forked from BilalY/Rasagar
49 lines
1.8 KiB
HLSL
49 lines
1.8 KiB
HLSL
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#ifndef COMMON_UTILITIES_INCLUDED
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#define COMMON_UTILITIES_INCLUDED
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// remaps a value based on a in:min/max and out:min/max
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// value = value to be remapped
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// remap = x = min in, y = max in, z = min out, w = max out
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float Remap(half value, half4 remap)
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{
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return remap.z + (value - remap.x) * (remap.w - remap.z) / (remap.y - remap.x);
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}
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// Converts greyscale height to normal
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// _tex = input texture(separate from a sampler)
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// _sampler = the sampler to use
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// _uv = uv coordinates
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// _intensity = intensity of the effect
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float3 HeightToNormal(Texture2D _tex, SamplerState _sampler, float2 _uv, half _intensity)
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{
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float3 bumpSamples;
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bumpSamples.x = _tex.Sample(_sampler, _uv).x; // Sample center
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bumpSamples.y = _tex.Sample(_sampler, float2(_uv.x + _intensity / _ScreenParams.x, _uv.y)).x; // Sample U
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bumpSamples.z = _tex.Sample(_sampler, float2(_uv.x, _uv.y + _intensity / _ScreenParams.y)).x; // Sample V
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half dHdU = bumpSamples.z - bumpSamples.x;//bump U offset
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half dHdV = bumpSamples.y - bumpSamples.x;//bump V offset
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return float3(-dHdU, dHdV, 0.5);//return tangent normal
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}
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// Simple noise from thebookofshaders.com
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// 2D Random
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float2 random(float2 st){
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st = float2( dot(st,float2(127.1,311.7)), dot(st,float2(269.5,183.3)) );
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return -1.0 + 2.0 * frac(sin(st) * 43758.5453123);
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}
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// 2D Noise based on Morgan McGuire @morgan3d
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// https://www.shadertoy.com/view/4dS3Wd
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float noise (float2 st) {
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float2 i = floor(st);
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float2 f = frac(st);
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float2 u = f*f*(3.0-2.0*f);
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return lerp( lerp( dot( random(i), f),
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dot( random(i + float2(1.0,0.0) ), f - float2(1.0,0.0) ), u.x),
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lerp( dot( random(i + float2(0.0,1.0) ), f - float2(0.0,1.0) ),
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dot( random(i + float2(1.0,1.0) ), f - float2(1.0,1.0) ), u.x), u.y);
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}
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#endif // COMMON_UTILITIES_INCLUDED
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