49 lines
1.3 KiB
GLSL
49 lines
1.3 KiB
GLSL
#version 330 core
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/*
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* Due to how GLSL shader linking works, we cannot share #defines or constants
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* across multiple shaders. As a workaround, we create functions that return
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* the constants. There should be no performance impact due to this because the
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* compiler inlines the function calls.
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*/
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float M_PI() { return 3.14159265358979323846; } // pi
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float M_2PI() { return 6.28318530717958647692; } // 2*pi
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float M_4PI() { return 12.5663706143591729539; } // 4*pi
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float M_PI_2() { return 1.57079632679489661923; } // pi/2
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float M_PI_4() { return 0.78539816339744830962; } // pi/4
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float M_1_PI() { return 0.31830988618379067154; } // 1/pi
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float M_1_4PI() { return 0.07957747154594766788; } // 1/(4*pi)
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float sqr(float x) {
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return x * x;
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}
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float saturate(float x) {
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return clamp(x, 0.0, 1.0);
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}
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float safe_sqrt(float x) {
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return sqrt(max(x, 0.0));
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}
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float safe_asin(float x) {
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return asin(clamp(x, -1.0, 1.0));
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}
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float safe_acos(float x) {
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return acos(clamp(x, -1.0, 1.0));
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}
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float pow5(float x) {
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float x2 = x*x;
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return x2 * x2 * x;
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}
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/*
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* Random number between 0 and 1, using interleaved gradient noise.
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* uv must not be normalized.
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*/
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float interleaved_gradient_noise(vec2 uv) {
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const vec3 m = vec3(0.06711056, 0.00583715, 52.9829189);
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return fract(m.z * fract(dot(uv, m.xy)));
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}
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