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++ #version 440
++
++ layout(location = 0) out vec4 fragOutput;
++
++ layout(location = 0) in vec2 uv_coord;
++
++ layout(std140, binding = 0) uniform buf {
++ int hemisphere;
++ } ubuf;
++
++ layout(binding = 1) uniform samplerCube shadowMapCube;
++
++ #define FORWARD_HEMISPHERE 0
++ #define REVERSE_HEMISPHERE 1
++
++ void main()
++ {
++ // Convert [0..1] to [-1..1]
++ vec2 uv = 2.0 * uv_coord - 1.0;
++ float r2 = dot(uv, uv);
++ float z = 0;
++
++ if (ubuf.hemisphere == FORWARD_HEMISPHERE) {
++ // Compute direction for the forward paraboloid
++ z = (1.0 - r2) / (1.0 + r2);
++ } else {
++ z = (r2 - 1.0) / (1.0 + r2);
++ }
++
++ float x = (2.0 * uv.x) / (1.0 + r2);
++ float y = (2.0 * uv.y) / (1.0 + r2);
++
++ // Sample radial depth from the cubemap
++ float depthVal = texture(shadowMapCube, vec3(x, y, z)).r;
++
++ fragOutput = vec4(depthVal);
++ }