wgpu-renderer/res/shaders/light.wgsl

29 lines
1 KiB
WebGPU Shading Language

fn sample_direct_light(index: i32, light_coords: vec4<f32>) -> f32 {
if (light_coords.w <= 0.0) {
return 0.0;
}
let flip_correction = vec2<f32>(0.5, -0.5);
let proj_correction = 1.0 / light_coords.w;
let light_local = light_coords.xy * flip_correction * proj_correction + vec2<f32>(0.5, 0.5);
let bias = 0.000001;
let reference_depth = light_coords.z * proj_correction - bias;
var total_sample = 0.0;
for (var x: i32 = -SHADOW_SAMPLES; x < SHADOW_SAMPLES; x++) {
for (var y: i32 = -SHADOW_SAMPLES; y < SHADOW_SAMPLES; y++) {
let texelSize = vec2<f32>(textureDimensions(t_light_depth));
let offset = vec2<f32>(f32(x), f32(y)) / texelSize.xy;
let s = textureSampleCompare(
t_light_depth,
s_light_depth,
light_local + offset,
index,
reference_depth
);
total_sample += s * INV_SHADOW_SAMPLES;
}
}
return total_sample;
}