switch to indexing child nodes by start and stop indices instead of start and length; this reduces a bit of arithmetic when traversing the bounding volume hierarchy and makes the code in Geometry.build() more concise. add an untested cuda kernel to interleave the bits in three uint64 arrays.

1 files changed, 20 insertions, 19 deletions

diff --git a/src/mesh.h b/src/mesh.h
index e0170ff..7c148af 100644
--- a/src/mesh.h
+++ b/src/mesh.h
@@ -18,7 +18,8 @@ texture<float4, 1, cudaReadModeElementType> lower_bounds;
 
 /* map to child nodes/triangles and the number of child nodes/triangles */
 texture<unsigned int, 1, cudaReadModeElementType> node_map;
-texture<unsigned int, 1, cudaReadModeElementType> node_length;
+texture<unsigned int, 1, cudaReadModeElementType> node_map_end;
+//texture<unsigned int, 1, cudaReadModeElementType> node_length;
 
 __device__ float3 make_float3(const float4 &a)
 {
@@ -48,7 +49,7 @@ __device__ bool intersect_node(const float3 &origin, const float3 &direction, co
    direction `direction` and the global mesh texture. If the ray intersects
    the texture return the index of the triangle which the ray intersected,
    else return -1. */
-__device__ __noinline__ int intersect_mesh(const float3 &origin, const float3& direction, float &min_distance, int last_hit_triangle = -1)
+__device__ int intersect_mesh(const float3 &origin, const float3& direction, float &min_distance, int last_hit_triangle = -1)
 {
 	int triangle_index = -1;
 
@@ -57,34 +58,34 @@ __device__ __noinline__ int intersect_mesh(const float3 &origin, const float3& d
 	if (!intersect_node(origin, direction, g_start_node))
 		return -1;
 
-	int stack[STACK_SIZE];
+	unsigned int stack[STACK_SIZE];
 
-	int *head = &stack[0];
-	int *node = &stack[1];
-	int *tail = &stack[STACK_SIZE-1];
+	unsigned int *head = &stack[0];
+	unsigned int *node = &stack[1];
+	unsigned int *tail = &stack[STACK_SIZE-1];
 	*node = g_start_node;
 
-	int i;
+	unsigned int i;
 
 	do
 	{
-		int first_child = tex1Dfetch(node_map, *node);
-		int child_count = tex1Dfetch(node_length, *node);
+		unsigned int first_child = tex1Dfetch(node_map, *node);
+		unsigned int stop = tex1Dfetch(node_map_end, *node);
 
-		while (*node >= g_first_node && child_count == 1)
+		while (*node >= g_first_node && stop == first_child+1)
 		{
 			*node = first_child;
 			first_child = tex1Dfetch(node_map, *node);
-			child_count = tex1Dfetch(node_length, *node);
+			stop = tex1Dfetch(node_map_end, *node);
 		}
 		
 		if (*node >= g_first_node)
 		{
-			for (i=0; i < child_count; i++)
+			for (i=first_child; i < stop; i++)
 			{
-				if (intersect_node(origin, direction, first_child+i))
+				if (intersect_node(origin, direction, i))
 				{
-					*node = first_child+i;
+					*node = i;
 					node++;
 				}
 			}
@@ -93,12 +94,12 @@ __device__ __noinline__ int intersect_mesh(const float3 &origin, const float3& d
 		}
 		else // node is a leaf
 		{
-			for (i=0; i < child_count; i++)
+			for (i=first_child; i < stop; i++)
 			{
-				if (last_hit_triangle == first_child+i)
+				if (last_hit_triangle == i)
 					continue;
 
-				uint4 triangle_data = g_triangles[first_child+i];
+				uint4 triangle_data = g_triangles[i];
 
 				float3 v0 = g_vertices[triangle_data.x];
 				float3 v1 = g_vertices[triangle_data.y];
@@ -108,14 +109,14 @@ __device__ __noinline__ int intersect_mesh(const float3 &origin, const float3& d
 				{
 					if (triangle_index == -1)
 					{
-						triangle_index = first_child + i;
+						triangle_index = i;
 						min_distance = distance;
 						continue;
 					}
 
 					if (distance < min_distance)
 					{
-						triangle_index = first_child + i;
+						triangle_index = i;
 						min_distance = distance;
 					}
 				}