#import "GPUImagePixellatePositionFilter.h"
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#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
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NSString *const kGPUImagePixellationPositionFragmentShaderString = SHADER_STRING
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(
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varying highp vec2 textureCoordinate;
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uniform sampler2D inputImageTexture;
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uniform highp float fractionalWidthOfPixel;
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uniform highp float aspectRatio;
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uniform lowp vec2 pixelateCenter;
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uniform highp float pixelateRadius;
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void main()
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{
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highp vec2 textureCoordinateToUse = vec2(textureCoordinate.x, (textureCoordinate.y * aspectRatio + 0.5 - 0.5 * aspectRatio));
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highp float dist = distance(pixelateCenter, textureCoordinateToUse);
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if (dist < pixelateRadius)
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{
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highp vec2 sampleDivisor = vec2(fractionalWidthOfPixel, fractionalWidthOfPixel / aspectRatio);
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highp vec2 samplePos = textureCoordinate - mod(textureCoordinate, sampleDivisor) + 0.5 * sampleDivisor;
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gl_FragColor = texture2D(inputImageTexture, samplePos );
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}
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else
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{
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gl_FragColor = texture2D(inputImageTexture, textureCoordinate );
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}
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}
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);
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#else
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NSString *const kGPUImagePixellationPositionFragmentShaderString = SHADER_STRING
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(
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varying vec2 textureCoordinate;
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uniform sampler2D inputImageTexture;
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uniform float fractionalWidthOfPixel;
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uniform float aspectRatio;
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uniform vec2 pixelateCenter;
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uniform float pixelateRadius;
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void main()
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{
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vec2 textureCoordinateToUse = vec2(textureCoordinate.x, (textureCoordinate.y * aspectRatio + 0.5 - 0.5 * aspectRatio));
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float dist = distance(pixelateCenter, textureCoordinateToUse);
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if (dist < pixelateRadius)
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{
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vec2 sampleDivisor = vec2(fractionalWidthOfPixel, fractionalWidthOfPixel / aspectRatio);
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vec2 samplePos = textureCoordinate - mod(textureCoordinate, sampleDivisor) + 0.5 * sampleDivisor;
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gl_FragColor = texture2D(inputImageTexture, samplePos );
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}
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else
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{
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gl_FragColor = texture2D(inputImageTexture, textureCoordinate );
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}
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}
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);
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#endif
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@interface GPUImagePixellatePositionFilter ()
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- (void)adjustAspectRatio;
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@property (readwrite, nonatomic) CGFloat aspectRatio;
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@end
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@implementation GPUImagePixellatePositionFilter
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@synthesize fractionalWidthOfAPixel = _fractionalWidthOfAPixel;
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@synthesize aspectRatio = _aspectRatio;
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@synthesize center = _center;
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@synthesize radius = _radius;
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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 = [self initWithFragmentShaderFromString:kGPUImagePixellationPositionFragmentShaderString]))
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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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- (id)initWithFragmentShaderFromString:(NSString *)fragmentShaderString;
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{
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if (!(self = [super initWithFragmentShaderFromString:fragmentShaderString]))
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{
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return nil;
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}
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fractionalWidthOfAPixelUniform = [filterProgram uniformIndex:@"fractionalWidthOfPixel"];
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aspectRatioUniform = [filterProgram uniformIndex:@"aspectRatio"];
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centerUniform = [filterProgram uniformIndex:@"pixelateCenter"];
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radiusUniform = [filterProgram uniformIndex:@"pixelateRadius"];
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self.fractionalWidthOfAPixel = 0.05;
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self.center = CGPointMake(0.5f, 0.5f);
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self.radius = 0.25f;
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return self;
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}
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- (void)setInputSize:(CGSize)newSize atIndex:(NSInteger)textureIndex;
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{
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CGSize oldInputSize = inputTextureSize;
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[super setInputSize:newSize atIndex:textureIndex];
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if ( (!CGSizeEqualToSize(oldInputSize, inputTextureSize)) && (!CGSizeEqualToSize(newSize, CGSizeZero)) )
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{
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[self adjustAspectRatio];
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}
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}
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#pragma mark -
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#pragma mark Accessors
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- (void)setInputRotation:(GPUImageRotationMode)newInputRotation atIndex:(NSInteger)textureIndex;
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{
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[super setInputRotation:newInputRotation atIndex:textureIndex];
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[self setCenter:self.center];
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[self adjustAspectRatio];
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}
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- (void)adjustAspectRatio;
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{
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if (GPUImageRotationSwapsWidthAndHeight(inputRotation))
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{
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[self setAspectRatio:(inputTextureSize.width / inputTextureSize.height)];
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}
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else
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{
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[self setAspectRatio:(inputTextureSize.height / inputTextureSize.width)];
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}
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}
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- (void)forceProcessingAtSize:(CGSize)frameSize;
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{
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[super forceProcessingAtSize:frameSize];
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[self adjustAspectRatio];
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}
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- (void)setFractionalWidthOfAPixel:(CGFloat)newValue;
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{
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CGFloat singlePixelSpacing;
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if (inputTextureSize.width != 0.0)
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{
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singlePixelSpacing = 1.0 / inputTextureSize.width;
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}
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else
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{
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singlePixelSpacing = 1.0 / 2048.0;
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}
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if (newValue < singlePixelSpacing)
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{
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_fractionalWidthOfAPixel = singlePixelSpacing;
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}
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else
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{
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_fractionalWidthOfAPixel = newValue;
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}
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[self setFloat:_fractionalWidthOfAPixel forUniform:fractionalWidthOfAPixelUniform program:filterProgram];
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}
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- (void)setAspectRatio:(CGFloat)newValue;
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{
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_aspectRatio = newValue;
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[self setFloat:_aspectRatio forUniform:aspectRatioUniform program:filterProgram];
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}
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- (void)setCenter:(CGPoint)center
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{
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_center = center;
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CGPoint rotatedPoint = [self rotatedPoint:center forRotation:inputRotation];
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[self setPoint:rotatedPoint forUniform:centerUniform program:filterProgram];
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}
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- (void)setRadius:(CGFloat)radius
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{
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_radius = radius;
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[self setFloat:_radius forUniform:radiusUniform program:filterProgram];
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}
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@end
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