diff --git a/res/shaders/hq2x.shader/hq2x.fs b/res/shaders/hq2x.shader/hq2x.fs new file mode 100644 index 000000000..97019bd3c --- /dev/null +++ b/res/shaders/hq2x.shader/hq2x.fs @@ -0,0 +1,143 @@ +/* MIT License +* +* Copyright (c) 2015-2023 Lior Halphon +* +* Permission is hereby granted, free of charge, to any person obtaining a copy +* of this software and associated documentation files (the "Software"), to deal +* in the Software without restriction, including without limitation the rights +* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +* copies of the Software, and to permit persons to whom the Software is +* furnished to do so, subject to the following conditions: +* +* The above copyright notice and this permission notice shall be included in all +* copies or substantial portions of the Software. +* +* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +* SOFTWARE. +*/ +/* Based on this (really good) article: http://blog.pkh.me/p/19-butchering-hqx-scaling-filters.html */ + +/* The colorspace used by the HQnx filters is not really YUV, despite the algorithm description claims it is. It is + also not normalized. Therefore, we shall call the colorspace used by HQnx "HQ Colorspace" to avoid confusion. */ +varying vec2 texCoord; +uniform sampler2D tex; +uniform vec2 texSize; + +vec3 rgb_to_hq_colospace(vec4 rgb) +{ + return vec3( 0.250 * rgb.r + 0.250 * rgb.g + 0.250 * rgb.b, + 0.250 * rgb.r - 0.000 * rgb.g - 0.250 * rgb.b, + -0.125 * rgb.r + 0.250 * rgb.g - 0.125 * rgb.b); +} + +bool is_different(vec4 a, vec4 b) +{ + vec3 diff = abs(rgb_to_hq_colospace(a) - rgb_to_hq_colospace(b)); + return diff.x > 0.018 || diff.y > 0.002 || diff.z > 0.005; +} + +#define P(m, r) ((pattern & (m)) == (r)) + +vec4 interp_2px(vec4 c1, float w1, vec4 c2, float w2) +{ + return (c1 * w1 + c2 * w2) / (w1 + w2); +} + +vec4 interp_3px(vec4 c1, float w1, vec4 c2, float w2, vec4 c3, float w3) +{ + return (c1 * w1 + c2 * w2 + c3 * w3) / (w1 + w2 + w3); +} + +vec4 scale(sampler2D image, vec2 position, vec2 input_resolution) +{ + // o = offset, the width of a pixel + vec2 o = vec2(1, 1) / input_resolution; + + /* We always calculate the top left pixel. If we need a different pixel, we flip the image */ + + // p = the position within a pixel [0...1] + vec2 p = fract(position * input_resolution); + + if (p.x > 0.5) o.x = -o.x; + if (p.y > 0.5) o.y = -o.y; + + vec4 w0 = texture2D(image, position + vec2( -o.x, -o.y)); + vec4 w1 = texture2D(image, position + vec2( 0, -o.y)); + vec4 w2 = texture2D(image, position + vec2( o.x, -o.y)); + vec4 w3 = texture2D(image, position + vec2( -o.x, 0)); + vec4 w4 = texture2D(image, position + vec2( 0, 0)); + vec4 w5 = texture2D(image, position + vec2( o.x, 0)); + vec4 w6 = texture2D(image, position + vec2( -o.x, o.y)); + vec4 w7 = texture2D(image, position + vec2( 0, o.y)); + vec4 w8 = texture2D(image, position + vec2( o.x, o.y)); + + int pattern = 0; + if (is_different(w0, w4)) pattern |= 1; + if (is_different(w1, w4)) pattern |= 2; + if (is_different(w2, w4)) pattern |= 4; + if (is_different(w3, w4)) pattern |= 8; + if (is_different(w5, w4)) pattern |= 16; + if (is_different(w6, w4)) pattern |= 32; + if (is_different(w7, w4)) pattern |= 64; + if (is_different(w8, w4)) pattern |= 128; + + if ((P(0xBF,0x37) || P(0xDB,0x13)) && is_different(w1, w5)) { + return interp_2px(w4, 3.0, w3, 1.0); + } + if ((P(0xDB,0x49) || P(0xEF,0x6D)) && is_different(w7, w3)) { + return interp_2px(w4, 3.0, w1, 1.0); + } + if ((P(0x0B,0x0B) || P(0xFE,0x4A) || P(0xFE,0x1A)) && is_different(w3, w1)) { + return w4; + } + if ((P(0x6F,0x2A) || P(0x5B,0x0A) || P(0xBF,0x3A) || P(0xDF,0x5A) || + P(0x9F,0x8A) || P(0xCF,0x8A) || P(0xEF,0x4E) || P(0x3F,0x0E) || + P(0xFB,0x5A) || P(0xBB,0x8A) || P(0x7F,0x5A) || P(0xAF,0x8A) || + P(0xEB,0x8A)) && is_different(w3, w1)) { + return interp_2px(w4, 3.0, w0, 1.0); + } + if (P(0x0B,0x08)) { + return interp_3px(w4, 2.0, w0, 1.0, w1, 1.0); + } + if (P(0x0B,0x02)) { + return interp_3px(w4, 2.0, w0, 1.0, w3, 1.0); + } + if (P(0x2F,0x2F)) { + return interp_3px(w4, 4.0, w3, 1.0, w1, 1.0); + } + if (P(0xBF,0x37) || P(0xDB,0x13)) { + return interp_3px(w4, 5.0, w1, 2.0, w3, 1.0); + } + if (P(0xDB,0x49) || P(0xEF,0x6D)) { + return interp_3px(w4, 5.0, w3, 2.0, w1, 1.0); + } + if (P(0x1B,0x03) || P(0x4F,0x43) || P(0x8B,0x83) || P(0x6B,0x43)) { + return interp_2px(w4, 3.0, w3, 1.0); + } + if (P(0x4B,0x09) || P(0x8B,0x89) || P(0x1F,0x19) || P(0x3B,0x19)) { + return interp_2px(w4, 3.0, w1, 1.0); + } + if (P(0x7E,0x2A) || P(0xEF,0xAB) || P(0xBF,0x8F) || P(0x7E,0x0E)) { + return interp_3px(w4, 2.0, w3, 3.0, w1, 3.0); + } + if (P(0xFB,0x6A) || P(0x6F,0x6E) || P(0x3F,0x3E) || P(0xFB,0xFA) || + P(0xDF,0xDE) || P(0xDF,0x1E)) { + return interp_2px(w4, 3.0, w0, 1.0); + } + if (P(0x0A,0x00) || P(0x4F,0x4B) || P(0x9F,0x1B) || P(0x2F,0x0B) || + P(0xBE,0x0A) || P(0xEE,0x0A) || P(0x7E,0x0A) || P(0xEB,0x4B) || + P(0x3B,0x1B)) { + return interp_3px(w4, 2.0, w3, 1.0, w1, 1.0); + } + + return interp_3px(w4, 6.0, w3, 1.0, w1, 1.0); +} + +void main() { + gl_FragColor = scale(tex, texCoord, texSize); +} diff --git a/res/shaders/hq2x.shader/manifest.ini b/res/shaders/hq2x.shader/manifest.ini new file mode 100644 index 000000000..06c457e81 --- /dev/null +++ b/res/shaders/hq2x.shader/manifest.ini @@ -0,0 +1,11 @@ +[shader] +name=hq2x +author=Lior Halphson +description="High Quality" 2x scaling +passes=1 + +[pass.0] +fragmentShader=hq2x.fs +blend=0 +width=-2 +height=-2