/*

     File: ChromaKey.m

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#if TARGET_OS_IPHONE

#import <CoreImage/CoreImage.h>

#else

#import <QuartzCore/QuartzCore.h>

#endif

@interface ChromaKey : CIFilter

{

    CIImage *inputImage;

    CIImage *inputBackgroundImage;

    NSNumber *inputCubeDimension;

    NSNumber *inputCenterAngle;

    NSNumber *inputAngleWidth;

}

@property (retain, nonatomic) CIImage *inputImage;

@property (retain, nonatomic) CIImage *inputBackgroundImage;

@property (copy, nonatomic) NSNumber *inputCubeDimension;

@property (copy, nonatomic) NSNumber *inputCenterAngle;

@property (copy, nonatomic) NSNumber *inputAngleWidth;

@end

@interface ColorAccent : CIFilter

{

    CIImage *inputImage;

    NSNumber *inputCubeDimension;

    NSNumber *inputCenterAngle;

    NSNumber *inputAngleWidth;

}

@property (retain, nonatomic) CIImage *inputImage;

@property (copy, nonatomic) NSNumber *inputCubeDimension;

@property (copy, nonatomic) NSNumber *inputCenterAngle;

@property (copy, nonatomic) NSNumber *inputAngleWidth;

@end

static const unsigned int minCubeSize = 2;

static const unsigned int maxCubeSize = 64;

static const unsigned int defaultCubeSize = 32;

typedef enum cubeOperation {

    cubeMakeTransparent = 0,

    cubeMakeGrayscale // this is "color accent" mode

} cubeOperation;

static void rgbToHSV(const float *rgb,float *hsv)

{

    float minV = MIN(rgb[0], MIN(rgb[1], rgb[2]));

    float maxV = MAX(rgb[0], MAX(rgb[1], rgb[2]));

    float chroma = maxV - minV;

    hsv[0] = hsv[1] = 0.0;

    hsv[2] = maxV;

    if ( maxV != 0.0 )

        hsv[1] = chroma / maxV;

    if ( hsv[1] != 0.0 )

    {

        if ( rgb[0] == maxV )

            hsv[0] = (rgb[1] - rgb[2])/chroma;

        else if ( rgb[1] == maxV )

            hsv[0] = 2.0 + (rgb[2] - rgb[0])/chroma;

        else

            hsv[0] = 4.0 + (rgb[0] - rgb[1])/chroma;

        hsv[0] /= 6.0;

        if ( hsv[0] < 0.0 )

            hsv[0] += 1.0;

    }

}

static

BOOL buildCubeData(NSMutableData *cubeData, unsigned int cubeSize, float centerAngle,float angleWidth,enum cubeOperation op)

{

    // input angles are in radians but let's make this function work with degrees instead

    centerAngle *= 180.0 / M_PI;

    angleWidth *= 180.0 / M_PI;

    uint8_t *c = (uint8_t *)[cubeData mutableBytes];

    float *cFloat = (float *)c;

    BOOL useFloat = FALSE;

    size_t baseMultiplier = cubeSize * cubeSize * cubeSize * 4;

    if ( [cubeData length] == (baseMultiplier * sizeof(uint8_t)) )

        useFloat = FALSE;

    else if ( [cubeData length] == (baseMultiplier * sizeof(float)) )

        useFloat = TRUE;

    else

        return FALSE;

    for(int z = 0; z < cubeSize; z++) {

        float blueValue = ((double)z)/(cubeSize-1);

        for(int y = 0; y < cubeSize; y++) {

            float greenValue = ((double)y)/(cubeSize-1);

            for(int x = 0; x < cubeSize; x++) {

                float redValue = ((double)x)/(cubeSize-1);

                float hsv[3] = { 0.0, 0.0, 0.0 };

                float rgb[3] = { redValue, greenValue, blueValue };

                rgbToHSV(rgb, hsv);

                // should have decent HSV values now. (H goes from [0 .. 1])

                // we should have the test for what colors we render as transparent

                // based on some set of hue angles; this not a chroma threshold.

