slang-shaders/crt/shaders/crt-geom-mini.slang
2023-09-25 19:11:43 +03:00

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#version 450
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 of the License, or (at your option)
// any later version.
layout(push_constant) uniform Push
{
vec4 SourceSize;
vec4 OriginalSize;
vec4 OutputSize;
uint FrameCount;
float CURV;
float SCAN;
float MASK;
float LUM;
float INTERL;
float SAT, LANC;
} params;
// Parameter lines go here:
#pragma parameter CURV "CRT-Geom Curvature" 1.0 0.0 1.0 1.0
#pragma parameter SCAN "CRT-Geom Scanline Weight" 0.25 0.2 0.6 0.05
#pragma parameter MASK "CRT-Geom Dotmask Strength" 0.25 0.0 1.0 0.05
#pragma parameter LUM "CRT-Geom Luminance" 0.1 0.0 0.5 0.01
#pragma parameter INTERL "CRT-Geom Interlacing Simulation" 1.0 0.0 1.0 1.0
#pragma parameter SAT "CRT-Geom Saturation" 1.1 0.0 2.0 0.01
#pragma parameter LANC "Filter profile: Accurate/Fast" 0.0 0.0 1.0 1.0
#define PI 3.1415926535897932384626433
#define SourceSize params.SourceSize
#define OriginalSize params.OriginalSize
#define OutputSize params.OutputSize
#define FrameCount params.FrameCount
#define CURV params.CURV
#define SCAN params.SCAN
#define MASK params.MASK
#define LUM params.LUM
#define INTERL params.INTERL
#define SAT params.SAT
#define LANC params.LANC
layout(std140, set = 0, binding = 0) uniform UBO
{
mat4 MVP;
} global;
#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 vTexCoord;
layout(location = 1) out vec2 scale;
layout(location = 2) out vec2 warpp;
layout(location = 3) out vec2 warp;
layout(location = 4) out float fragpos;
void main()
{
gl_Position = global.MVP * Position;
vTexCoord = TexCoord * 1.0001;
scale = SourceSize.xy/OriginalSize.xy;
warpp = vTexCoord.xy*scale;
fragpos = warpp.x*OutputSize.x*PI;
warp = warpp*2.0-1.0;
}
#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 0) out vec4 FragColor;
layout(location = 1) in vec2 scale;
layout(location = 2) in vec2 warpp;
layout(location = 3) in vec2 warp;
layout(location = 4) in float fragpos;
layout(set = 0, binding = 1) uniform sampler2D Source;
float scan(float pos, vec3 color)
{
float wid = SCAN + 0.1 * max(max(color.r,color.g),color.b);
float weight = pos / wid;
return LUM + (0.1 + SCAN) * exp(-weight * weight ) / wid;
}
vec2 Warp(vec2 pos)
{
pos = warp;
pos *= vec2(1.0+pos.y*pos.y*0.031, 1.0+pos.x*pos.x*0.05);
pos = pos*0.5+0.5;
return pos;
}
void main()
{
vec2 pos;
if (CURV == 1.0) pos = Warp(warpp);
else pos = vTexCoord;
vec2 corn = min(pos,1.0-pos); // This is used to mask the rounded
corn.x = 0.0001/corn.x; // corners later on
if (CURV == 1.0) pos /= scale;
// Lanczos 2
// Source position in fractions of a texel
vec2 src_pos = pos*SourceSize.xy;
// Source bottom left texel centre
vec2 src_centre = floor(src_pos - 0.5) + 0.5;
// f is position. f.x runs left to right, y bottom to top, z right to left, w top to bottom
vec4 f;
f.xy = src_pos - src_centre;
f.zw = 1.0 - f.xy;
// Calculate weights in x and y in parallel.
// These polynomials are piecewise approximation of Lanczos kernel
// Calculator here: https://gist.github.com/going-digital/752271db735a07da7617079482394543
vec4 l2_w0_o3, l2_w1_o3;
if (LANC == 0.0)
{l2_w0_o3 = (((1.5672) * f - 2.6445) * f + 0.0837) * f + 0.9976;
l2_w1_o3 = (((-0.7389) * f + 1.3652) * f - 0.6295) * f - 0.0004;}
else {l2_w0_o3 = (-1.1828) * f + 1.1298;
l2_w1_o3 = (0.0858) * f - 0.0792;}
vec4 w1_2 = l2_w0_o3;
vec2 w12 = w1_2.xy + w1_2.zw;
vec4 wedge = l2_w1_o3 * vec4 (w12.yx, w12.yx);
// Calculate texture read positions. tc12 uses bilinear interpolation to do 4 reads in 1.
vec2 tc12 = SourceSize.zw * (src_centre + w1_2.zw / w12);
vec2 tc0 = SourceSize.zw * (src_centre - 1.0);
vec2 tc3 = SourceSize.zw * (src_centre + 2.0);
// Sharpening adjustment
float sum = wedge.x + wedge.y + wedge.z + wedge.w + w12.x * w12.y;
wedge /= sum;
vec3 res = vec3(
texture(Source, vec2(tc12.x, tc0.y)).rgb * wedge.y +
texture(Source, vec2(tc0.x, tc12.y)).rgb * wedge.x +
texture(Source, tc12.xy).rgb * (w12.x * w12.y) +
texture(Source, vec2(tc3.x, tc12.y)).rgb * wedge.z +
texture(Source, vec2(tc12.x, tc3.y)).rgb * wedge.w
);
float fp = fract(src_pos.y-0.5);
if (OriginalSize.y > 400.0) fp = fract(src_pos.y/2.0-0.5);
if (INTERL == 1.0 && OriginalSize.y > 400.0)
{
fp = mod(float(FrameCount),2.0) <1.0 ? 0.5+fp:fp;
}
float scn = scan(fp,res) + scan(1.0-fp,res);
float msk = MASK*sin(fragpos)+1.0-MASK;
res *= sqrt(scn*msk);
float l = dot(vec3(0.29, 0.6, 0.11), res);
res = mix(vec3(l), res, SAT);
if (corn.y <= corn.x && CURV == 1.0 || corn.x < 0.0001 && CURV == 1.0 ) res = vec3(0.0);
FragColor = vec4(res,1.0);
}