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#ifndef __MESH_H__
#define __MESH_H__
#include "intersect.h"
#define STACK_SIZE 500
/* flattened triangle mesh */
__device__ float3 *g_vertices;
__device__ uint4 *g_triangles;
__device__ unsigned int *g_colors;
__device__ unsigned int g_start_node;
__device__ unsigned int g_first_node;
/* lower/upper bounds for the bounding box associated with each node/leaf */
texture<float4, 1, cudaReadModeElementType> upper_bounds;
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;
__device__ float3 make_float3(const float4 &a)
{
return make_float3(a.x, a.y, a.z);
}
__device__ int convert(int c)
{
if (c & 0x80)
return (0xFFFFFF00 | c);
else
return c;
}
/* Test the intersection between a ray starting at `origin` traveling in the
direction `direction` and the bounding box around node `i`. If the ray
intersects the bounding box return true, else return false. */
__device__ bool intersect_node(const float3 &origin, const float3 &direction, const int &i)
{
float3 lower_bound = make_float3(tex1Dfetch(lower_bounds, i));
float3 upper_bound = make_float3(tex1Dfetch(upper_bounds, i));
return intersect_box(origin, direction, lower_bound, upper_bound);
}
/* Find the intersection between a ray starting at `origin` traveling in the
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)
{
int triangle_index = -1;
float distance;
if (!intersect_node(origin, direction, g_start_node))
return -1;
int stack[STACK_SIZE];
int *head = &stack[0];
int *node = &stack[1];
int *tail = &stack[STACK_SIZE-1];
*node = g_start_node;
int i;
do
{
int first_child = tex1Dfetch(node_map, *node);
int child_count = tex1Dfetch(node_length, *node);
while (*node >= g_first_node && child_count == 1)
{
*node = first_child;
first_child = tex1Dfetch(node_map, *node);
child_count = tex1Dfetch(node_length, *node);
}
if (*node >= g_first_node)
{
for (i=0; i < child_count; i++)
{
if (intersect_node(origin, direction, first_child+i))
{
*node = first_child+i;
node++;
}
}
node--;
}
else // node is a leaf
{
for (i=0; i < child_count; i++)
{
if (last_hit_triangle == first_child+i)
continue;
uint4 triangle_data = g_triangles[first_child+i];
float3 v0 = g_vertices[triangle_data.x];
float3 v1 = g_vertices[triangle_data.y];
float3 v2 = g_vertices[triangle_data.z];
if (intersect_triangle(origin, direction, v0, v1, v2, distance))
{
if (triangle_index == -1)
{
triangle_index = first_child + i;
min_distance = distance;
continue;
}
if (distance < min_distance)
{
triangle_index = first_child + i;
min_distance = distance;
}
}
} // triangle loop
node--;
} // node is a leaf
} // while loop
while (node != head);
return triangle_index;
}
extern "C"
{
__global__ void set_global_mesh_variables(uint4 *triangles, float3 *vertices, unsigned int *colors, unsigned int start_node, unsigned int first_node)
{
g_triangles = triangles;
g_vertices = vertices;
g_colors = colors;
g_start_node = start_node;
g_first_node = first_node;
}
__global__ void set_colors(unsigned int *colors)
{
g_colors = colors;
}
__global__ void color_solids(int nthreads, unsigned int ntriangles, int *solid_id_map, int *solid_ids, unsigned int *solid_colors)
{
int id = blockIdx.x*blockDim.x + threadIdx.x;
if (id >= nthreads)
return;
int solid_id = solid_ids[id];
unsigned int color = solid_colors[id];
for (int i=0; i < ntriangles; i++)
{
if (solid_id_map[i] == solid_id)
g_colors[i] = color;
}
}
} // extern "c"
#endif
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