CCEffectHue - Remove non-color matrix version of the hue transform

Author: Thayer J Andrews

cocos2d/CCEffectHue.m

@@ -4,63 +4,20 @@
 //
 //  Created by Thayer J Andrews on 7/9/14.
 //
-//
-//  This effect makes use of algorithms and GLSL shaders from GPUImage whose
-//  license is included here.
-//
-//  <Begin GPUImage license>
-//
-//  Copyright (c) 2012, Brad Larson, Ben Cochran, Hugues Lismonde, Keitaroh
-//  Kobayashi, Alaric Cole, Matthew Clark, Jacob Gundersen, Chris Williams.
-//  All rights reserved.
-//
-//  Redistribution and use in source and binary forms, with or without
-//  modification, are permitted provided that the following conditions are met:
-//
-//  Redistributions of source code must retain the above copyright notice, this
-//  list of conditions and the following disclaimer.
-//  Redistributions in binary form must reproduce the above copyright notice,
-//  this list of conditions and the following disclaimer in the documentation
-//  and/or other materials provided with the distribution.
-//  Neither the name of the GPUImage framework nor the names of its contributors
-//  may be used to endorse or promote products derived from this software
-//  without specific prior written permission.
-//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-//  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-//  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-//  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
-//  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-//  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-//  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-//  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-//  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-//  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-//  POSSIBILITY OF SUCH DAMAGE.
-//
-//  <End GPUImage license>
 
 
 #import "CCEffectHue.h"
 #import "CCEffect_Private.h"
 #import "CCRenderer.h"
 #import "CCTexture.h"
 
-#define CCEFFECTHUE_USES_COLOR_MATRIX 1
-
-
 static float conditionHue(float hue);
 
-#if CCEFFECTHUE_USES_COLOR_MATRIX
 static GLKMatrix4 matrixWithHue(float hue);
-#endif
 
 
 @interface CCEffectHue ()
-#if CCEFFECTHUE_USES_COLOR_MATRIX
 @property (nonatomic, strong) NSValue *hueRotationMtx;
-#else
-@property (nonatomic, strong) NSNumber *conditionedHue;
-#endif
 @end
 
 
@@ -74,21 +31,13 @@ -(id)init
 -(id)initWithHue:(float)hue
 {
     NSArray *uniforms = @[
-#if CCEFFECTHUE_USES_COLOR_MATRIX
                           [CCEffectUniform uniform:@"mat4" name:@"u_hueRotationMtx" value:[NSValue valueWithGLKMatrix4:GLKMatrix4Identity]]
-#else
-                          [CCEffectUniform uniform:@"float" name:@"u_hue" value:[NSNumber numberWithFloat:hue]]
-#endif
                           ];
 
     if((self = [super initWithFragmentUniforms:uniforms vertexUniforms:nil varyings:nil]))
     {
         _hue = hue;
-#if CCEFFECTHUE_USES_COLOR_MATRIX
         _hueRotationMtx = [NSValue valueWithGLKMatrix4:matrixWithHue(conditionHue(hue))];
-#else
-        _conditionedHue = [NSNumber numberWithFloat:conditionHue(hue)];
-#endif
         self.debugName = @"CCEffectHue";
     }
     return self;
@@ -106,47 +55,9 @@ -(void)buildFragmentFunctions
     CCEffectFunctionInput *input = [[CCEffectFunctionInput alloc] initWithType:@"vec4" name:@"inputValue" initialSnippet:@"cc_FragColor * texture2D(cc_PreviousPassTexture, cc_FragTexCoord1)" snippet:@"texture2D(cc_PreviousPassTexture, cc_FragTexCoord1)"];
 
