minor)
{
    return ( ((ctx->glsl_major << 16) | (ctx->glsl_minor & 0xFFFF)) >=
             ((major << 16) | (minor & 0xFFFF)) );
} // glsl_version_atleast
#endif

static void detect_glsl_version(void)
{
    ctx->glsl_major = ctx->glsl_minor = 0;

#if SUPPORT_PROFILE_GLSL
    if (!ctx->have_core_opengl)
        return;  // everything's busted, give up.

    #if PLATFORM_MACOSX
    // If running on Mac OS X <= 10.4, don't ever use GLSL, even if
    //  the system claims it is available.
    if (!macosx_version_atleast(10, 5, 0))
        return;
    #endif

    if ( ctx->have_opengl_2 ||
         ( ctx->have_GL_ARB_shader_objects &&
           ctx->have_GL_ARB_vertex_shader &&
           ctx->have_GL_ARB_fragment_shader &&
           ctx->have_GL_ARB_shading_language_100 ) )
    {
        // the GL2.0 and ARB enum is the same value.
        const GLenum enumval = GL_SHADING_LANGUAGE_VERSION;
        ctx->glGetError();  // flush any existing error state.
        const char *str = (const char *) ctx->glGetString(enumval);
        if (ctx->glGetError() == GL_INVALID_ENUM)
            str = NULL;
        parse_opengl_version_str(str, &ctx->glsl_major, &ctx->glsl_minor);
    } // if
#endif
} // detect_glsl_version


static int iswhitespace(const char ch)
{
    switch (ch)
    {
        case ' ': case '\t': case '\r': case '\n': return 1;
        default: return 0;
    } // switch
} // iswhitespace


static void load_extensions(MOJOSHADER_glGetProcAddress lookup, void *d)
{
    StringCache *exts = stringcache_create(ctx->malloc_fn, ctx->free_fn, ctx->malloc_data);
    if (!exts)
    {
        out_of_memory();
        return;
    } // if

    ctx->have_core_opengl = 1;
    ctx->have_opengl_2 = 1;
    ctx->have_opengl_3 = 1;
    ctx->have_GL_ARB_vertex_program = 1;
    ctx->have_GL_ARB_fragment_program = 1;
    ctx->have_GL_NV_vertex_program2_option = 1;
    ctx->have_GL_NV_fragment_program2 = 1;
    ctx->have_GL_NV_vertex_program3 = 1;
    ctx->have_GL_NV_gpu_program4 = 1;
    ctx->have_GL_ARB_shader_objects = 1;
    ctx->have_GL_ARB_vertex_shader = 1;
    ctx->have_GL_ARB_fragment_shader = 1;
    ctx->have_GL_ARB_shading_language_100 = 1;
    ctx->have_GL_NV_half_float = 1;
    ctx->have_GL_ARB_half_float_vertex = 1;
    ctx->have_GL_OES_vertex_half_float = 1;
    ctx->have_GL_ARB_instanced_arrays = 1;

    lookup_entry_points(lookup, d);

    if (!ctx->have_core_opengl)
        set_error("missing basic OpenGL entry points");
    else
    {
        const char *str = (const char *) ctx->glGetString(GL_VERSION);
        parse_opengl_version_str(str, &ctx->opengl_major, &ctx->opengl_minor);

        if ((ctx->have_opengl_3) && (opengl_version_atleast(3, 0)))
        {
            GLint i;
            GLint num_exts = 0;
            ctx->glGetIntegerv(GL_NUM_EXTENSIONS, &num_exts);
            for (i = 0; i < num_exts; i++)
            {
                if (!stringcache(exts, (const char *) ctx->glGetStringi(GL_EXTENSIONS, i)))
                    out_of_memory();
            } // for
        } // if
        else
        {
            const char *str = (const char *) ctx->glGetString(GL_EXTENSIONS);
            const char *ext;
            ctx->have_opengl_3 = 0;

            while (*str && iswhitespace(*str))
                str++;
            ext = str;

            while (1)
            {
                const char ch = *str;
                if (ch && (!iswhitespace(ch)))
                {
                    str++;
                    continue;
                } // else if

                if (str != ext)
                {
                    if (!stringcache_len(exts, ext, (unsigned int) (str - ext)))
                    {
                        out_of_memory();
                        break;
                    } // if
                } // if

                if (ch == '\0')
                    break;

                str++;
                while (*str && iswhitespace(*str))
                    str++;
                ext = str;
            } // while
        } // else
    } // else

    if ((ctx->have_opengl_2) && (!opengl_version_atleast(2, 0)))
    {
        ctx->have_opengl_2 = 0;  // Not GL2! must have the ARB extensions!

        // Force compatible ARB function pointers in...this keeps the code
        //  cleaner when they are identical, so we don't have to if/else
        //  every function call, but we definitely have the right entry
        //  point. Be careful what you add here.
        // These may be NULL, btw.
        ctx->glUniform1i = ctx->glUniform1iARB;
        ctx->glUniform4fv = ctx->glUniform4fvARB;
        ctx->glUniform4iv = ctx->glUniform4ivARB;
        ctx->glDisableVertexAttribArray = ctx->glDisableVertexAttribArrayARB;
        ctx->glEnableVertexAttribArray = ctx->glEnableVertexAttribArrayARB;
        ctx->glVertexAttribPointer = ctx->glVertexAttribPointerARB;
    } // if

    #define VERIFY_EXT(ext, major, minor) \
        ctx->have_##ext = verify_extension(#ext, ctx->have_##ext, exts, major, minor)

    VERIFY_EXT(GL_ARB_vertex_program, -1, -1);
    VERIFY_EXT(GL_ARB_fragment_program, -1, -1);
    VERIFY_EXT(GL_ARB_shader_objects, -1, -1);
    VERIFY_EXT(GL_ARB_vertex_shader, -1, -1);
    VERIFY_EXT(GL_ARB_fragment_shader, -1, -1);
    VERIFY_EXT(GL_ARB_shading_language_100, -1, -1);
    VERIFY_EXT(GL_NV_vertex_program2_option, -1, -1);
    VERIFY_EXT(GL_NV_fragment_program2, -1, -1);
    VERIFY_EXT(GL_NV_vertex_program3, -1, -1);
    VERIFY_EXT(GL_NV_half_float, -1, -1);
    VERIFY_EXT(GL_ARB_half_float_vertex, 3, 0);
    VERIFY_EXT(GL_OES_vertex_half_float, -1, -1);
    VERIFY_EXT(GL_ARB_instanced_arrays, 3, 3);

    #undef VERIFY_EXT

    stringcache_destroy(exts);

    detect_glsl_version();
} // load_extensions


static int valid_profile(const char *profile)
{
    if (!ctx->have_core_opengl)
        return 0;

    #define MUST_HAVE(p, x) \
        if (!ctx->have_##x) { set_error(#p " profile needs " #x); return 0; }

    // we might actually _have_ maj.min, but forcibly disabled GLSL elsewhere.
    #define MUST_HAVE_GLSL(p, maj, min) \
        if (!glsl_version_atleast(maj, min)) { \
            set_error(#p " profile needs missing GLSL support"); return 0; \
        }

    if (profile == NULL)
    {
        set_error("NULL profile");
        return 0;
    } // if

    #if SUPPORT_PROFILE_ARB1
    else if (strcmp(profile, MOJOSHADER_PROFILE_ARB1) == 0)
    {
        MUST_HAVE(MOJOSHADER_PROFILE_ARB1, GL_ARB_vertex_program);
        MUST_HAVE(MOJOSHADER_PROFILE_ARB1, GL_ARB_fragment_program);
    } // else if
    #endif

    #if SUPPORT_PROFILE_ARB1_NV
    else if (strcmp(profile, MOJOSHADER_PROFILE_NV2) == 0)
    {
        MUST_HAVE(MOJOSHADER_PROFILE_NV2, GL_ARB_vertex_program);
        MUST_HAVE(MOJOSHADER_PROFILE_NV2, GL_ARB_fragment_program);
        MUST_HAVE(MOJOSHADER_PROFILE_NV2, GL_NV_vertex_program2_option);
        MUST_HAVE(MOJOSHADER_PROFILE_NV2, GL_NV_fragment_program2);
    } // else if

    else if (strcmp(profile, MOJOSHADER_PROFILE_NV3) == 0)
    {
        MUST_HAVE(MOJOSHADER_PROFILE_NV3, GL_ARB_vertex_program);
        MUST_HAVE(MOJOSHADER_PROFILE_NV3, GL_ARB_fragment_program);
        MUST_HAVE(MOJOSHADER_PROFILE_NV3, GL_NV_vertex_program3);
        MUST_HAVE(MOJOSHADER_PROFILE_NV3, GL_NV_fragment_program2);
    } // else if

    else if (strcmp(profile, MOJOSHADER_PROFILE_NV4) == 0)
    {
        MUST_HAVE(MOJOSHADER_PROFILE_NV4, GL_NV_gpu_program4);
    } // else if
    #endif

    #if SUPPORT_PROFILE_GLSL120
    else if (strcmp(profile, MOJOSHADER_PROFILE_GLSL120) == 0)
    {
        MUST_HAVE_GLSL(MOJOSHADER_PROFILE_GLSL120, 1, 20);
    } // else if
    #endif

    #if SUPPORT_PROFILE_GLSL
    else if (strcmp(profile, MOJOSHADER_PROFILE_GLSL) == 0)
    {
        MUST_HAVE_GLSL(MOJOSHADER_PROFILE_GLSL, 1, 10);
    } // else if
    #endif

    else
    {
        set_error("unknown or unsupported profile");
        return 0;
    } // else

    #undef MUST_HAVE

    return 1;
} // valid_profile


static const char *profile_priorities[] = {
#if SUPPORT_PROFILE_GLSL120
    MOJOSHADER_PROFILE_GLSL120,
#endif
#if SUPPORT_PROFILE_GLSL
    MOJOSHADER_PROFILE_GLSL,
#endif
#if SUPPORT_PROFILE_ARB1_NV
    MOJOSHADER_PROFILE_NV4,
    MOJOSHADER_PROFILE_NV3,
    MOJOSHADER_PROFILE_NV2,
#endif
#if SUPPORT_PROFILE_ARB1
    MOJOSHADER_PROFILE_ARB1,
#endif
};

int MOJOSHADER_glAvailableProfiles(MOJOSHADER_glGetProcAddress lookup,
                                   void *lookup_d,
                                   const char **profs, const int size,
                                   MOJOSHADER_malloc m, MOJOSHADER_free f,
                                   void *malloc_d)
{
    int retval = 0;
    MOJOSHADER_glContext _ctx;
    MOJOSHADER_glContext *current_ctx = ctx;

    if (m == NULL) m = MOJOSHADER_internal_malloc;
    if (f == NULL) f = MOJOSHADER_internal_free;

    ctx = &_ctx;
    memset(ctx, '\0', sizeof (MOJOSHADER_glContext));
    ctx->malloc_fn = m;
    ctx->free_fn = f;
    ctx->malloc_data = malloc_d;

    load_extensions(lookup, lookup_d);

    if (ctx->have_core_opengl)
    {
        size_t i;
        for (i = 0; i < STATICARRAYLEN(profile_priorities); i++)
        {
            const char *profile = profile_priorities[i];
            if (valid_profile(profile))
            {
                if (retval < size)
                    profs[retval] = profile;
                retval++;
            } // if
        } // for
    } // if

    ctx = current_ctx;
    return retval;
} // MOJOSHADER_glAvailableProfiles


const char *MOJOSHADER_glBestProfile(MOJOSHADER_glGetProcAddress gpa,
                                     void *lookup_d,
                                     MOJOSHADER_malloc m, MOJOSHADER_free f,
                                     void *malloc_d)
{
    const char *prof[STATICARRAYLEN(profile_priorities)];
    const int avail = MOJOSHADER_glAvailableProfiles(gpa, lookup_d, prof,
                                                     STATICARRAYLEN(prof),
                                                     m, f, malloc_d);
    if (avail <= 0)
    {
        set_error("no profiles available");
        return NULL;
    } // if

    return prof[0];  // profiles are sorted "best" to "worst."
} // MOJOSHADER_glBestProfile


