#import "GPUImageTiltShiftFilter.h"
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#import "GPUImageFilter.h"
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#import "GPUImageTwoInputFilter.h"
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#import "GPUImageGaussianBlurFilter.h"
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#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
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NSString *const kGPUImageTiltShiftFragmentShaderString = SHADER_STRING
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(
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varying highp vec2 textureCoordinate;
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varying highp vec2 textureCoordinate2;
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uniform sampler2D inputImageTexture;
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uniform sampler2D inputImageTexture2;
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uniform highp float topFocusLevel;
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uniform highp float bottomFocusLevel;
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uniform highp float focusFallOffRate;
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void main()
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{
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lowp vec4 sharpImageColor = texture2D(inputImageTexture, textureCoordinate);
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lowp vec4 blurredImageColor = texture2D(inputImageTexture2, textureCoordinate2);
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lowp float blurIntensity = 1.0 - smoothstep(topFocusLevel - focusFallOffRate, topFocusLevel, textureCoordinate2.y);
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blurIntensity += smoothstep(bottomFocusLevel, bottomFocusLevel + focusFallOffRate, textureCoordinate2.y);
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gl_FragColor = mix(sharpImageColor, blurredImageColor, blurIntensity);
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}
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);
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#else
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NSString *const kGPUImageTiltShiftFragmentShaderString = SHADER_STRING
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(
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varying vec2 textureCoordinate;
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varying vec2 textureCoordinate2;
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uniform sampler2D inputImageTexture;
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uniform sampler2D inputImageTexture2;
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uniform float topFocusLevel;
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uniform float bottomFocusLevel;
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uniform float focusFallOffRate;
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void main()
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{
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vec4 sharpImageColor = texture2D(inputImageTexture, textureCoordinate);
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vec4 blurredImageColor = texture2D(inputImageTexture2, textureCoordinate2);
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float blurIntensity = 1.0 - smoothstep(topFocusLevel - focusFallOffRate, topFocusLevel, textureCoordinate2.y);
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blurIntensity += smoothstep(bottomFocusLevel, bottomFocusLevel + focusFallOffRate, textureCoordinate2.y);
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gl_FragColor = mix(sharpImageColor, blurredImageColor, blurIntensity);
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}
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);
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#endif
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@implementation GPUImageTiltShiftFilter
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@synthesize blurRadiusInPixels;
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@synthesize topFocusLevel = _topFocusLevel;
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@synthesize bottomFocusLevel = _bottomFocusLevel;
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@synthesize focusFallOffRate = _focusFallOffRate;
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- (id)init;
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{
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if (!(self = [super init]))
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{
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return nil;
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}
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// First pass: apply a variable Gaussian blur
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blurFilter = [[GPUImageGaussianBlurFilter alloc] init];
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[self addFilter:blurFilter];
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// Second pass: combine the blurred image with the original sharp one
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tiltShiftFilter = [[GPUImageTwoInputFilter alloc] initWithFragmentShaderFromString:kGPUImageTiltShiftFragmentShaderString];
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[self addFilter:tiltShiftFilter];
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// Texture location 0 needs to be the sharp image for both the blur and the second stage processing
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[blurFilter addTarget:tiltShiftFilter atTextureLocation:1];
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// To prevent double updating of this filter, disable updates from the sharp image side
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// self.inputFilterToIgnoreForUpdates = tiltShiftFilter;
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self.initialFilters = [NSArray arrayWithObjects:blurFilter, tiltShiftFilter, nil];
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self.terminalFilter = tiltShiftFilter;
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self.topFocusLevel = 0.4;
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self.bottomFocusLevel = 0.6;
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self.focusFallOffRate = 0.2;
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self.blurRadiusInPixels = 7.0;
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return self;
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}
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#pragma mark -
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#pragma mark Accessors
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- (void)setBlurRadiusInPixels:(CGFloat)newValue;
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{
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blurFilter.blurRadiusInPixels = newValue;
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}
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- (CGFloat)blurRadiusInPixels;
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{
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return blurFilter.blurRadiusInPixels;
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}
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- (void)setTopFocusLevel:(CGFloat)newValue;
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{
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_topFocusLevel = newValue;
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[tiltShiftFilter setFloat:newValue forUniformName:@"topFocusLevel"];
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}
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- (void)setBottomFocusLevel:(CGFloat)newValue;
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{
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_bottomFocusLevel = newValue;
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[tiltShiftFilter setFloat:newValue forUniformName:@"bottomFocusLevel"];
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}
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- (void)setFocusFallOffRate:(CGFloat)newValue;
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{
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_focusFallOffRate = newValue;
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[tiltShiftFilter setFloat:newValue forUniformName:@"focusFallOffRate"];
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}
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@end
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