Fix frStepWorld() not discarding invalid cache entries

jdeokkim · Sep 28, 2024 · f178650 · f178650
1 parent 6bd5c3f
commit f178650
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Showing 9 changed files with 78 additions and 59 deletions.
diff --git a/.clang-format b/.clang-format
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2021-2023 Jaedeok Kim <[email protected]>
+# Copyright (c) 2021-2024 Jaedeok Kim <[email protected]>
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal

diff --git a/.gitignore b/.gitignore
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2021-2023 Jaedeok Kim <[email protected]>
+# Copyright (c) 2021-2024 Jaedeok Kim <[email protected]>
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal

diff --git a/examples/src/query.c b/examples/src/query.c
@@ -71,7 +71,7 @@ static void DeinitExample(void);
 static void DrawCursorBounds(void);
 static frAABB GetCursorBounds(void);
 
-static bool OnHashQuery(frIndexedData arg);
+static bool OnHashQuery(frContextNode ctx);
 
 /* Public Functions ======================================================== */
 
@@ -210,8 +210,8 @@ static frAABB GetCursorBounds(void) {
     };
 }
 
-static bool OnHashQuery(frIndexedData arg) {
-    frSetBodyUserData(bodies[arg.idx], (void *) &secondaryColor);
+static bool OnHashQuery(frContextNode ctx) {
+    frSetBodyUserData(bodies[ctx.id], (void *) &secondaryColor);
 
     return true;
 }
diff --git a/include/ferox.h b/include/ferox.h
@@ -74,7 +74,7 @@ extern "C" {
 #define FR_WORLD_DEFAULT_GRAVITY      ((frVector2) { .y = 9.8f })
 
 /* Defines the iteration count for the constraint solver. */
-#define FR_WORLD_ITERATION_COUNT      10
+#define FR_WORLD_ITERATION_COUNT      12
 
 /* Defines the maximum number of objects in a world. */
 #define FR_WORLD_MAX_OBJECT_COUNT     2048
@@ -93,12 +93,6 @@ typedef struct frAABB_ {
     float x, y, width, height;
 } frAABB;
 
-/* A structure that represents arbitrary data with an index. */
-typedef struct frIndexedData_ {
-    int idx;
-    void *data;
-} frIndexedData;
-
 /* 
     A structure that represents a collision shape, 
     which can be attached to a rigid body.
@@ -111,13 +105,19 @@ typedef struct frBody_ frBody;
 /* A structure that represents a simulation container. */
 typedef struct frWorld_ frWorld;
 
+/* A structure that represents arbitrary data with an identifier. */
+typedef struct frContextNode_ {
+    int id;
+    void *data;
+} frContextNode;
+
 /* (From 'broad-phase.c') ================================================== */
 
 /* A structure that represents a spatial hash. */
 typedef struct frSpatialHash_ frSpatialHash;
 
 /* A callback function type for `frQuerySpatialHash()`. */
-typedef bool (*frHashQueryFunc)(frIndexedData arg);
+typedef bool (*frHashQueryFunc)(frContextNode ctx);
 
 /* (From 'collision.c') ==================================================== */
 
@@ -127,6 +127,7 @@ typedef struct frCollision_ {
     struct {
         int id;
         float depth;
+        float timestamp;
         frVector2 point;
         struct {
             float normalMass, normalScalar;
@@ -503,11 +504,11 @@ frRingBuffer *frCreateRingBuffer(size_t length);
 /* Releases the memory allocated for `rbf`. */
 void frReleaseRingBuffer(frRingBuffer *rbf);
 
-/* Adds a `value` to `rbf`. */
-bool frAddValueToRingBuffer(frRingBuffer *rbf, frIndexedData value);
+/* Adds a `node` to `rbf`. */
+bool frAddNodeToRingBuffer(frRingBuffer *rbf, frContextNode node);
 
-/* Removes a value from `rbf` and stores it to `value`. */
-bool frRemoveValueFromRingBuffer(frRingBuffer *rbf, frIndexedData *value);
+/* Removes a node from `rbf` and stores it to `node`. */
+bool frRemoveNodeFromRingBuffer(frRingBuffer *rbf, frContextNode *node);
 