MOJOSHADER_glContext *MOJOSHADER_glCreateContext(const char *profile,
                                        MOJOSHADER_glGetProcAddress lookup,
                                        void *lookup_d,
                                        MOJOSHADER_malloc m, MOJOSHADER_free f,
                                        void *malloc_d)
{
    MOJOSHADER_glContext *retval = NULL;
    MOJOSHADER_glContext *current_ctx = ctx;

    ctx = NULL;

    if (m == NULL) m = MOJOSHADER_internal_malloc;
    if (f == NULL) f = MOJOSHADER_internal_free;

    ctx = (MOJOSHADER_glContext *) m(sizeof (MOJOSHADER_glContext), malloc_d);
    if (ctx == NULL)
    {
        out_of_memory();
        goto init_fail;
    } // if

    memset(ctx, '\0', sizeof (MOJOSHADER_glContext));
    ctx->malloc_fn = m;
    ctx->free_fn = f;
    ctx->malloc_data = malloc_d;
    snprintf(ctx->profile, sizeof (ctx->profile), "%s", profile);

    load_extensions(lookup, lookup_d);
    if (!valid_profile(profile))
        goto init_fail;

    MOJOSHADER_glBindProgram(NULL);

    // !!! FIXME: generalize this part.
    if (profile == NULL) {}

    // We don't check SUPPORT_PROFILE_GLSL120 here, since valid_profile() does.
#if SUPPORT_PROFILE_GLSL
    else if ( (strcmp(profile, MOJOSHADER_PROFILE_GLSL) == 0) ||
              (strcmp(profile, MOJOSHADER_PROFILE_GLSL120) == 0) )
    {
        ctx->profileMaxUniforms = impl_GLSL_MaxUniforms;
        ctx->profileCompileShader = impl_GLSL_CompileShader;
        ctx->profileDeleteShader = impl_GLSL_DeleteShader;
        ctx->profileDeleteProgram = impl_GLSL_DeleteProgram;
        ctx->profileGetAttribLocation = impl_GLSL_GetAttribLocation;
        ctx->profileGetUniformLocation = impl_GLSL_GetUniformLocation;
        ctx->profileGetSamplerLocation = impl_GLSL_GetSamplerLocation;
        ctx->profileLinkProgram = impl_GLSL_LinkProgram;
        ctx->profileFinalInitProgram = impl_GLSL_FinalInitProgram;
        ctx->profileUseProgram = impl_GLSL_UseProgram;
        ctx->profilePushConstantArray = impl_GLSL_PushConstantArray;
        ctx->profilePushUniforms = impl_GLSL_PushUniforms;
        ctx->profilePushSampler = impl_GLSL_PushSampler;
        ctx->profileMustPushConstantArrays = impl_GLSL_MustPushConstantArrays;
        ctx->profileMustPushSamplers = impl_GLSL_MustPushSamplers;
    } // if
#endif

    // We don't check SUPPORT_PROFILE_ARB1_NV here, since valid_profile() does.
#if SUPPORT_PROFILE_ARB1
    else if ( (strcmp(profile, MOJOSHADER_PROFILE_ARB1) == 0) ||
              (strcmp(profile, MOJOSHADER_PROFILE_NV2) == 0) ||
              (strcmp(profile, MOJOSHADER_PROFILE_NV3) == 0) ||
              (strcmp(profile, MOJOSHADER_PROFILE_NV4) == 0) )
    {
        ctx->profileMaxUniforms = impl_ARB1_MaxUniforms;
        ctx->profileCompileShader = impl_ARB1_CompileShader;
        ctx->profileDeleteShader = impl_ARB1_DeleteShader;
        ctx->profileDeleteProgram = impl_ARB1_DeleteProgram;
        ctx->profileGetAttribLocation = impl_ARB1_GetAttribLocation;
        ctx->profileGetUniformLocation = impl_ARB1_GetUniformLocation;
        ctx->profileGetSamplerLocation = impl_ARB1_GetSamplerLocation;
        ctx->profileLinkProgram = impl_ARB1_LinkProgram;
        ctx->profileFinalInitProgram = impl_ARB1_FinalInitProgram;
        ctx->profileUseProgram = impl_ARB1_UseProgram;
        ctx->profilePushConstantArray = impl_ARB1_PushConstantArray;
        ctx->profilePushUniforms = impl_ARB1_PushUniforms;
        ctx->profilePushSampler = impl_ARB1_PushSampler;
        ctx->profileMustPushConstantArrays = impl_ARB1_MustPushConstantArrays;
        ctx->profileMustPushSamplers = impl_ARB1_MustPushSamplers;
    } // if
#endif

    assert(ctx->profileMaxUniforms != NULL);
    assert(ctx->profileCompileShader != NULL);
    assert(ctx->profileDeleteShader != NULL);
    assert(ctx->profileDeleteProgram != NULL);
    assert(ctx->profileMaxUniforms != NULL);
    assert(ctx->profileGetAttribLocation != NULL);
    assert(ctx->profileGetUniformLocation != NULL);
    assert(ctx->profileGetSamplerLocation != NULL);
    assert(ctx->profileLinkProgram != NULL);
    assert(ctx->profileFinalInitProgram != NULL);
    assert(ctx->profileUseProgram != NULL);
    assert(ctx->profilePushConstantArray != NULL);
    assert(ctx->profilePushUniforms != NULL);
    assert(ctx->profilePushSampler != NULL);
    assert(ctx->profileMustPushConstantArrays != NULL);
    assert(ctx->profileMustPushSamplers != NULL);

    retval = ctx;
    ctx = current_ctx;
    return retval;

init_fail:
    if (ctx != NULL)
        f(ctx, malloc_d);
    ctx = current_ctx;
    return NULL;
} // MOJOSHADER_glCreateContext


void MOJOSHADER_glMakeContextCurrent(MOJOSHADER_glContext *_ctx)
{
    ctx = _ctx;
} // MOJOSHADER_glMakeContextCurrent


int MOJOSHADER_glMaxUniforms(MOJOSHADER_shaderType shader_type)
{
    return ctx->profileMaxUniforms(shader_type);
} // MOJOSHADER_glMaxUniforms


MOJOSHADER_glShader *MOJOSHADER_glCompileShader(const unsigned char *tokenbuf,
                                                const unsigned int bufsize,
                                                const MOJOSHADER_swizzle *swiz,
                                                const unsigned int swizcount,
                                                const MOJOSHADER_samplerMap *smap,
                                                const unsigned int smapcount)
{
    MOJOSHADER_glShader *retval = NULL;
    GLuint shader = 0;
    const MOJOSHADER_parseData *pd = MOJOSHADER_parse(ctx->profile, tokenbuf,
                                                      bufsize, swiz, swizcount,
                                                      smap, smapcount,
                                                      ctx->malloc_fn,
                                                      ctx->free_fn,
                                                      ctx->malloc_data);
    if (pd->error_count > 0)
    {
        // !!! FIXME: put multiple errors in the buffer? Don't use
        // !!! FIXME:  MOJOSHADER_glGetError() for this?
        set_error(pd->errors[0].error);
        goto compile_shader_fail;
    } // if

    retval = (MOJOSHADER_glShader *) Malloc(sizeof (MOJOSHADER_glShader));
    if (retval == NULL)
        goto compile_shader_fail;

    if (!ctx->profileCompileShader(pd, &shader))
        goto compile_shader_fail;

    retval->parseData = pd;
    retval->handle = shader;
    retval->refcount = 1;
    return retval;

compile_shader_fail:
    MOJOSHADER_freeParseData(pd);
    Free(retval);
    if (shader != 0)
        ctx->profileDeleteShader(shader);
    return NULL;
} // MOJOSHADER_glCompileShader


const MOJOSHADER_parseData *MOJOSHADER_glGetShaderParseData(
                                                MOJOSHADER_glShader *shader)
{
    return (shader != NULL) ? shader->parseData : NULL;
} // MOJOSHADER_glGetShaderParseData


static void shader_unref(MOJOSHADER_glShader *shader)
{
    if (shader != NULL)
    {
        const uint32 refcount = shader->refcount;
        if (refcount > 1)
            shader->refcount--;
        else
        {
            ctx->profileDeleteShader(shader->handle);
            MOJOSHADER_freeParseData(shader->parseData);
            Free(shader);
        } // else
    } // if
} // shader_unref


static void program_unref(MOJOSHADER_glProgram *program)
{
    if (program != NULL)
    {
        const uint32 refcount = program->refcount;
        if (refcount > 1)
            program->refcount--;
        else
        {
            ctx->profileDeleteProgram(program->handle);
            shader_unref(program->vertex);
            shader_unref(program->fragment);
            Free(program->vs_preshader_regs);
            Free(program->ps_preshader_regs);
            Free(program->vs_uniforms_float4);
            Free(program->vs_uniforms_int4);
            Free(program->vs_uniforms_bool);
            Free(program->ps_uniforms_float4);
            Free(program->ps_uniforms_int4);
            Free(program->ps_uniforms_bool);
            Free(program->uniforms);
            Free(program->attributes);
            Free(program);
        } // else
    } // if
} // program_unref


static void effect_unref(MOJOSHADER_glEffect *effect)
{
    if (effect != NULL)
    {
        const uint32 refcount = effect->refcount;
        if (refcount > 1)
            effect->refcount--;
        else
        {
            uint32 i = 0;

            for (i = 0; i < effect->program_count; i++)
            {
                MOJOSHADER_glDeleteProgram(effect->programs[i]);
            }
            Free(effect->programs);

            for (i = 0; i < effect->shader_count; i++)
            {
                MOJOSHADER_glDeleteShader(effect->shaders[i]);
            }
            Free(effect->shaders);

            for (i = 0; i < effect->technique_count; i++)
            {
                Free(effect->techniques[i].passes);
            }
            Free(effect->techniques);

            for (i = 0; i < effect->param_count; i++)
            {
                Free(effect->param_cache[i].data);
                Free(effect->param_cache[i].shader_symbols);
                Free(effect->param_cache[i].preshader_symbols);
            }
            Free(effect->param_cache);
            
