/*

     File: CIMicroPaintView.m

 Abstract: Subclass of SampleCIView to handle painting.

  Version: 1.1

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 */

#import "CIMicroPaintView.h"

@interface CIMicroPaintView ()

@property (nonatomic, strong) CIImageAccumulator *imageAccumulator;

@property (nonatomic, strong) NSColor *color;

@property (nonatomic, strong) CIFilter *brushFilter;

@property (nonatomic, strong) CIFilter *compositeFilter;

@property (assign) CGFloat brushSize;

@end

@implementation CIMicroPaintView

{

}

- (id)initWithFrame:(NSRect)frame 

{

    self = [super initWithFrame:frame];

    if (self != nil) {

        _brushSize = 25.0;

        _color = [NSColor colorWithDeviceRed:0.0 green:0.0 blue:0.0 alpha:1.0];

        _brushFilter = [CIFilter filterWithName: @"CIRadialGradient" keysAndValues:

               @"inputColor1", [CIColor colorWithRed:0.0 green:0.0

               blue:0.0 alpha:0.0], @"inputRadius0", @0.0, nil];

        _compositeFilter = [CIFilter filterWithName: @"CISourceOverCompositing"];

    }

    return self;

}

- (void)viewBoundsDidChange:(NSRect)bounds

{

    if ((self.imageAccumulator != nil) && (CGRectEqualToRect (*(CGRect *)&bounds, [self.imageAccumulator extent]))) {

        return;

    }

    /* Create a new accumulator and composite the old one over the it. */

    CIImageAccumulator *newAccumulator = [[CIImageAccumulator alloc] initWithExtent:*(CGRect *)&bounds format:kCIFormatRGBA16];

    CIFilter *filter = [CIFilter filterWithName:@"CIConstantColorGenerator" keysAndValues:@"inputColor", [CIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:1.0], nil];

    [newAccumulator setImage:[filter valueForKey:@"outputImage"]];

    if (self.imageAccumulator != nil)

    {

        filter = [CIFilter filterWithName:@"CISourceOverCompositing"

             keysAndValues:@"inputImage", [self.imageAccumulator image],

             @"inputBackgroundImage", [newAccumulator image], nil];

        [newAccumulator setImage:[filter valueForKey:@"outputImage"]];

    }

    self.imageAccumulator = newAccumulator;

    [self setImage:[self.imageAccumulator image]];

}

- (void)mouseDragged:(NSEvent *)event

{

    CIFilter *brushFilter = self.brushFilter;

    NSPoint  loc = [self convertPoint:[event locationInWindow] fromView:nil];

    [brushFilter setValue:@(self.brushSize) forKey:@"inputRadius1"];

    CIColor *cicolor = [[CIColor alloc] initWithColor:self.color];

    [brushFilter setValue:cicolor forKey:@"inputColor0"];

    CIVector *inputCenter = [CIVector vectorWithX:loc.x Y:loc.y];

    [brushFilter setValue:inputCenter forKey:@"inputCenter"];

    CIFilter *compositeFilter = self.compositeFilter;

    [compositeFilter setValue:[brushFilter valueForKey:@"outputImage"] forKey:@"inputImage"];

    [compositeFilter setValue:[self.imageAccumulator image] forKey:@"inputBackgroundImage"];

    CGFloat brushSize = self.brushSize;

    CGRect rect = CGRectMake(loc.x-brushSize, loc.y-brushSize, 2.0*brushSize, 2.0*brushSize);

    [self.imageAccumulator setImage:[compositeFilter valueForKey:@"outputImage"] dirtyRect:rect];

    [self setImage:[self.imageAccumulator image] dirtyRect:rect];

}

- (void)mouseDown:(NSEvent *)event

{

    [self mouseDragged: event];

}

@end