80 lines
2.5 KiB
WebGPU Shading Language
80 lines
2.5 KiB
WebGPU Shading Language
#define_import_path bevy_pbr::fog
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#import bevy_pbr::{
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mesh_view_bindings::fog,
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mesh_view_types::Fog,
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}
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// Fog formulas adapted from:
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// https://learn.microsoft.com/en-us/windows/win32/direct3d9/fog-formulas
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// https://catlikecoding.com/unity/tutorials/rendering/part-14/
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// https://iquilezles.org/articles/fog/ (Atmospheric Fog and Scattering)
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fn scattering_adjusted_fog_color(
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fog_params: Fog,
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scattering: vec3<f32>,
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) -> vec4<f32> {
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if (fog_params.directional_light_color.a > 0.0) {
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return vec4<f32>(
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fog_params.base_color.rgb
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+ scattering * fog_params.directional_light_color.rgb * fog_params.directional_light_color.a,
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fog_params.base_color.a,
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);
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} else {
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return fog_params.base_color;
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}
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}
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fn linear_fog(
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fog_params: Fog,
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input_color: vec4<f32>,
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distance: f32,
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scattering: vec3<f32>,
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) -> vec4<f32> {
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var fog_color = scattering_adjusted_fog_color(fog_params, scattering);
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let start = fog_params.be.x;
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let end = fog_params.be.y;
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fog_color.a *= 1.0 - clamp((end - distance) / (end - start), 0.0, 1.0);
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return vec4<f32>(mix(input_color.rgb, fog_color.rgb, fog_color.a), input_color.a);
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}
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fn exponential_fog(
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fog_params: Fog,
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input_color: vec4<f32>,
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distance: f32,
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scattering: vec3<f32>,
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) -> vec4<f32> {
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var fog_color = scattering_adjusted_fog_color(fog_params, scattering);
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let density = fog_params.be.x;
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fog_color.a *= 1.0 - 1.0 / exp(distance * density);
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return vec4<f32>(mix(input_color.rgb, fog_color.rgb, fog_color.a), input_color.a);
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}
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fn exponential_squared_fog(
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fog_params: Fog,
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input_color: vec4<f32>,
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distance: f32,
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scattering: vec3<f32>,
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) -> vec4<f32> {
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var fog_color = scattering_adjusted_fog_color(fog_params, scattering);
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let distance_times_density = distance * fog_params.be.x;
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fog_color.a *= 1.0 - 1.0 / exp(distance_times_density * distance_times_density);
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return vec4<f32>(mix(input_color.rgb, fog_color.rgb, fog_color.a), input_color.a);
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}
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fn atmospheric_fog(
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fog_params: Fog,
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input_color: vec4<f32>,
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distance: f32,
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scattering: vec3<f32>,
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) -> vec4<f32> {
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var fog_color = scattering_adjusted_fog_color(fog_params, scattering);
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let extinction_factor = 1.0 - 1.0 / exp(distance * fog_params.be);
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let inscattering_factor = 1.0 - 1.0 / exp(distance * fog_params.bi);
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return vec4<f32>(
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input_color.rgb * (1.0 - extinction_factor * fog_color.a)
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+ fog_color.rgb * inscattering_factor * fog_color.a,
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input_color.a
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);
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}
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