From 9edd7782c6f34e15df10ded18a82e7ccbab4b7a9 Mon Sep 17 00:00:00 2001
From: Valerie <sleeplessval@gmail.com>
Date: Thu, 18 Apr 2024 00:22:26 -0400
Subject: [PATCH] added chromatic aberration

---
 README.md                      |  1 +
 shaders/composite.fsh          |  3 ++-
 shaders/final.fsh              | 17 +++++++++++++----
 shaders/gbuffers_basic.vsh     |  2 +-
 shaders/lang/en_US.lang        |  1 +
 shaders/module/aberration.frag | 10 ++++++++++
 shaders/module/common.glsl     |  3 +++
 shaders/shaders.properties     |  2 +-
 8 files changed, 32 insertions(+), 7 deletions(-)
 create mode 100644 shaders/module/aberration.frag
 create mode 100644 shaders/module/common.glsl

diff --git a/README.md b/README.md
index 54578d8..ca39ecd 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,7 @@ aimed at providing a variety of effects in the vein of its parent project.
 
 ## Features
 
+- Chromatic Aberration
 - Color depth reduction
 - Depth of Field
 - Dithering
diff --git a/shaders/composite.fsh b/shaders/composite.fsh
index 55438a7..881cce2 100644
--- a/shaders/composite.fsh
+++ b/shaders/composite.fsh
@@ -1,6 +1,7 @@
 #version 120
 
-#define pixelSize 2 // the size of pixels [1 2 4 8 16]
+#include "/module/common.glsl"
+
 float renderRes = pixelSize;
 
 #define dithering // whether or not to apply dithering
diff --git a/shaders/final.fsh b/shaders/final.fsh
index ad6c7c9..1ad9801 100644
--- a/shaders/final.fsh
+++ b/shaders/final.fsh
@@ -1,6 +1,8 @@
 #version 120
 
-#define pixelSize // [1 2 4 8 16]
+#include "/module/common.glsl"
+
+//#define aberration
 //#define hBlur
 
 varying vec2 texcoord;
@@ -8,14 +10,21 @@ varying vec2 texcoord;
 uniform sampler2D gcolor;
 uniform float viewWidth;
 
+#include "/module/aberration.frag"
 #include "/module/horizontal_blur.frag"
 
 void main() {
+	vec3 color;
 	#ifdef hBlur
-		vec3 blurred = hblur();
-		gl_FragData[0] = vec4(blurred, 1);
+		color = hblur();
 	#else
-		gl_FragData[0] = texture2D(gcolor, texcoord);
+		color = texture2D(gcolor, texcoord).rgb;
 	#endif
+
+	#ifdef aberration
+		color.rb = aberrate().rb;
+	#endif
+
+	gl_FragData[0] = vec4(color, 1);
 }
 
diff --git a/shaders/gbuffers_basic.vsh b/shaders/gbuffers_basic.vsh
index 1952a0f..6942a19 100644
--- a/shaders/gbuffers_basic.vsh
+++ b/shaders/gbuffers_basic.vsh
@@ -1,6 +1,6 @@
 #version 120
 
-#define pixelSize 2 // [1 2 4 8 16]
+#include "/module/common.glsl"
 
 #define worldCurvature 0 // [0 1 2]
 
diff --git a/shaders/lang/en_US.lang b/shaders/lang/en_US.lang
index 63e555e..52eef69 100644
--- a/shaders/lang/en_US.lang
+++ b/shaders/lang/en_US.lang
@@ -24,6 +24,7 @@ option.satSteps=Saturation Depth
 option.valSteps=Value Depth
 
 screen.SCREEN=Screen
+option.aberration=Chromatic Aberration
 
 screen.CONSOLE=Consoles
 
diff --git a/shaders/module/aberration.frag b/shaders/module/aberration.frag
new file mode 100644
index 0000000..fcb5eb4
--- /dev/null
+++ b/shaders/module/aberration.frag
@@ -0,0 +1,10 @@
+
+vec2 caOffset = vec2(pixelSize / viewWidth, 0);
+
+vec3 aberrate() {
+	float red	= texture2D(gcolor, texcoord - caOffset).r;
+	float blue	= texture2D(gcolor, texcoord + caOffset).b;
+
+	return vec3(red, 0, blue);
+}
+
diff --git a/shaders/module/common.glsl b/shaders/module/common.glsl
new file mode 100644
index 0000000..4326128
--- /dev/null
+++ b/shaders/module/common.glsl
@@ -0,0 +1,3 @@
+
+#define pixelSize 2 // [1 2 4 8 16]
+
diff --git a/shaders/shaders.properties b/shaders/shaders.properties
index 806d7b5..cf3fb46 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=<empty>
+screen.SCREEN=aberration
 
 #	console effects
 screen.CONSOLE.columns=1