 /* (From 'world.c') ======================================================== */
 

diff --git a/src/broad-phase.c b/src/broad-phase.c
@@ -184,7 +184,7 @@ void frQuerySpatialHash(frSpatialHash *sh,
         will be called with the user data pointer `ctx`.
     */
     for (int i = 0; i < arrlen(sh->queryResult); i++)
-        func((frIndexedData) { .idx = sh->queryResult[i], .data = ctx});
+        func((frContextNode) { .id = sh->queryResult[i], .data = ctx });
 }
 
 /* Private Functions ======================================================= */

diff --git a/src/utils.c b/src/utils.c
@@ -30,7 +30,7 @@
 
 /* A structure that represents a ring buffer for storing indexed data. */
 struct frRingBuffer_ {
-    frIndexedData *buffer;
+    frContextNode *buffer;
     int head, tail, length;
 };
 
@@ -61,23 +61,23 @@ void frReleaseRingBuffer(frRingBuffer *rbf) {
     if (rbf != NULL) free(rbf->buffer), free(rbf);
 }
 
-/* Adds a `value` to `rbf`. */
-bool frAddValueToRingBuffer(frRingBuffer *rbf, frIndexedData value) {
+/* Adds a `node` to `rbf`. */
+bool frAddNodeToRingBuffer(frRingBuffer *rbf, frContextNode node) {
     if (rbf == NULL || ((rbf->head + 1) & (rbf->length - 1)) == rbf->tail)
         return false;
 
-    rbf->buffer[rbf->head] = value;
+    rbf->buffer[rbf->head] = node;
 
     rbf->head = (rbf->head + 1) & (rbf->length - 1);
 
     return true;
 }
 
-/* Removes a value from `rbf` and stores it to `value`. */
-bool frRemoveValueFromRingBuffer(frRingBuffer *rbf, frIndexedData *value) {
+/* Removes a node from `rbf` and stores it to `node`. */
+bool frRemoveNodeFromRingBuffer(frRingBuffer *rbf, frContextNode *node) {
     if (rbf == NULL || (rbf->head == rbf->tail)) return false;
 
-    if (value != NULL) *value = rbf->buffer[rbf->tail];
+    if (node != NULL) *node = rbf->buffer[rbf->tail];
 
     rbf->tail = (rbf->tail + 1) & (rbf->length - 1);
 

diff --git a/src/world.c b/src/world.c
@@ -44,13 +44,13 @@ typedef struct frContactCacheEntry_ {
 
 /* A structure that represents a simulation container. */
 struct frWorld_ {
-    frVector2 gravity;
     frBody **bodies;
     frRingBuffer *rbf;
     frSpatialHash *hash;
     frContactCacheEntry *cache;
-    frCollisionHandler handler;
     float accumulator, timestamp;
+    frCollisionHandler handler;
+    frVector2 gravity;
 };
 
 /* 
@@ -78,13 +78,13 @@ typedef struct frRaycastHashQueryCtx_ {
     A callback function for `frQuerySpatialHash()` 
     that will be called during `frPreStepWorld()`. 
 */
-static bool frPreStepHashQueryCallback(frIndexedData arg);
+static bool frPreStepHashQueryCallback(frContextNode ctx);
 
 /* 
     A callback function for `frQuerySpatialHash()` 
     that will be called during `frComputeRaycastForWorld()`.
 */
-static bool frRaycastHashQueryCallback(frIndexedData arg);
+static bool frRaycastHashQueryCallback(frContextNode ctx);
 
 /* Finds all pairs of bodies in `w` that are colliding. */
 static void frPreStepWorld(frWorld *w);
@@ -143,17 +143,17 @@ bool frAddBodyToWorld(frWorld *w, frBody *b) {
         || arrlen(w->bodies) >= FR_WORLD_MAX_OBJECT_COUNT)
         return false;
 