            Free(effect);
        } // else
    } // if
} // program_unref


static void fill_constant_array(GLfloat *f, const int base, const int size,
                                const MOJOSHADER_parseData *pd)
{
    int i;
    int filled = 0;
    for (i = 0; i < pd->constant_count; i++)
    {
        const MOJOSHADER_constant *c = &pd->constants[i];
        if (c->type != MOJOSHADER_UNIFORM_FLOAT)
            continue;
        else if (c->index < base)
            continue;
        else if (c->index >= (base+size))
            continue;
        memcpy(&f[(c->index-base) * 4], &c->value.f, sizeof (c->value.f));
        filled++;
    } // for

    assert(filled == size);
} // fill_constant_array


static int lookup_uniforms(MOJOSHADER_glProgram *program,
                           MOJOSHADER_glShader *shader, int *bound)
{
    const MOJOSHADER_parseData *pd = shader->parseData;
    const MOJOSHADER_shaderType shader_type = pd->shader_type;
    uint32 float4_count = 0;
    uint32 int4_count = 0;
    uint32 bool_count = 0;
    int i;

    for (i = 0; i < pd->uniform_count; i++)
    {
        const MOJOSHADER_uniform *u = &pd->uniforms[i];

        if (u->constant)
        {
            // only do constants once, at link time. These aren't changed ever.
            if (ctx->profileMustPushConstantArrays())
            {
                const int base = u->index;
                const int size = u->array_count;
                GLfloat *f = (GLfloat *) alloca(sizeof (GLfloat) * (size * 4));
                fill_constant_array(f, base, size, pd);
                if (!(*bound))
                {
                    ctx->profileUseProgram(program);
                    *bound = 1;
                } // if
                ctx->profilePushConstantArray(program, u, f);
            } // if
        } // if

        else
        {
            const GLint loc = ctx->profileGetUniformLocation(program, shader, i);
            if (loc != -1)  // -1 means it was optimized out, or failure.
            {
                const int regcount = u->array_count;
                UniformMap *map = &program->uniforms[program->uniform_count];
                map->shader_type = shader_type;
                map->uniform = u;
                map->location = (GLuint) loc;
                program->uniform_count++;

                if (u->type == MOJOSHADER_UNIFORM_FLOAT)
                    float4_count += regcount ? regcount : 1;
                else if (u->type == MOJOSHADER_UNIFORM_INT)
                    int4_count += regcount ? regcount : 1;
                else if (u->type == MOJOSHADER_UNIFORM_BOOL)
                    bool_count += regcount ? regcount : 1;
                else
                    assert(0 && "Unexpected register type");
            } // if
        } // else
    } // for

    if (shader_type == MOJOSHADER_TYPE_PIXEL)
    {
        for (i = 0; i < pd->sampler_count; i++)
        {
            if (pd->samplers[i].texbem)
            {
                float4_count += 2;
                program->texbem_count++;
            } // if
        } // for
    } // if

    #define MAKE_ARRAY(typ, gltyp, siz, count) \
        if (count) { \
            const size_t buflen = sizeof (gltyp) * siz * count; \
            gltyp *ptr = (gltyp *) Malloc(buflen); \
            if (ptr == NULL) { \
                return 0; \
            } else if (shader_type == MOJOSHADER_TYPE_VERTEX) { \
                program->vs_uniforms_##typ = ptr; \
                program->vs_uniforms_##typ##_count = count; \
            } else if (shader_type == MOJOSHADER_TYPE_PIXEL) { \
                program->ps_uniforms_##typ = ptr; \
                program->ps_uniforms_##typ##_count = count; \
            } else { \
                assert(0 && "unsupported shader type"); \
            } \
            memset(ptr, '\0', buflen); \
        }

    MAKE_ARRAY(float4, GLfloat, 4, float4_count);
    MAKE_ARRAY(int4, GLint, 4, int4_count);
    MAKE_ARRAY(bool, GLint, 1, bool_count);

    #undef MAKE_ARRAY

    if (pd->preshader)
    {
        unsigned int largest = 0;
        const MOJOSHADER_symbol *sym = pd->preshader->symbols;
        for (i = 0; i < (int)pd->preshader->symbol_count; i++, sym++)
        {
            const unsigned int val = sym->register_index + sym->register_count;
            if (val > largest)
                largest = val;
        } // for

        if (largest > 0)
        {
            const size_t len = largest * sizeof (GLfloat) * 4;
            GLfloat *buf = (GLfloat *) Malloc(len);
            if (buf == NULL)
                return 0;
            memset(buf, '\0', len);

            if (shader_type == MOJOSHADER_TYPE_VERTEX)
            {
                program->vs_preshader_reg_count = largest;
                program->vs_preshader_regs = buf;
            } // if
            else if (shader_type == MOJOSHADER_TYPE_PIXEL)
            {
                program->ps_preshader_reg_count = largest;
                program->ps_preshader_regs = buf;
            } // else if
        } // if
    } // if

    return 1;
} // lookup_uniforms


static void lookup_samplers(MOJOSHADER_glProgram *program,
                            MOJOSHADER_glShader *shader, int *bound)
{
    const MOJOSHADER_parseData *pd = shader->parseData;
    const MOJOSHADER_sampler *s = pd->samplers;
    int i;

    if ((pd->sampler_count == 0) || (!ctx->profileMustPushSamplers()))
        return;   // nothing to do here, so don't bother binding, etc.

    // Link up the Samplers. These never change after link time, since they
    //  are meant to be constant texture unit ids and not textures.

    if (!(*bound))
    {
        ctx->profileUseProgram(program);
        *bound = 1;
    } // if

    for (i = 0; i < pd->sampler_count; i++)
    {
        const GLint loc = ctx->profileGetSamplerLocation(program, shader, i);
        if (loc >= 0)  // maybe the Sampler was optimized out?
            ctx->profilePushSampler(loc, s[i].index);
    } // for
} // lookup_samplers


// Right now, this just decides if we have to toggle pointsize support later.
static void lookup_outputs(MOJOSHADER_glProgram *program,
                           MOJOSHADER_glShader *shader)
{
    if (shader == NULL)
        return;

    const MOJOSHADER_parseData *pd = shader->parseData;
    int i;

    for (i = 0; i < pd->output_count; i++)
    {
        if (pd->outputs[i].usage == MOJOSHADER_USAGE_POINTSIZE)
        {
            program->uses_pointsize = 1;
            break;
        } // if
    } // for
} // lookup_outputs


static int lookup_attributes(MOJOSHADER_glProgram *program)
{
    int i;
    const MOJOSHADER_parseData *pd = program->vertex->parseData;
    const MOJOSHADER_attribute *a = pd->attributes;

    for (i = 0; i < pd->attribute_count; i++)
    {
        const GLint loc = ctx->profileGetAttribLocation(program, i);
        if (loc >= 0)  // maybe the Attribute was optimized out?
        {
            AttributeMap *map = &program->attributes[program->attribute_count];
            map->attribute = &a[i];
            map->location = loc;
            program->attribute_count++;

            if (((size_t)loc) > STATICARRAYLEN(ctx->want_attr))
            {
                assert(0 && "Static array is too small.");  // laziness fail.
                return 0;
            } // if
        } // if
    } // for

    return 1;
} // lookup_attributes


// !!! FIXME: misnamed
// build a list of indexes that need to be overwritten with constant values
//  when pushing a uniform array to the GL.
static int build_constants_lists(MOJOSHADER_glProgram *program)
{
    int i;
    const int count = program->uniform_count;
    for (i = 0; i < count; i++)
    {
        UniformMap *map = &program->uniforms[i];
        const MOJOSHADER_uniform *u = map->uniform;
        const int size = u->array_count;

        assert(!u->constant);

        if (size == 0)
            continue;  // nothing to see here.

        // only use arrays for 'c' registers.
        assert(u->type == MOJOSHADER_UNIFORM_FLOAT);

        // !!! FIXME: deal with this.
    } // for

    return 1;
} // build_constants_lists


MOJOSHADER_glProgram *MOJOSHADER_glLinkProgram(MOJOSHADER_glShader *vshader,
                                               MOJOSHADER_glShader *pshader)
{
    int bound = 0;

    if ((vshader == NULL) && (pshader == NULL))
        return NULL;

    int numregs = 0;
    MOJOSHADER_glProgram *retval = NULL;
    const GLuint program = ctx->profileLinkProgram(vshader, pshader);
    if (program == 0)
        goto link_program_fail;

    retval = (MOJOSHADER_glProgram *) Malloc(sizeof (MOJOSHADER_glProgram));
    if (retval == NULL)
        goto link_program_fail;
    memset(retval, '\0', sizeof (MOJOSHADER_glProgram));

    numregs = 0;
    if (vshader != NULL) numregs += vshader->parseData->uniform_count;
    if (pshader != NULL) numregs += pshader->parseData->uniform_count;
    if (numregs > 0)
    {
        const size_t len = sizeof (UniformMap) * numregs;
        retval->uniforms = (UniformMap *) Malloc(len);
        if (retval->uniforms == NULL)
            goto link_program_fail;
        memset(retval->uniforms, '\0', len);
    } // if

    retval->handle = program;
    retval->vertex = vshader;
    retval->fragment = pshader;
    retval->generation = ctx->generation - 1;
    retval->refcount = 1;

    if (vshader != NULL)
    {
        if (vshader->parseData->attribute_count > 0)
        {
            const int count = vshader->parseData->attribute_count;
            const size_t len = sizeof (AttributeMap) * count;
            retval->attributes = (AttributeMap *) Malloc(len);
            if (retval->attributes == NULL)
                goto link_program_fail;

            memset(retval->attributes, '\0', len);
            if (!lookup_attributes(retval))
                goto link_program_fail;
        } // if

        if (!lookup_uniforms(retval, vshader, &bound))
            goto link_program_fail;
        lookup_samplers(retval, vshader, &bound);
        lookup_outputs(retval, pshader);
        vshader->refcount++;
    } // if

    if (pshader != NULL)
    {
        if (!lookup_uniforms(retval, pshader, &bound))
            goto link_program_fail;
        lookup_samplers(retval, pshader, &bound);
        lookup_outputs(retval, pshader);
        pshader->refcount++;
    } // if

    if (!build_constants_lists(retval))
        goto link_program_fail;

    if (bound)  // reset the old binding.
        ctx->profileUseProgram(ctx->bound_program);

    ctx->profileFinalInitProgram(retval);

    return retval;

link_program_fail:
    if (retval != NULL)
    {
        Free(retval->vs_uniforms_float4);
        Free(retval->vs_uniforms_int4);
        Free(retval->vs_uniforms_bool);
        Free(retval->ps_uniforms_float4);
        Free(retval->ps_uniforms_int4);
        Free(retval->ps_uniforms_bool);
        Free(retval->uniforms);
        Free(retval->attributes);
        Free(retval);
    } // if

    if (program != 0)
        ctx->profileDeleteProgram(program);

    if (bound)
        ctx->profileUseProgram(ctx->bound_program);

    return NULL;
} // MOJOSHADER_glLinkProgram


static void update_enabled_arrays(void)
{
    int highest_enabled = 0;
    int i;

