1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
//-*-c-*-
#include "linalg.h"
#include "intersect.h"
#include "mesh.h"
#include "sorting.h"
#include "geometry.h"
#include "stdio.h"
__device__ float4
get_color(const float3 &direction, const Triangle &triangle, unsigned int rgba)
{
float3 v01 = triangle.v1 - triangle.v0;
float3 v12 = triangle.v2 - triangle.v1;
float3 surface_normal = normalize(cross(v01,v12));
float cos_theta = dot(surface_normal,-direction);
if (cos_theta < 0.0f)
cos_theta = dot(-surface_normal,-direction);
unsigned int a0 = 0xff & (rgba >> 24);
unsigned int r0 = 0xff & (rgba >> 16);
unsigned int g0 = 0xff & (rgba >> 8);
unsigned int b0 = 0xff & rgba;
float alpha = (255 - a0)/255.0f;
return make_float4(r0*cos_theta, g0*cos_theta, b0*cos_theta, alpha);
}
extern "C"
{
__global__ void
render(int nthreads, float3 *_origin, float3 *_direction, Geometry *geometry,
unsigned int alpha_depth, unsigned int *pixels, float *_dx,
unsigned int *dxlen, float4 *_color)
{
int id = blockIdx.x*blockDim.x + threadIdx.x;
if (id >= nthreads)
return;
float3 origin = _origin[id];
float3 direction = _direction[id];
unsigned int n = dxlen[id];
float distance;
if (n < 1 && !intersect_node(origin, direction, geometry,
geometry->start_node, -1.0f)) {
pixels[id] = 0;
return;
}
unsigned int stack[STACK_SIZE];
unsigned int *head = &stack[0];
unsigned int *node = &stack[1];
unsigned int *tail = &stack[STACK_SIZE-1];
*node = geometry->start_node;
float *dx = _dx + id*alpha_depth;
float4 *color_a = _color + id*alpha_depth;
unsigned int i;
do {
unsigned int first_child = geometry->node_map[*node];
unsigned int stop = geometry->node_map_end[*node];
while (*node >= geometry->first_node && stop == first_child+1) {
*node = first_child;
first_child = geometry->node_map[*node];
stop = geometry->node_map_end[*node];
}
if (*node >= geometry->first_node) {
for (i=first_child; i < stop; i++) {
if (intersect_node(origin, direction, geometry, i, -1.0f)) {
*node = i;
node++;
}
}
node--;
}
else {
// node is a leaf
for (i=first_child; i < stop; i++) {
Triangle triangle = get_triangle(geometry, i);
if (intersect_triangle(origin, direction, triangle,
distance)) {
if (n < 1) {
dx[0] = distance;
unsigned int rgba = geometry->colors[i];
float4 color = get_color(direction, triangle, rgba);
color_a[0] = color;
}
else {
unsigned long j = searchsorted(n, dx, distance);
if (j <= alpha_depth-1) {
insert(alpha_depth, dx, j, distance);
unsigned int rgba = geometry->colors[i];
float4 color = get_color(direction, triangle,
rgba);
insert(alpha_depth, color_a, j, color);
}
}
if (n < alpha_depth)
n++;
}
} // triangle loop
node--;
} // node is a leaf
} // while loop
while (node != head);
if (n < 1) {
pixels[id] = 0;
return;
}
dxlen[id] = n;
float scale = 1.0f;
float fr = 0.0f;
float fg = 0.0f;
float fb = 0.0f;
for (i=0; i < n; i++) {
float alpha;
if (i < alpha_depth-1)
alpha = color_a[i].w;
else
alpha = 1.0;
fr += scale*color_a[i].x*alpha;
fg += scale*color_a[i].y*alpha;
fb += scale*color_a[i].z*alpha;
scale *= (1.0f-alpha);
}
unsigned int a;
if (n < alpha_depth)
a = floorf(255*(1.0f-scale));
else
a = 255;
unsigned int r = floorf(fr);
unsigned int g = floorf(fg);
unsigned int b = floorf(fb);
pixels[id] = a << 24 | r << 16 | g << 8 | b;
}
} // extern "C"
|
