FbDev

Readme.md

@@ -97,7 +97,7 @@ This project is an implementation of the Web Canvas API and implements that API
 ### createCanvas()
 
 > ```ts
-> createCanvas(width: number, height: number, type?: 'PDF'|'SVG') => Canvas
+> createCanvas(width: number, height: number, type?: 'fbdev'|'pdf'|'svg') => Canvas
 > ```
 
 Creates a Canvas instance. This method works in both Node.js and Web browsers, where there is no Canvas constructor. (See `browser.js` for the implementation that runs in browsers.)

binding.gyp

@@ -145,6 +145,11 @@
             'GCC_ENABLE_CPP_EXCEPTIONS': 'YES'
           }
         }],
+        ['OS=="linux" and has_FBDev=="true"',
+        {
+            'defines': ['HAS_FBDEV'],
+            'sources': ['src/backend/FBDevBackend.cc']
+        }],
         ['with_jpeg=="true"', {
           'defines': [
             'HAVE_JPEG'
@@ -216,7 +221,10 @@
             }]
           ]
         }]
-      ]
+      ],
+      'variables': {
+        'has_FBDev%': 'true',
+      }
     }
   ]
 }

examples/simple_fbdev.js

@@ -0,0 +1,40 @@
+#!/usr/bin/env node
+
+/**
+* Module dependencies.
+*/
+
+const fs = require('fs')
+const { join } = require('path')
+
+const { backends: { FBDevBackend }, Canvas } = require('..')
+
+const squareSize = 100
+
+var device = process.argv[2]
+
+var backend = new FBDevBackend(device)
+var canvas = new Canvas(backend)
+var ctx = canvas.getContext('2d')
+
+var offsetX = canvas.width - squareSize
+var offsetY = canvas.height - squareSize
+
+ctx.fillStyle = '#FF0000'
+ctx.fillRect(0, 0, squareSize, squareSize)
+
+ctx.fillStyle = '#00FF00'
+ctx.fillRect(offsetX, 0, squareSize, squareSize)
+
+ctx.fillStyle = '#0000FF'
+ctx.fillRect(0, offsetY, squareSize, squareSize)
+
+ctx.fillStyle = '#FFFFFF'
+ctx.fillRect(offsetX, offsetY, squareSize, squareSize)
+
+console.log('Width: ' + canvas.width + ', Height: ' + canvas.height +
+            'Pixel format: ' + ctx.pixelFormat)
+
+var outPath = join(__dirname, 'rectangle.png')
+
+canvas.createPNGStream().pipe(fs.createWriteStream(outPath))

lib/DOMMatrix.js

@@ -4,7 +4,7 @@ const util = require('util')
 
 // DOMMatrix per https://drafts.fxtf.org/geometry/#DOMMatrix
 
-function DOMPoint(x, y, z, w) {
+function DOMPoint (x, y, z, w) {
   if (!(this instanceof DOMPoint)) {
     throw new TypeError("Class constructors cannot be invoked without 'new'")
   }
@@ -22,15 +22,15 @@ function DOMPoint(x, y, z, w) {
 }
 
 // Constants to index into _values (col-major)
-const M11 = 0, M12 = 1, M13 = 2, M14 = 3
-const M21 = 4, M22 = 5, M23 = 6, M24 = 7
-const M31 = 8, M32 = 9, M33 = 10, M34 = 11
-const M41 = 12, M42 = 13, M43 = 14, M44 = 15
+const M11 = 0; const M12 = 1; const M13 = 2; const M14 = 3
+const M21 = 4; const M22 = 5; const M23 = 6; const M24 = 7
+const M31 = 8; const M32 = 9; const M33 = 10; const M34 = 11
+const M41 = 12; const M42 = 13; const M43 = 14; const M44 = 15
 
 const DEGREE_PER_RAD = 180 / Math.PI
 const RAD_PER_DEGREE = Math.PI / 180
 
-function parseMatrix(init) {
+function parseMatrix (init) {
   var parsed = init.replace(/matrix\(/, '')
   parsed = parsed.split(/,/, 7) // 6 + 1 to handle too many params
   if (parsed.length !== 6) throw new Error(`Failed to parse ${init}`)
@@ -43,14 +43,14 @@ function parseMatrix(init) {
   ]
 }
 