    // Enable/disable vertex arrays to match our needs.
    // this happens to work in both ARB1 and GLSL, but if something alien
    //  shows up, we'll have to split these into profile*() functions.
    for (i = 0; i < ctx->max_attrs; i++)
    {
        const int want = (const int) ctx->want_attr[i];
        const int have = (const int) ctx->have_attr[i];
        if (want != have)
        {
            if (want)
                ctx->glEnableVertexAttribArray(i);
            else
                ctx->glDisableVertexAttribArray(i);
            ctx->have_attr[i] = want;
        } // if

        if (want)
            highest_enabled = i + 1;
    } // for

    ctx->max_attrs = highest_enabled;  // trim unneeded iterations next time.
} // update_enabled_arrays


void MOJOSHADER_glBindProgram(MOJOSHADER_glProgram *program)
{
    if (program == ctx->bound_program)
        return;  // nothing to do.

    if (program != NULL)
        program->refcount++;

    memset(ctx->want_attr, '\0', sizeof (ctx->want_attr[0]) * ctx->max_attrs);

    // If no program bound, disable all arrays, in case we're switching to
    //  fixed function pipeline. Otherwise, we try to minimize state changes
    //  by toggling just the changed set of needed arrays in ProgramReady().
    if (program == NULL)
        update_enabled_arrays();

    ctx->profileUseProgram(program);
    program_unref(ctx->bound_program);
    ctx->bound_program = program;
} // MOJOSHADER_glBindProgram


typedef struct
{
    MOJOSHADER_glShader *vertex;
    MOJOSHADER_glShader *fragment;
} BoundShaders;

static uint32 hash_shaders(const void *sym, void *data)
{
    (void) data;
    const BoundShaders *s = (const BoundShaders *) sym;
    const uint32 v = (s->vertex) ? (uint32) s->vertex->handle : 0;
    const uint32 f = (s->fragment) ? (uint32) s->fragment->handle : 0;
    return ((v & 0xFFFF) << 16) | (f & 0xFFFF);
} // hash_shaders

static int match_shaders(const void *_a, const void *_b, void *data)
{
    (void) data;
    const BoundShaders *a = (const BoundShaders *) _a;
    const BoundShaders *b = (const BoundShaders *) _b;

    const GLuint av = (a->vertex) ? a->vertex->handle : 0;
    const GLuint bv = (b->vertex) ? b->vertex->handle : 0;
    if (av != bv)
        return 0;

    const GLuint af = (a->fragment) ? a->fragment->handle : 0;
    const GLuint bf = (b->fragment) ? b->fragment->handle : 0;
    if (af != bf)
        return 0;

    return 1;
} // match_shaders

static void nuke_shaders(const void *key, const void *value, void *data)
{
    (void) data;
    Free((void *) key);  // this was a BoundShaders struct.
    MOJOSHADER_glDeleteProgram((MOJOSHADER_glProgram *) value);
} // nuke_shaders

void MOJOSHADER_glBindShaders(MOJOSHADER_glShader *v, MOJOSHADER_glShader *p)
{
    if ((v == NULL) && (p == NULL))
    {
        MOJOSHADER_glBindProgram(NULL);
        return;
    } // if

    // !!! FIXME: eventually support GL_EXT_separate_shader_objects.
    if (ctx->linker_cache == NULL)
    {
        ctx->linker_cache = hash_create(NULL, hash_shaders, match_shaders,
                                        nuke_shaders, 0, ctx->malloc_fn,
                                        ctx->free_fn, ctx->malloc_data);

        if (ctx->linker_cache == NULL)
        {
            out_of_memory();
            return;
        } // if
    } // if

    MOJOSHADER_glProgram *program = NULL;
    BoundShaders shaders;
    shaders.vertex = v;
    shaders.fragment = p;

    const void *val = NULL;
    if (hash_find(ctx->linker_cache, &shaders, &val))
        program = (MOJOSHADER_glProgram *) val;
    else
    {
        program = MOJOSHADER_glLinkProgram(v, p);
        if (program == NULL)
            return;

        BoundShaders *item = (BoundShaders *) Malloc(sizeof (BoundShaders));
        if (item == NULL)
        {
            MOJOSHADER_glDeleteProgram(program);
            return;
        } // if

        memcpy(item, &shaders, sizeof (BoundShaders));
        if (hash_insert(ctx->linker_cache, item, program) != 1)
        {
            Free(item);
            MOJOSHADER_glDeleteProgram(program);
            out_of_memory();
            return;
        } // if
    } // else

    assert(program != NULL);
    MOJOSHADER_glBindProgram(program);
} // MOJOSHADER_glBindShaders


static inline uint minuint(const uint a, const uint b)
{
    return ((a < b) ? a : b);
} // minuint


void MOJOSHADER_glSetVertexShaderUniformF(unsigned int idx, const float *data,
                                          unsigned int vec4n)
{
    const uint maxregs = STATICARRAYLEN(ctx->vs_reg_file_f) / 4;
    if (idx < maxregs)
    {
        assert(sizeof (GLfloat) == sizeof (float));
        const uint cpy = (minuint(maxregs - idx, vec4n) * sizeof (*data)) * 4;
        memcpy(ctx->vs_reg_file_f + (idx * 4), data, cpy);
        ctx->generation++;
    } // if
} // MOJOSHADER_glSetVertexShaderUniformF


void MOJOSHADER_glGetVertexShaderUniformF(unsigned int idx, float *data,
                                          unsigned int vec4n)
{
    const uint maxregs = STATICARRAYLEN(ctx->vs_reg_file_f) / 4;
    if (idx < maxregs)
    {
        assert(sizeof (GLfloat) == sizeof (float));
        const uint cpy = (minuint(maxregs - idx, vec4n) * sizeof (*data)) * 4;
        memcpy(data, ctx->vs_reg_file_f + (idx * 4), cpy);
    } // if
} // MOJOSHADER_glGetVertexShaderUniformF


void MOJOSHADER_glSetVertexShaderUniformI(unsigned int idx, const int *data,
                                          unsigned int ivec4n)
{
    const uint maxregs = STATICARRAYLEN(ctx->vs_reg_file_i) / 4;
    if (idx < maxregs)
    {
        assert(sizeof (GLint) == sizeof (int));
        const uint cpy = (minuint(maxregs - idx, ivec4n) * sizeof (*data)) * 4;
        memcpy(ctx->vs_reg_file_i + (idx * 4), data, cpy);
        ctx->generation++;
    } // if
} // MOJOSHADER_glSetVertexShaderUniformI


void MOJOSHADER_glGetVertexShaderUniformI(unsigned int idx, int *data,
                                          unsigned int ivec4n)
{
    const uint maxregs = STATICARRAYLEN(ctx->vs_reg_file_i) / 4;
    if (idx < maxregs)
    {
        assert(sizeof (GLint) == sizeof (int));
        const uint cpy = (minuint(maxregs - idx, ivec4n) * sizeof (*data)) * 4;
        memcpy(data, ctx->vs_reg_file_i + (idx * 4), cpy);
    } // if
} // MOJOSHADER_glGetVertexShaderUniformI


void MOJOSHADER_glSetVertexShaderUniformB(unsigned int idx, const int *data,
                                          unsigned int bcount)
{
    const uint maxregs = STATICARRAYLEN(ctx->vs_reg_file_f) / 4;
    if (idx < maxregs)
    {
        uint8 *wptr = ctx->vs_reg_file_b + idx;
        uint8 *endptr = wptr + minuint(maxregs - idx, bcount);
        while (wptr != endptr)
            *(wptr++) = *(data++) ? 1 : 0;
        ctx->generation++;
    } // if
} // MOJOSHADER_glSetVertexShaderUniformB


void MOJOSHADER_glGetVertexShaderUniformB(unsigned int idx, int *data,
                                          unsigned int bcount)
{
    const uint maxregs = STATICARRAYLEN(ctx->vs_reg_file_f) / 4;
    if (idx < maxregs)
    {
        uint8 *rptr = ctx->vs_reg_file_b + idx;
        uint8 *endptr = rptr + minuint(maxregs - idx, bcount);
        while (rptr != endptr)
            *(data++) = (int) *(rptr++);
    } // if
} // MOJOSHADER_glGetVertexShaderUniformB


void MOJOSHADER_glSetPixelShaderUniformF(unsigned int idx, const float *data,
                                         unsigned int vec4n)
{
    const uint maxregs = STATICARRAYLEN(ctx->ps_reg_file_f) / 4;
    if (idx < maxregs)
    {
        assert(sizeof (GLfloat) == sizeof (float));
        const uint cpy = (minuint(maxregs - idx, vec4n) * sizeof (*data)) * 4;
        memcpy(ctx->ps_reg_file_f + (idx * 4), data, cpy);
        ctx->generation++;
    } // if
} // MOJOSHADER_glSetPixelShaderUniformF


void MOJOSHADER_glGetPixelShaderUniformF(unsigned int idx, float *data,
                                         unsigned int vec4n)
{
    const uint maxregs = STATICARRAYLEN(ctx->ps_reg_file_f) / 4;
    if (idx < maxregs)
    {
        assert(sizeof (GLfloat) == sizeof (float));
        const uint cpy = (minuint(maxregs - idx, vec4n) * sizeof (*data)) * 4;
        memcpy(data, ctx->ps_reg_file_f + (idx * 4), cpy);
    } // if
} // MOJOSHADER_glGetPixelShaderUniformF


void MOJOSHADER_glSetPixelShaderUniformI(unsigned int idx, const int *data,
                                         unsigned int ivec4n)
{
    const uint maxregs = STATICARRAYLEN(ctx->ps_reg_file_i) / 4;
    if (idx < maxregs)
    {
        assert(sizeof (GLint) == sizeof (int));
        const uint cpy = (minuint(maxregs - idx, ivec4n) * sizeof (*data)) * 4;
        memcpy(ctx->ps_reg_file_i + (idx * 4), data, cpy);
        ctx->generation++;
    } // if
} // MOJOSHADER_glSetPixelShaderUniformI


void MOJOSHADER_glGetPixelShaderUniformI(unsigned int idx, int *data,
                                         unsigned int ivec4n)
{
    const uint maxregs = STATICARRAYLEN(ctx->ps_reg_file_i) / 4;
    if (idx < maxregs)
    {
        assert(sizeof (GLint) == sizeof (int));
        const uint cpy = (minuint(maxregs - idx, ivec4n) * sizeof (*data)) * 4;
        memcpy(data, ctx->ps_reg_file_i + (idx * 4), cpy);
    } // if
} // MOJOSHADER_glGetPixelShaderUniformI


void MOJOSHADER_glSetPixelShaderUniformB(unsigned int idx, const int *data,
                                         unsigned int bcount)
{
    const uint maxregs = STATICARRAYLEN(ctx->ps_reg_file_f) / 4;
    if (idx < maxregs)
    {
        uint8 *wptr = ctx->ps_reg_file_b + idx;
        uint8 *endptr = wptr + minuint(maxregs - idx, bcount);
        while (wptr != endptr)
            *(wptr++) = *(data++) ? 1 : 0;
        ctx->generation++;
    } // if
} // MOJOSHADER_glSetPixelShaderUniformB


void MOJOSHADER_glGetPixelShaderUniformB(unsigned int idx, int *data,
                                         unsigned int bcount)
{
    const uint maxregs = STATICARRAYLEN(ctx->ps_reg_file_f) / 4;
    if (idx < maxregs)
    {
        uint8 *rptr = ctx->ps_reg_file_b + idx;
        uint8 *endptr = rptr + minuint(maxregs - idx, bcount);
        while (rptr != endptr)
            *(data++) = (int) *(rptr++);
    } // if
} // MOJOSHADER_glGetPixelShaderUniformB


