GPUImage 滤波算法详解

#import "GPUImageFilter.h"#import "GPUImagePicture.h"#import <AVFoundation/AVFoundation.h>//GPUImage 源码详解//顶点着色器//vertex.shader//顶点着色器是一个可编程的处理单元，执行顶点变换、纹理坐标变换、光照、材质等顶点的相关操作，每顶点执行一次。替代了传统渲染管线中顶点变换、光照以及纹理坐标的处理，开发人员可以根据自己的需求自行开发，大大增加了程序的灵活性。//顶点着色器主要是传入相应的Attribute变量、Uniforms变量、采样器以及临时变量，经过顶点着色器后生成Varying变量。//vec2                包含了2个浮点数的向量//vec3                包含了3个浮点数的向量//vec4                包含了4个浮点数的向量//（1）attribute变量(属性变量)只能用于顶点着色器中，不能用于片元着色器。一般用该变量来表示一些顶点数据，如：顶点坐标、纹理坐标、颜色等。//（2）uniforms变量(一致变量)用来将数据值从应用程其序传递到顶点着色器或者片元着色器。该变量有点类似C语言中的常量（const），即该变量的值不能被shader程序修改。一般用该变量表示变换矩阵、光照参数、纹理采样器等。//（3）varying变量(易变变量)是从顶点着色器传递到片元着色器的数据变量。顶点着色器可以使用易变变量来传递需要插值的颜色、法向量、纹理坐标等任意值。在顶点与片元shader程序间传递数据是很容易的，一般在顶点shader中修改varying变量值，然后片元shader中使用该值，当然，该变量在顶点及片元这两段shader程序中声明必须是一致的。例如：下面代码中应用程序中由顶点着色器传入片元着色器中的coord变量。//（4）gl_Position为内建变量，表示变换后点的空间位置。顶点着色器从应用程序中获得原始的顶点位置数据，这些原始的顶点数据在顶点着色器中经过平移、旋转、缩放等数学变换后，生成新的顶点位置。新的顶点位置通过在顶点着色器中写入gl_Position传递到渲染管线的后继阶段继续处理。//顶点着色器// Hardcode the vertex shader for standard filters, but this can be overriddenNSString *const kGPUImageVertexShaderString = SHADER_STRING( attribute vec4 position;// 应用程序传入顶点着色器的顶点位置 attribute vec4 inputTextureCoordinate;// 应用程序传入顶点着色器的顶点纹理坐标  varying vec2 textureCoordinate;// 用于传递给片元着色器的顶点纹理数据  void main() {     gl_Position = position;     textureCoordinate = inputTextureCoordinate.xy; } );#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE//片元着色器//    此片元着色器的主要功能为根据接收的记录中的 片元纹理坐标的易变变量中的纹理坐标，调用texture2D内建函数从采样器中进行纹理采样，得到此片元的颜色值。最后，将采样到的颜色值传给gl_FragColor内建变量，完成片元的着色。//    片元着色器是一个处理片元值及其相关联数据的可编程单元，片元着色器可执行纹理的访问、颜色的汇总、雾化等操作，每片元执行一次。片元着色器替代了纹理、颜色求和、雾以及Alpha测试，这一部分是需要开发者自己开发的。////    （1）varying指的是从顶点着色器传递到片元着色器的数据变量//    （2）gl_FragColor为内置变量，用来保存片元着色器计算完成的片元颜色值，此颜色值将送入渲染管线的后继阶段进行处理。//varying在片元着色器里面表示从顶点着色器传过来的输入参数;//片元着色器不能直接传如参数,只能接收顶点着色器的输出;NSString *const kGPUImagePassthroughFragmentShaderString = SHADER_STRING( varying highp vec2 textureCoordinate;// 接收从顶点着色器过来的纹理坐标  uniform sampler2D inputImageTexture;// 纹理采样器，代表一幅纹理 也可以说是纹理像素  void main() {     //片元的颜色 由“texture2D”函数计算出来，实际上就是按纹理坐标从纹理像素(一副纹理或者认为一张图片)中取样。     gl_FragColor = texture2D(inputImageTexture, textureCoordinate); });#elseNSString *const kGPUImagePassthroughFragmentShaderString = SHADER_STRING( varying vec2 textureCoordinate;  uniform sampler2D inputImageTexture;  void main() {     gl_FragColor = texture2D(inputImageTexture, textureCoordinate); });#endif@implementation GPUImageFilter@synthesize preventRendering = _preventRendering;@synthesize currentlyReceivingMonochromeInput;#pragma mark -#pragma mark Initialization and teardown- (id)initWithVertexShaderFromString:(NSString *)vertexShaderString fragmentShaderFromString:(NSString *)fragmentShaderString;{    if (!(self = [super init]))    {return nil;    }    uniformStateRestorationBlocks = [NSMutableDictionary dictionaryWithCapacity:10];    _preventRendering = NO;    currentlyReceivingMonochromeInput = NO;    inputRotation = kGPUImageNoRotation;    backgroundColorRed = 0.0;    backgroundColorGreen = 0.0;    backgroundColorBlue = 0.0;    backgroundColorAlpha = 0.0;    imageCaptureSemaphore = dispatch_semaphore_create(0);    dispatch_semaphore_signal(imageCaptureSemaphore);    runSynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext useImageProcessingContext];        filterProgram = [[GPUImageContext sharedImageProcessingContext] programForVertexShaderString:vertexShaderString fragmentShaderString:fragmentShaderString];                if (!filterProgram.initialized)        {            [self initializeAttributes];                        if (![filterProgram link])            {                NSString *progLog = [filterProgram programLog];                NSLog(@"Program