     // The non-color matrix shader is based on the hue filter in GPUImage - https://github.com/BradLarson/GPUImage
-#if CCEFFECTHUE_USES_COLOR_MATRIX
     NSString* effectBody = CC_GLSL(
                                    return u_hueRotationMtx * inputValue;
                                    );
-#else
-    NSString* effectBody = CC_GLSL(
-                                   const highp vec4  kRGBToYPrime = vec4 (0.299, 0.587, 0.114, 0.0);
-                                   const highp vec4  kRGBToI      = vec4 (0.595716, -0.274453, -0.321263, 0.0);
-                                   const highp vec4  kRGBToQ      = vec4 (0.211456, -0.522591, 0.31135, 0.0);
-                                   
-                                   const highp vec4  kYIQToR      = vec4 (1.0, 0.9563, 0.6210, 0.0);
-                                   const highp vec4  kYIQToG      = vec4 (1.0, -0.2721, -0.6474, 0.0);
-                                   const highp vec4  kYIQToB      = vec4 (1.0, -1.1070, 1.7046, 0.0);
-                                   
-                                   // Convert to YIQ
-                                   highp float YPrime = dot (inputValue, kRGBToYPrime);
-                                   highp float I      = dot (inputValue, kRGBToI);
-                                   highp float Q      = dot (inputValue, kRGBToQ);
-                                   
-                                   // Calculate the hue and chroma
-                                   highp float hue    = atan (Q, I);
-                                   highp float chroma = sqrt (I * I + Q * Q);
-                                   
-                                   // Make the user's adjustments.
-                                   hue += -u_hue; // Why is this negative?
-                                   
-                                   // Convert back to YIQ
-                                   Q = chroma * sin (hue);
-                                   I = chroma * cos (hue);
-                                   
-                                   // Convert back to RGB
-                                   vec4 outputColor;
-                                   highp vec4    yIQ   = vec4 (YPrime, I, Q, 0.0);
-                                   outputColor.r = dot (yIQ, kYIQToR);
-                                   outputColor.g = dot (yIQ, kYIQToG);
-                                   outputColor.b = dot (yIQ, kYIQToB);
-                                   outputColor.a = inputValue.a;
-                                   
-                                   return outputColor;
-                                   );
-#endif
 
     CCEffectFunction* fragmentFunction = [[CCEffectFunction alloc] initWithName:@"hueEffect" body:effectBody inputs:@[input] returnType:@"vec4"];
     [self.fragmentFunctions addObject:fragmentFunction];
@@ -163,11 +74,7 @@ -(void)buildRenderPasses
 
         pass.shaderUniforms[CCShaderUniformMainTexture] = previousPassTexture;
         pass.shaderUniforms[CCShaderUniformPreviousPassTexture] = previousPassTexture;
-#if CCEFFECTHUE_USES_COLOR_MATRIX
         pass.shaderUniforms[weakSelf.uniformTranslationTable[@"u_hueRotationMtx"]] = weakSelf.hueRotationMtx;
-#else
-        pass.shaderUniforms[weakSelf.uniformTranslationTable[@"u_hue"]] = weakSelf.conditionedHue;
-#endif
     } copy]];
 
     self.renderPasses = @[pass0];
@@ -176,11 +83,7 @@ -(void)buildRenderPasses
 -(void)setHue:(float)hue
 {
     _hue = hue;
-#if CCEFFECTHUE_USES_COLOR_MATRIX
     _hueRotationMtx = [NSValue valueWithGLKMatrix4:matrixWithHue(conditionHue(hue))];
-#else
-    _conditionedHue = [NSNumber numberWithFloat:conditionHue(hue)];
-#endif
 }
 
 @end
@@ -191,12 +94,9 @@ float conditionHue(float hue)
     return clampf(hue, -180.0f, 180.0f) * M_PI / 180.0f;
 }
 
-#if CCEFFECTHUE_USES_COLOR_MATRIX
 GLKMatrix4 matrixWithHue(float hue)
 {
     // RGB to YIQ and YIQ to RGB matrix values source from here:
-    //   https://github.com/BradLarson/GPUImage/blob/master/framework/Source/GPUImageHueFilter.m
-    // And here:
     //   http://en.wikipedia.org/wiki/YIQ
     //
     // Note that GL matrices are column major so we have to transpose them when loading them in
@@ -224,5 +124,4 @@ GLKMatrix4 matrixWithHue(float hue)
     GLKMatrix4 composed = GLKMatrix4Multiply(yiqToRgb, GLKMatrix4Multiply(rotation, rgbToYiq));
     return composed;
 }
-#endif