static inline GLenum opengl_attr_type(const MOJOSHADER_attributeType type)
{
    switch (type)
    {
        case MOJOSHADER_ATTRIBUTE_UNKNOWN: return GL_NONE; // oh well.
        case MOJOSHADER_ATTRIBUTE_BYTE: return GL_BYTE;
        case MOJOSHADER_ATTRIBUTE_UBYTE: return GL_UNSIGNED_BYTE;
        case MOJOSHADER_ATTRIBUTE_SHORT: return GL_SHORT;
        case MOJOSHADER_ATTRIBUTE_USHORT: return GL_UNSIGNED_SHORT;
        case MOJOSHADER_ATTRIBUTE_INT: return GL_INT;
        case MOJOSHADER_ATTRIBUTE_UINT: return GL_UNSIGNED_INT;
        case MOJOSHADER_ATTRIBUTE_FLOAT: return GL_FLOAT;
        case MOJOSHADER_ATTRIBUTE_DOUBLE: return GL_DOUBLE;

        case MOJOSHADER_ATTRIBUTE_HALF_FLOAT:
            if (ctx->have_GL_NV_half_float)
                return GL_HALF_FLOAT_NV;
            else if (ctx->have_GL_ARB_half_float_vertex)
                return GL_HALF_FLOAT_ARB;
            else if (ctx->have_GL_OES_vertex_half_float)
                return GL_HALF_FLOAT_OES;
            break;
    } // switch

    return GL_NONE;  // oh well. Raises a GL error later.
} // opengl_attr_type


// !!! FIXME: shouldn't (index) be unsigned?
void MOJOSHADER_glSetVertexAttribute(MOJOSHADER_usage usage,
                                     int index, unsigned int size,
                                     MOJOSHADER_attributeType type,
                                     int normalized, unsigned int stride,
                                     const void *ptr, unsigned int diviser)
{
    if ((ctx->bound_program == NULL) || (ctx->bound_program->vertex == NULL))
        return;

    const GLenum gl_type = opengl_attr_type(type);
    const GLboolean norm = (normalized) ? GL_TRUE : GL_FALSE;
    const int count = ctx->bound_program->attribute_count;
    GLint gl_index = 0;
    int i;

    for (i = 0; i < count; i++)
    {
        const AttributeMap *map = &ctx->bound_program->attributes[i];
        const MOJOSHADER_attribute *a = map->attribute;

        // !!! FIXME: is this array guaranteed to be sorted by usage?
        // !!! FIXME:  if so, we can break if a->usage > usage.

        if ((a->usage == usage) && (a->index == index))
        {
            gl_index = map->location;
            break;
        } // if
    } // for

    if (i == count)
        return;  // nothing to do, this shader doesn't use this stream.

    // this happens to work in both ARB1 and GLSL, but if something alien
    //  shows up, we'll have to split these into profile*() functions.
    ctx->glVertexAttribPointer(gl_index, size, gl_type, norm, stride, ptr);
    if (ctx->have_GL_ARB_instanced_arrays)
    {
        ctx->glVertexAttribDivisorARB(gl_index, diviser);
    }

    // flag this array as in use, so we can enable it later.
    ctx->want_attr[gl_index] = 1;
    if (ctx->max_attrs < (gl_index + 1))
        ctx->max_attrs = gl_index + 1;
} // MOJOSHADER_glSetVertexAttribute


MOJOSHADER_glEffect* MOJOSHADER_glCompileEffect(const unsigned char *tokenbuf,
                                                 const unsigned int bufsize,
                                                 const MOJOSHADER_swizzle *swiz,
                                                 const unsigned int swizcount,
                                                 const MOJOSHADER_samplerMap *smap,
                                                 const unsigned int smapcount)
{
    MOJOSHADER_glEffect *retval = NULL;
    GLuint shader = 0;
    const MOJOSHADER_effect *pd = MOJOSHADER_parseEffect(ctx->profile, tokenbuf,
                                                         bufsize, swiz, swizcount,
                                                         smap, smapcount,
                                                         ctx->malloc_fn,
                                                         ctx->free_fn,
                                                         ctx->malloc_data);
    if (pd->error_count > 0)
    {
        // !!! FIXME: put multiple errors in the buffer? Don't use
        // !!! FIXME:  MOJOSHADER_glGetError() for this?
        set_error(pd->errors[0].error);
        goto compile_shader_fail;
    } // if

    retval = (MOJOSHADER_glEffect *) Malloc(sizeof (MOJOSHADER_glEffect));
    if (retval == NULL)
        goto compile_shader_fail;

    // Lets compile all the shaders.
    {
        uint32 i = 0;

        retval->shader_count = pd->shader_count;
        retval->shaders = (MOJOSHADER_glShader **) Malloc(sizeof (MOJOSHADER_glShader*) * retval->shader_count);
        if (retval->shaders == NULL)
            goto compile_shader_fail;

        for (i = 0; i < retval->shader_count; i++)
        {
            retval->shaders[i] = (MOJOSHADER_glShader *) Malloc(sizeof (MOJOSHADER_glShader) * retval->shader_count);
            if (retval->shaders[i] == NULL)
                goto compile_shader_fail;

            if (!ctx->profileCompileShader(pd->shaders[i].shader, &shader))
                goto compile_shader_fail;

            retval->shaders[i]->parseData = pd->shaders[i].shader;
            retval->shaders[i]->handle = shader;
            retval->shaders[i]->refcount = 1;
        }
    }

    // Lets link all programs that may get bound.
    // TODO: may want to defer this until draw to minimize shader mem
    // TODO: can probably save a bit of mem if we hash shader combos instead of 1:1 program to tech->pass ratio.
    {
        uint32 program_count = 0;
        uint32 tech_index = 0;
        uint32 pass_index = 0;
        uint32 shader_index = 0;

        retval->technique_count = pd->technique_count;
        retval->techniques = (MOJOSHADER_glTechnique *) Malloc(sizeof (MOJOSHADER_glTechnique) * retval->technique_count);
        if (retval->techniques == NULL)
            goto compile_shader_fail;

        // Count and alloc memory for techniques and programs
        for (tech_index = 0; tech_index < retval->technique_count; tech_index++)
        {
            program_count += pd->techniques[tech_index].pass_count;

            retval->techniques[tech_index].pass_count = pd->techniques[tech_index].pass_count;
            retval->techniques[tech_index].passes = (MOJOSHADER_glPass *) Malloc(sizeof (MOJOSHADER_glPass) * retval->techniques[tech_index].pass_count);
            if (retval->techniques[tech_index].passes == NULL)
                goto compile_shader_fail;

            memset(retval->techniques[tech_index].passes, '\0', sizeof (MOJOSHADER_glPass) * retval->techniques[tech_index].pass_count);
        }

        retval->program_count = 0;
        retval->programs = (MOJOSHADER_glProgram **) Malloc(sizeof (MOJOSHADER_glProgram*) * program_count);
        if (retval->programs == NULL)
            goto compile_shader_fail;

        // NOTE: sort of weird that the tech->pass doesn't index the shader list...
        // Collect shaders
        for (tech_index = 0; tech_index < retval->technique_count; tech_index++)
        {
            for (pass_index = 0; pass_index < retval->techniques[tech_index].pass_count; pass_index++)
            {
                for (shader_index = 0; shader_index < retval->shader_count; shader_index++)
                {
                    if (pd->shaders[shader_index].technique == tech_index
                        && pd->shaders[shader_index].pass == pass_index)
                    {
                        if (pd->shaders[shader_index].shader->shader_type == MOJOSHADER_TYPE_VERTEX)
                            retval->techniques[tech_index].passes[pass_index].vs_index = shader_index;
                        else if (pd->shaders[shader_index].shader->shader_type == MOJOSHADER_TYPE_PIXEL)
                            retval->techniques[tech_index].passes[pass_index].ps_index = shader_index;
                        else // NOTE: other shader types not supported.
                            goto compile_shader_fail;
                    }
                }
            }
        }

        // Link all the programs we can.
        for (tech_index = 0; tech_index < retval->technique_count; tech_index++)
        {
            for (pass_index = 0; pass_index < retval->techniques[tech_index].pass_count; pass_index++)
            {
                assert(retval->techniques[tech_index].passes[pass_index].vs_index >= 0
                    && retval->techniques[tech_index].passes[pass_index].vs_index < retval->shader_count
                    && retval->techniques[tech_index].passes[pass_index].ps_index >= 0
                    && retval->techniques[tech_index].passes[pass_index].ps_index < retval->shader_count);

                retval->techniques[tech_index].passes[pass_index].program_index = retval->program_count;
                retval->programs[retval->program_count] =
                    MOJOSHADER_glLinkProgram(retval->shaders[retval->techniques[tech_index].passes[pass_index].vs_index],
                                             retval->shaders[retval->techniques[tech_index].passes[pass_index].ps_index]);

                if (retval->programs[retval->program_count] == NULL)
                    goto compile_shader_fail;
                retval->program_count++;
                assert(retval->program_count <= program_count);
            }
        }
    }

    // Reserve memory for the value cache.
    {
        uint32 param_index = 0;
        uint32 shader_index = 0;
        MOJOSHADER_effectParam *param = NULL;
        MOJOSHADER_symbol *symbol = NULL;
        const MOJOSHADER_parseData *shader_data = NULL;
        glEffectParam *effect_param = NULL;
        uint32 symbolidx = 0;

        retval->param_count = pd->param_count;
        retval->param_cache = (glEffectParam *) Malloc(sizeof (glEffectParam) * retval->param_count);
        if (retval->param_cache == NULL)
            goto compile_shader_fail;
        memset(retval->param_cache, '\0', sizeof (glEffectParam) * retval->param_count);

        for (param_index = 0; param_index < retval->param_count; ++param_index)
		{
            param = &(pd->params[param_index]);
            effect_param = &(retval->param_cache[param_index]);

            // need to find a matching symbol in a shader to figure out size.
            symbol = NULL;
            for (shader_index = 0; shader_index < retval->shader_count && symbol == NULL; ++shader_index)
			{
                shader_data = pd->shaders[shader_index].shader;

                if (shader_data->preshader)
                {
                    for (symbolidx = 0;
                        symbolidx < shader_data->preshader->symbol_count;
                        ++symbolidx)
                    {
                        symbol = &(shader_data->preshader->symbols[symbolidx]);
                        if (strcmp(param->name, symbol->name) == 0)
                        {
                            break;
                        }
                        symbol = NULL;
                    }
                }
            }

            for (shader_index = 0; shader_index < retval->shader_count && symbol == NULL; ++shader_index)
            {
                shader_data = pd->shaders[shader_index].shader;
				for (symbolidx = 0; (int)symbolidx < shader_data->symbol_count; ++symbolidx)
				{
                    symbol = &(shader_data->symbols[symbolidx]);
					if (strcmp(param->name, symbol->name) == 0)
					{
						break;
					}
                    symbol = NULL;
				}
			}

			// this means the param isn't actually referenced by any shaders.
			if (symbol == NULL)
				continue;

            effect_param->data_size = symbol->register_count * 16;
            effect_param->data = Malloc(effect_param->data_size);
            if (effect_param->data == NULL)
                goto compile_shader_fail;

            memset(effect_param->data, '\0', effect_param->data_size);

