From 1351b17f224f85396ec7a86f653282a69be168f9 Mon Sep 17 00:00:00 2001
From: Valerie <sleeplessval@gmail.com>
Date: Sat, 20 Apr 2024 22:13:24 -0400
Subject: [PATCH] initial implementation for scanlines

---
 README.md                  | 2 ++
 shaders/final.fsh          | 8 ++++++++
 shaders/lang/en_US.lang    | 1 +
 shaders/shaders.properties | 2 +-
 4 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index ca39ecd..a91b1da 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,8 @@ aimed at providing a variety of effects in the vein of its parent project.
 - Dithering
 - Downscaling
 - Horizontal Blur
+- Interlacing
+- Scanlines
 - Screen-Space Vertex Warping
 - Affine Texture Warping
 - World Curvature
diff --git a/shaders/final.fsh b/shaders/final.fsh
index 1ad9801..d2c3624 100644
--- a/shaders/final.fsh
+++ b/shaders/final.fsh
@@ -4,6 +4,7 @@
 
 //#define aberration
 //#define hBlur
+//#define scanlines
 
 varying vec2 texcoord;
 
@@ -25,6 +26,13 @@ void main() {
 		color.rb = aberrate().rb;
 	#endif
 
+	#ifdef scanlines
+		if(mod(int(gl_FragCoord.y / (pixelSize * 2)), 2) == 0)
+			color.rgb *= 0.95;
+		else
+			color.rgb /= 0.95;
+	#endif
+
 	gl_FragData[0] = vec4(color, 1);
 }
 
diff --git a/shaders/lang/en_US.lang b/shaders/lang/en_US.lang
index 150b3d9..4da6505 100644
--- a/shaders/lang/en_US.lang
+++ b/shaders/lang/en_US.lang
@@ -25,6 +25,7 @@ option.valSteps=Value Depth
 
 screen.SCREEN=Screen
 option.interlacing=Interlacing
+option.scanlines=Scanlines
 option.aberration=Chromatic Aberration
 
 screen.CONSOLE=Consoles
diff --git a/shaders/shaders.properties b/shaders/shaders.properties
index 33c9ba8..af5624c 100644
--- a/shaders/shaders.properties
+++ b/shaders/shaders.properties
@@ -17,7 +17,7 @@ screen.COLOR.columns=3
 screen.COLOR=colorMode dithering <empty> rgbSteps <empty> <empty> hueSteps satSteps valSteps
 
 #	screen effects
-screen.SCREEN=interlacing aberration
+screen.SCREEN=interlacing scanlines aberration
 
 #	console effects
 screen.CONSOLE.columns=1