From be86380ca2765095e74d6a38164c2a5c65da4490 Mon Sep 17 00:00:00 2001
From: hunterk <hunter_kaller@yahoo.com>
Date: Sat, 20 Nov 2021 09:18:02 -0600
Subject: [PATCH] add scanlines-rere and fix typo

---
 ...langp => res-independent-scanlines.slangp} |  0
 scanlines/scanlines-rere.slangp               |  4 +
 scanlines/shaders/scanlines-rere.slang        | 81 +++++++++++++++++++
 3 files changed, 85 insertions(+)
 rename scanlines/{res-independent-scalines.slangp => res-independent-scanlines.slangp} (100%)
 create mode 100644 scanlines/scanlines-rere.slangp
 create mode 100644 scanlines/shaders/scanlines-rere.slang

diff --git a/scanlines/res-independent-scalines.slangp b/scanlines/res-independent-scanlines.slangp
similarity index 100%
rename from scanlines/res-independent-scalines.slangp
rename to scanlines/res-independent-scanlines.slangp
diff --git a/scanlines/scanlines-rere.slangp b/scanlines/scanlines-rere.slangp
new file mode 100644
index 0000000..a448987
--- /dev/null
+++ b/scanlines/scanlines-rere.slangp
@@ -0,0 +1,4 @@
+shaders = 1
+
+shader0 = shaders/scanlines-rere.slang
+filter_linear0 = true
diff --git a/scanlines/shaders/scanlines-rere.slang b/scanlines/shaders/scanlines-rere.slang
new file mode 100644
index 0000000..4ae8381
--- /dev/null
+++ b/scanlines/shaders/scanlines-rere.slang
@@ -0,0 +1,81 @@
+#version 450
+
+/*
+    by Rere
+	license: public domain
+*/
+
+layout(push_constant) uniform Push
+{
+	vec4 SourceSize;
+	vec4 OriginalSize;
+	vec4 OutputSize;
+	uint FrameCount;
+	float thickness;
+	float glow;
+	float sGamma;
+	float tGamma;
+	float highlights;
+	float boost;
+} params;
+
+#pragma parameter thickness  "Scanline thickness"        0.50 0.00 1.00 0.01
+#pragma parameter glow       "Scanline glow"             0.75 0.00 1.00 0.01
+#pragma parameter highlights "Scanline highlights"       0.75 0.00 1.00 0.01
+#pragma parameter boost      "Luminance boost"           0.25 0.00 1.00 0.01
+#pragma parameter sGamma     "Source gamma"              2.40 1.00 3.00 0.01
+#pragma parameter tGamma     "Target gamma"              2.20 1.00 3.00 0.01
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+	mat4 MVP;
+} global;
+
+#define pi 3.141592654
+#define luminance(c) (0.2126 * c.r + 0.7152 * c.g + 0.0722 * c.b)
+
+vec3 gammaFn(vec3 c, float gamma) {
+  return vec3(pow(c.x, gamma), pow(c.y, gamma), pow(c.z, gamma));
+}
+
+#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 thickness;
+layout(location = 2) out float glow;
+layout(location = 3) out float highlights;
+layout(location = 4) out float boost;
+
+void main()
+{
+   gl_Position = global.MVP * Position;
+   vTexCoord = TexCoord;
+   thickness = 0.5 + mix(0.0, 2.0, params.thickness);
+   glow = mix(-0.5, 0.5, params.glow);
+   highlights = mix(0.0, 1.0, params.highlights);
+   boost = mix(0.0, 5.0, params.boost);
+}
+
+#pragma stage fragment
+layout(location = 0) in vec2 vTexCoord;
+layout(location = 1) in float thickness;
+layout(location = 2) in float glow;
+layout(location = 3) in float highlights;
+layout(location = 4) in float boost;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+
+void main()
+{
+	vec2 uv = vTexCoord.xy;
+    vec3 col = texture(Source, uv).rgb;
+    col = gammaFn(col, params.sGamma);
+    float L = luminance(col);
+    float y = fract(uv.y * params.SourceSize.y * 1.0);
+	y = pow(sin(y * pi), thickness);
+	y = (y + glow) / (1.0 + glow);
+	float g = 1.0 + L * (1.0 - L) * boost;
+	col = mix(col, col * g * y, 1.0 - L * highlights);
+    FragColor = vec4(gammaFn(col, 1.0 / params.tGamma), 1.0);
+}