From 2348712f39454343369e99c93442b09652bcb4a3 Mon Sep 17 00:00:00 2001
From: Hyllian <sergiogdb@gmail.com>
Date: Thu, 22 Sep 2022 19:08:53 -0300
Subject: [PATCH] Add crt-nobody

- A fast crt shader intended for potato devices.
---
 crt/crt-nobody.slangp        |   4 ++
 crt/shaders/crt-nobody.slang | 118 +++++++++++++++++++++++++++++++++++
 2 files changed, 122 insertions(+)
 create mode 100644 crt/crt-nobody.slangp
 create mode 100644 crt/shaders/crt-nobody.slang

diff --git a/crt/crt-nobody.slangp b/crt/crt-nobody.slangp
new file mode 100644
index 0000000..0fdab5a
--- /dev/null
+++ b/crt/crt-nobody.slangp
@@ -0,0 +1,4 @@
+shaders = 1
+
+shader0 = shaders/crt-nobody.slang
+filter_linear0 = false
diff --git a/crt/shaders/crt-nobody.slang b/crt/shaders/crt-nobody.slang
new file mode 100644
index 0000000..9033e2a
--- /dev/null
+++ b/crt/shaders/crt-nobody.slang
@@ -0,0 +1,118 @@
+#version 450
+
+/*
+   Hyllian's crt-nobody Shader
+   
+   Copyright (C) 2011-2022 Hyllian - sergiogdb@gmail.com
+
+   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.
+*/
+
+layout(push_constant) uniform Push
+{
+    vec4 SourceSize;
+    vec4 OriginalSize;
+    vec4 OutputSize;
+    uint FrameCount;
+    float VSCANLINES;
+    float SCAN_SIZE;
+    float COLOR_BOOST;
+    float InputGamma;
+    float OutputGamma;
+} param;
+
+#pragma parameter VSCANLINES   "Vertical Scanlines"  0.0   0.0   1.0 1.0
+#pragma parameter SCAN_SIZE    "Scanlines Size"      0.86  0.0   1.0 0.01
+#pragma parameter COLOR_BOOST  "Color Boost"         1.25  1.0   2.0 0.05
+#pragma parameter InputGamma   "INPUT GAMMA"         2.4   0.0   4.0 0.1
+#pragma parameter OutputGamma  "OUTPUT GAMMA"        2.2   0.0   3.0 0.1
+
+#define VSCANLINES   param.VSCANLINES
+#define SCAN_SIZE    param.SCAN_SIZE
+#define COLOR_BOOST  param.COLOR_BOOST
+#define InputGamma   param.InputGamma
+#define OutputGamma  param.OutputGamma
+
+#define GAMMA_IN(color)     pow(color, vec3(InputGamma, InputGamma, InputGamma))
+#define GAMMA_OUT(color)    pow(color, vec3(1.0 / OutputGamma, 1.0 / OutputGamma, 1.0 / OutputGamma))
+
+#define PIX_SIZE    1.11
+
+float pix_sizex  = mix(PIX_SIZE, SCAN_SIZE, VSCANLINES);
+float scan_sizey = mix(SCAN_SIZE, PIX_SIZE, VSCANLINES);
+
+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;
+
+void main()
+{
+    gl_Position = global.MVP * Position;
+    vTexCoord = TexCoord * 1.0001;
+}
+
+
+#pragma stage fragment
+layout(location = 0) in vec2 vTexCoord;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+
+float wgt(float size)
+{
+   size = clamp(size, -1.0, 1.0);
+
+   size = 1.0 - size * size;
+
+   return size * size * size;
+}
+
+void main()
+{
+    vec2 pix_coord = vTexCoord*param.SourceSize.xy;
+    vec2 tc  = (floor(pix_coord)+vec2(0.5, 0.5)) * param.SourceSize.zw; // tc  = texel coord
+    vec2 pos = fract(pix_coord)-vec2(0.5, 0.5); // pos = pixel position
+    vec2 dir = sign(pos); // dir = pixel direction
+    pos      = abs(pos);
+
+    vec2 g1 = dir*vec2( param.SourceSize.z,  0);
+    vec2 g2 = dir*vec2(  0, param.SourceSize.w);
+
+    vec3 A = GAMMA_IN(texture(Source, tc       ).xyz);
+    vec3 B = GAMMA_IN(texture(Source, tc +g1   ).xyz);
+    vec3 C = GAMMA_IN(texture(Source, tc    +g2).xyz);
+    vec3 D = GAMMA_IN(texture(Source, tc +g1+g2).xyz);
+
+    vec2 dx = vec2(pos.x, 1.0-pos.x) / pix_sizex;
+    vec2 dy = vec2(pos.y, 1.0-pos.y) / scan_sizey;
+
+    vec2 wx = vec2(wgt(dx.x), wgt(dx.y));
+    vec2 wy = vec2(wgt(dy.x), wgt(dy.y));
+
+    vec3 color = (A*wx.x + B*wx.y)*wy.x + (C*wx.x + D*wx.y)*wy.y;
+
+    color *= COLOR_BOOST;
+
+    FragColor = vec4(GAMMA_OUT(color), 1.0);
+}