veloren/assets/voxygen/shaders/include/rain_occlusion.glsl

#ifndef RAIN_OCCLUSION_GLSL
#define RAIN_OCCLUSION_GLSL

// Use with sampler2DShadow
layout(set = 1, binding = 4)
uniform texture2D t_directed_occlusion_maps;
layout(set = 1, binding = 5)
uniform samplerShadow s_directed_occlusion_maps;

layout (std140, set = 0, binding = 14)
uniform u_rain_occlusion {
    mat4 occlusionMatrices;
    mat4 occlusion_texture_mat;
};

float rain_occlusion_at(in vec3 fragPos)
{
    float bias = 0.5;
    float diskRadius = 0.01;
    const vec3 sampleOffsetDirections[20] = vec3[]
    (
       vec3( 1,  1,  1), vec3( 1, -1,  1), vec3(-1, -1,  1), vec3(-1,  1,  1),
       vec3( 1,  1, -1), vec3( 1, -1, -1), vec3(-1, -1, -1), vec3(-1,  1, -1),
       vec3( 1,  1,  0), vec3( 1, -1,  0), vec3(-1, -1,  0), vec3(-1,  1,  0),
       vec3( 1,  0,  1), vec3(-1,  0,  1), vec3( 1,  0, -1), vec3(-1,  0, -1),
       vec3( 0,  1,  1), vec3( 0, -1,  1), vec3( 0, -1, -1), vec3( 0,  1, -1)
    );

    vec4 rain_pos = occlusion_texture_mat * vec4(fragPos - vec3(0, 0, bias), 1.0);

    float visibility = textureProj(sampler2DShadow(t_directed_occlusion_maps, s_directed_occlusion_maps), rain_pos);

    return visibility;
}
#endif