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Features: -produces nearest neighbor look with fractional scales. -uses texture AA shader code. -uses hotizontal subpixel scaling. -due to different pixel sizes, moving sprites change dimension if nearest neighbor is used with fractional scaling. This looks unsteady. This shader uniforms pixel dimensions. Output looks much quieter. https://forums.libretro.com/t/uniform-nearest-interpolation-shader/41492
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/* | ||
* gizmo98 uniform-nearest shader | ||
* Copyright (C) 2023 gizmo98 | ||
* | ||
* 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. | ||
* | ||
* version 0.1, 28.04.2023 | ||
* --------------------------------------------------------------------------------------- | ||
* - initial commit | ||
* | ||
* https://github.com/gizmo98/gizmo-crt-shader | ||
* | ||
* This shader texture AA shader code and subpixel scaling to produce a nearest neighbor | ||
* look with even placed pixels. If nearest neighbor is applied to fractional scaled output | ||
* pixels look uneven and moving sprites change dimension which looks ugly. | ||
* | ||
* BGR_LCD_PATTERN most LCDs have a RGB pixel pattern. Enable BGR pattern with this switch | ||
* | ||
* uses parts of texture anti-aliasing shader from Ikaros https://www.shadertoy.com/view/ldsSRX | ||
*/ | ||
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#pragma parameter BGR_LCD_PATTERN "BGR output pattern" 0.0 0.0 1.0 1.0 | ||
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#if defined(VERTEX) | ||
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#if __VERSION__ >= 130 | ||
#define COMPAT_VARYING out | ||
#define COMPAT_ATTRIBUTE in | ||
#define COMPAT_TEXTURE texture | ||
#else | ||
#define COMPAT_VARYING varying | ||
#define COMPAT_ATTRIBUTE attribute | ||
#define COMPAT_TEXTURE texture2D | ||
#endif | ||
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#ifdef GL_ES | ||
#define COMPAT_PRECISION mediump | ||
#else | ||
#define COMPAT_PRECISION | ||
#endif | ||
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COMPAT_ATTRIBUTE vec4 VertexCoord; | ||
COMPAT_ATTRIBUTE vec4 COLOR; | ||
COMPAT_ATTRIBUTE vec4 TexCoord; | ||
COMPAT_VARYING vec4 COL0; | ||
COMPAT_VARYING vec4 TEX0; | ||
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uniform mat4 MVPMatrix; | ||
uniform COMPAT_PRECISION int FrameDirection; | ||
uniform COMPAT_PRECISION int FrameCount; | ||
uniform COMPAT_PRECISION vec2 OutputSize; | ||
uniform COMPAT_PRECISION vec2 TextureSize; | ||
uniform COMPAT_PRECISION vec2 InputSize; | ||
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#ifdef PARAMETER_UNIFORM | ||
uniform COMPAT_PRECISION float BGR_LCD_PATTERN; | ||
#else | ||
#define BGR_LCD_PATTERN 0.0 | ||
#endif | ||
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void main() | ||
{ | ||
gl_Position = VertexCoord.x * MVPMatrix[0] + VertexCoord.y * MVPMatrix[1] + VertexCoord.z * MVPMatrix[2] + VertexCoord.w * MVPMatrix[3]; | ||
TEX0.xy = TexCoord.xy; | ||
} | ||
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#elif defined(FRAGMENT) | ||
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#if __VERSION__ >= 130 | ||
#define COMPAT_VARYING in | ||
#define COMPAT_TEXTURE texture | ||
out vec4 FragColor; | ||
#else | ||
#define COMPAT_VARYING varying | ||
#define FragColor gl_FragColor | ||
#define COMPAT_TEXTURE texture2D | ||
#endif | ||
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#ifdef GL_ES | ||
#ifdef GL_FRAGMENT_PRECISION_HIGH | ||
