From 671046a6d5e75b3af9a68d72ff52ab9dc83def14 Mon Sep 17 00:00:00 2001
From: Cameron Taylor <cameron.taylor.ninja@gmail.com>
Date: Sat, 20 Mar 2021 14:55:29 -0400
Subject: [PATCH] SHADERRRR

---
 source/TitleState.hx             | 13 +++++---
 source/shaderslmfao/ColorSwap.hx | 52 ++++++++++++++------------------
 2 files changed, 32 insertions(+), 33 deletions(-)

diff --git a/source/TitleState.hx b/source/TitleState.hx
index fef57d275..23b5eac82 100644
--- a/source/TitleState.hx
+++ b/source/TitleState.hx
@@ -1,9 +1,5 @@
 package;
 
-#if desktop
-import Discord.DiscordClient;
-import sys.thread.Thread;
-#end
 import flixel.FlxG;
 import flixel.FlxSprite;
 import flixel.addons.transition.FlxTransitionSprite.GraphicTransTileDiamond;
@@ -21,9 +17,15 @@ import flixel.util.FlxTimer;
 import io.newgrounds.NG;
 import lime.app.Application;
 import openfl.Assets;
+import shaderslmfao.ColorSwap;
 
 using StringTools;
 
+#if desktop
+import Discord.DiscordClient;
+import sys.thread.Thread;
+#end
+
 class TitleState extends MusicBeatState
 {
 	static var initialized:Bool = false;
@@ -158,6 +160,9 @@ class TitleState extends MusicBeatState
 		gfDance.animation.addByIndices('danceRight', 'gfDance', [15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29], "", 24, false);
 		gfDance.antialiasing = true;
 		add(gfDance);
+
+		gfDance.shader = new ColorSwap().shader;
+
 		add(logoBl);
 
 		titleText = new FlxSprite(100, FlxG.height * 0.8);
diff --git a/source/shaderslmfao/ColorSwap.hx b/source/shaderslmfao/ColorSwap.hx
index 4d2eac78e..cb2e2bcde 100644
--- a/source/shaderslmfao/ColorSwap.hx
+++ b/source/shaderslmfao/ColorSwap.hx
@@ -12,18 +12,12 @@ class ColorSwap
 	public function new():Void
 	{
 		shader = new ColorSwapShader();
-		shader.colorOld.value = [];
-		shader.colorNew.value = [];
 	}
 
 	function set_colorToReplace(color:FlxColor):FlxColor
 	{
 		colorToReplace = color;
 
-		shader.colorOld.value[0] = color.red;
-		shader.colorOld.value[1] = color.green;
-		shader.colorOld.value[2] = color.blue;
-
 		return color;
 	}
 
@@ -31,10 +25,6 @@ class ColorSwap
 	{
 		newColor = color;
 
-		shader.colorNew.value[0] = color.red;
-		shader.colorNew.value[1] = color.green;
-		shader.colorNew.value[2] = color.blue;
-
 		return color;
 	}
 }
@@ -44,10 +34,6 @@ class ColorSwapShader extends FlxShader
 	@:glFragmentSource('
         #pragma header
 
-        uniform vec3 colorOld;
-        uniform vec3 colorNew;
-        uniform float u_time;
-
         vec3 normalizeColor(vec3 color)
         {
             return vec3(
@@ -57,29 +43,37 @@ class ColorSwapShader extends FlxShader
             );
         }
 
-        vec3 hueShift(vec3 color, float hue) {
-            const vec3 k = vec3(0.57735, 0.57735, 0.57735);
-            float cosAngle = cos(hue);
-            return vec3(color * cosAngle + cross(k, color) * sin(hue) + k * dot(k, color) * (1.0 - cosAngle));
+        vec3 rgb2hsv(vec3 c)
+        {
+            vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+            vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
+            vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
+
+            float d = q.x - min(q.w, q.y);
+            float e = 1.0e-10;
+            return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
         }
 
+        vec3 hsv2rgb(vec3 c)
+        {
+            vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+            vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+            return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+        }
 
         void main()
         {
-            vec4 pixel = texture2D(bitmap, openfl_TextureCoordv);
+            vec4 color = flixel_texture2D(bitmap, openfl_TextureCoordv);
 
-            vec3 eps = vec3(0.02, 0.02, 0.02);
+            vec4 swagColor = vec4(rgb2hsv(vec3(color[0], color[1], color[2])), color[3]);
+            
+            // [0] is the hue???
+            swagColor[0] += 2;
+            // swagColor[1] += 0.5;
 
-            vec3 colorOldNormalized = normalizeColor(colorOld);
-            vec3 colorNewNormalized = normalizeColor(colorNew);
+            color = vec4(hsv2rgb(vec3(swagColor[0], swagColor[1], swagColor[2])), swagColor[3]);
 
-            if (all(greaterThanEqual(pixel, vec4(colorOldNormalized - eps, 1.0)) ) && all(lessThanEqual(pixel, vec4(colorOldNormalized + eps, 1.0)) )
-            )
-            {
-                pixel = vec4(hueShift(colorOldNormalized, 0.7), 1.0);
-            }
-
-            gl_FragColor = pixel;
+            gl_FragColor = color;
         }
 
     ')