step closer to GPU bvh traversal

opencl/gpu_sat/kernels/bvhTraversal.cl

@@ -0,0 +1,109 @@
+//keep this enum in sync with the CPU version (in btCollidable.h)
+//written by Erwin Coumans
+
+#define SHAPE_CONVEX_HULL 3
+#define SHAPE_CONCAVE_TRIMESH 5
+#define TRIANGLE_NUM_CONVEX_FACES 5
+#define SHAPE_COMPOUND_OF_CONVEX_HULLS 6
+
+typedef unsigned int u32;
+
+///keep this in sync with btCollidable.h
+typedef struct
+{
+	int m_numChildShapes;
+	int blaat2;
+	int m_shapeType;
+	int m_shapeIndex;
+	
+} btCollidableGpu;
+
+typedef struct
+{
+	float4	m_childPosition;
+	float4	m_childOrientation;
+	int m_shapeIndex;
+	int m_unused0;
+	int m_unused1;
+	int m_unused2;
+} btGpuChildShape;
+
+
+typedef struct
+{
+	float4 m_pos;
+	float4 m_quat;
+	float4 m_linVel;
+	float4 m_angVel;
+
+	u32 m_collidableIdx;
+	float m_invMass;
+	float m_restituitionCoeff;
+	float m_frictionCoeff;
+} BodyData;
+
+typedef struct 
+{
+	union
+	{
+		float4	m_min;
+		float   m_minElems[4];
+		int			m_minIndices[4];
+	};
+	union
+	{
+		float4	m_max;
+		float   m_maxElems[4];
+		int			m_maxIndices[4];
+	};
+} btAabbCL;
+
+// work-in-progress
+__kernel void   bvhTraversalKernel( __global const int2* pairs, 
+																					__global const BodyData* rigidBodies, 
+																					__global const btCollidableGpu* collidables,
+																					__global btAabbCL* aabbs,
+																					__global int4* concavePairsOut,
+																					__global volatile int* numConcavePairsOut,
+																					int numPairs,
+																					int maxNumConcavePairsCapacity
+																					)
+{
+
+	int i = get_global_id(0);
+	
+	if (i<numPairs)
+	{
+
+	
+		int bodyIndexA = pairs[i].x;
+		int bodyIndexB = pairs[i].y;
+
+		int collidableIndexA = rigidBodies[bodyIndexA].m_collidableIdx;
+		int collidableIndexB = rigidBodies[bodyIndexB].m_collidableIdx;
+	
+		int shapeIndexA = collidables[collidableIndexA].m_shapeIndex;
+		int shapeIndexB = collidables[collidableIndexB].m_shapeIndex;
+		
+		
+		//once the broadphase avoids static-static pairs, we can remove this test
+		if ((rigidBodies[bodyIndexA].m_invMass==0) &&(rigidBodies[bodyIndexB].m_invMass==0))
+		{
+			return;
+		}
+		
+		if ((collidables[collidableIndexA].m_shapeType==SHAPE_CONCAVE_TRIMESH))// && (collidables[collidableIndexB].m_shapeType==SHAPE_CONVEX_HULL))
+		{
+			int pairIdx = atomic_inc(numConcavePairsOut);
+			if (pairIdx<maxNumConcavePairsCapacity)
+			{
+				//int4 newPair;
+				concavePairsOut[pairIdx].x = bodyIndexA;
+				concavePairsOut[pairIdx].y = bodyIndexB;
+				concavePairsOut[pairIdx].z = 5;
+				concavePairsOut[pairIdx].w = 3;
+			}
+		}//SHAPE_CONCAVE_TRIMESH
+		
+	}//i<numpairs
+}