precision highp float; | ||
#else | ||
precision mediump float; | ||
#endif | ||
#define COMPAT_PRECISION mediump | ||
#else | ||
#define COMPAT_PRECISION | ||
#endif | ||
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uniform COMPAT_PRECISION int FrameDirection; | ||
uniform COMPAT_PRECISION int FrameCount; | ||
uniform COMPAT_PRECISION vec2 OutputSize; | ||
uniform COMPAT_PRECISION vec2 TextureSize; | ||
uniform COMPAT_PRECISION vec2 InputSize; | ||
uniform sampler2D Texture; | ||
COMPAT_VARYING vec4 TEX0; | ||
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#ifdef PARAMETER_UNIFORM | ||
uniform COMPAT_PRECISION float BGR_LCD_PATTERN; | ||
#endif | ||
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float Y(in float X) | ||
{ | ||
return 4.0 * (-X * X + X); | ||
} | ||
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vec2 saturateA(in vec2 x) | ||
{ | ||
return clamp(x, 0.0, 1.0); | ||
} | ||
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vec2 magnify(in vec2 uv, in vec2 res) | ||
{ | ||
uv *= res; | ||
return (saturateA(fract(uv) / saturateA(fwidth(uv))) + floor(uv) - 0.5) / res.xy; | ||
} | ||
vec4 textureAA(in vec2 uv){ | ||
uv = magnify(uv,TextureSize.xy); | ||
uv = uv*TextureSize.xy + 0.5; | ||
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COMPAT_PRECISION vec2 iuv = floor(uv); | ||
COMPAT_PRECISION vec2 fuv = uv - iuv; | ||
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uv = vec2(uv + vec2(-0.5,-0.5)) / TextureSize.xy; | ||
return COMPAT_TEXTURE( Texture, uv ); | ||
} | ||
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vec4 textureSubSample(in vec2 uvr, in vec2 uvg, in vec2 uvb ){ | ||
return vec4(textureAA(uvr).r,textureAA(uvg).g, textureAA(uvb).b, 255); | ||
} | ||
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vec3 XCoords(in float coord, in float factor){ | ||
COMPAT_PRECISION float iGlobalTime = float(FrameCount)*0.025; | ||
COMPAT_PRECISION float spread = 0.333; | ||
COMPAT_PRECISION vec3 coords = vec3(coord); | ||
if(BGR_LCD_PATTERN == 1.0) | ||
coords.r += spread * 2.0; | ||
else | ||
coords.b += spread * 2.0; | ||
coords.g += spread; | ||
coords *= factor; | ||
return coords; | ||
} | ||
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float YCoord(in float coord, in float factor){ | ||
return coord * factor; | ||
} | ||
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void main() | ||
{ | ||
vec2 texcoord = TEX0.xy; | ||
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COMPAT_PRECISION vec2 fragCoord = texcoord.xy * OutputSize.xy; | ||
COMPAT_PRECISION vec2 factor = TextureSize.xy / OutputSize.xy ; | ||
COMPAT_PRECISION float yCoord = YCoord(fragCoord.y, factor.y) ; | ||
COMPAT_PRECISION vec3 xCoords = XCoords(fragCoord.x, factor.x); | ||
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COMPAT_PRECISION vec2 coord_r = vec2(xCoords.r, yCoord) / TextureSize.xy; | ||
COMPAT_PRECISION vec2 coord_g = vec2(xCoords.g, yCoord) / TextureSize.xy; | ||
COMPAT_PRECISION vec2 coord_b = vec2(xCoords.b, yCoord) / TextureSize.xy; | ||
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FragColor = textureSubSample(coord_r,coord_g,coord_b); | ||
} | ||
#endif |
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shaders = "1" | ||
shader0 = "shaders/uniform-nearest.glsl" | ||
filter_linear0 = "true" | ||
scale_type0 = viewport | ||
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parameters = "BGR_LCD_PATTERN" | ||
BGR_LCD_PATTERN = "0.0" | ||
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