            // collect symbol references for fast uniform setting later.
            effect_param->shader_symbol_count = pd->shader_count;
            effect_param->shader_symbols = (MOJOSHADER_symbol**) Malloc(sizeof (MOJOSHADER_symbol*) * effect_param->shader_symbol_count);
            if (effect_param->shader_symbols == NULL)
                goto compile_shader_fail;

            memset(effect_param->shader_symbols, '\0', sizeof(MOJOSHADER_symbol*) * effect_param->shader_symbol_count);

            effect_param->preshader_symbols = (MOJOSHADER_symbol**) Malloc(sizeof (MOJOSHADER_symbol*) * effect_param->shader_symbol_count);
            if (effect_param->preshader_symbols == NULL)
                goto compile_shader_fail;

            memset(effect_param->preshader_symbols, '\0', sizeof(MOJOSHADER_symbol*) * effect_param->shader_symbol_count);

            for (shader_index = 0; shader_index < retval->shader_count; ++shader_index)
            {
                shader_data = pd->shaders[shader_index].shader;

                if (shader_data->preshader)
                {
                    for (symbolidx = 0;
                        symbolidx < shader_data->preshader->symbol_count;
                        ++symbolidx)
                    {
                        symbol = &(shader_data->preshader->symbols[symbolidx]);
                        if (strcmp(param->name, symbol->name) == 0)
                        {
                            effect_param->preshader_symbols[shader_index] = symbol;
                            break;
                        }
                    }
                }

                for (symbolidx = 0; symbolidx < (uint32)shader_data->symbol_count; ++symbolidx)
                {
                    symbol = &(shader_data->symbols[symbolidx]);
                    if (strcmp(param->name, symbol->name) == 0)
                    {
                        effect_param->shader_symbols[shader_index] = symbol;
                        break;
                    }
                }
            }
        }
    }

    retval->effect = pd;
    retval->refcount = 1;
    retval->bound_technique_index = 0;
    return retval;

compile_shader_fail:
    if (shader != 0)
        ctx->profileDeleteShader(shader);
    if (retval != NULL)
        MOJOSHADER_glDeleteEffect(retval);
    MOJOSHADER_freeEffect(pd);
    return NULL;
}


const MOJOSHADER_effect *MOJOSHADER_glGetEffectParseData(MOJOSHADER_glEffect *effect)
{
    return effect->effect;
}

void MOJOSHADER_glSetEffectValue(MOJOSHADER_glEffect *effect, int idx,
                                 void *data, unsigned int bytes)
{
    glEffectParam *param = NULL;

    assert(effect);
    assert(idx >=0 && idx < (int)effect->param_count);

    param = &(effect->param_cache[idx]);

    if (param->data != NULL)
    {
        assert(data);
        assert(bytes > 0 && bytes <= param->data_size);

        memcpy(param->data, data, bytes);
        param->isset = 1;
    }

    // TODO: return whether the param could be set perhaps?
}

int MOJOSHADER_glGetEffectParameterBySemantic(MOJOSHADER_glEffect *effect,
                                              const char *name)
{
    int retval = -1;
    uint32 i = 0;
    assert(effect);
    assert(name);

    for (; i < (uint32)effect->effect->param_count; i++)
    {
        if (strcmp(effect->effect->params[i].semantic, name) == 0)
        {
            retval = i;
            break;
        }
    }
    
    return retval;
}

void MOJOSHADER_glEffectBegin(MOJOSHADER_glEffect *effect, unsigned int *pass_count)
{
    assert(effect);
    assert(pass_count);

    assert(effect->techniques && effect->bound_technique_index < effect->technique_count);
    *pass_count = effect->techniques[effect->bound_technique_index].pass_count;

    // TODO: maybe some other context prep or something.
}

static const GLenum blend_map[] =
{
    -1,
    GL_ZERO, // D3DBLEND_ZERO
    GL_ONE, // D3DBLEND_ONE
    GL_SRC_COLOR, // D3DBLEND_SRCCOLOR
    GL_ONE_MINUS_SRC_COLOR, // D3DBLEND_INVSRCCOLOR
    GL_SRC_ALPHA, // D3DBLEND_SRCALPHA
    GL_ONE_MINUS_SRC_ALPHA, // D3DBLEND_INVSRCALPHA
    GL_DST_ALPHA, // D3DBLEND_DESTALPHA
    GL_ONE_MINUS_DST_ALPHA, // D3DBLEND_INVDESTALPHA
    GL_DST_COLOR, // D3DBLEND_DESTCOLOR
    GL_ONE_MINUS_DST_COLOR, // D3DBLEND_INVDESTCOLOR
    GL_SRC_ALPHA_SATURATE // D3DBLEND_SRCALPHASAT
};

static const GLenum cmpfunc_map[] =
{
    -1,
    GL_NEVER, // D3DCMP_NEVER
    GL_LESS, // D3DCMP_LESS
    GL_EQUAL, // D3DCMP_EQUAL
    GL_LEQUAL, // D3DCMP_LESSEQUAL
    GL_GREATER, // D3DCMP_GREATER
    GL_NOTEQUAL, // D3DCMP_NOTEQUAL
    GL_GEQUAL, // D3DCMP_GREATEREQUAL
    GL_ALWAYS
};

static const GLenum func_map[] =
{
    -1,
    GL_FUNC_ADD, // D3DBLENDOP_ADD
    GL_FUNC_SUBTRACT, // D3DBLENDOP_SUBTRACT
    GL_FUNC_REVERSE_SUBTRACT, // D3DBLENDOP_REVSUBTRACT
    GL_MIN, // D3DBLENDOP_MIN
    GL_MAX, // D3DBLENDOP_MAX
};

static const GLenum fill_map[] =
{
    -1,
    GL_POINT, // D3DFILL_POINT
    GL_LINE, // D3DFILL_WIREFRAME
    GL_FILL // D3DFILL_SOLID
};

static const GLenum cullmode_map[] =
{
    -1,
    GL_CCW, // D3DCULL_NONE
    GL_CCW, // D3DCULL_CW
    GL_CW // D3DCULL_CCW
};

#define D3DCOLORWRITEENABLE_RED     (1L<<0)
#define D3DCOLORWRITEENABLE_GREEN   (1L<<1)
#define D3DCOLORWRITEENABLE_BLUE    (1L<<2)
#define D3DCOLORWRITEENABLE_ALPHA   (1L<<3)

void MOJOSHADER_glEffectBeginPass(MOJOSHADER_glEffect *effect, unsigned int pass_index)
{
    MOJOSHADER_glPass *pass = NULL;

    if (effect == ctx->bound_effect)
        return;  // nothing to do.

    if (effect != NULL)
        effect->refcount++;

    effect_unref(ctx->bound_effect);
    ctx->bound_effect = effect;

    assert(effect->techniques && effect->bound_technique_index < effect->technique_count);
    assert(pass_index < effect->techniques[effect->bound_technique_index].pass_count);
    assert(effect->techniques[effect->bound_technique_index].passes);

    pass = &(effect->techniques[effect->bound_technique_index].passes[pass_index]);

    // bind the program for this effect pass
    {
        uint32 program_index = pass->program_index;
        assert(program_index < effect->program_count);
        MOJOSHADER_glBindProgram(effect->programs[program_index]);
    }

    effect->bound_pass_index = pass_index;

    { // apply render state for pass
        // TODO: register all gl functions with ctx
        MOJOSHADER_effectPass *effectpass = &effect->effect->techniques[effect->bound_technique_index].passes[effect->bound_pass_index];
        MOJOSHADER_stateType state_type;

        // default state.
        unsigned int state_value;
        int enable_blend = 0;
        int enable_seperate_blend = 0;
        GLenum src_blend = GL_ONE;
        GLenum dest_blend = GL_ZERO;
        GLenum src_alpha_blend = GL_ONE;
        GLenum dest_alpha_blend = GL_ZERO;
        GLenum blend_op = GL_FUNC_ADD;
        int enable_alpha_test = 0;
        GLenum alpha_cmp = GL_GREATER;
        GLclampf alpha_ref = 0.0f;
        int enable_depth_test = 0;
        GLenum depth_func = GL_LESS;
        GLboolean depth_mask = GL_TRUE;
        GLenum polygon_fill = GL_FILL;
        int enable_poly_cull = 0;
        GLenum front_face = GL_CCW;
        int enable_point_sprite = 0;
        GLboolean color_mask_r = GL_TRUE;
        GLboolean color_mask_g = GL_TRUE;
        GLboolean color_mask_b = GL_TRUE;
        GLboolean color_mask_a = GL_TRUE;

        for (unsigned int i = 0; i < effectpass->state_count; ++i)
        {
            state_type = effectpass->states[i].type;
            state_value = effectpass->states[i].value;

            if (state_type == MOJOSHADER_STATE_ZENABLE)
                enable_depth_test = state_value;
            else if (state_type == MOJOSHADER_STATE_FILLMODE)
                polygon_fill = fill_map[state_value];
            else if (state_type == MOJOSHADER_STATE_SHADEMODE)
                assert(0); // TODO:
            else if (state_type == MOJOSHADER_STATE_ZWRITEENABLE)
                depth_mask = state_value;
            else if (state_type == MOJOSHADER_STATE_ALPHATESTENABLE)
                enable_alpha_test = state_value;
            else if (state_type == MOJOSHADER_STATE_LASTPIXEL)
                assert(0); // TODO:
            else if (state_type == MOJOSHADER_STATE_SRCBLEND)
                src_blend = blend_map[state_value];
            else if (state_type == MOJOSHADER_STATE_DESTBLEND)
                dest_blend = blend_map[state_value];
            else if (state_type == MOJOSHADER_STATE_CULLMODE)
            {
                if (state_value == 1) // D3DCULL_NONE
                {
                    enable_poly_cull = 0;
                }
                else
                {
                    enable_poly_cull = 1;
                    front_face = cullmode_map[state_value];
                }
            }
            else if (state_type == MOJOSHADER_STATE_ZFUNC)
                depth_func = cmpfunc_map[state_value];
            else if (state_type == MOJOSHADER_STATE_ALPHAREF)
                alpha_ref = state_value / 255.0f;
            else if (state_type == MOJOSHADER_STATE_ALPHAFUNC)
                alpha_cmp = cmpfunc_map[state_value];
            else if (state_type == MOJOSHADER_STATE_DITHERENABLE)
                assert(0); // TODO:
            else if (state_type == MOJOSHADER_STATE_ALPHABLENDENABLE)
                enable_blend = state_value;
            else if (state_type == MOJOSHADER_STATE_POINTSPRITEENABLE)
                enable_point_sprite = state_value;
            else if (state_type == MOJOSHADER_STATE_COLORWRITEENABLE)
            {
                color_mask_r = (state_value & D3DCOLORWRITEENABLE_RED) != 0 ? 1 : 0;
                color_mask_g = (state_value & D3DCOLORWRITEENABLE_GREEN) != 0 ? 1 : 0;
                color_mask_b = (state_value & D3DCOLORWRITEENABLE_BLUE) != 0 ? 1 : 0;
                color_mask_a = (state_value & D3DCOLORWRITEENABLE_ALPHA) != 0 ? 1 : 0;
            }
            else if (state_type == MOJOSHADER_STATE_TWEENFACTOR)
                assert(0); // TODO:
            else if (state_type == MOJOSHADER_STATE_BLENDOP)
                blend_op = func_map[state_value];
            else if (state_type == MOJOSHADER_STATE_SEPERATEALPHABLENDENABLE)
                enable_seperate_blend = state_value;
            else if (state_type == MOJOSHADER_STATE_SRCBLENDALPHA)
                src_alpha_blend = blend_map[state_value];
            else if (state_type == MOJOSHADER_STATE_DESTBLENDALPHA)
                dest_alpha_blend = blend_map[state_value];
        }

