Pixel-Composer/datafiles/data/Nodes/Custom/ShaderToy/ShaderToy_CRT/shader.fs
2025-01-11 10:31:00 +07:00

110 lines
No EOL
3.4 KiB
GLSL

cbuffer Base : register(b4) {
float2 uResolution;
};
cbuffer Data : register(b10) {
float2 uWarp;
float uHardScan;
float uHardPix;
};
Texture2D gm_BaseTextureObject : register(t0);
SamplerState gm_BaseTexture : register(s0);
struct VertexShaderOutput {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
struct PixelShaderOutput {
float4 color : SV_TARGET0;
};
// sRGB to Linear.
float ToLinear1(float c) { return (c <= 0.04045) ? c / 12.92 : pow((c + 0.055) / 1.055, 2.4); }
float3 ToLinear(float3 c) { return float3(ToLinear1(c.r), ToLinear1(c.g), ToLinear1(c.b)); }
// Linear to sRGB.
float ToSrgb1(float c) { return (c < 0.0031308) ? c * 12.92 : 1.055 * pow(c, 0.41666) - 0.055; }
float3 ToSrgb(float3 c) { return float3(ToSrgb1(c.r), ToSrgb1(c.g), ToSrgb1(c.b)); }
// Nearest emulated sample given floating point position and texel offset.
float3 Fetch(float2 pos, float2 off) {
pos = floor(pos * uResolution / 6.0 + off) / (uResolution / 6.0);
if (max(abs(pos.x - 0.5), abs(pos.y - 0.5)) > 0.5) return float3(0.0, 0.0, 0.0);
return ToLinear(gm_BaseTextureObject.Sample(gm_BaseTexture, pos.xy).rgb);
}
// Distance in emulated pixels to nearest texel.
float2 Dist(float2 pos) { pos = pos * uResolution / 6.0; return -((pos - floor(pos)) - float2(.5, .5)); }
// 1D Gaussian.
float Gaus(float pos, float scale) { return exp2(scale * pos * pos); }
// 3-tap Gaussian filter along horz line.
float3 Horz3(float2 pos, float off) {
float3 b = Fetch(pos, float2(-1.0, off));
float3 c = Fetch(pos, float2(0.0, off));
float3 d = Fetch(pos, float2(1.0, off));
float dst = Dist(pos).x;
float scale = uHardPix;
float wb = Gaus(dst - 1.0, scale);
float wc = Gaus(dst + 0.0, scale);
float wd = Gaus(dst + 1.0, scale);
return (b * wb + c * wc + d * wd) / (wb + wc + wd);
}
// 5-tap Gaussian filter along horz line.
float3 Horz5(float2 pos, float off) {
float3 a = Fetch(pos, float2(-2.0, off));
float3 b = Fetch(pos, float2(-1.0, off));
float3 c = Fetch(pos, float2(0.0, off));
float3 d = Fetch(pos, float2(1.0, off));
float3 e = Fetch(pos, float2(2.0, off));
float dst = Dist(pos).x;
float scale = uHardPix;
float wa = Gaus(dst - 2.0, scale);
float wb = Gaus(dst - 1.0, scale);
float wc = Gaus(dst + 0.0, scale);
float wd = Gaus(dst + 1.0, scale);
float we = Gaus(dst + 2.0, scale);
return (a * wa + b * wb + c * wc + d * wd + e * we) / (wa + wb + wc + wd + we);
}
// Return scanline weight.
float Scan(float2 pos, float off) {
float dst = Dist(pos).y;
return Gaus(dst + off, uHardScan);
}
// Allow nearest three lines to effect pixel.
float3 Tri(float2 pos) {
float3 a = Horz3(pos, -1.0);
float3 b = Horz5(pos, 0.0);
float3 c = Horz3(pos, 1.0);
float wa = Scan(pos, -1.0);
float wb = Scan(pos, 0.0);
float wc = Scan(pos, 1.0);
return a * wa + b * wb + c * wc;
}
// Distortion of scanlines, and end of screen alpha.
float2 Warp(float2 pos) {
pos = pos * 2.0 - 1.0;
pos *= float2(1.0 + (pos.y * pos.y) * uWarp.x, 1.0 + (pos.x * pos.x) * uWarp.y);
return pos * 0.5 + 0.5;
}
void main(in VertexShaderOutput _input, out PixelShaderOutput output) {
float4 fragColor;
float2 pos = Warp(_input.uv + float2(-0.333, 0.0) / uResolution);
fragColor.rgb = Tri(pos);
fragColor.a = 1.0;
fragColor.rgb = ToSrgb(fragColor.rgb);
output.color = fragColor;
}