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
|
/* clang-format off */
#[vertex]
#version 450
#VERSION_DEFINES
#include "luminance_reduce_raster_inc.glsl"
layout(location = 0) out vec2 uv_interp;
/* clang-format on */
void main() {
vec2 base_arr[4] = vec2[](vec2(0.0, 0.0), vec2(0.0, 1.0), vec2(1.0, 1.0), vec2(1.0, 0.0));
uv_interp = base_arr[gl_VertexIndex];
gl_Position = vec4(uv_interp * 2.0 - 1.0, 0.0, 1.0);
}
/* clang-format off */
#[fragment]
#version 450
#VERSION_DEFINES
#include "luminance_reduce_raster_inc.glsl"
layout(location = 0) in vec2 uv_interp;
/* clang-format on */
layout(set = 0, binding = 0) uniform sampler2D source_exposure;
#ifdef FINAL_PASS
layout(set = 1, binding = 0) uniform sampler2D prev_luminance;
#endif
layout(location = 0) out highp float luminance;
void main() {
ivec2 dest_pos = ivec2(uv_interp * settings.dest_size);
ivec2 src_pos = ivec2(uv_interp * settings.source_size);
ivec2 next_pos = (dest_pos + ivec2(1)) * settings.source_size / settings.dest_size;
next_pos = max(next_pos, src_pos + ivec2(1)); //so it at least reads one pixel
highp vec3 source_color = vec3(0.0);
for (int i = src_pos.x; i < next_pos.x; i++) {
for (int j = src_pos.y; j < next_pos.y; j++) {
source_color += texelFetch(source_exposure, ivec2(i, j), 0).rgb;
}
}
source_color /= float((next_pos.x - src_pos.x) * (next_pos.y - src_pos.y));
#ifdef FIRST_PASS
luminance = max(source_color.r, max(source_color.g, source_color.b));
// This formula should be more "accurate" but gave an overexposed result when testing.
// Leaving it here so we can revisit it if we want.
// luminance = source_color.r * 0.21 + source_color.g * 0.71 + source_color.b * 0.07;
#else
luminance = source_color.r;
#endif
#ifdef FINAL_PASS
// Obtain our target luminance
luminance = clamp(luminance, settings.min_luminance, settings.max_luminance);
// Now smooth to our transition
highp float prev_lum = texelFetch(prev_luminance, ivec2(0, 0), 0).r; //1 pixel previous luminance
luminance = prev_lum + (luminance - prev_lum) * clamp(settings.exposure_adjust, 0.0, 1.0);
#endif
}
|