slang-shaders/handheld/shaders/mgba/agb001.slang

#version 450

/*
   AGB-001 shader
   A glorious recreation of the original Game Boy Advance
   Author: endrift
   License: MPL 2.0

   This Source Code Form is subject to the terms of the Mozilla Public
   License, v. 2.0. If a copy of the MPL was not distributed with this
   file, You can obtain one at http://mozilla.org/MPL/2.0/. 
*/

layout(std140, set = 0, binding = 0) uniform UBO
{
   mat4 MVP;
   vec4 OutputSize;
   vec4 OriginalSize;
   vec4 SourceSize;
} global;

#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;
   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()
{
	vec4 color = texture(Source, vTexCoord);
	vec3 arrayX[4];
	arrayX[0] = vec3(1.0, 0.2, 0.2);
	arrayX[1] = vec3(0.2, 1.0, 0.2);
	arrayX[2] = vec3(0.2, 0.2, 1.0);
	arrayX[3] = vec3(0.4, 0.4, 0.4);
	vec3 arrayY[4];
	arrayY[0] = vec3(1.0, 1.0, 1.0);
	arrayY[1] = vec3(1.0, 1.0, 1.0);
	arrayY[2] = vec3(1.0, 1.0, 1.0);
	arrayY[3] = vec3(0.8, 0.8, 0.8);
	color.rgb = pow(color.rgb * vec3(0.8, 0.8, 0.8), vec3(1.8, 1.8, 1.8)) + vec3(0.16, 0.16, 0.16);
	color.rgb *= arrayX[int(mod(vTexCoord.s * global.SourceSize.x * 4.0, 4.0))];
	color.rgb *= arrayY[int(mod(vTexCoord.t * global.SourceSize.y * 4.0, 4.0))];
	color.a = 0.5;
	FragColor = color;

}