bunch of new cloth API stuff

src/Silkworm.c

@@ -47,18 +47,19 @@ typedef struct Silkworm_Context
 
 	Silkworm_Cloth** cloths;
 	uint32_t clothCount;
-
+	uint32_t clothCapacity;
-	uint64_t* nodeIndicesToDestroy;
-	uint32_t nodeIndicesToDestroyCount;
-
-	uint64_t* linkIndicesToDestroy;
-	uint32_t linkIndicesToDestroyCount;
 
 	uint64_t* nodeIndexStack;
 	uint32_t nodeIndexStackCount;
+	uint32_t nodeIndexStackCapacity;
 
 	uint64_t* linkIndexStack;
 	uint32_t linkIndexStackCount;
+	uint32_t linkIndexStackCapacity;
+
+	uint64_t* clothIndexStack;
+	uint32_t clothIndexStackCount;
+	uint32_t clothIndexStackCapacity;
 
 	float gravity;
 	float xBound;
@@ -78,30 +79,167 @@ void Silkworm_Init()
 
 	context->nodes = NULL;
 	context->nodeCount = 0;
+
 	context->links = NULL;
 	context->linkCount = 0;
 
-	context->nodeIndicesToDestroy = NULL;
-	context->nodeIndicesToDestroyCount = 0;
-
-	context->linkIndicesToDestroy = NULL;
-	context->linkIndicesToDestroyCount = 0;
-
-	context->nodeIndexStack = NULL;
-	context->nodeIndexStackCount = 0;
-
-	context->linkIndexStack = NULL;
-	context->linkIndexStackCount = 0;
-
 	context->cloths = NULL;
 	context->clothCount = 0;
 
+	context->nodeIndexStackCapacity = 16;
+	context->nodeIndexStack = malloc(sizeof(uint64_t) * context->nodeIndexStackCapacity);
+	context->nodeIndexStackCount = 0;
+
+	context->linkIndexStackCapacity = 16;
+	context->linkIndexStack = malloc(sizeof(uint64_t) * context->linkIndexStackCapacity);
+	context->linkIndexStackCount = 0;
+
+	context->clothIndexStackCapacity = 16;
+	context->clothIndexStack = malloc(sizeof(uint64_t) * context->clothIndexStackCapacity);
+	context->clothIndexStackCount = 0;
+
 	context->gravity = 200;
 	context->xBound = 1000;
 	context->yBound = 1000;
 	context->clothDensity = 4;
 }
 
