GPUImageFilter.h

#import "GPUImageOutput.h"

#define STRINGIZE(x) #x
#define STRINGIZE2(x) STRINGIZE(x)
#define SHADER_STRING(text) @ STRINGIZE2(text)

extern NSString *const kGPUImageVertexShaderString;
extern NSString *const kGPUImagePassthroughFragmentShaderString;

struct GPUVector4 {
    GLfloat one;
    GLfloat two;
    GLfloat three;
    GLfloat four;
};
typedef struct GPUVector4 GPUVector4;

struct GPUVector3 {
    GLfloat one;
    GLfloat two;
    GLfloat three;
};
typedef struct GPUVector3 GPUVector3;

struct GPUMatrix4x4 {
    GPUVector4 one;
    GPUVector4 two;
    GPUVector4 three;
    GPUVector4 four;
};
typedef struct GPUMatrix4x4 GPUMatrix4x4;

struct GPUMatrix3x3 {
    GPUVector3 one;
    GPUVector3 two;
    GPUVector3 three;
};
typedef struct GPUMatrix3x3 GPUMatrix3x3;

/** GPUImage's base filter class
 
 Filters and other subsequent elements in the chain conform to the GPUImageInput protocol, which lets them take in the supplied or processed texture from the previous link in the chain and do something with it. Objects one step further down the chain are considered targets, and processing can be branched by adding multiple targets to a single output or filter.
 */
@interface GPUImageFilter : GPUImageOutput <GPUImageInput>
{
    GLuint filterSourceTexture;

    GLuint filterFramebuffer;

    GLProgram *filterProgram;
    GLint filterPositionAttribute, filterTextureCoordinateAttribute;
    GLint filterInputTextureUniform;
    GLfloat backgroundColorRed, backgroundColorGreen, backgroundColorBlue, backgroundColorAlpha;
    
    BOOL preparedToCaptureImage;
    
    CVOpenGLESTextureCacheRef filterTextureCache;
    CVPixelBufferRef renderTarget;
    CVOpenGLESTextureRef renderTexture;
    
    CGSize currentFilterSize;
    GPUImageRotationMode inputRotation;
}

@property(readonly) CVPixelBufferRef renderTarget;
@property(readwrite, nonatomic) BOOL preventRendering;

/// @name Initialization and teardown

/**
 Initialize with vertex and fragment shaders
 
 You make take advantage of the SHADER_STRING macro to write your shaders in-line.
 @param vertexShaderString Source code of the vertex shader to use
 @param fragmentShaderString Source code of the fragment shader to use
 */
- (id)initWithVertexShaderFromString:(NSString *)vertexShaderString fragmentShaderFromString:(NSString *)fragmentShaderString;

/**
 Initialize with a fragment shader
 
 You may take advantage of the SHADER_STRING macro to write your shader in-line.
 @param fragmentShaderString Source code of fragment shader to use
 */
- (id)initWithFragmentShaderFromString:(NSString *)fragmentShaderString;
/**
 Initialize with a fragment shader
 @param fragmentShaderFilename Filename of fragment shader to load
 */
- (id)initWithFragmentShaderFromFile:(NSString *)fragmentShaderFilename;
- (void)initializeAttributes;
- (void)setupFilterForSize:(CGSize)filterFrameSize;
- (CGSize)rotatedSize:(CGSize)sizeToRotate forIndex:(NSInteger)textureIndex;
- (CGPoint)rotatedPoint:(CGPoint)pointToRotate forRotation:(GPUImageRotationMode)rotation;

- (void)recreateFilterFBO;

/// @name Managing the display FBOs
/** Size of the frame buffer object
 */
- (CGSize)sizeOfFBO;
- (void)createFilterFBOofSize:(CGSize)currentFBOSize;

/** Destroy the current filter frame buffer object
 */
- (void)destroyFilterFBO;
- (void)setFilterFBO;
- (void)setOutputFBO;

/// @name Rendering
+ (const GLfloat *)textureCoordinatesForRotation:(GPUImageRotationMode)rotationMode;
- (void)renderToTextureWithVertices:(const GLfloat *)vertices textureCoordinates:(const GLfloat *)textureCoordinates sourceTexture:(GLuint)sourceTexture;
- (void)informTargetsAboutNewFrameAtTime:(CMTime)frameTime;
- (CGSize)outputFrameSize;

/// @name Input parameters
- (void)setBackgroundColorRed:(GLfloat)redComponent green:(GLfloat)greenComponent blue:(GLfloat)blueComponent alpha:(GLfloat)alphaComponent;
- (void)setInteger:(GLint)newInteger forUniformName:(NSString *)uniformName;
- (void)setFloat:(GLfloat)newFloat forUniformName:(NSString *)uniformName;
- (void)setSize:(CGSize)newSize forUniformName:(NSString *)uniformName;
- (void)setPoint:(CGPoint)newPoint forUniformName:(NSString *)uniformName;
- (void)setFloatVec3:(GLfloat *)newVec3 forUniformName:(NSString *)uniformName;
- (void)setFloatVec4:(GLfloat *)newVec4 forUniform:(NSString *)uniformName;
- (void)setFloatArray:(GLfloat *)array length:(GLsizei)count forUniform:(NSString*)uniformName;

- (void)setMatrix3f:(GLfloat *)matrix forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;
- (void)setMatrix4f:(GLfloat *)matrix forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;
- (void)setFloat:(GLfloat)floatValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;
- (void)setPoint:(CGPoint)pointValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;
- (void)setSize:(CGSize)sizeValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;
- (void)setVec3:(GLfloat *)vectorValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;
- (void)setVec4:(GLfloat *)vectorValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;
- (void)setFloatArray:(GLfloat *)arrayValue length:(GLsizei)arrayLength forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;
- (void)setInteger:(GLint)intValue forUniform:(GLint)uniform program:(GLProgram *)shaderProgram;

@end