65 lines
2.2 KiB
GLSL
65 lines
2.2 KiB
GLSL
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#ifndef _GBUFFER_GLSL_
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#define _GBUFFER_GLSL_
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vec2 octahedronWrap(const vec2 v) {
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return (1.0 - abs(v.yx)) * (vec2(v.x >= 0.0 ? 1.0 : -1.0, v.y >= 0.0 ? 1.0 : -1.0));
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}
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vec3 getNor(const vec2 enc) {
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vec3 n;
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n.z = 1.0 - abs(enc.x) - abs(enc.y);
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n.xy = n.z >= 0.0 ? enc.xy : octahedronWrap(enc.xy);
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n = normalize(n);
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return n;
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}
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vec3 getPosView(const vec3 viewRay, const float depth, const vec2 cameraProj) {
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float linearDepth = cameraProj.y / (cameraProj.x - depth);
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// float linearDepth = cameraProj.y / ((depth * 0.5 + 0.5) - cameraProj.x);
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return viewRay * linearDepth;
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}
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vec3 getPos(const vec3 eye, const vec3 eyeLook, const vec3 viewRay, const float depth, const vec2 cameraProj) {
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// eyeLook, viewRay should be normalized
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float linearDepth = cameraProj.y / ((depth * 0.5 + 0.5) - cameraProj.x);
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float viewZDist = dot(eyeLook, viewRay);
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vec3 wposition = eye + viewRay * (linearDepth / viewZDist);
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return wposition;
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}
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// GBuffer helper - Sebastien Lagarde
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// https://seblagarde.wordpress.com/2018/09/02/gbuffer-helper-packing-integer-and-float-together/
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float packFloatInt16(const float f, const uint i) {
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// Constant optimize by compiler
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const int numBitTarget = 16;
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const int numBitI = 4;
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const float prec = float(1 << numBitTarget);
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const float maxi = float(1 << numBitI);
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const float precMinusOne = prec - 1.0;
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const float t1 = ((prec / maxi) - 1.0) / precMinusOne;
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const float t2 = (prec / maxi) / precMinusOne;
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// Code
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return t1 * f + t2 * float(i);
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}
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void unpackFloatInt16(const float val, out float f, out uint i) {
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// Constant optimize by compiler
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const int numBitTarget = 16;
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const int numBitI = 4;
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const float prec = float(1 << numBitTarget);
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const float maxi = float(1 << numBitI);
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const float precMinusOne = prec - 1.0;
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const float t1 = ((prec / maxi) - 1.0) / precMinusOne;
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const float t2 = (prec / maxi) / precMinusOne;
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// Code
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// extract integer part
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// + rcp(precMinusOne) to deal with precision issue
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i = int((val / t2) + (1.0 / precMinusOne));
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// Now that we have i, solve formula in packFloatInt for f
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//f = (val - t2 * float(i)) / t1 => convert in mads form
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f = clamp((-t2 * float(i) + val) / t1, 0.0, 1.0); // Saturate in case of precision issue
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}
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#endif
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