+static inline Silkworm_Node* LookupNode(uint64_t nodeId)
+{
+	return context->nodes[nodeId];
+}
+
+static inline Silkworm_Link* LookupLink(uint64_t linkId)
+{
+	return context->links[linkId];
+}
+
+static inline Silkworm_Cloth* LookupCloth(uint64_t clothId)
+{
+	return context->cloths[clothId];
+}
+
+/* we defer actual destruction to Update to avoid issues with NULL */
+
+void Silkworm_DestroyNode(double nodeId)
+{
+	uint32_t i;
+	Silkworm_Node* node = LookupNode((uint64_t)nodeId);
+
+	if (node != NULL)
+	{
+		node->markedForDestroy = true;
+
+		for (i = 0; i < node->linkCount; i += 1)
+		{
+			if (node->links[i] != NULL)
+			{
+				node->links[i]->markedForDestroy = true;
+			}
+		}
+	}
+}
+
+void Silkworm_Internal_DestroyLink(Silkworm_Link* link)
+{
+	link->markedForDestroy = true;
+}
+
+void Silkworm_DestroyLink(double linkId)
+{
+	Silkworm_Internal_DestroyLink(LookupLink((uint64_t)linkId));
+}
+
+void Silkworm_Internal_DestroyCloth(Silkworm_Cloth* cloth)
+{
+	uint32_t i, j;
+
+	context->cloths[cloth->id] = NULL;
+
+	for (i = 0; i < cloth->horizontalNodeCount; i += 1)
+	{
+		for (j = 0; j < cloth->verticalNodeCount; j += 1)
+		{
+			Silkworm_DestroyNode((double)cloth->nodeIndices[i][j]);
+		}
+		free(cloth->nodeIndices[i]);
+	}
+	free(cloth->nodeIndices);
+	free(cloth);
+
+	if (context->clothIndexStackCount >= context->clothIndexStackCapacity)
+	{
+		context->clothIndexStackCapacity *= 2;
+		context->nodeIndexStack = realloc(context->nodeIndexStack, sizeof(uint64_t) * context->nodeIndexStackCapacity);
+	}
+
+	context->clothIndexStack[context->clothIndexStackCount] = cloth->id;
+	context->clothIndexStackCount += 1;
+}
+
+void Silkworm_DestroyCloth(double clothId)
+{
+	Silkworm_Internal_DestroyCloth(LookupCloth((uint64_t)clothId));
+}
+
+void Silkworm_PerformDestroys()
+{
+	uint32_t i, j;
+
+	for (i = 0; i < context->linkCount; i += 1)
+	{
+		if (context->links[i] != NULL && context->links[i]->markedForDestroy)
+		{
+			for (j = 0; j < context->links[i]->a->linkCount; j += 1)
+			{
+				if (context->links[i]->a->links[j] == context->links[i])
+				{
+					context->links[i]->a->links[j] = NULL;
+				}
+			}
+
+			for (j = 0; j < context->links[i]->b->linkCount; j += 1)
+			{
+				if (context->links[i]->b->links[j] == context->links[i])
+				{
+					context->links[i]->b->links[j] = NULL;
+				}
+			}
+
+			free(context->links[i]);
+			context->links[i] = NULL;
+
+			if (context->linkIndexStackCount >= context->linkIndexStackCapacity)
+			{
+				context->linkIndexStackCapacity *= 2;
+				context->linkIndexStack = realloc(context->linkIndexStack, sizeof(uint64_t) * context->linkIndexStackCapacity);
+			}
+
+			context->linkIndexStack[context->linkIndexStackCount] = i;
+			context->linkIndexStackCount += 1;
+		}
+	}
+
+	for (i = 0; i < context->nodeCount; i += 1)
+	{
+		if (context->nodes[i] != NULL && context->nodes[i]->markedForDestroy)
+		{
+			free(context->nodes[i]->links);
+			free(context->nodes[i]);
+			context->nodes[i] = NULL;
+
+			if (context->nodeIndexStackCount >= context->nodeIndexStackCapacity)
+			{
+				context->nodeIndexStackCapacity *= 2;
+				context->nodeIndexStack = realloc(context->nodeIndexStack, sizeof(uint64_t) * context->nodeIndexStackCapacity);
+			}
+
+			context->nodeIndexStack[context->nodeIndexStackCount] = i;
+			context->nodeIndexStackCount += 1;
+		}
+	}
+}
+
 void Silkworm_Update(double deltaTime)
 {
 	uint32_t i, j;
@@ -131,9 +269,7 @@ void Silkworm_Update(double deltaTime)
 
 				if (distanceMoved > link->tearThreshold)
 				{
-					context->linkIndicesToDestroy = realloc(context->linkIndicesToDestroy, sizeof(uint64_t) * (context->linkIndicesToDestroyCount + 1));
+					Silkworm_DestroyLink((double)link->id);
-					context->linkIndicesToDestroy[context->linkIndicesToDestroyCount] = link->id;
-					context->linkIndicesToDestroyCount += 1;
 				}
 				else
 				{
@@ -151,7 +287,6 @@ void Silkworm_Update(double deltaTime)
 				}
 			}
 		}
-		
 	}
 
 	for (j = 0; j < context->nodeCount; j += 1)
@@ -179,50 +314,13 @@ void Silkworm_Update(double deltaTime)
 
 				if (fabs(node->position.x) > context->xBound || fabs(node->position.x) > context->yBound)
 				{
-					context->nodeIndicesToDestroy = realloc(context->nodeIndicesToDestroy, sizeof(uint64_t) * (context->nodeIndicesToDestroyCount + 1));
+					Silkworm_DestroyNode((double)node->id);
-					context->nodeIndicesToDestroy[context->nodeIndicesToDestroyCount] = node->id;
-					context->nodeIndicesToDestroyCount += 1;
 				}
 			}
 		}
 	}
 