link log: %@", progLog);                NSString *fragLog = [filterProgram fragmentShaderLog];                NSLog(@"Fragment shader compile log: %@", fragLog);                NSString *vertLog = [filterProgram vertexShaderLog];                NSLog(@"Vertex shader compile log: %@", vertLog);                filterProgram = nil;                NSAssert(NO, @"Filter shader link failed");            }        }                filterPositionAttribute = [filterProgram attributeIndex:@"position"];        filterTextureCoordinateAttribute = [filterProgram attributeIndex:@"inputTextureCoordinate"];        filterInputTextureUniform = [filterProgram uniformIndex:@"inputImageTexture"]; // This does assume a name of "inputImageTexture" for the fragment shader                [GPUImageContext setActiveShaderProgram:filterProgram];                glEnableVertexAttribArray(filterPositionAttribute);        glEnableVertexAttribArray(filterTextureCoordinateAttribute);        });        return self;}- (id)initWithFragmentShaderFromString:(NSString *)fragmentShaderString;{    if (!(self = [self initWithVertexShaderFromString:kGPUImageVertexShaderString fragmentShaderFromString:fragmentShaderString]))    {return nil;    }        return self;}- (id)initWithFragmentShaderFromFile:(NSString *)fragmentShaderFilename;{    NSString *fragmentShaderPathname = [[NSBundle mainBundle] pathForResource:fragmentShaderFilename ofType:@"fsh"];    NSString *fragmentShaderString = [NSString stringWithContentsOfFile:fragmentShaderPathname encoding:NSUTF8StringEncoding error:nil];    if (!(self = [self initWithFragmentShaderFromString:fragmentShaderString]))    {return nil;    }        return self;}- (id)init;{    if (!(self = [self initWithFragmentShaderFromString:kGPUImagePassthroughFragmentShaderString]))    {return nil;    }        return self;}- (void)initializeAttributes;{    [filterProgram addAttribute:@"position"];[filterProgram addAttribute:@"inputTextureCoordinate"];    // Override this, calling back to this super method, in order to add new attributes to your vertex shader}- (void)setupFilterForSize:(CGSize)filterFrameSize;{    // This is where you can override to provide some custom setup, if your filter has a size-dependent element}- (void)dealloc{#if !OS_OBJECT_USE_OBJC    if (imageCaptureSemaphore != NULL)    {        dispatch_release(imageCaptureSemaphore);    }#endif}#pragma mark -#pragma mark Still image processing- (void)useNextFrameForImageCapture;{    usingNextFrameForImageCapture = YES;    // Set the semaphore high, if it isn't already    if (dispatch_semaphore_wait(imageCaptureSemaphore, DISPATCH_TIME_NOW) != 0)    {        return;    }}- (CGImageRef)newCGImageFromCurrentlyProcessedOutput{    // Give it three seconds to process, then abort if they forgot to set up the image capture properly    double timeoutForImageCapture = 3.0;    dispatch_time_t convertedTimeout = dispatch_time(DISPATCH_TIME_NOW, timeoutForImageCapture * NSEC_PER_SEC);    if (dispatch_semaphore_wait(imageCaptureSemaphore, convertedTimeout) != 0)    {        return NULL;    }    GPUImageFramebuffer* framebuffer = [self framebufferForOutput];        usingNextFrameForImageCapture = NO;    dispatch_semaphore_signal(imageCaptureSemaphore);        CGImageRef image = [framebuffer newCGImageFromFramebufferContents];    return image;}#pragma mark -#pragma mark Managing the display FBOs- (CGSize)sizeOfFBO;{    CGSize outputSize = [self maximumOutputSize];    if ( (CGSizeEqualToSize(outputSize, CGSizeZero)) || (inputTextureSize.width < outputSize.width) )    {        return inputTextureSize;    }    else    {        return outputSize;    }}#pragma mark -#pragma mark Rendering//纹理顶点坐标 根据不同的方向设置不同的值+ (const GLfloat *)textureCoordinatesForRotation:(GPUImageRotationMode)rotationMode;{    static const GLfloat noRotationTextureCoordinates[] = {        0.0f, 0.0f,        1.0f, 0.0f,        0.0f, 1.0f,        1.0f, 1.0f,    };        static const GLfloat rotateLeftTextureCoordinates[] = {        1.0f, 0.0f,        1.0f, 1.0f,        0.0f, 0.0f,        0.0f, 1.0f,    };        static const GLfloat rotateRightTextureCoordinates[] = {        0.0f, 1.0f,        0.0f, 0.0f,        1.0f, 1.0f,        1.0f, 0.0f,    };        static const GLfloat verticalFlipTextureCoordinates[] = {        0.0f, 1.0f,        1.0f, 1.0f,        0.0f,  0.0f,        1.0f,  0.0f,    };        static const GLfloat horizontalFlipTextureCoordinates[] = {        1.0f, 0.0f,        0.0f, 0.0f,        1.0f,  1.0f,        0.0f,  1.0f,    };        static const GLfloat rotateRightVerticalFlipTextureCoordinates[] = {        0.0f, 0.0f,        0.0f, 1.0f,        1.0f, 0.0f,        1.0f, 1.0f,    };    static const GLfloat rotateRightHorizontalFlipTextureCoordinates[] = {        1.0f, 1.0f,        1.0f, 0.0f,        0.0f, 1.0f,        0.0f, 0.0f,    };    static const GLfloat rotate180TextureCoordinates[] = {        1.0f, 1.0f,        0.0f, 1.0f,        1.0f, 0.0f,        0.0f, 0.0f,    };    switch(rotationMode)    {        case kGPUImageNoRotation: return noRotationTextureCoordinates;        case kGPUImageRotateLeft: return rotateLeftTextureCoordinates;        case kGPUImageRotateRight: return rotateRightTextureCoordinates;        case kGPUImageFlipVertical: return verticalFlipTextureCoordinates;        case kGPUImageFlipHorizonal: return horizontalFlipTextureCoordinates;        case kGPUImageRotateRightFlipVertical: return rotateRightVerticalFlipTextureCoordinates;        case kGPUImageRotateRightFlipHorizontal: return rotateRightHorizontalFlipTextureCoordinates;        case kGPUImageRotate180: return rotate180TextureCoordinates;    }}- (void)renderToTextureWithVertices:(const GLfloat *)vertices textureCoordinates:(const GLfloat *)textureCoordinates;{    if (self.preventRendering)    {        [firstInputFramebuffer unlock];        return;    }        [GPUImageContext setActiveShaderProgram:filterProgram];    outputFramebuffer = [[GPUImageContext sharedFramebufferCache] fetchFramebufferForSize:[self sizeOfFBO] textureOptions:self.outputTextureOptions onlyTexture:NO];    [outputFramebuffer activateFramebuffer];    if (usingNextFrameForImageCapture)    {        [outputFramebuffer lock];    }    [self setUniformsForProgramAtIndex:0];        glClearColor(backgroundColorRed, backgroundColorGreen, backgroundColorBlue, backgroundColorAlpha);    glClear(GL_COLOR_BUFFER_BIT);glActiveTexture(GL_TEXTURE2);glBindTexture(GL_TEXTURE_2D, [firstInputFramebuffer texture]);glUniform1i(filterInputTextureUniform, 2);    glVertexAttribPointer(filterPositionAttribute, 2, GL_FLOAT, 0, 0, vertices);glVertexAttribPointer(filterTextureCoordinateAttribute, 2, GL_FLOAT, 0, 0, textureCoordinates);        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);        [firstInputFramebuffer unlock];        if (usingNextFrameForImageCapture)    {        dispatch_semaphore_signal(imageCaptureSemaphore);    }}- (void)informTargetsAboutNewFrameAtTime:(CMTime)frameTime;{    if (self.frameProcessingCompletionBlock != NULL)    {        self.frameProcessingCompletionBlock(self, frameTime);    }        // Get all targets the framebuffer so they can grab a lock on it    for (id<GPUImageInput> currentTarget in targets)    {        if (currentTarget != self.targetToIgnoreForUpdates)        {            NSInteger indexOfObject = [targets indexOfObject:currentTarget];            NSInteger textureIndex = [[targetTextureIndices