From 1001cf9000178e2117bf5372db47054c002f0f7b Mon Sep 17 00:00:00 2001
From: Raffi Bedikian <rbedikian@leapmotion.com>
Date: Sun, 30 Aug 2015 20:48:06 -0700
Subject: [PATCH] Add shader files for FXAA

---
 libraries/render-utils/src/fxaa.slf       | 77 +++++++++++++++++++++++
 libraries/render-utils/src/fxaa.slv       | 26 ++++++++
 libraries/render-utils/src/fxaa_blend.slf | 24 +++++++
 3 files changed, 127 insertions(+)
 create mode 100644 libraries/render-utils/src/fxaa.slf
 create mode 100644 libraries/render-utils/src/fxaa.slv
 create mode 100644 libraries/render-utils/src/fxaa_blend.slf

diff --git a/libraries/render-utils/src/fxaa.slf b/libraries/render-utils/src/fxaa.slf
new file mode 100644
index 0000000000..1f10756ce6
--- /dev/null
+++ b/libraries/render-utils/src/fxaa.slf
@@ -0,0 +1,77 @@
+<@include gpu/Config.slh@>
+<$VERSION_HEADER$>
+//  Generated on <$_SCRIBE_DATE$>
+//
+//  fxaa.frag
+//  fragment shader
+//
+//  Created by Raffi Bedikian on 8/30/15
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+// FXAA shader, GLSL code adapted from:
+// http://horde3d.org/wiki/index.php5?title=Shading_Technique_-_FXAA
+// Whitepaper describing the technique:
+// http://developer.download.nvidia.com/assets/gamedev/files/sdk/11/FXAA_WhitePaper.pdf
+
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
+uniform sampler2D colorTexture;
+uniform vec2 texcoordOffset;
+
+in vec2 varTexcoord;
+out vec4 outFragColor;
+
+void main() {
+    float FXAA_SPAN_MAX = 8.0;
+    float FXAA_REDUCE_MUL = 1.0/8.0;
+    float FXAA_REDUCE_MIN = (1.0/128.0);
+
+    vec3 rgbNW = texture2D(colorTexture, varTexcoord + (vec2(-1.0, -1.0) * texcoordOffset)).xyz;
+    vec3 rgbNE = texture2D(colorTexture, varTexcoord + (vec2(+1.0, -1.0) * texcoordOffset)).xyz;
+    vec3 rgbSW = texture2D(colorTexture, varTexcoord + (vec2(-1.0, +1.0) * texcoordOffset)).xyz;
+    vec3 rgbSE = texture2D(colorTexture, varTexcoord + (vec2(+1.0, +1.0) * texcoordOffset)).xyz;
+    vec3 rgbM  = texture2D(colorTexture, varTexcoord).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;
+    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)) * texcoordOffset;
+		
+    vec3 rgbA = (1.0/2.0) * (
+                texture2D(colorTexture, varTexcoord + dir * (1.0/3.0 - 0.5)).xyz +
+                texture2D(colorTexture, varTexcoord + dir * (2.0/3.0 - 0.5)).xyz);
+    vec3 rgbB = rgbA * (1.0/2.0) + (1.0/4.0) * (
+                texture2D(colorTexture, varTexcoord + dir * (0.0/3.0 - 0.5)).xyz +
+                texture2D(colorTexture, varTexcoord + dir * (3.0/3.0 - 0.5)).xyz);
+    float lumaB = dot(rgbB, luma);
+
+    if (lumaB < lumaMin || lumaB > lumaMax) {
+        outFragColor.xyz=rgbA;
+    } else {
+        outFragColor.xyz=rgbB;
+    }
+    outFragColor.a = 1.0;
+}
diff --git a/libraries/render-utils/src/fxaa.slv b/libraries/render-utils/src/fxaa.slv
new file mode 100644
index 0000000000..35a96ceb24
--- /dev/null
+++ b/libraries/render-utils/src/fxaa.slv
@@ -0,0 +1,26 @@
+<@include gpu/Config.slh@>
+<$VERSION_HEADER$>
+//  Generated on <$_SCRIBE_DATE$>
+//
+//  fxaa.vert
+//  vertex shader
+//
+//  Created by Raffi Bedikian on 8/30/15
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+<@include gpu/Inputs.slh@>
+
+<@include gpu/Transform.slh@>
+
+<$declareStandardTransform()$>
+
+out vec2 varTexcoord;
+
+void main(void) {
+    varTexcoord = inTexCoord0.xy;
+    gl_Position = inPosition;
+}
diff --git a/libraries/render-utils/src/fxaa_blend.slf b/libraries/render-utils/src/fxaa_blend.slf
new file mode 100644
index 0000000000..d5819cc9a6
--- /dev/null
+++ b/libraries/render-utils/src/fxaa_blend.slf
@@ -0,0 +1,24 @@
+<@include gpu/Config.slh@>
+<$VERSION_HEADER$>
+//  Generated on <$_SCRIBE_DATE$>
+//
+//  fxaa_blend.frag
+//  fragment shader
+//
+//  Created by Raffi Bedikian on 8/30/15
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+<@include DeferredBufferWrite.slh@>
+
+in vec2 varTexcoord;
+out vec4 outFragColor;
+
+uniform sampler2D colorTexture;
+
+void main(void) {
+    outFragColor = texture(colorTexture, varTexcoord);
+}