-	for (j = 0; j < context->nodeIndicesToDestroyCount; j += 1)
+	Silkworm_PerformDestroys();
-	{
-		uint64_t nodeIndex = context->nodeIndicesToDestroy[j];
-
-		free(context->nodes[nodeIndex]);
-		context->nodes[nodeIndex] = NULL;
-
-		context->nodeIndexStack = realloc(context->nodeIndexStack, sizeof(uint64_t) * (context->nodeIndexStackCount + 1));
-		context->nodeIndexStack[context->nodeIndexStackCount] = nodeIndex;
-		context->nodeIndexStackCount += 1;
-	}
-
-	for (j = 0; j < context->linkIndicesToDestroyCount; j += 1)
-	{
-		uint64_t linkIndex = context->linkIndicesToDestroy[j];
-
-		free(context->links[linkIndex]);
-		context->links[linkIndex] = NULL;
-
-		context->linkIndexStack = realloc(context->linkIndexStack, sizeof(uint64_t) * (context->linkIndexStackCount + 1));
-		context->linkIndexStack[context->linkIndexStackCount] = linkIndex;
-		context->linkIndexStackCount += 1;
-	}
-
-	context->nodeIndicesToDestroyCount = 0;
-	context->linkIndicesToDestroyCount = 0;
-}
-
-static inline Silkworm_Node* LookupNode(double nodeId)
-{
-	return context->nodes[(uint64_t)nodeId];
-}
-
-static inline Silkworm_Cloth* LookupCloth(double clothId)
-{
-	return context->cloths[(uint64_t)clothId];
 }
 
 double Silkworm_CreateNode(double xPosition, double yPosition, double mass, double friction, double radius, double pushFactor)
@@ -233,20 +331,18 @@ double Silkworm_CreateNode(double xPosition, double yPosition, double mass, doub
 	if (context->nodeIndexStackCount > 0)
 	{
 		id = context->nodeIndexStack[context->nodeIndexStackCount - 1];
-		context->nodeIndexStack = realloc(context->nodeIndexStack, sizeof(uint64_t) * (context->nodeIndexStackCount - 1));
 		context->nodeIndexStackCount -= 1;
-
-		context->nodes[id] = node;
 	}
 	else
 	{
 		id = context->nodeCount;
 
 		context->nodes = realloc(context->nodes, sizeof(Silkworm_Node*) * (context->nodeCount + 1));
-		context->nodes[context->nodeCount] = node;
 		context->nodeCount += 1;
 	}
 
+	context->nodes[id] = node;
+
 	node->id = id;
 	node->position.x = (float)xPosition;
 	node->position.y = (float)yPosition;
@@ -262,6 +358,9 @@ double Silkworm_CreateNode(double xPosition, double yPosition, double mass, doub
 	node->pushFactor = (float)pushFactor;
 	node->pinned = false;
 	node->destroyable = false;
+	node->markedForDestroy = false;
+	node->links = NULL;
+	node->linkCount = 0;
 
 	return (double)node->id;
 }
@@ -295,6 +394,29 @@ void Silkworm_ClothNodeUnpin(double clothId, double i, double j)
 	context->nodes[cloth->nodeIndices[(uint64_t)i][(uint64_t)j]]->pinned = false;
 }
 
