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forked from Rowland/EG
EG/RenderPipelineFile/rpplugins/scattering/shader/compute_godrays.frag.glsl
2025-07-24 11:37:46 +08:00

81 lines
2.7 KiB
GLSL

/**
*
* RenderPipeline
*
* Copyright (c) 2014-2016 tobspr <tobias.springer1@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
*/
#version 430
#define USE_TIME_OF_DAY 1
#define USE_GBUFFER_EXTENSIONS
#pragma include "render_pipeline_base.inc.glsl"
#pragma include "includes/gbuffer.inc.glsl"
#pragma include "includes/color_spaces.inc.glsl"
#pragma include "includes/noise.inc.glsl"
uniform sampler2D ShadedScene;
out vec3 result;
void main() {
vec2 texcoord = get_texcoord();
Material m = unpack_material(GBuffer);
// compute sun position on screen
// TODO: could move to vertex shader
vec3 sun_vector = get_sun_vector();
vec3 sun_pos = sun_vector * 1e5;
vec4 sun_proj = MainSceneData.view_proj_mat_no_jitter * vec4(sun_pos, 1);
sun_proj.xyz /= sun_proj.w;
if (sun_proj.w < 0.0) {
result = textureLod(ShadedScene, texcoord, 0).xyz;
return;
}
sun_proj.xy = sun_proj.xy * 0.5 + 0.5;
// raymarch to sun and collect .. whatever
float jitter = rand(texcoord) * 0.9;
const int num_samples = 32;
vec3 accum = vec3(0);
for (int i = 0; i < num_samples; ++i) {
float t = (i + jitter) / float(num_samples - 1);
vec2 sample_coord = mix(texcoord, sun_proj.xy, pow(t, 1.0));
vec3 sample_data = textureLod(ShadedScene, sample_coord, 0).xyz;
// float weight = step(get_luminance(sample_data), 1.0);
float weight = step(1.0, get_luminance(sample_data));
// float weight = 1.0;
accum += sample_data * weight * saturate(5 * (1 - t)) * 1;
// accum += sample_data * weight;
}
accum /= num_samples;
accum *= 0.001;
accum += textureLod(ShadedScene, texcoord, 0).xyz;
result = vec3(accum);
}