From 5dc2001f4bbbf26aed999d1704bb8e617c995270 Mon Sep 17 00:00:00 2001
From: Gregori Francisco Cavichioli <gregori.cavichioli@meta.com.br>
Date: Wed, 28 Sep 2022 08:37:33 -0300
Subject: [PATCH] Add Zfast Composite shader

---
 .../zfast_crt/zfast_crt_composite.slang       | 99 +++++++++++++++++++
 crt/zfast-crt-composite.slangp                |  7 ++
 2 files changed, 106 insertions(+)
 create mode 100644 crt/shaders/zfast_crt/zfast_crt_composite.slang
 create mode 100644 crt/zfast-crt-composite.slangp

diff --git a/crt/shaders/zfast_crt/zfast_crt_composite.slang b/crt/shaders/zfast_crt/zfast_crt_composite.slang
new file mode 100644
index 0000000..d1cd980
--- /dev/null
+++ b/crt/shaders/zfast_crt/zfast_crt_composite.slang
@@ -0,0 +1,99 @@
+#version 450
+/*
+    zfast_crt - A very simple CRT shader.
+
+    Copyright (C) 2017 Greg Hogan (SoltanGris42)
+	edited by metallic 77.
+	ported to slang by gregoricavichioli & hunterk.
+
+    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.
+
+*/
+
+layout(push_constant) uniform Push
+{
+    vec4 SourceSize;
+    vec4 OriginalSize;
+    vec4 OutputSize;
+    uint FrameCount;
+float pi, blurx, blury, HIGHSCANAMOUNT1, HIGHSCANAMOUNT2, MASK_DARK, MASK_FADE, sat;
+} params;
+
+#pragma parameter blurx "Convergence X-Axis" 0.45 -1.0 2.0 0.05
+#pragma parameter blury "Convergence Y-Axis" -0.25 -1.0 1.0 0.05
+#pragma parameter HIGHSCANAMOUNT1 "Scanline Amount (Low)" 0.3 0.0 1.0 0.05
+#pragma parameter HIGHSCANAMOUNT2 "Scanline Amount (High)" 0.2 0.0 1.0 0.05
+#pragma parameter MASK_DARK "Mask Effect Amount" 0.25 0.0 1.0 0.05
+#pragma parameter MASK_FADE "Mask/Scanline Fade" 0.8 0.0 1.0 0.05
+#pragma parameter sat "Saturation" 1.1 0.0 3.0 0.05
+
+#define pi 3.14159
+#define blurx params.blurx
+#define blury params.blury
+#define HIGHSCANAMOUNT1 params.HIGHSCANAMOUNT1
+#define HIGHSCANAMOUNT2 params.HIGHSCANAMOUNT2
+#define BRIGHTBOOST params.BRIGHTBOOST
+#define MASK_DARK params.MASK_DARK
+#define MASK_FADE params.MASK_FADE
+#define sat params.sat
+
+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;
+layout(location = 1) out float maskFade;
+
+void main()
+{
+    gl_Position = global.MVP * Position;
+    vTexCoord = TexCoord;
+    maskFade = 0.3333*MASK_FADE;
+}
+
+
+#pragma stage fragment
+layout(location = 0) in vec2 vTexCoord;
+layout(location = 1) in float maskFade;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+
+void main()
+{
+    vec2 pos = vTexCoord.xy;
+    
+    vec3 sample1 = texture(Source,vec2(pos.x + blurx/1000.0, pos.y - blury/1000.0)).rgb;
+    vec3 sample2 = texture(Source,pos).rgb;
+    vec3 sample3 = texture(Source,vec2(pos.x - blurx/1000.0, pos.y + blury/1000.0)).rgb;
+    
+    vec3 colour = vec3 (sample1.r*0.5+sample2.r*0.5, sample1.g*0.25 + sample2.g*0.5 + sample3.g*0.25, sample2.b*0.5 + sample3.b*0.5);
+    float lum = colour.r*0.4 + colour.g*0.4 + colour.b*0.2;
+    
+    vec3 lumweight=vec3(0.3,0.6,0.1);
+    float gray = dot(colour,lumweight);
+    vec3 graycolour = vec3(gray);
+
+    //Gamma-like
+    colour*=mix(0.4,1.0,lum);    
+    
+    float SCANAMOUNT = mix(HIGHSCANAMOUNT1,HIGHSCANAMOUNT2,lum);
+    float scanLine =  SCANAMOUNT * sin(2.0*pi*pos.y*params.SourceSize.y);
+    
+    float whichmask = fract(gl_FragCoord.x*-0.4999);
+    float mask = 1.0 + float(whichmask < 0.5) * -MASK_DARK;
+
+    //Gamma-like 
+    colour*=mix(2.0,1.0,lum);    
+    
+    colour = vec3(mix(graycolour,colour.rgb,sat));
+
+    colour.rgb *= mix(mask*(1.0-scanLine), 1.0-scanLine, dot(colour.rgb,vec3(maskFade)));
+    FragColor.rgb = colour.rgb;
+}
diff --git a/crt/zfast-crt-composite.slangp b/crt/zfast-crt-composite.slangp
new file mode 100644
index 0000000..ef4f6fd
--- /dev/null
+++ b/crt/zfast-crt-composite.slangp
@@ -0,0 +1,7 @@
+shaders = 1
+shader0 = shaders/zfast_crt/zfast_crt_composite.slang
+filter_linear0 = true
+wrap_mode0 = clamp_to_border
+mipmap_input0 = false
+float_framebuffer0 = false
+srgb_framebuffer0 = false