+void Silkworm_ClothNodeDestroy(double clothId, double i, double j)
+{
+	uint32_t iterator;
+
+	Silkworm_Cloth* cloth = LookupCloth(clothId);
+	uint64_t nodeIndex = cloth->nodeIndices[(uint64_t)i][(uint64_t)j];
+	Silkworm_Node* node = context->nodes[nodeIndex];
+	Silkworm_DestroyNode(nodeIndex);
+
+	/* fixme: this should be hashed */
+	for (iterator = 0; iterator < cloth->triangleCount; iterator += 1)
+	{
+		if (cloth->triangles[iterator] != NULL)
+		{
+			if (cloth->triangles[iterator]->a == node || cloth->triangles[iterator]->b == node || cloth->triangles[iterator]->c == node)
+			{
+				free(cloth->triangles[iterator]);
+				cloth->triangles[iterator] = NULL;
+			}
+		}
+	}
+}
+
 double Silkworm_CreateLink(double aId, double bId, double distance, double tearThreshold)
 {
 	Silkworm_Node *nodeA = LookupNode(aId);
@@ -307,25 +429,32 @@ double Silkworm_CreateLink(double aId, double bId, double distance, double tearT
 	if (context->linkIndexStackCount > 0)
 	{
 		id = context->linkIndexStack[context->linkIndexStackCount - 1];
-		context->linkIndexStack = realloc(context->linkIndexStack, sizeof(uint64_t) * (context->linkIndexStackCount - 1));
 		context->linkIndexStackCount -= 1;
-
-		context->links[id] = link;
 	}
 	else 
 	{
 		id = context->linkCount;
 
 		context->links = realloc(context->links, sizeof(Silkworm_Link*) * (context->linkCount + 1));
-		context->links[context->linkCount] = link;
 		context->linkCount += 1;
 	}
 
+	context->links[id] = link;
+
 	link->id = id;
 	link->a = nodeA;
 	link->b = nodeB;
 	link->distance = (float)distance;
 	link->tearThreshold = (float)tearThreshold;
+	link->markedForDestroy = false;
+
+	link->a->links = realloc(link->a->links, sizeof(Silkworm_Link*) * (link->a->linkCount + 1));
+	link->a->links[link->a->linkCount] = link;
+	link->a->linkCount += 1;
+
+	link->b->links = realloc(link->b->links, sizeof(Silkworm_Link*) * (link->b->linkCount + 1));
+	link->b->links[link->b->linkCount] = link;
+	link->b->linkCount += 1;
 
 	return (double)link->id;
 }
@@ -341,10 +470,25 @@ double Silkworm_CreateCloth(double xPosition, double yPosition, double horizonta
 	cloth->verticalNodeCount = (uint32_t) verticalNodeCount;
 	cloth->nodeIndices = malloc(sizeof(uint64_t*) * cloth->horizontalNodeCount);
 
-	cloth->id = context->clothCount;
+	uint64_t id;
+
+	if (context->clothIndexStackCount > 0)
+	{
+		id = context->clothIndexStack[context->clothIndexStackCount - 1];
+		context->clothIndexStackCount -= 1;
+
+		context->cloths[id] = cloth;
+	}
+	else
+	{
+		id = context->clothCount;
+
 		context->cloths = realloc(context->cloths, sizeof(Silkworm_Cloth*) * (context->clothCount + 1));
-	context->cloths[context->clothCount] = cloth;
+		context->cloths[id] = cloth;
 		context->clothCount += 1;
+	}
+
+	cloth->id = id;
 
 	for (i = 0; i < horizontalNodeCount; i += 1)
 	{
@@ -437,6 +581,35 @@ double Silkworm_CreateCloth(double xPosition, double yPosition, double horizonta
 	return (double)cloth->id;
 }
 