-function parseMatrix3d(init) {
+function parseMatrix3d (init) {
   var parsed = init.replace(/matrix3d\(/, '')
   parsed = parsed.split(/,/, 17) // 16 + 1 to handle too many params
   if (parsed.length !== 16) throw new Error(`Failed to parse ${init}`)
   return parsed.map(parseFloat)
 }
 
-function parseTransform(tform) {
+function parseTransform (tform) {
   var type = tform.split(/\(/, 1)[0]
   switch (type) {
     case 'matrix':
@@ -161,15 +161,15 @@ DOMMatrix.prototype[util.inspect.custom || 'inspect'] = function (depth, options
 }
 
 DOMMatrix.prototype.toString = function () {
-  return this.is2D ?
-    `matrix(${this.a}, ${this.b}, ${this.c}, ${this.d}, ${this.e}, ${this.f})` :
-    `matrix3d(${this._values.join(', ')})`
+  return this.is2D
+    ? `matrix(${this.a}, ${this.b}, ${this.c}, ${this.d}, ${this.e}, ${this.f})`
+    : `matrix3d(${this._values.join(', ')})`
 }
 
 /**
  * Checks that `value` is a number and sets the value.
  */
-function setNumber2D(receiver, index, value) {
+function setNumber2D (receiver, index, value) {
   if (typeof value !== 'number') throw new TypeError('Expected number')
   return receiver._values[index] = value
 }
@@ -178,7 +178,7 @@ function setNumber2D(receiver, index, value) {
  * Checks that `value` is a number, sets `_is2D = false` if necessary and sets
  * the value.
  */
-function setNumber3D(receiver, index, value) {
+function setNumber3D (receiver, index, value) {
   if (typeof value !== 'number') throw new TypeError('Expected number')
   if (index === M33 || index === M44) {
     if (value !== 1) receiver._is2D = false
@@ -187,31 +187,31 @@ function setNumber3D(receiver, index, value) {
 }
 
