////////////////////////////////////////////////////////////
// Triangular Dither //
// By The Sandvich Maker //
// Ported to ReShade by TreyM //
////////////////////////////////////////////////////////////
#include "ReShade.fxh"
uniform float Timer < source = "timer"; >;
#define remap(v, a, b) (((v) - (a)) / ((b) - (a)))
// FUNCTIONS /////////////////////////////////////
float rand21(float2 uv)
{
float2 noise = frac(sin(dot(uv, float2(12.9898, 78.233) * 2.0)) * 43758.5453);
return (noise.x + noise.y) * 0.5;
}
float rand11(float x) { return frac(x * 0.024390243); }
float permute(float x) { return ((34.0 * x + 1.0) * x) % 289.0; }
float3 triDither(float3 color, float2 uv, float timer)
{
static const float bitstep = pow(2.0, 8) - 1.0;
static const float lsb = 1.0 / bitstep;
static const float lobit = 0.5 / bitstep;
static const float hibit = (bitstep - 0.5) / bitstep;
float3 m = float3(uv, rand21(uv + timer)) + 1.0;
float h = permute(permute(permute(m.x) + m.y) + m.z);
float3 noise1, noise2;
noise1.x = rand11(h); h = permute(h);
noise2.x = rand11(h); h = permute(h);
noise1.y = rand11(h); h = permute(h);
noise2.y = rand11(h); h = permute(h);
noise1.z = rand11(h); h = permute(h);
noise2.z = rand11(h);
float3 lo = saturate(remap(color.xyz, 0.0, lobit));
float3 hi = saturate(remap(color.xyz, 1.0, hibit));
float3 uni = noise1 - 0.5;
float3 tri = noise1 - noise2;
return lerp(uni, tri, min(lo, hi)) * lsb;
}
// SHADER ////////////////////////////////////////
float3 PS_TriDither(float4 pos : SV_Position, float2 texcoord : TEXCOORD) : SV_Target
{
float3 color = tex2D(ReShade::BackBuffer, texcoord).rgb;
// Blend
color.rgb += triDither(color.rgb, texcoord, Timer.x);
// Output
return color;
}
// TECHNIQUE /////////////////////////////////////
technique TriDither
{
pass
{
VertexShader = PostProcessVS;
PixelShader = PS_TriDither;
}
}