#import "GPUImageGrayscaleFilter.h"
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@implementation GPUImageGrayscaleFilter
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#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
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NSString *const kGPUImageLuminanceFragmentShaderString = SHADER_STRING
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(
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precision highp float;
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varying vec2 textureCoordinate;
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uniform sampler2D inputImageTexture;
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const highp vec3 W = vec3(0.2125, 0.7154, 0.0721);
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void main()
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{
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lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
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float luminance = dot(textureColor.rgb, W);
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gl_FragColor = vec4(vec3(luminance), textureColor.a);
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}
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);
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#else
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NSString *const kGPUImageLuminanceFragmentShaderString = SHADER_STRING
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(
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varying vec2 textureCoordinate;
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uniform sampler2D inputImageTexture;
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const vec3 W = vec3(0.2125, 0.7154, 0.0721);
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void main()
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{
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vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
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float luminance = dot(textureColor.rgb, W);
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gl_FragColor = vec4(vec3(luminance), textureColor.a);
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}
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);
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#endif
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- (void)renderToTextureWithVertices:(const GLfloat *)vertices textureCoordinates:(const GLfloat *)textureCoordinates;
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{
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if (!currentlyReceivingMonochromeInput)
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{
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[super renderToTextureWithVertices:vertices textureCoordinates:textureCoordinates];
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}
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}
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//- (void)setInputTexture:(GLuint)newInputTexture atIndex:(NSInteger)textureIndex;
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//{
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// [super setInputTexture:newInputTexture atIndex:textureIndex];
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// if (currentlyReceivingMonochromeInput)
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// {
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// [self notifyTargetsAboutNewOutputTexture];
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// }
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//}
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//- (GLuint)textureForOutput;
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//{
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// if (currentlyReceivingMonochromeInput)
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// {
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// return filterSourceTexture;
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// }
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// else
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// {
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// return outputTexture;
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// }
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//}
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- (BOOL)wantsMonochromeInput;
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{
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// return YES;
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return NO;
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}
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- (BOOL)providesMonochromeOutput;
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{
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// return YES;
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return NO;
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}
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// TODO: Rewrite this based on the new GPUImageFilter implementation
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//- (void)informTargetsAboutNewFrameAtTime:(CMTime)frameTime;
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//{
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// if (self.frameProcessingCompletionBlock != NULL)
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// {
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// self.frameProcessingCompletionBlock(self, frameTime);
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// }
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//
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// for (id<GPUImageInput> currentTarget in targets)
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// {
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// if (currentTarget != self.targetToIgnoreForUpdates)
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// {
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// NSInteger indexOfObject = [targets indexOfObject:currentTarget];
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// NSInteger textureIndex = [[targetTextureIndices objectAtIndex:indexOfObject] integerValue];
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//
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// if ([GPUImageContext supportsFastTextureUpload] && preparedToCaptureImage)
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// {
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// [self setInputTextureForTarget:currentTarget atIndex:textureIndex];
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// }
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//
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// if (currentlyReceivingMonochromeInput)
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// {
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// [currentTarget setInputRotation:inputRotation atIndex:textureIndex];
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//
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// CGSize sizeToRotate = [self outputFrameSize];
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// CGSize rotatedSize = sizeToRotate;
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// if (GPUImageRotationSwapsWidthAndHeight(inputRotation))
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// {
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// rotatedSize.width = sizeToRotate.height;
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// rotatedSize.height = sizeToRotate.width;
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// }
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// [currentTarget setInputSize:rotatedSize atIndex:textureIndex];
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// }
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// else
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// {
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// [currentTarget setInputSize:[self outputFrameSize] atIndex:textureIndex];
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// }
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// [currentTarget newFrameReadyAtTime:frameTime atIndex:textureIndex];
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// }
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// }
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//}
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#pragma mark -
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#pragma mark Initialization and teardown
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- (id)init;
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{
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if (!(self = [super initWithFragmentShaderFromString:kGPUImageLuminanceFragmentShaderString]))
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{
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return nil;
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}
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return self;
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}
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@end
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