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
|
/**
* Simple downsample shader. Takes the average of the 4 texels of lower mip.
**/
uniform sampler2D source;
uniform float fireflyFactor;
out vec4 FragColor;
float brightness(vec3 c)
{
return max(max(c.r, c.g), c.b);
}
void main()
{
#if 0
/* Reconstructing Target uvs like this avoid missing pixels if NPO2 */
vec2 uvs = gl_FragCoord.xy * 2.0 / vec2(textureSize(source, 0));
FragColor = textureLod(source, uvs, 0.0);
#else
vec2 texel_size = 1.0 / vec2(textureSize(source, 0));
vec2 uvs = gl_FragCoord.xy * 2.0 * texel_size;
vec4 ofs = texel_size.xyxy * vec4(0.75, 0.75, -0.75, -0.75);
FragColor = textureLod(source, uvs + ofs.xy, 0.0);
FragColor += textureLod(source, uvs + ofs.xw, 0.0);
FragColor += textureLod(source, uvs + ofs.zy, 0.0);
FragColor += textureLod(source, uvs + ofs.zw, 0.0);
FragColor *= 0.25;
/* Clamped brightness. */
float luma = max(1e-8, brightness(FragColor.rgb));
FragColor *= 1.0 - max(0.0, luma - fireflyFactor) / luma;
#endif
}
|