                double hueValue = hsv[0] * 360.0;

                float alphaValue = 1.0;

                float delta = fmodf(hueValue - centerAngle, 360.0);

                delta = delta < 0.0 ? delta + 360.0 : delta;

                BOOL shouldProcessPixels = delta < (angleWidth / 2.0);

                switch ( op ) {

                    case cubeMakeTransparent:

                        if ( shouldProcessPixels )

                            alphaValue = 0.0;

                        break;

                    case cubeMakeGrayscale:

                        if ( ! shouldProcessPixels ) // convert from RGB to luminance value

                            rgb[0] = rgb[1] = rgb[2] = 0.299f * rgb[0] + 0.587f * rgb[1] + 0.114f * rgb[2];

                        break;

                    default:

                        // no-op

                        break;

                }

                // RGBA channel order.

                if ( useFloat ) {

                    *cFloat++ = rgb[0] * alphaValue;

                    *cFloat++ = rgb[1] * alphaValue;

                    *cFloat++ = rgb[2] * alphaValue;

                    *cFloat++ = alphaValue;

                } else {

                    *c++ = (uint8_t) (255.0 * rgb[0] * 1); //alphaValue);

                    *c++ = (uint8_t) (255.0 * rgb[1] * 1); // alphaValue);

                    *c++ = (uint8_t) (255.0 * rgb[2] * 1); //alphaValue);

                    *c++ = (uint8_t) (255.0 * alphaValue);

                }

            }

        }

    }

    return TRUE;

}

static

NSDictionary *customAttrs(cubeOperation op)

{

    CGFloat centerAngle = 0.0;

    CGFloat angleWidth = 0.0;

    NSString *displayName = @"";

    switch ( op ) {

        case cubeMakeTransparent:

            centerAngle = 120.0;

            angleWidth = 100.0;

            displayName = @"Chroma Key";

            break;

        case cubeMakeGrayscale:

            centerAngle = 0.0;

            angleWidth = 60.0;

            displayName = @"Color Accent";

            break;

        default:

            break;

    }

    return @{

             kCIAttributeFilterDisplayName : displayName,

             kCIAttributeFilterCategories :

                 @[kCICategoryColorEffect, kCICategoryVideo, kCICategoryInterlaced, kCICategoryNonSquarePixels, kCICategoryStillImage],

             @"inputCubeDimension" :

                 @{

                     kCIAttributeMin       : @2.0,

                     kCIAttributeSliderMin : @2.0,

                     kCIAttributeSliderMax : @64.0,

                     kCIAttributeMax       : @64.0,

                     kCIAttributeDefault   : @(defaultCubeSize),

                     kCIAttributeType      : kCIAttributeTypeDistance

                     },

             @"inputCenterAngle" :

                 @{

                     kCIAttributeSliderMin : @(-M_PI),

                     kCIAttributeSliderMax : @(M_PI),

                     kCIAttributeDefault   : @(centerAngle * M_PI / 180.0),

                     kCIAttributeType      : kCIAttributeTypeAngle

                     },

             @"inputAngleWidth" :

                 @{

                     kCIAttributeMin       : @0.0,

                     kCIAttributeSliderMin : @0.0,

                     kCIAttributeSliderMax : @(2.0*M_PI),

                     kCIAttributeMax       : @(2.0*M_PI),

                     kCIAttributeDefault   : @(angleWidth * M_PI / 180.0),

                     kCIAttributeType      : kCIAttributeTypeAngle

                     },

            };

}

@implementation ChromaKey

@synthesize inputImage, inputBackgroundImage;

@synthesize inputCubeDimension, inputCenterAngle, inputAngleWidth;

+ (NSDictionary *)customAttributes

{

    return customAttrs(cubeMakeTransparent);

}

- (void)setDefaults

{

    const double centerAngle = 120.0;

    const double angleWidth = 100.0;

    self.inputCubeDimension = @(defaultCubeSize);

    self.inputCenterAngle = @(centerAngle * M_PI / 180.0);

    self.inputAngleWidth = @(angleWidth * M_PI / 180.0);

}

- (CIImage *)outputImage

{

    if ( inputCubeDimension.intValue <= 0 || nil == inputBackgroundImage || [inputAngleWidth floatValue] == 0.0 )

        return inputImage;

