#import "GPUImageOpacityFilter.h"
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@implementation GPUImageOpacityFilter
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@synthesize opacity = _opacity;
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#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
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NSString *const kGPUImageOpacityFragmentShaderString = 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 lowp float opacity;
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void main()
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{
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lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
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gl_FragColor = vec4(textureColor.rgb, textureColor.a * opacity);
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}
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);
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#else
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NSString *const kGPUImageOpacityFragmentShaderString = 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 opacity;
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void main()
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{
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vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
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gl_FragColor = vec4(textureColor.rgb, textureColor.a * opacity);
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}
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);
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#endif
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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 = [super initWithFragmentShaderFromString:kGPUImageOpacityFragmentShaderString]))
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{
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return nil;
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}
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opacityUniform = [filterProgram uniformIndex:@"opacity"];
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self.opacity = 1.0;
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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)setOpacity:(CGFloat)newValue;
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{
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_opacity = newValue;
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[self setFloat:_opacity forUniform:opacityUniform program:filterProgram];
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}
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@end
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