objectAtIndex:indexOfObject] integerValue];            [self setInputFramebufferForTarget:currentTarget atIndex:textureIndex];            [currentTarget setInputSize:[self outputFrameSize] atIndex:textureIndex];        }    }        // Release our hold so it can return to the cache immediately upon processing    [[self framebufferForOutput] unlock];        if (usingNextFrameForImageCapture)    {//        usingNextFrameForImageCapture = NO;    }    else    {        [self removeOutputFramebuffer];    }            // Trigger processing last, so that our unlock comes first in serial execution, avoiding the need for a callback    for (id<GPUImageInput> currentTarget in targets)    {        if (currentTarget != self.targetToIgnoreForUpdates)        {            NSInteger indexOfObject = [targets indexOfObject:currentTarget];            NSInteger textureIndex = [[targetTextureIndices objectAtIndex:indexOfObject] integerValue];            [currentTarget newFrameReadyAtTime:frameTime atIndex:textureIndex];        }    }}- (CGSize)outputFrameSize;{    return inputTextureSize;}#pragma mark -#pragma mark Input parameters- (void)setBackgroundColorRed:(GLfloat)redComponent green:(GLfloat)greenComponent blue:(GLfloat)blueComponent alpha:(GLfloat)alphaComponent;{    backgroundColorRed = redComponent;    backgroundColorGreen = greenComponent;    backgroundColorBlue = blueComponent;    backgroundColorAlpha = alphaComponent;}- (void)setInteger:(GLint)newInteger forUniformName:(NSString *)uniformName;{    GLint uniformIndex = [filterProgram uniformIndex:uniformName];    [self setInteger:newInteger forUniform:uniformIndex program:filterProgram];}- (void)setFloat:(GLfloat)newFloat forUniformName:(NSString *)uniformName;{    GLint uniformIndex = [filterProgram uniformIndex:uniformName];    [self setFloat:newFloat forUniform:uniformIndex program:filterProgram];}- (void)setSize:(CGSize)newSize forUniformName:(NSString *)uniformName;{    GLint uniformIndex = [filterProgram uniformIndex:uniformName];    [self setSize:newSize forUniform:uniformIndex program:filterProgram];}- (void)setPoint:(CGPoint)newPoint forUniformName:(NSString *)uniformName;{    GLint uniformIndex = [filterProgram uniformIndex:uniformName];    [self setPoint:newPoint forUniform:uniformIndex program:filterProgram];}- (void)setFloatVec3:(GPUVector3)newVec3 forUniformName:(NSString *)uniformName;{    GLint uniformIndex = [filterProgram uniformIndex:uniformName];    [self setVec3:newVec3 forUniform:uniformIndex program:filterProgram];}- (void)setFloatVec4:(GPUVector4)newVec4 forUniform:(NSString *)uniformName;{    GLint uniformIndex = [filterProgram uniformIndex:uniformName];    [self setVec4:newVec4 forUniform:uniformIndex program:filterProgram];}- (void)setFloatArray:(GLfloat *)array length:(GLsizei)count forUniform:(NSString*)uniformName{    GLint uniformIndex = [filterProgram uniformIndex:uniformName];        [self setFloatArray:array length:count forUniform:uniformIndex program:filterProgram];}- (void)setMatrix3f:(GPUMatrix3x3)matrix forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];        [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            glUniformMatrix3fv(uniform, 1, GL_FALSE, (GLfloat *)&matrix);        }];    });}- (void)setMatrix4f:(GPUMatrix4x4)matrix forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];        [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            glUniformMatrix4fv(uniform, 1, GL_FALSE, (GLfloat *)&matrix);        }];    });}- (void)setFloat:(GLfloat)floatValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];        [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            glUniform1f(uniform, floatValue);        }];    });}- (void)setPoint:(CGPoint)pointValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];        [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            GLfloat positionArray[2];            positionArray[0] = pointValue.x;            positionArray[1] = pointValue.y;                        glUniform2fv(uniform, 1, positionArray);        }];    });}- (void)setSize:(CGSize)sizeValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];                [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            GLfloat sizeArray[2];            sizeArray[0] = sizeValue.width;            sizeArray[1] = sizeValue.height;                        glUniform2fv(uniform, 1, sizeArray);        }];    });}- (void)setVec3:(GPUVector3)vectorValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];        [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            glUniform3fv(uniform, 1, (GLfloat *)&vectorValue);        }];    });}- (void)setVec4:(GPUVector4)vectorValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];                [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            glUniform4fv(uniform, 1, (GLfloat *)&vectorValue);        }];    });}- (void)setFloatArray:(GLfloat *)arrayValue length:(GLsizei)arrayLength forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    // Make a copy of the data, so it doesn't get overwritten before async call executes    NSData* arrayData = [NSData dataWithBytes:arrayValue length:arrayLength * sizeof(arrayValue[0])];    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];                [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            glUniform1fv(uniform, arrayLength, [arrayData bytes]);        }];    });}- (void)setInteger:(GLint)intValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;{    runAsynchronouslyOnVideoProcessingQueue(^{        [GPUImageContext setActiveShaderProgram:shaderProgram];        [self setAndExecuteUniformStateCallbackAtIndex:uniform forProgram:shaderProgram toBlock:^{            glUniform1i(uniform, intValue);        }];    });}- (void)setAndExecuteUniformStateCallbackAtIndex:(GLint)uniform forProgram:(GLProgram *)shaderProgram toBlock:(dispatch_block_t)uniformStateBlock;{    [uniformStateRestorationBlocks setObject:[uniformStateBlock copy] forKey:[NSNumber numberWithInt:uniform]];    uniformStateBlock();}- (void)setUniformsForProgramAtIndex:(NSUInteger)programIndex;{    [uniformStateRestorationBlocks enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop){        dispatch_block_t currentBlock = obj;        currentBlock();    }];}#pragma mark -#pragma mark GPUImageInput- (void)newFrameReadyAtTime:(CMTime)frameTime atIndex:(NSInteger)textureIndex;{    static const GLfloat imageVertices[] = {        -1.0f, -1.0f,        1.0f, -1.0f,        -1.0f,  1.0f,        1.0f,  1.0f,    };        [self renderToTextureWithVertices:imageVertices textureCoordinates:[[self class] textureCoordinatesForRotation:inputRotation]];    [self informTargetsAboutNewFrameAtTime:frameTime];}- (NSInteger)nextAvailableTextureIndex;{    return 0;}- (void)setInputFramebuffer:(GPUImageFramebuffer *)newInputFramebuffer atIndex:(NSInteger)textureIndex;{    firstInputFramebuffer = newInputFramebuffer;    [firstInputFramebuffer lock];}- (CGSize)rotatedSize:(CGSize)sizeToRotate forIndex:(NSInteger)textureIndex;{    CGSize rotatedSize = sizeToRotate;        if (GPUImageRotationSwapsWidthAndHeight(inputRotation))    {        rotatedSize.width = sizeToRotate.height;        rotatedSize.height = sizeToRotate.width;    }        return rotatedSize; }- (CGPoint)rotatedPoint:(CGPoint)pointToRotate forRotation:(GPUImageRotationMode)rotation;{    CGPoint