 Object.defineProperties(DOMMatrix.prototype, {
-  m11: {get: function () { return this._values[M11] }, set: function (v) { return setNumber2D(this, M11, v) }},
-  m12: {get: function () { return this._values[M12] }, set: function (v) { return setNumber2D(this, M12, v) }},
-  m13: {get: function () { return this._values[M13] }, set: function (v) { return setNumber3D(this, M13, v) }},
-  m14: {get: function () { return this._values[M14] }, set: function (v) { return setNumber3D(this, M14, v) }},
-  m21: {get: function () { return this._values[M21] }, set: function (v) { return setNumber2D(this, M21, v) }},
-  m22: {get: function () { return this._values[M22] }, set: function (v) { return setNumber2D(this, M22, v) }},
-  m23: {get: function () { return this._values[M23] }, set: function (v) { return setNumber3D(this, M23, v) }},
-  m24: {get: function () { return this._values[M24] }, set: function (v) { return setNumber3D(this, M24, v) }},
-  m31: {get: function () { return this._values[M31] }, set: function (v) { return setNumber3D(this, M31, v) }},
-  m32: {get: function () { return this._values[M32] }, set: function (v) { return setNumber3D(this, M32, v) }},
-  m33: {get: function () { return this._values[M33] }, set: function (v) { return setNumber3D(this, M33, v) }},
-  m34: {get: function () { return this._values[M34] }, set: function (v) { return setNumber3D(this, M34, v) }},
-  m41: {get: function () { return this._values[M41] }, set: function (v) { return setNumber2D(this, M41, v) }},
-  m42: {get: function () { return this._values[M42] }, set: function (v) { return setNumber2D(this, M42, v) }},
-  m43: {get: function () { return this._values[M43] }, set: function (v) { return setNumber3D(this, M43, v) }},
-  m44: {get: function () { return this._values[M44] }, set: function (v) { return setNumber3D(this, M44, v) }},
-
-  a: {get: function () { return this.m11 }, set: function (v) { return this.m11 = v }},
-  b: {get: function () { return this.m12 }, set: function (v) { return this.m12 = v }},
-  c: {get: function () { return this.m21 }, set: function (v) { return this.m21 = v }},
-  d: {get: function () { return this.m22 }, set: function (v) { return this.m22 = v }},
-  e: {get: function () { return this.m41 }, set: function (v) { return this.m41 = v }},
-  f: {get: function () { return this.m42 }, set: function (v) { return this.m42 = v }},
-
-  is2D: {get: function () { return this._is2D }}, // read-only
+  m11: { get: function () { return this._values[M11] }, set: function (v) { return setNumber2D(this, M11, v) } },
+  m12: { get: function () { return this._values[M12] }, set: function (v) { return setNumber2D(this, M12, v) } },
+  m13: { get: function () { return this._values[M13] }, set: function (v) { return setNumber3D(this, M13, v) } },
+  m14: { get: function () { return this._values[M14] }, set: function (v) { return setNumber3D(this, M14, v) } },
+  m21: { get: function () { return this._values[M21] }, set: function (v) { return setNumber2D(this, M21, v) } },
+  m22: { get: function () { return this._values[M22] }, set: function (v) { return setNumber2D(this, M22, v) } },
+  m23: { get: function () { return this._values[M23] }, set: function (v) { return setNumber3D(this, M23, v) } },
+  m24: { get: function () { return this._values[M24] }, set: function (v) { return setNumber3D(this, M24, v) } },
+  m31: { get: function () { return this._values[M31] }, set: function (v) { return setNumber3D(this, M31, v) } },
+  m32: { get: function () { return this._values[M32] }, set: function (v) { return setNumber3D(this, M32, v) } },
+  m33: { get: function () { return this._values[M33] }, set: function (v) { return setNumber3D(this, M33, v) } },
+  m34: { get: function () { return this._values[M34] }, set: function (v) { return setNumber3D(this, M34, v) } },
+  m41: { get: function () { return this._values[M41] }, set: function (v) { return setNumber2D(this, M41, v) } },
+  m42: { get: function () { return this._values[M42] }, set: function (v) { return setNumber2D(this, M42, v) } },
+  m43: { get: function () { return this._values[M43] }, set: function (v) { return setNumber3D(this, M43, v) } },
+  m44: { get: function () { return this._values[M44] }, set: function (v) { return setNumber3D(this, M44, v) } },
+
+  a: { get: function () { return this.m11 }, set: function (v) { return this.m11 = v } },
+  b: { get: function () { return this.m12 }, set: function (v) { return this.m12 = v } },
+  c: { get: function () { return this.m21 }, set: function (v) { return this.m21 = v } },
+  d: { get: function () { return this.m22 }, set: function (v) { return this.m22 = v } },
+  e: { get: function () { return this.m41 }, set: function (v) { return this.m41 = v } },
+  f: { get: function () { return this.m42 }, set: function (v) { return this.m42 = v } },
+
+  is2D: { get: function () { return this._is2D } }, // read-only
 
   isIdentity: {
     get: function () {
@@ -229,15 +229,15 @@ Object.defineProperties(DOMMatrix.prototype, {
  * @param {Float64Array} values Value to assign to `_values`. This is assigned
  *   without copying (okay because all usages are followed by a  multiply).
  */
-function newInstance(values) {
+function newInstance (values) {
   var instance = Object.create(DOMMatrix.prototype)
   instance.constructor = DOMMatrix
   instance._is2D = true
   instance._values = values
   return instance
 }
 
-function multiply(A, B) {
+function multiply (A, B) {
   var dest = new Float64Array(16)
   for (var i = 0; i < 4; i++) {
     for (var j = 0; j < 4; j++) {
@@ -386,10 +386,10 @@ DOMMatrix.prototype.rotateAxisAngleSelf = function (x, y, z, angle) {
   // NB: This is the generic transform. If the axis is a major axis, there are
   // faster transforms.
   this._values = multiply([
-    tx * x + c,      tx * y + s * z,  tx * z - s * y,  0,
-    tx * y - s * z,  ty * y + c,      ty * z + s * x,  0,
-    tx * z + s * y,  ty * z - s * x,  t * z * z + c,   0,
-    0,               0,               0,               1
+    tx * x + c, tx * y + s * z, tx * z - s * y, 0,
+    tx * y - s * z, ty * y + c, ty * z + s * x, 0,
+    tx * z + s * y, ty * z - s * x, t * z * z + c, 0,
+    0, 0, 0, 1
   ], this._values)
   if (x !== 0 || y !== 0) this._is2D = false
   return this
@@ -606,4 +606,4 @@ DOMMatrix.prototype.toFloat64Array = function () {
   return this._values.slice(0)
 }
 