-    return frAddValueToRingBuffer(w->rbf,
-                                  (frIndexedData) { .idx = FR_OPT_ADD_BODY,
+    return frAddNodeToRingBuffer(w->rbf,
+                                  (frContextNode) { .id = FR_OPT_ADD_BODY,
                                                     .data = b });
 }
 
 /* Removes a rigid `b`ody from `w`. */
 bool frRemoveBodyFromWorld(frWorld *w, frBody *b) {
     if (w == NULL || b == NULL) return false;
 
-    return frAddValueToRingBuffer(w->rbf,
-                                  (frIndexedData) { .idx = FR_OPT_REMOVE_BODY,
+    return frAddNodeToRingBuffer(w->rbf,
+                                  (frContextNode) { .id = FR_OPT_REMOVE_BODY,
                                                     .data = b });
 }
 
@@ -213,6 +213,21 @@ void frStepWorld(frWorld *w, float dt) {
         frIntegrateForBodyVelocity(w->bodies[i], dt);
     }
 
+    int entryCount = hmlen(w->cache);
+
+    for (int j = 0; j < entryCount; j++) {
+        frBodyPair key = w->cache[j].key;
+
+        const frCollision *value = &w->cache[j].value;
+
+        for (int k = 0; k < value->count; k++)
+            if (value->contacts[k].timestamp < w->timestamp) {
+                hmdel(w->cache, key);
+
+                break;
+            }
+    }
+
     for (int j = 0; j < hmlen(w->cache); j++)
         frApplyAccumulatedImpulses(w->cache[j].key.first,
                                    w->cache[j].key.second,
@@ -290,15 +305,17 @@ void frComputeRaycastForWorld(frWorld *w, frRay ray, frRaycastQueryFunc func) {
     A callback function for `frQuerySpatialHash()` 
     that will be called during `frPreStepWorld()`. 
 */
-static bool frPreStepHashQueryCallback(frIndexedData arg) {
-    frPreStepHashQueryCtx *queryCtx = arg.data;
+static bool frPreStepHashQueryCallback(frContextNode ctx) {
+    frPreStepHashQueryCtx *queryCtx = ctx.data;
 
-    int firstIndex = queryCtx->bodyIndex, secondIndex = arg.idx;
+    int firstIndex = queryCtx->bodyIndex, secondIndex = ctx.id;
 
     if (firstIndex >= secondIndex) return false;
 
-    frBody *b1 = queryCtx->world->bodies[firstIndex];
-    frBody *b2 = queryCtx->world->bodies[secondIndex];
+    frWorld *world = queryCtx->world;
+
+    frBody *b1 = world->bodies[firstIndex];
+    frBody *b2 = world->bodies[secondIndex];
 
     if (frGetBodyInverseMass(b1) + frGetBodyInverseMass(b2) <= 0.0f)
         return false;
@@ -310,18 +327,21 @@ static bool frPreStepHashQueryCallback(frIndexedData arg) {
     if (!frComputeCollision(b1, b2, &collision)) {
         /*
             NOTE: `hmdel()` returns `0` if `key` is not 
-            in `queryCtx->world->cache`!
+            in `world->cache`!
         */
 
-        hmdel(queryCtx->world->cache, key);
+        hmdel(world->cache, key);
 
         return false;
     }
 
-    frContactCacheEntry *entry = hmgetp_null(queryCtx->world->cache, key);
+    frContactCacheEntry *entry = hmgetp_null(world->cache, key);
 
     const frShape *s1 = frGetBodyShape(b1), *s2 = frGetBodyShape(b2);
 
+    for (int i = 0; i < collision.count; i++)
+        collision.contacts[i].timestamp = world->timestamp;
+
     if (entry != NULL) {
         collision.friction = entry->value.friction;
         collision.restitution = entry->value.restitution;
@@ -348,12 +368,12 @@ static bool frPreStepHashQueryCallback(frIndexedData arg) {
     A callback function for `frQuerySpatialHash()` 
     that will be called during `frComputeRaycastForWorld()`.
 */
-static bool frRaycastHashQueryCallback(frIndexedData arg) {
-    frRaycastHashQueryCtx *queryCtx = arg.data;
+static bool frRaycastHashQueryCallback(frContextNode ctx) {
+    frRaycastHashQueryCtx *queryCtx = ctx.data;
 
     frRaycastHit raycastHit = { .distance = 0.0f };
 
