node pushing

src/Silkworm.c

@@ -352,7 +352,7 @@ void Silkworm_Init()
 	context->gravity = 200;
 	context->xBound = 1000;
 	context->yBound = 1000;
-	context->clothDensity = 2;
+	context->clothDensity = 4;
 }
 
 static inline Silkworm_Node* LookupNode(uint64_t nodeId)
@@ -582,7 +582,7 @@ void Silkworm_Update(double deltaTime)
 
 				float translateX = diffX * 0.5f * difference;
 				float translateY = diffY * 0.5f * difference;
-				
+
 				float distanceMoved = (float)sqrt(translateX * translateX + translateY * translateY);
 
 				if (distanceMoved > link->tearThreshold)
@@ -734,7 +734,7 @@ double Silkworm_CreateLink(double aId, double bId, double distance, double tearT
 		id = context->linkIndexStack[context->linkIndexStackCount - 1];
 		context->linkIndexStackCount -= 1;
 	}
-	else 
+	else
 	{
 		id = context->linkCount;
 
@@ -762,15 +762,15 @@ double Silkworm_CreateLink(double aId, double bId, double distance, double tearT
 	return (double)link->id;
 }
 
-double Silkworm_CreateCloth(double xPosition, double yPosition, double horizontalNodeCount, double verticalNodeCount, double mass, double friction, double windFactor, double tearThreshold)
+double Silkworm_CreateCloth(double xPosition, double yPosition, double width, double height, double mass, double friction, double windFactor, double tearThreshold)
 {
 	int32_t i, j, k, m;
 
 	Silkworm_Cloth* cloth = malloc(sizeof(Silkworm_Cloth));
 
 	cloth->windFactor = (float)windFactor;
-	cloth->horizontalNodeCount = (uint32_t) horizontalNodeCount;
+	cloth->horizontalNodeCount = ((uint32_t)width / context->clothDensity) + 1;
-	cloth->verticalNodeCount = (uint32_t) verticalNodeCount;
+	cloth->verticalNodeCount = ((uint32_t)height / context->clothDensity) + 1;
 	cloth->nodeIndices = malloc(sizeof(uint64_t*) * cloth->horizontalNodeCount);
 
 	uint64_t id;
@@ -805,11 +805,11 @@ double Silkworm_CreateCloth(double xPosition, double yPosition, double horizonta
 		cloth->linkHash.buckets[i].count = 0;
 	}
 
-	for (i = 0; i < horizontalNodeCount; i += 1)
+	for (i = 0; i < cloth->horizontalNodeCount; i += 1)
 	{
 		cloth->nodeIndices[i] = malloc(sizeof(uint64_t) * cloth->verticalNodeCount);
 
-		for (j = 0; j < verticalNodeCount; j += 1)
+		for (j = 0; j < cloth->verticalNodeCount; j += 1)
 		{
 			uint64_t nodeId = (uint64_t) Silkworm_CreateNode(xPosition + i * context->clothDensity, yPosition + j * context->clothDensity, mass, friction, 1, 0.5);
 
@@ -827,11 +827,11 @@ double Silkworm_CreateCloth(double xPosition, double yPosition, double horizonta
 	cloth->triangles = malloc(sizeof(Silkworm_Triangle*) * cloth->horizontalNodeCount * cloth->verticalNodeCount * 2);
 	uint32_t triangleIndex = 0;
 
-	for (i = 0; i < horizontalNodeCount; i += 1)
+	for (i = 0; i < cloth->horizontalNodeCount; i += 1)
 	{
-		for (j = 0; j < verticalNodeCount; j += 1)
+		for (j = 0; j < cloth->verticalNodeCount; j += 1)
 		{
-			if (i + 1 < horizontalNodeCount && j + 1 < verticalNodeCount)
+			if (i + 1 < cloth->horizontalNodeCount && j + 1 < cloth->verticalNodeCount)
 			{
 				cloth->triangles[triangleIndex] = malloc(sizeof(Silkworm_Triangle));
 
@@ -885,9 +885,9 @@ double Silkworm_CreateCloth(double xPosition, double yPosition, double horizonta
 
 	cloth->triangleCount = triangleIndex;
 
-	for (i = 0; i < horizontalNodeCount; i += 1)
+	for (i = 0; i < cloth->horizontalNodeCount; i += 1)
 	{
-		for (j = 0; j < verticalNodeCount; j += 1)
+		for (j = 0; j < cloth->verticalNodeCount; j += 1)
 		{
 			if (i - 1 >= 0)
 			{
@@ -960,8 +960,8 @@ void Silkworm_ApplyWind(double xSpeed, double ySpeed)
 
 					if (node != NULL && !node->pinned)
 					{
-						node->position.x += (float)xSpeed * 0.05f * cloth->windFactor;
+						node->position.x += (float)xSpeed * 0.025f * cloth->windFactor;
-						node->position.y += (float)ySpeed * 0.05f * cloth->windFactor;
+						node->position.y += (float)ySpeed * 0.025f * cloth->windFactor;
 					}
 				}
 			}
@@ -1090,6 +1090,32 @@ double Silkworm_ClothFillTriangleBuffer(double clothId, double leftUV, double wi
 	return (double)triangleCount;
 }
 
+void Silkworm_PushNodesInRadius(double x, double y, double radius, double xDirection, double yDirection)
+{
+	/* TODO: spatial hash implementation */
+
+	uint32_t i;
+
+	for (i = 0; i < context->nodeCount; i += 1)
+	{
+		Silkworm_Node* node = context->nodes[i];
+
+		if (node != NULL)
+		{
+			float xDistance = (float)fabs((float)x - node->position.x);
+			float yDistance = (float)fabs((float)y - node->position.y);
+
+			float squareDistance = xDistance * xDistance + yDistance * yDistance;
+
+			if (squareDistance <= radius * radius)
+			{
+				node->position.x += (float)xDirection;
+				node->position.y += (float)yDirection;
+			}
+		}
+	}
+}
+
 void Silkworm_DestroyNodesInRadius(double x, double y, double radius)
 {
 	/* TODO: spatial hash implementation */
@@ -1118,7 +1144,7 @@ void Silkworm_DestroyNodesInRadius(double x, double y, double radius)
 void Silkworm_ClearAll()
 {
 	uint32_t i;
-	
+
 	for (i = 0; i < context->clothCount; i += 1)
 	{
 		if (context->cloths[i] != NULL)

src/Silkworm.h

@@ -77,6 +77,7 @@ SILKWORMAPI double Silkworm_ClothFillTriangleBuffer(double clothId, double leftU
 
 SILKWORMAPI void Silkworm_DestroyNode(double nodeId);
 
+SILKWORMAPI void Silkworm_PushNodesInRadius(double x, double y, double radius, double xDirection, double yDirection);
 SILKWORMAPI void Silkworm_DestroyNodesInRadius(double x, double y, double radius);
 
 SILKWORMAPI void Silkworm_ClearAll();