From 0da9a3e3253e3673cba4d0c753273def79ff4e46 Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Wed, 8 Jul 2015 14:31:07 +1000
Subject: [PATCH] Add new FXAA filter.

---
 DefaultPlugin/DefaultPlugin.cs      |  1 +
 DefaultPlugin/DefaultPlugin.csproj  |  1 +
 DefaultPlugin/Shaders/FXAAFilter.cs | 86 +++++++++++++++++++++++++++++
 GraphicsAPI/PostProcessor.cs        |  1 +
 4 files changed, 89 insertions(+)
 create mode 100644 DefaultPlugin/Shaders/FXAAFilter.cs

diff --git a/DefaultPlugin/DefaultPlugin.cs b/DefaultPlugin/DefaultPlugin.cs
index 8b75b824f..c22afeb04 100644
--- a/DefaultPlugin/DefaultPlugin.cs
+++ b/DefaultPlugin/DefaultPlugin.cs
@@ -48,6 +48,7 @@ namespace DefaultPlugin {
 					new PluginModule( PluginModuleType.MapRenderer, typeof( StandardMapRenderer ) ),
 					
 					new PluginModule( PluginModuleType.PostProcessingShader, typeof( GrayscaleFilter ) ),
+					new PluginModule( PluginModuleType.PostProcessingShader, typeof( FXAAFilter ) ),
 					
 					new PluginModule( PluginModuleType.NetworkProcessor, typeof( ClassicNetworkProcessor ) ),
 					new PluginModule( PluginModuleType.BlockInfo, typeof( ClassicBlockInfo ) ),
diff --git a/DefaultPlugin/DefaultPlugin.csproj b/DefaultPlugin/DefaultPlugin.csproj
index f2fa5ab13..a8401073d 100644
--- a/DefaultPlugin/DefaultPlugin.csproj
+++ b/DefaultPlugin/DefaultPlugin.csproj
@@ -60,6 +60,7 @@
     <Compile Include="Network\ClassicNetwork.cs" />
     <Compile Include="Network\ClassicNetwork.Wom.cs" />
     <Compile Include="Renderers\PickingRenderer.cs" />
+    <Compile Include="Shaders\FXAAFilter.cs" />
     <Compile Include="Shaders\GrayscaleFilter.cs" />
     <Compile Include="StandardChunkMeshBuilder.cs" />
     <Compile Include="DefaultCommands.cs" />
diff --git a/DefaultPlugin/Shaders/FXAAFilter.cs b/DefaultPlugin/Shaders/FXAAFilter.cs
new file mode 100644
index 000000000..57de429dc
--- /dev/null
+++ b/DefaultPlugin/Shaders/FXAAFilter.cs
@@ -0,0 +1,86 @@
+using System;
+using ClassicalSharp.GraphicsAPI;
+using OpenTK;
+
+namespace DefaultPlugin.Shaders {
+	
+	public sealed class FXAAFilter : PostProcessingShader {
+		
+		public FXAAFilter() : base() {
+			FragmentSource = @"
+#version 130
+in vec2 out_texcoords;
+out vec4 final_colour;
+uniform sampler2D texScene;
+uniform vec2 invViewport;
+
+#define FXAA_REDUCE_MIN (1.0 / 128.0)
+#define FXAA_REDUCE_MUL (1.0 / 8.0)
+#define FXAA_SPAN_MAX 8.0
+
+void main() {
+	vec2 fragCoord = out_texcoords / invViewport;
+    vec2 inverseVP = invViewport;
+    vec3 rgbNW = texture2D(texScene, (fragCoord + vec2(-1.0, -1.0)) * inverseVP).xyz;
+    vec3 rgbNE = texture2D(texScene, (fragCoord + vec2(1.0, -1.0)) * inverseVP).xyz;
+    vec3 rgbSW = texture2D(texScene, (fragCoord + vec2(-1.0, 1.0)) * inverseVP).xyz;
+    vec3 rgbSE = texture2D(texScene, (fragCoord + vec2(1.0, 1.0)) * inverseVP).xyz;
+    vec3 rgbM  = texture2D(texScene, fragCoord  * inverseVP).xyz;
+    
+    vec3 luma = vec3(0.299, 0.587, 0.114);
+    float lumaNW = dot(rgbNW, luma);
+    float lumaNE = dot(rgbNE, luma);
+    float lumaSW = dot(rgbSW, luma);
+    float lumaSE = dot(rgbSE, luma);
+    float lumaM  = dot(rgbM,  luma);
+    float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
+    float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
+    
+    vec2 dir = vec2(
+    dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
+    dir.y =  ((lumaNW + lumaSW) - (lumaNE + lumaSE));
+    
+    float dirReduce = max((lumaNW + lumaNE + lumaSW + lumaSE) *
+                          (0.25 * FXAA_REDUCE_MUL), FXAA_REDUCE_MIN);
+    
+    float rcpDirMin = 1.0 / (min(abs(dir.x), abs(dir.y)) + dirReduce);
+    dir = min(vec2(FXAA_SPAN_MAX, FXAA_SPAN_MAX),
+          max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX),
+          dir * rcpDirMin)) * inverseVP;
+      
+    vec3 rgbA = 0.5 * (
+        texture2D(texScene, fragCoord * inverseVP + dir * (1.0 / 3.0 - 0.5)).xyz +
+        texture2D(texScene, fragCoord * inverseVP + dir * (2.0 / 3.0 - 0.5)).xyz);
+    vec3 rgbB = rgbA * 0.5 + 0.25 * (
+        texture2D(texScene, fragCoord * inverseVP + dir * -0.5).xyz +
+        texture2D(texScene, fragCoord * inverseVP + dir * 0.5).xyz);
+
+    float lumaB = dot(rgbB, luma);
+    if ((lumaB < lumaMin) || (lumaB > lumaMax))
+        final_colour = vec4(rgbA, 1.0);
+    else
+        final_colour = vec4(rgbB, 1.0);
+}
+";
+		}
+		
+		int viewportLoc;
+		protected override void GetLocations() {
+			base.GetLocations();
+			viewportLoc = GetUniformLocation( "invViewport" );
+		}
+		
+		int width = 640, height = 480;
+		protected override void EnableVertexAttribStates( int stride ) {
+			base.EnableVertexAttribStates( stride );
+			Vector2 invViewport = new Vector2( 1f / width, 1f / height );
+			Console.WriteLine( invViewport );
+			SetUniform( viewportLoc, ref invViewport );
+		}
+		
+		protected override void RenderTargetResized( int newWidth, int newHeight ) {
+			width = newWidth;
+			height = newHeight;
+		}
+	}
+}
\ No newline at end of file
diff --git a/GraphicsAPI/PostProcessor.cs b/GraphicsAPI/PostProcessor.cs
index 72ecaf6fd..671704a63 100644
--- a/GraphicsAPI/PostProcessor.cs
+++ b/GraphicsAPI/PostProcessor.cs
@@ -31,6 +31,7 @@ namespace ClassicalSharp.GraphicsAPI {
 			if( shader.ProgramId <= 0 ) {
 				shader.Init( api );
 			}
+			shader.RenderTargetResized( window.Width, window.Height );
 		}
 
 		void Resize( object sender, EventArgs e ) {