-    if (!frComputeRaycast(queryCtx->world->bodies[arg.idx],
+    if (!frComputeRaycast(queryCtx->world->bodies[ctx.id],
                           queryCtx->ray,
                           &raycastHit))
         return false;
@@ -365,8 +385,6 @@ static bool frRaycastHashQueryCallback(frIndexedData arg) {
 
 /* Finds all pairs of bodies in `w` that are colliding. */
 static void frPreStepWorld(frWorld *w) {
-    /* TODO: ... */
-
     for (int i = 0; i < arrlen(w->bodies); i++)
         frInsertIntoSpatialHash(w->hash, frGetBodyAABB(w->bodies[i]), i);
 
@@ -383,18 +401,18 @@ static void frPreStepWorld(frWorld *w) {
     then clears the spatial hash of `w`. 
 */
 static void frPostStepWorld(frWorld *w) {
-    frIndexedData value = { .idx = FR_OPT_UNKNOWN };
+    frContextNode node = { .id = FR_OPT_UNKNOWN };
 
-    while (frRemoveValueFromRingBuffer(w->rbf, &value)) {
-        switch (value.idx) {
+    while (frRemoveNodeFromRingBuffer(w->rbf, &node)) {
+        switch (node.id) {
             case FR_OPT_ADD_BODY:
-                arrput(w->bodies, value.data);
+                arrput(w->bodies, node.data);
 
                 break;
 
             case FR_OPT_REMOVE_BODY:
                 for (int i = 0; i < arrlen(w->bodies); i++)
-                    if (w->bodies[i] == value.data) {
+                    if (w->bodies[i] == node.data) {
                         arrdelswap(w->bodies, i);
 
                         break;

diff --git a/tests/Makefile.mingw b/tests/Makefile.mingw
@@ -40,6 +40,6 @@ CC = x86_64-w64-mingw32-gcc
 # =============================================================================
 
 all clean rebuild:
-	@${MAKE} TARGETS=${TARGETS} CC=${CC} $@
+	@${MAKE} TARGET_SUFFIX=${TARGET_SUFFIX} CC=${CC} $@
 
 # =============================================================================
diff --git a/tests/src/utils.c b/tests/src/utils.c
@@ -45,27 +45,27 @@ TEST utRingBufferOps(void) {
     frRingBuffer *rbf = frCreateRingBuffer(RING_BUFFER_LENGTH);
 
     {
-        frIndexedData value = { .idx = 0 };
+        frContextNode node = { .id = 0 };
 
         for (int i = 0; i < RING_BUFFER_LENGTH; i++) {
-            value.idx = i;
+            node.id = i;
 
             bool result = (i < (RING_BUFFER_LENGTH - 1));
 
-            ASSERT_EQ(result, frAddValueToRingBuffer(rbf, value));
+            ASSERT_EQ(result, frAddNodeToRingBuffer(rbf, node));
         }
 
-        ASSERT_EQ(false, frAddValueToRingBuffer(rbf, value));
+        ASSERT_EQ(false, frAddNodeToRingBuffer(rbf, node));
 
         for (int i = 0; i < RING_BUFFER_LENGTH; i++) {
             bool result = (i < (RING_BUFFER_LENGTH - 1));
 
-            ASSERT_EQ(result, frRemoveValueFromRingBuffer(rbf, &value));
+            ASSERT_EQ(result, frRemoveNodeFromRingBuffer(rbf, &node));
 
-            if (result == true) ASSERT_EQ(i, value.idx);
+            if (result == true) ASSERT_EQ(i, node.id);
         }
 
-        ASSERT_EQ(false, frRemoveValueFromRingBuffer(rbf, NULL));
+        ASSERT_EQ(false, frRemoveNodeFromRingBuffer(rbf, NULL));
     }
 
     frReleaseRingBuffer(rbf);