+void Silkworm_ApplyWind(double xSpeed, double ySpeed)
+{
+	uint32_t i, j, k;
+	Silkworm_Cloth* cloth;
+	Silkworm_Node* node;
+
+	for (i = 0; i < context->clothCount; i += 1)
+	{
+		if (context->cloths[i] != NULL)
+		{
+			cloth = context->cloths[i];
+
+			for (j = 0; j < cloth->horizontalNodeCount; j += 1)
+			{
+				for (k = 0; k < cloth->verticalNodeCount; k += 1)
+				{
+					node = context->nodes[cloth->nodeIndices[j][k]];
+
+					if (node != NULL && !node->pinned)
+					{
+						node->position.x += (float)xSpeed * 0.05f * cloth->windFactor;
+						node->position.y += (float)ySpeed * 0.05f * cloth->windFactor;
+					}
+				}
+			}
+		}
+	}
+}
+
 void Silkworm_SetTriangleBuffer(const char* bufferId)
 {
 	context->currentBufferAddress = (uint8_t*)bufferId;
@@ -557,3 +730,18 @@ double Silkworm_ClothFillTriangleBuffer(double clothId, double leftUV, double wi
 
 	return (double)triangleCount;
 }
+
+void Silkworm_ClearAll()
+{
+	uint32_t i;
+	
+	for (i = 0; i < context->clothCount; i += 1)
+	{
+		if (context->cloths[i] != NULL)
+		{
+			Silkworm_Internal_DestroyCloth(context->cloths[i]);
+		}
+	}
+
+	Silkworm_PerformDestroys();
+}

src/Silkworm.h

@@ -49,6 +49,8 @@ typedef struct Silkworm_Vector2
 	float y;
 } Silkworm_Vector2;
 
+typedef struct Silkworm_Link Silkworm_Link;
+
 typedef struct Silkworm_Node
 {
 	uint64_t id;
@@ -62,16 +64,23 @@ typedef struct Silkworm_Node
 	float pinned;
 	float pushFactor;
 	bool destroyable;
+
+	bool markedForDestroy; /* mutual recursion on nodes/links so this makes it easier to track destroys */
+
+	Silkworm_Link** links;
+	uint32_t linkCount;
 } Silkworm_Node;
 
-typedef struct Silkworm_Link
+struct Silkworm_Link
 {
 	uint64_t id;
 	Silkworm_Node *a;
 	Silkworm_Node *b;
 	float distance;
 	float tearThreshold;
-} Silkworm_Link;
+
+	bool markedForDestroy; /* mutual recursion on nodes/links so this makes it easier to track destroys */
+};
 
 typedef enum Silkworm_ClothTriangleOrientation
 {
@@ -133,18 +142,25 @@ typedef struct Silkworm_Rope
 
 SILKWORMAPI void Silkworm_Init();
 SILKWORMAPI void Silkworm_Update(double delta);
+SILKWORMAPI void Silkworm_ApplyWind(double xSpeed, double ySpeed);
 
 SILKWORMAPI double Silkworm_CreateNode(double xPosition, double yPosition, double mass, double friction, double radius, double pushFactor);
 
 SILKWORMAPI void Silkworm_NodeSetDestroyable(double nodeId);
-SILKWORMAPI void Silkworm_ClothNodePin(double clothId, double i, double j);
+
-SILKWORMAPI void Silkworm_ClothNodeUnpin(double clothId, double i, double j);
 
 SILKWORMAPI double Silkworm_CreateLink(double aId, double bId, double distance, double tearThreshold);
 
 SILKWORMAPI double Silkworm_CreateCloth(double xPosition, double yPosition, double horizontalNodeCount, double verticalNodeCount, double mass, double friction, double windFactor, double tearThreshold);
+SILKWORMAPI void Silkworm_ClothNodePin(double clothId, double i, double j);
+SILKWORMAPI void Silkworm_ClothNodeUnpin(double clothId, double i, double j);
+SILKWORMAPI void Silkworm_ClothNodeDestroy(double clothId, double i, double j);
+SILKWORMAPI void Silkworm_DestroyCloth(double clothId);
 
 SILKWORMAPI void Silkworm_SetTriangleBuffer(const char* bufferId);
 SILKWORMAPI double Silkworm_ClothFillTriangleBuffer(double clothId, double leftUV, double widthUV, double topUV, double heightUV);
 
+SILKWORMAPI void Silkworm_DestroyNode(double nodeId);
+SILKWORMAPI void Silkworm_ClearAll();
+
 #endif /* SILKWORM_H */