slang-shaders/crt/shaders/gtu-famicom/scaleX.slang

#version 450

layout(push_constant) uniform Push
{
	vec4 SourceSize;
	vec4 OriginalSize;
	vec4 OutputSize;
	uint FrameCount;
	float cropOverscan_x;
	float signalResolutionY;
	float signalResolutionI;
	float signalResolutionQ;
} params;

#pragma parameter cropOverscan_x "Crop Overscan X" 0.0 0.0 1.0 1.0
#pragma parameter signalResolutionY "Signal Res Y" 200.0 20.0 500.0 10.0
#pragma parameter signalResolutionI "Signal Res I" 125.0 20.0 350.0 10.0
#pragma parameter signalResolutionQ "Signal Res Q" 125.0 20.0 350.0 10.0

layout(std140, set = 0, binding = 0) uniform UBO
{
	mat4 MVP;
} global;

////////////////////////////////////////////////////////
//	GTU-famicom version 0.50
//	Author: aliaspider - aliaspider@gmail.com
//	License: GPLv3
////////////////////////////////////////////////////////

#define pi			3.14159265358

float d(float x, float b){
return (pi*b*min(abs(x)+0.5,1.0/b));
}

float e(float x, float b){
return (pi*b*min(max(abs(x)-0.5,-1.0/b),1.0/b));
}

#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 vTexCoord;

void main()
{
   gl_Position = global.MVP * Position;
   if (params.cropOverscan_x > 0.0)
	gl_Position.x /= (240.0 / 256.0);
   vTexCoord = TexCoord;
}

#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;

void main()
{
	float	offset	= fract((vTexCoord.x * params.SourceSize.x) - 0.5);
	vec3	YIQ	=	vec3(0.0);
	vec3	RGB	=	vec3(0.0);
	float 	X;
	vec3 	c;
	float	Y = params.signalResolutionY * params.SourceSize.z;
	float	I = params.signalResolutionI * params.SourceSize.z;
	float	Q = params.signalResolutionQ * params.SourceSize.z;
	
	float range = ceil(0.5 + params.SourceSize.x / min(min(params.signalResolutionY, params.signalResolutionI), params.signalResolutionQ));
	
	float i;
//	for (i=-range;i<range+2.0;i++){
	for (i=1.0-range;i<range+1.0;i++){
		X = (offset-(i));
		c = texture(Source, vec2(vTexCoord.x - X * params.SourceSize.z, vTexCoord.y)).rgb;
		c.x *= ((d(X,Y) + sin(d(X,Y)) - e(X,Y) - sin(e(X,Y))) / (2.0 * pi));
		c.y *= ((d(X,I) + sin(d(X,I)) - e(X,I) - sin(e(X,I))) / (2.0 * pi));
		c.z *= ((d(X,Q) + sin(d(X,Q)) - e(X,Q) - sin(e(X,Q))) / (2.0 * pi));
		YIQ+=c;
	}

	RGB.r = YIQ.r + 0.956 * YIQ.g + 0.621 * YIQ.b;
	RGB.g = YIQ.r - 0.272 * YIQ.g - 0.647 * YIQ.b;
	RGB.b = YIQ.r - 1.106 * YIQ.g + 1.703 * YIQ.b;

	FragColor = vec4(clamp(RGB, 0.0, 1.0), 1.0);
}