    CIFilter *colorCube = [CIFilter filterWithName:@"CIColorCube"];

    const unsigned int cubeSize = MAX(MIN(inputCubeDimension.intValue, maxCubeSize), minCubeSize);

    size_t baseMultiplier = cubeSize * cubeSize * cubeSize * 4;

    // you can use either uint8 data or float data by just setting this variable

    BOOL useFloat = FALSE;    

    NSMutableData *cubeData = [NSMutableData dataWithLength:baseMultiplier * (useFloat ? sizeof(float) : sizeof(uint8_t))];

    if ( ! cubeData )

        return inputImage;

    if ( ! buildCubeData(cubeData, cubeSize, [inputCenterAngle floatValue], [inputAngleWidth floatValue], cubeMakeTransparent) )

        return inputImage;

    // don't just use inputCubeSize directly because it is a float and we want to use an int.

    [colorCube setValue:[NSNumber numberWithInt:cubeSize] forKey:@"inputCubeDimension"];

    [colorCube setValue:cubeData forKey:@"inputCubeData"];

    [colorCube setValue:inputImage forKey:kCIInputImageKey];

    CIImage *coloredKeyedImage = [colorCube valueForKey:kCIOutputImageKey];

    [colorCube setValue:nil forKey:@"inputCubeData"];

    [colorCube setValue:nil forKey:kCIInputImageKey];

    CIFilter *sourceOver = [CIFilter filterWithName:@"CISourceOverCompositing"];

    [sourceOver setValue:coloredKeyedImage forKey:kCIInputImageKey];

    [sourceOver setValue:inputBackgroundImage forKey:kCIInputBackgroundImageKey];

    CIImage *outputImage = [sourceOver valueForKey:kCIOutputImageKey];

    [sourceOver setValue:nil forKey:kCIInputImageKey];

    [sourceOver setValue:nil forKey:kCIInputBackgroundImageKey];

    return outputImage;

}

@end

@implementation ColorAccent

@synthesize inputImage;

@synthesize inputCubeDimension, inputCenterAngle, inputAngleWidth;

+ (NSDictionary *)customAttributes

{

    return customAttrs(cubeMakeGrayscale);

}

- (void)setDefaults

{

    const double centerAngle = 0.0;

    const double angleWidth = 60.0;

    self.inputCubeDimension = @(defaultCubeSize);

    self.inputCenterAngle = @(centerAngle * M_PI / 180.0);

    self.inputAngleWidth = @(angleWidth * M_PI / 180.0);

}

- (CIImage *)outputImage

{

    if ( inputCubeDimension.intValue <= 0 || [inputAngleWidth floatValue] == 0.0)

        return inputImage;

    CIFilter *colorCube = [CIFilter filterWithName:@"CIColorCube"];

    const unsigned int cubeSize = MAX(MIN(inputCubeDimension.intValue, maxCubeSize), minCubeSize);

    size_t baseMultiplier = cubeSize * cubeSize * cubeSize * 4;

    // you can use either uint8 data or float data by just setting this variable

    BOOL useFloat = FALSE;    

    NSMutableData *cubeData = [NSMutableData dataWithLength:baseMultiplier * (useFloat ? sizeof(float) : sizeof(uint8_t))];

    if ( ! cubeData )

        return inputImage;

    if ( ! buildCubeData(cubeData, cubeSize, [inputCenterAngle floatValue], [inputAngleWidth floatValue], cubeMakeGrayscale) )

        return inputImage;

    // don't just use inputCubeSize directly because it is a float and we want to use an int.

    [colorCube setValue:[NSNumber numberWithInt:cubeSize] forKey:@"inputCubeDimension"];

    [colorCube setValue:cubeData forKey:@"inputCubeData"];

    [colorCube setValue:inputImage forKey:kCIInputImageKey];

    CIImage *outputImage = [colorCube valueForKey:kCIOutputImageKey];

    [colorCube setValue:nil forKey:@"inputCubeData"];

    [colorCube setValue:nil forKey:kCIInputImageKey];

    return outputImage;

}

@end