        // raster state state.
        toggle_gl_state(GL_DEPTH_TEST, enable_depth_test);
        glDepthFunc(depth_func);
        glDepthMask(depth_mask);
        glColorMask(color_mask_r, color_mask_g, color_mask_b, color_mask_a);
        glPolygonMode(GL_FRONT_AND_BACK, polygon_fill);

        // cull state.
        toggle_gl_state(GL_CULL_FACE, enable_poly_cull);
        glFrontFace(front_face);

        // blend state.
        toggle_gl_state(GL_BLEND, enable_blend | enable_seperate_blend);
        if (enable_seperate_blend == 0) // make alpha blends match if seperate isn't enabled.
        {
            src_alpha_blend = src_blend;
            dest_alpha_blend = dest_blend;
        }
        ctx->glBlendFuncSeparate(src_blend, dest_blend, src_alpha_blend, dest_alpha_blend);
        ctx->glBlendEquation(blend_op);

        // alpha test state.
        toggle_gl_state(GL_ALPHA_TEST, enable_alpha_test);
        glAlphaFunc(alpha_cmp, alpha_ref);

        // Misc. state.
        toggle_gl_state(GL_POINT_SPRITE, enable_point_sprite);
    }
}

void MOJOSHADER_glEffectEndPass(MOJOSHADER_glEffect *effect)
{
    effect->bound_pass_index = 0;
    
    MOJOSHADER_glBindProgram(NULL);

    assert(effect == ctx->bound_effect);

    effect_unref(ctx->bound_effect);
    ctx->bound_effect = NULL;
}

void MOJOSHADER_glEffectEnd(MOJOSHADER_glEffect *effect)
{
    // TODO: maybe something?
}

void MOJOSHADER_glDeleteEffect(MOJOSHADER_glEffect *effect)
{
    effect_unref(effect);
}


void MOJOSHADER_glSetVertexPreshaderUniformF(unsigned int idx,
                                             const float *data,
                                             unsigned int vec4n)
{
    MOJOSHADER_glProgram *program = ctx->bound_program;
    if (program == NULL)
        return;  // nothing to do.

    const uint maxregs = program->vs_preshader_reg_count;
    if (idx < maxregs)
    {
        assert(sizeof (GLfloat) == sizeof (float));
        const uint cpy = (minuint(maxregs - idx, vec4n) * sizeof (*data)) * 4;
        memcpy(program->vs_preshader_regs + (idx * 4), data, cpy);
        program->generation = ctx->generation-1;
    } // if
} // MOJOSHADER_glSetVertexPreshaderUniformF


void MOJOSHADER_glGetVertexPreshaderUniformF(unsigned int idx, float *data,
                                             unsigned int vec4n)
{
    MOJOSHADER_glProgram *program = ctx->bound_program;
    if (program == NULL)
        return;  // nothing to do.

    const uint maxregs = program->vs_preshader_reg_count;
    if (idx < maxregs)
    {
        assert(sizeof (GLfloat) == sizeof (float));
        const uint cpy = (minuint(maxregs - idx, vec4n) * sizeof (*data)) * 4;
        memcpy(data, program->vs_preshader_regs + (idx * 4), cpy);
    } // if
} // MOJOSHADER_glGetVertexPreshaderUniformF


void MOJOSHADER_glSetPixelPreshaderUniformF(unsigned int idx,
                                             const float *data,
                                             unsigned int vec4n)
{
    MOJOSHADER_glProgram *program = ctx->bound_program;
    if (program == NULL)
        return;  // nothing to do.

    const uint maxregs = program->ps_preshader_reg_count;
    if (idx < maxregs)
    {
        assert(sizeof (GLfloat) == sizeof (float));
        const uint cpy = (minuint(maxregs - idx, vec4n) * sizeof (*data)) * 4;
        memcpy(program->ps_preshader_regs + (idx * 4), data, cpy);
        program->generation = ctx->generation-1;
    } // if
} // MOJOSHADER_glSetPixelPreshaderUniformF


void MOJOSHADER_glGetPixelPreshaderUniformF(unsigned int idx, float *data,
                                             unsigned int vec4n)
{
    MOJOSHADER_glProgram *program = ctx->bound_program;
    if (program == NULL)
        return;  // nothing to do.

    const uint maxregs = program->ps_preshader_reg_count;
    if (idx < maxregs)
    {
        assert(sizeof (GLfloat) == sizeof (float));
        const uint cpy = (minuint(maxregs - idx, vec4n) * sizeof (*data)) * 4;
        memcpy(data, program->ps_preshader_regs + (idx * 4), cpy);
    } // if
} // MOJOSHADER_glGetPixelPreshaderUniformF


void MOJOSHADER_glInvalidateRenderState()
{
    // default state.
    int enable_blend = 0;
    int enable_seperate_blend = 0;
    GLenum src_blend = GL_ONE;
    GLenum dest_blend = GL_ZERO;
    GLenum src_alpha_blend = GL_ONE;
    GLenum dest_alpha_blend = GL_ZERO;
    GLenum blend_op = GL_FUNC_ADD;
    int enable_alpha_test = 0;
    GLenum alpha_cmp = GL_GREATER;
    GLclampf alpha_ref = 0.0f;
    int enable_depth_test = 0;
    GLenum depth_func = GL_LESS;
    GLboolean depth_mask = GL_TRUE;
    GLenum polygon_fill = GL_FILL;
    int enable_poly_cull = 0;
    GLenum front_face = GL_CCW;
    int enable_point_sprite = 0;
    GLboolean color_mask_r = GL_TRUE;
    GLboolean color_mask_g = GL_TRUE;
    GLboolean color_mask_b = GL_TRUE;
    GLboolean color_mask_a = GL_TRUE;

    // raster state state.
    toggle_gl_state(GL_DEPTH_TEST, enable_depth_test);
    glDepthFunc(depth_func);
    glDepthMask(depth_mask);
    glColorMask(color_mask_r, color_mask_g, color_mask_b, color_mask_a);
    glPolygonMode(GL_FRONT_AND_BACK, polygon_fill);

    // cull state.
    toggle_gl_state(GL_CULL_FACE, enable_poly_cull);
    glFrontFace(front_face);

    // blend state.
    toggle_gl_state(GL_BLEND, enable_blend | enable_seperate_blend);
    if (enable_seperate_blend == 0) // reset alpha blends if it is not enabled.
    {
        src_alpha_blend = GL_ONE;
        dest_alpha_blend = GL_ZERO;
    }
    ctx->glBlendFuncSeparate(src_blend, dest_blend, src_alpha_blend, dest_alpha_blend);
    ctx->glBlendEquation(blend_op);

    // alpha test state.
    toggle_gl_state(GL_ALPHA_TEST, enable_alpha_test);
    glAlphaFunc(alpha_cmp, alpha_ref);

    // Misc. state.
    toggle_gl_state(GL_POINT_SPRITE, enable_point_sprite);
}


void MOJOSHADER_glSetLegacyBumpMapEnv(unsigned int sampler, float mat00,
                                      float mat01, float mat10, float mat11,
                                      float lscale, float loffset)
{
    if ((sampler == 0) || (sampler > (MAX_TEXBEMS+1)))
        return;

    GLfloat *dstf = ctx->texbem_state + (6 * (sampler-1));
    *(dstf++) = (GLfloat) mat00;
    *(dstf++) = (GLfloat) mat01;
    *(dstf++) = (GLfloat) mat10;
    *(dstf++) = (GLfloat) mat11;
    *(dstf++) = (GLfloat) lscale;
    *(dstf++) = (GLfloat) loffset;
    ctx->generation++;
} // MOJOSHADER_glSetLegacyBumpMapEnv

static const GLint wrap_map[] =
{
    GL_REPEAT,
    GL_REPEAT,
    GL_MIRRORED_REPEAT,
    GL_CLAMP_TO_EDGE
};

static const GLint mag_filter_map[] =
{
    GL_NEAREST,
    GL_NEAREST,
    GL_LINEAR
};

static const GLint min_mip_filter_map[3][3] =
{
    {GL_NEAREST, GL_NEAREST_MIPMAP_NEAREST, GL_NEAREST_MIPMAP_LINEAR},
    {GL_NEAREST, GL_NEAREST_MIPMAP_NEAREST, GL_NEAREST_MIPMAP_LINEAR},
    {GL_LINEAR, GL_LINEAR_MIPMAP_NEAREST, GL_LINEAR_MIPMAP_LINEAR}
};

void MOJOSHADER_glProgramReady(void)
{
    MOJOSHADER_glProgram *program = ctx->bound_program;
    MOJOSHADER_glEffect *effect = ctx->bound_effect;

    if (program == NULL)
        return;  // nothing to do.

    // If we have an effect bound apply the current param cache to this program's context.
    if (effect)
    {
        MOJOSHADER_glPass *pass = NULL;
        glEffectParam *param = NULL;
        MOJOSHADER_symbol *symbol = NULL;
        uint32 param_index = 0;
        int shader_index = 0;
        int i, j;
        MOJOSHADER_glTechnique * technique = &effect->techniques[effect->bound_technique_index];
        void (*set_shader_uniform_b)(unsigned int, const int *, unsigned int);
        void (*set_shader_uniform_i)(unsigned int, const int *, unsigned int);
        void (*set_shader_uniform_f)(unsigned int, const float *, unsigned int);
        void (*set_preshader_uniform_f)(unsigned int, const float *, unsigned int);
        void *paramdata = NULL;

        assert(effect->techniques && effect->bound_technique_index < effect->technique_count);
        assert(effect->bound_pass_index < technique->pass_count);
        assert(technique->passes);

        pass = &(technique->passes[effect->bound_pass_index]);

        for (; param_index < effect->param_count; param_index++)
        {
            param = &(effect->param_cache[param_index]);
            if (param->data == NULL)
            {
                continue;
            }

            for(i = 0; i < 2; ++i)
            {
                shader_index = i == 0 ? pass->vs_index : pass->ps_index;
                set_shader_uniform_b = i == 0 ? MOJOSHADER_glSetVertexShaderUniformB : MOJOSHADER_glSetPixelShaderUniformB;
                set_shader_uniform_i = i == 0 ? MOJOSHADER_glSetVertexShaderUniformI : MOJOSHADER_glSetPixelShaderUniformI;
                set_shader_uniform_f = i == 0 ? MOJOSHADER_glSetVertexShaderUniformF : MOJOSHADER_glSetPixelShaderUniformF;
                set_preshader_uniform_f = i == 0 ? MOJOSHADER_glSetVertexPreshaderUniformF : MOJOSHADER_glSetPixelPreshaderUniformF;
                paramdata = effect->effect->params[param_index].values;
                if (param->isset || paramdata == NULL)
                {
                    paramdata = param->data;
                }

                symbol = param->shader_symbols[shader_index];
                if (symbol != NULL)
                {
                    assert(symbol->register_count <= param->data_size / 16);
                    if (symbol->register_set == MOJOSHADER_SYMREGSET_BOOL)
                    {
                        set_shader_uniform_b(symbol->register_index,
                            (const int *)paramdata, symbol->register_count );
                    }
                    else if (symbol->register_set == MOJOSHADER_SYMREGSET_INT4)
                    {
                        set_shader_uniform_i(symbol->register_index,
                            (const int *)paramdata, symbol->register_count );
                    }
                    else if (symbol->register_set == MOJOSHADER_SYMREGSET_FLOAT4)
                    {
                        set_shader_uniform_f(symbol->register_index,
                            (const float *)paramdata, symbol->register_count );
                    }
                    else if (symbol->register_set == MOJOSHADER_SYMREGSET_SAMPLER)
                    {
                        MOJOSHADER_effectParam *effectparam = &effect->effect->params[param_index];
                        MOJOSHADER_samplerAddressType addressu = MOJOSHADER_SAMPLER_ADDRESS_0;
                        MOJOSHADER_samplerAddressType addressv = MOJOSHADER_SAMPLER_ADDRESS_0;
                        MOJOSHADER_samplerFilterType magfilter = MOJOSHADER_SAMPLER_FILTER_0;
                        MOJOSHADER_samplerFilterType minfilter = MOJOSHADER_SAMPLER_FILTER_0;
                        MOJOSHADER_samplerFilterType mipfilter = MOJOSHADER_SAMPLER_FILTER_0;
                        GLfloat lodbias = 0.0f;

