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
|
uniform sampler2D colorHistoryBuffer;
uniform sampler2D velocityBuffer;
out vec4 FragColor;
vec4 safe_color(vec4 c)
{
/* Clamp to avoid black square artifacts if a pixel goes NaN. */
return clamp(c, vec4(0.0), vec4(1e20)); /* 1e20 arbitrary. */
}
#ifdef USE_REPROJECTION
/**
* Adapted from https://casual-effects.com/g3d/G3D10/data-files/shader/Film/Film_temporalAA.pix
* which is adapted from https://github.com/gokselgoktas/temporal-anti-aliasing/blob/master/Assets/Resources/Shaders/TemporalAntiAliasing.cginc
* which is adapted from https://github.com/playdeadgames/temporal
* Optimization by Stubbesaurus and epsilon adjustment to avoid division by zero.
*
* This can cause 3x3 blocks of color when there is a thin edge of a similar color that
* is varying in intensity.
*/
vec3 clip_to_aabb(vec3 color, vec3 minimum, vec3 maximum, vec3 average)
{
/* note: only clips towards aabb center (but fast!) */
vec3 center = 0.5 * (maximum + minimum);
vec3 extents = 0.5 * (maximum - minimum);
vec3 dist = color - center;
vec3 ts = abs(extents) / max(abs(dist), vec3(0.0001));
float t = saturate(min_v3(ts));
return center + dist * t;
}
/**
* Vastly based on https://github.com/playdeadgames/temporal
*/
void main()
{
ivec2 texel = ivec2(gl_FragCoord.xy);
float depth = texelFetch(depthBuffer, texel, 0).r;
vec2 motion = texelFetch(velocityBuffer, texel, 0).rg;
/* Decode from unsigned normalized 16bit texture. */
motion = motion * 2.0 - 1.0;
/* Compute pixel position in previous frame. */
vec2 screen_res = vec2(textureSize(colorBuffer, 0).xy);
vec2 uv = gl_FragCoord.xy / screen_res;
vec2 uv_history = uv - motion;
ivec2 texel_history = ivec2(uv_history * screen_res);
vec4 color_history = textureLod(colorHistoryBuffer, uv_history, 0.0);
/* Color bounding box clamping. 3x3 neighborhood. */
vec4 c02 = texelFetchOffset(colorBuffer, texel, 0, ivec2(-1, 1));
vec4 c12 = texelFetchOffset(colorBuffer, texel, 0, ivec2( 0, 1));
vec4 c22 = texelFetchOffset(colorBuffer, texel, 0, ivec2( 1, 1));
vec4 c01 = texelFetchOffset(colorBuffer, texel, 0, ivec2(-1, 0));
vec4 c11 = texelFetchOffset(colorBuffer, texel, 0, ivec2( 0, 0));
vec4 c21 = texelFetchOffset(colorBuffer, texel, 0, ivec2( 1, 0));
vec4 c00 = texelFetchOffset(colorBuffer, texel, 0, ivec2(-1, -1));
vec4 c10 = texelFetchOffset(colorBuffer, texel, 0, ivec2( 0, -1));
vec4 c20 = texelFetchOffset(colorBuffer, texel, 0, ivec2( 1, -1));
vec4 color = c11;
/* AABB minmax */
vec4 min_col = min9(c02, c12, c22, c01, c11, c21, c00, c10, c20);
vec4 max_col = max9(c02, c12, c22, c01, c11, c21, c00, c10, c20);
vec4 avg_col = avg9(c02, c12, c22, c01, c11, c21, c00, c10, c20);
/* bias the color aabb toward the center (rounding the shape) */
vec4 min_center = min5(c12, c01, c11, c21, c10);
vec4 max_center = max5(c12, c01, c11, c21, c10);
vec4 avg_center = avg5(c12, c01, c11, c21, c10);
min_col = (min_col + min_center) * 0.5;
max_col = (max_col + max_center) * 0.5;
avg_col = (avg_col + avg_center) * 0.5;
/* Clip color toward the center of the neighborhood colors AABB box. */
color_history.rgb = clip_to_aabb(color_history.rgb, min_col.rgb, max_col.rgb, avg_col.rgb);
/* Luminance weighting. */
/* TODO correct luminance */
float lum0 = dot(color.rgb, vec3(0.333));
float lum1 = dot(color_history.rgb, vec3(0.333));
float diff = abs(lum0 - lum1) / max(lum0, max(lum1, 0.2));
float weight = 1.0 - diff;
float alpha = mix(0.04, 0.12, weight * weight);
color_history = mix(color_history, color, alpha);
bool out_of_view = any(greaterThanEqual(abs(uv_history - 0.5), vec2(0.5)));
color_history = (out_of_view) ? color : color_history;
FragColor = safe_color(color_history);
}
#else
uniform float alpha;
void main()
{
ivec2 texel = ivec2(gl_FragCoord.xy);
vec4 color = texelFetch(colorBuffer, texel, 0);
vec4 color_history = texelFetch(colorHistoryBuffer, texel, 0);
FragColor = safe_color(mix(color_history, color, alpha));
}
#endif
|
