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
|
layout(binding=0, std430) buffer offsetBuffer
{
uint maxDepth;
uint offset[];
};
layout(binding=2, std430) buffer countBuffer
{
uint maxSize;
uint count[];
};
layout(binding=4, std430) buffer fragmentBuffer
{
vec4 fragment[];
};
layout(binding=5, std430) buffer depthBuffer
{
float depth[];
};
layout(binding=6, std430) buffer opaqueBuffer {
vec4 opaqueColor[];
};
layout(binding=7, std430) buffer opaqueDepthBuffer {
float opaqueDepth[];
};
#ifdef GPUCOMPRESS
layout(binding=1, std430) buffer indexBuffer
{
uint index[];
};
#define INDEX(pixel) index[pixel]
#define COUNT(pixel) index[pixel]
#else
#define INDEX(pixel) pixel
#define COUNT(pixel) count[pixel]
#endif
out vec4 outColor;
uniform uint width;
uniform vec4 background;
vec4 blend(vec4 outColor, vec4 color)
{
return mix(outColor,color,color.a);
}
void main()
{
uint pixel=uint(gl_FragCoord.y)*width+uint(gl_FragCoord.x);
float OpaqueDepth=opaqueDepth[pixel];
uint element=INDEX(pixel);
#ifdef GPUCOMPRESS
if(element == 0u) {
if(OpaqueDepth != 0.0)
opaqueDepth[pixel]=0.0;
discard;
}
#endif
#ifdef GPUINDEXING
uint listIndex=offset[element];
uint size=offset[element+1u]-listIndex;
#else
uint size=count[element];
#endif
#ifndef GPUCOMPRESS
if(size == 0u) {
if(OpaqueDepth != 0.0)
opaqueDepth[pixel]=0.0;
discard;
}
#endif
outColor=OpaqueDepth != 0.0 ? opaqueColor[pixel] : background;
#ifndef GPUINDEXING
uint listIndex=offset[element]-size;
#endif
uint k=0u;
if(OpaqueDepth != 0.0)
while(k < size && depth[listIndex+k] >= OpaqueDepth)
++k;
uint n=size-k;
// Sort the fragments with respect to descending depth
if(n <= ARRAYSIZE) {
if(n == 1)
outColor=blend(outColor,fragment[listIndex+k]);
else if(n > 0) {
struct element {
uint index;
float depth;
};
element E[ARRAYSIZE];
E[0]=element(k,depth[listIndex+k]);
uint i=1u;
while(++k < size) {
float d=depth[listIndex+k];
if(OpaqueDepth != 0.0) {
while(k < size && d >= OpaqueDepth) {
++k;
d=depth[listIndex+k];
}
if(k == size) break;
}
uint j=i;
while(j > 0u && d > E[j-1u].depth) {
E[j]=E[j-1u];
--j;
}
E[j]=element(k,d);
++i;
}
for(uint j=0u; j < i; ++j)
outColor=blend(outColor,fragment[listIndex+E[j].index]);
}
if(OpaqueDepth != 0.0)
opaqueDepth[pixel]=0.0;
} else {
atomicMax(maxDepth,size);
#ifndef GPUINDEXING
maxSize=maxDepth;
#endif
for(uint i=k+1u; i < size; i++) {
vec4 temp=fragment[listIndex+i];
float d=depth[listIndex+i];
uint j=i;
while(j > 0u && d > depth[listIndex+j-1u]) {
fragment[listIndex+j]=fragment[listIndex+j-1u];
depth[listIndex+j]=depth[listIndex+j-1u];
--j;
}
fragment[listIndex+j]=temp;
depth[listIndex+j]=d;
}
uint stop=listIndex+size;
if(OpaqueDepth == 0.0)
for(uint i=listIndex+k; i < stop; i++)
outColor=blend(outColor,fragment[i]);
else {
for(uint i=listIndex+k; i < stop; i++) {
if(depth[i] < OpaqueDepth)
outColor=blend(outColor,fragment[i]);
}
opaqueDepth[pixel]=0.0;
}
}
COUNT(pixel)=0u;
}
|