-module.exports = {DOMMatrix, DOMPoint}
+module.exports = { DOMMatrix, DOMPoint }

lib/bindings.js

@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = require('../build/Release/canvas.node');
+module.exports = require('../build/Release/canvas.node')

lib/canvas.js

@@ -1,4 +1,4 @@
-'use strict';
+'use strict'
 
 /*!
  * Canvas
@@ -21,28 +21,28 @@ Canvas.prototype[util.inspect.custom || 'inspect'] = function () {
 }
 
 Canvas.prototype.getContext = function (contextType, contextAttributes) {
-  if ('2d' == contextType) {
-    var ctx = this._context2d || (this._context2d = new Context2d(this, contextAttributes));
-    this.context = ctx;
-    ctx.canvas = this;
-    return ctx;
+  if (contextType == '2d') {
+    var ctx = this._context2d || (this._context2d = new Context2d(this, contextAttributes))
+    this.context = ctx
+    ctx.canvas = this
+    return ctx
   }
-};
+}
 
 Canvas.prototype.pngStream =
-Canvas.prototype.createPNGStream = function(options){
-  return new PNGStream(this, options);
-};
+Canvas.prototype.createPNGStream = function (options) {
+  return new PNGStream(this, options)
+}
 
 Canvas.prototype.pdfStream =
 Canvas.prototype.createPDFStream = function(options){
   return new PDFStream(this, options);
 };
 
 Canvas.prototype.jpegStream =
-Canvas.prototype.createJPEGStream = function(options){
-  return new JPEGStream(this, options);
-};
+Canvas.prototype.createJPEGStream = function (options) {
+  return new JPEGStream(this, options)
+}
 
 Canvas.prototype.toDataURL = function(a1, a2, a3){
   // valid arg patterns (args -> [type, opts, fn]):
@@ -63,51 +63,51 @@ Canvas.prototype.toDataURL = function(a1, a2, a3){
   // ['image/jpeg', opts] -> ['image/jpeg', opts, fn]
   // ['image/jpeg', qual] -> ['image/jpeg', {quality: qual}, fn]
 
-  var type = 'image/png';
-  var opts = {};
-  var fn;
+  var type = 'image/png'
+  var opts = {}
+  var fn
 
-  if ('function' === typeof a1) {
-    fn = a1;
+  if (typeof a1 === 'function') {
+    fn = a1
   } else {
-    if ('string' === typeof a1 && FORMATS.includes(a1.toLowerCase())) {
-      type = a1.toLowerCase();
+    if (typeof a1 === 'string' && FORMATS.includes(a1.toLowerCase())) {
+      type = a1.toLowerCase()
     }
 
-    if ('function' === typeof a2) {
-      fn = a2;
+    if (typeof a2 === 'function') {
+      fn = a2
     } else {
-      if ('object' === typeof a2) {
-        opts = a2;
-      } else if ('number' === typeof a2) {
-        opts = {quality: Math.max(0, Math.min(1, a2))};
+      if (typeof a2 === 'object') {
+        opts = a2
+      } else if (typeof a2 === 'number') {
+        opts = { quality: Math.max(0, Math.min(1, a2)) }
       }
 
-      if ('function' === typeof a3) {
-        fn = a3;
+      if (typeof a3 === 'function') {
+        fn = a3
       } else if (undefined !== a3) {
-        throw new TypeError(typeof a3 + ' is not a function');
+        throw new TypeError(typeof a3 + ' is not a function')
       }
     }
   }
 
   if (this.width === 0 || this.height === 0) {
     // Per spec, if the bitmap has no pixels, return this string:
-    var str = "data:,";
+    var str = 'data:,'
     if (fn) {
-      setTimeout(() => fn(null, str));
-      return;
+      setTimeout(() => fn(null, str))
+      return
     } else {
-      return str;
+      return str
     }
   }
 
   if (fn) {
     this.toBuffer((err, buf) => {
-      if (err) return fn(err);
-      fn(null, `data:${type};base64,${buf.toString('base64')}`);
+      if (err) return fn(err)
+      fn(null, `data:${type};base64,${buf.toString('base64')}`)
     }, type, opts)
   } else {
     return `data:${type};base64,${this.toBuffer(type, opts).toString('base64')}`
   }
-};
+}