rotatedPoint;    switch(rotation)    {        case kGPUImageNoRotation: return pointToRotate; break;        case kGPUImageFlipHorizonal:        {            rotatedPoint.x = 1.0 - pointToRotate.x;            rotatedPoint.y = pointToRotate.y;        }; break;        case kGPUImageFlipVertical:        {            rotatedPoint.x = pointToRotate.x;            rotatedPoint.y = 1.0 - pointToRotate.y;        }; break;        case kGPUImageRotateLeft:        {            rotatedPoint.x = 1.0 - pointToRotate.y;            rotatedPoint.y = pointToRotate.x;        }; break;        case kGPUImageRotateRight:        {            rotatedPoint.x = pointToRotate.y;            rotatedPoint.y = 1.0 - pointToRotate.x;        }; break;        case kGPUImageRotateRightFlipVertical:        {            rotatedPoint.x = pointToRotate.y;            rotatedPoint.y = pointToRotate.x;        }; break;        case kGPUImageRotateRightFlipHorizontal:        {            rotatedPoint.x = 1.0 - pointToRotate.y;            rotatedPoint.y = 1.0 - pointToRotate.x;        }; break;        case kGPUImageRotate180:        {            rotatedPoint.x = 1.0 - pointToRotate.x;            rotatedPoint.y = 1.0 - pointToRotate.y;        }; break;    }        return rotatedPoint;}- (void)setInputSize:(CGSize)newSize atIndex:(NSInteger)textureIndex;{    if (self.preventRendering)    {        return;    }        if (overrideInputSize)    {        if (CGSizeEqualToSize(forcedMaximumSize, CGSizeZero))        {        }        else        {            CGRect insetRect = AVMakeRectWithAspectRatioInsideRect(newSize, CGRectMake(0.0, 0.0, forcedMaximumSize.width, forcedMaximumSize.height));            inputTextureSize = insetRect.size;        }    }    else    {        CGSize rotatedSize = [self rotatedSize:newSize forIndex:textureIndex];                if (CGSizeEqualToSize(rotatedSize, CGSizeZero))        {            inputTextureSize = rotatedSize;        }        else if (!CGSizeEqualToSize(inputTextureSize, rotatedSize))        {            inputTextureSize = rotatedSize;        }    }        [self setupFilterForSize:[self sizeOfFBO]];}- (void)setInputRotation:(GPUImageRotationMode)newInputRotation atIndex:(NSInteger)textureIndex;{    inputRotation = newInputRotation;}- (void)forceProcessingAtSize:(CGSize)frameSize;{        if (CGSizeEqualToSize(frameSize, CGSizeZero))    {        overrideInputSize = NO;    }    else    {        overrideInputSize = YES;        inputTextureSize = frameSize;        forcedMaximumSize = CGSizeZero;    }}- (void)forceProcessingAtSizeRespectingAspectRatio:(CGSize)frameSize;{    if (CGSizeEqualToSize(frameSize, CGSizeZero))    {        overrideInputSize = NO;        inputTextureSize = CGSizeZero;        forcedMaximumSize = CGSizeZero;    }    else    {        overrideInputSize = YES;        forcedMaximumSize = frameSize;    }}- (CGSize)maximumOutputSize;{    // I'm temporarily disabling adjustments for smaller output sizes until I figure out how to make this work better    return CGSizeZero;    /*    if (CGSizeEqualToSize(cachedMaximumOutputSize, CGSizeZero))    {        for (id<GPUImageInput> currentTarget in targets)        {            if ([currentTarget maximumOutputSize].width > cachedMaximumOutputSize.width)            {                cachedMaximumOutputSize = [currentTarget maximumOutputSize];            }        }    }        return cachedMaximumOutputSize;     */}- (void)endProcessing {    if (!isEndProcessing)    {        isEndProcessing = YES;                for (id<GPUImageInput> currentTarget in targets)        {            [currentTarget endProcessing];        }    }}- (BOOL)wantsMonochromeInput;{    return NO;}#pragma mark -#pragma mark Accessors@end