                        // TODO: confirm this.
                        // TODO: take MOJOSHADER_symbolType into account for texture target.
                        ctx->glActiveTexture(GL_TEXTURE0+symbol->register_index);
                        glBindTexture(GL_TEXTURE_2D, *( (GLuint*)paramdata) );

                        // Apply the sample state.
                        for (j = 0; j < (int)effectparam->sampler_state_count; ++j)
                        {
                            const MOJOSHADER_effectSamplerState *state = &effectparam->sampler_states[j];
                            if (state->type == MOJOSHADER_SAMPLER_STATE_ADDRESSU)
                            {
                                addressu = (MOJOSHADER_samplerAddressType)state->value;
                            }
                            else if (state->type == MOJOSHADER_SAMPLER_STATE_ADDRESSV)
                            {
                                addressv = (MOJOSHADER_samplerAddressType)state->value;
                            }
                            else if (state->type == MOJOSHADER_SAMPLER_STATE_ADDRESSW)
                            {
                                assert(0); // TODO:
                            }
                            else if (state->type == MOJOSHADER_SAMPLER_STATE_BORDER)
                            {
                                assert(0); // TODO:
                            }
                            else if (state->type == MOJOSHADER_SAMPLER_STATE_MAGFILTER)
                            {
                                magfilter = (MOJOSHADER_samplerFilterType)state->value;
                            }
                            else if (state->type == MOJOSHADER_SAMPLER_STATE_MINFILTER)
                            {
                                minfilter = (MOJOSHADER_samplerFilterType)state->value;
                            }
                            else if (state->type == MOJOSHADER_SAMPLER_STATE_MIPFILTER)
                            {
                                mipfilter = (MOJOSHADER_samplerFilterType)state->value;
                            }
                            else if (state->type == MOJOSHADER_SAMPLER_STATE_MIPMAPLODBIAS)
                            {
                                lodbias = state->value_float;
                            }
                        }

                        // TODO: use symbols in ctx.
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrap_map[addressu]);
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap_map[addressv]);
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, mag_filter_map[magfilter]);
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, min_mip_filter_map[minfilter][mipfilter]);
                        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_LOD_BIAS, lodbias);
                    }
                }

                symbol = param->preshader_symbols[shader_index];
                if (symbol != NULL)
                {
                    assert(symbol->register_count <= param->data_size / 16);
                    if (symbol->register_set == MOJOSHADER_SYMREGSET_FLOAT4)
                    {
                        set_preshader_uniform_f(symbol->register_index,
                            (const float *)paramdata, symbol->register_count );
                    }
                    else
                    {
                        assert(0);
                    }
                }
            }
        }
    }

    // Toggle vertex attribute arrays on/off, based on our needs.
    update_enabled_arrays();

    if (program->uses_pointsize != ctx->pointsize_enabled)
    {
        if (program->uses_pointsize)
            ctx->glEnable(GL_PROGRAM_POINT_SIZE);
        else
            ctx->glDisable(GL_PROGRAM_POINT_SIZE);
        ctx->pointsize_enabled = program->uses_pointsize;
    } // if

    // push Uniforms to the program from our register files...
    if ( ((program->uniform_count) || (program->texbem_count)) &&
         (program->generation != ctx->generation))
    {
        // vertex shader uniforms come first in program->uniforms array.
        const uint32 count = program->uniform_count;
        const GLfloat *srcf = ctx->vs_reg_file_f;
        const GLint *srci = ctx->vs_reg_file_i;
        const uint8 *srcb = ctx->vs_reg_file_b;
        MOJOSHADER_shaderType shader_type = MOJOSHADER_TYPE_VERTEX;
        GLfloat *dstf = program->vs_uniforms_float4;
        GLint *dsti = program->vs_uniforms_int4;
        GLint *dstb = program->vs_uniforms_bool;
        const MOJOSHADER_preshader *preshader = NULL;
        uint32 i;

        // !!! FIXME: shouldn't this run even if the generation hasn't changed?
        #if SUPPORT_PRESHADERS
        int ran_preshader = 0;
        if (program->vertex)
        {
            preshader = program->vertex->parseData->preshader;
            if (preshader)
            {
                MOJOSHADER_runPreshader(preshader, program->vs_preshader_regs,
                                        ctx->vs_reg_file_f);
                ran_preshader = 1;
            } // if
        } // if

        if (program->fragment)
        {
            preshader = program->fragment->parseData->preshader;
            if (preshader)
            {
                MOJOSHADER_runPreshader(preshader, program->ps_preshader_regs,
                                        ctx->ps_reg_file_f);
                ran_preshader = 1;
            } // if
        } // if

        if (ran_preshader)
            ctx->generation++;
        #endif

        for (i = 0; i < count; i++)
        {
            UniformMap *map = &program->uniforms[i];
            const MOJOSHADER_shaderType uniform_shader_type = map->shader_type;
            const MOJOSHADER_uniform *u = map->uniform;
            const MOJOSHADER_uniformType type = u->type;
            const int index = u->index;
            const int size = u->array_count ? u->array_count : 1;

            assert(!u->constant);

            // Did we switch from vertex to pixel (to geometry, etc)?
            if (shader_type != uniform_shader_type)
            {
                // we start with vertex, move to pixel, then to geometry, etc.
                //  The array should always be sorted as such.
                if (uniform_shader_type == MOJOSHADER_TYPE_PIXEL)
                {
                    assert(shader_type == MOJOSHADER_TYPE_VERTEX);
                    srcf = ctx->ps_reg_file_f;
                    srci = ctx->ps_reg_file_i;
                    srcb = ctx->ps_reg_file_b;
                    dstf = program->ps_uniforms_float4;
                    dsti = program->ps_uniforms_int4;
                    dstb = program->ps_uniforms_bool;
                } // if
                else
                {
                    // Should be ordered vertex, then pixel, then geometry.
                    assert(0 && "Unexpected shader type");
                } // else

                shader_type = uniform_shader_type;
            } // if

            if (type == MOJOSHADER_UNIFORM_FLOAT)
            {
                const size_t count = 4 * size;
                const GLfloat *f = &srcf[index * 4];
                memcpy(dstf, f, sizeof (GLfloat) * count);
                dstf += count;
            } // if
            else if (type == MOJOSHADER_UNIFORM_INT)
            {
                const size_t count = 4 * size;
                const GLint *i = &srci[index * 4];
                memcpy(dsti, i, sizeof (GLint) * count);
                dsti += count;
            } // else if
            else if (type == MOJOSHADER_UNIFORM_BOOL)
            {
                const size_t count = size;
                const uint8 *b = &srcb[index];
                size_t i;
                for (i = 0; i < count; i++)
                    dstb[i] = (GLint) b[i];
                dstb += count;
            } // else if

            // !!! FIXME: set constants that overlap the array.
        } // for

        assert((!program->texbem_count) || (program->fragment));
        if ((program->texbem_count) && (program->fragment))
        {
            const MOJOSHADER_parseData *pd = program->fragment->parseData;
            const int samp_count = pd->sampler_count;
            const MOJOSHADER_sampler *samps = pd->samplers;
            GLfloat *dstf = program->ps_uniforms_float4;
            int texbem_count = 0;

            dstf += (program->ps_uniforms_float4_count * 4) -
                     (program->texbem_count * 8);

            assert(program->texbem_count <= MAX_TEXBEMS);
            for (i = 0; (int)i < samp_count; i++)
            {
                if (samps[i].texbem)
                {
                    assert(samps[i].index > 0);
                    assert(samps[i].index <= MAX_TEXBEMS);
                    memcpy(dstf, &ctx->texbem_state[6 * (samps[i].index-1)],
                           sizeof (GLfloat) * 6);
                    dstf[6] = 0.0f;
                    dstf[7] = 0.0f;
                    dstf += 8;
                    texbem_count++;
                } // if
            } // for

            assert(texbem_count == program->texbem_count);
        } // if

        program->generation = ctx->generation;

        ctx->profilePushUniforms();
    } // if
} // MOJOSHADER_glProgramReady


void MOJOSHADER_glDeleteProgram(MOJOSHADER_glProgram *program)
{
    program_unref(program);
} // MOJOSHADER_glDeleteProgram


void MOJOSHADER_glDeleteShader(MOJOSHADER_glShader *shader)
{
    // See if this was bound as an unlinked program anywhere...
    if (ctx->linker_cache)
    {
        const void *key = NULL;
        void *iter = NULL;
        int morekeys = hash_iter_keys(ctx->linker_cache, &key, &iter);
        while (morekeys)
        {
            const BoundShaders *shaders = (const BoundShaders *) key;
            // Do this here so we don't confuse the iteration by removing...
            morekeys = hash_iter_keys(ctx->linker_cache, &key, &iter);
            if ((shaders->vertex == shader) || (shaders->fragment == shader))
            {
                // Deletes the linked program, which will unref the shader.
                hash_remove(ctx->linker_cache, shaders);
            } // if
        } // while
    } // if

    shader_unref(shader);
} // MOJOSHADER_glDeleteShader


void MOJOSHADER_glDestroyContext(MOJOSHADER_glContext *_ctx)
{
    MOJOSHADER_glContext *current_ctx = ctx;
    ctx = _ctx;
    MOJOSHADER_glBindProgram(NULL);
    if (ctx->linker_cache)
        hash_destroy(ctx->linker_cache);
    lookup_entry_points(NULL, NULL);   // !!! FIXME: is there a value to this?
    Free(ctx);
    ctx = ((current_ctx == _ctx) ? NULL : current_ctx);
} // MOJOSHADER_glDestroyContext

// end of mojoshader_opengl.c ...