687d53d1fe91846b9460295c3b90f701b84a812b.svn-base
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#import "GPUImageColorPackingFilter.h"
NSString *const kGPUImageColorPackingVertexShaderString = SHADER_STRING
(
attribute vec4 position;
attribute vec4 inputTextureCoordinate;
uniform float texelWidth;
uniform float texelHeight;
varying vec2 upperLeftInputTextureCoordinate;
varying vec2 upperRightInputTextureCoordinate;
varying vec2 lowerLeftInputTextureCoordinate;
varying vec2 lowerRightInputTextureCoordinate;
void main()
{
gl_Position = position;
upperLeftInputTextureCoordinate = inputTextureCoordinate.xy + vec2(-texelWidth, -texelHeight);
upperRightInputTextureCoordinate = inputTextureCoordinate.xy + vec2(texelWidth, -texelHeight);
lowerLeftInputTextureCoordinate = inputTextureCoordinate.xy + vec2(-texelWidth, texelHeight);
lowerRightInputTextureCoordinate = inputTextureCoordinate.xy + vec2(texelWidth, texelHeight);
}
);
#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
NSString *const kGPUImageColorPackingFragmentShaderString = SHADER_STRING
(
precision lowp float;
uniform sampler2D inputImageTexture;
uniform mediump mat3 convolutionMatrix;
varying highp vec2 outputTextureCoordinate;
varying highp vec2 upperLeftInputTextureCoordinate;
varying highp vec2 upperRightInputTextureCoordinate;
varying highp vec2 lowerLeftInputTextureCoordinate;
varying highp vec2 lowerRightInputTextureCoordinate;
void main()
{
float upperLeftIntensity = texture2D(inputImageTexture, upperLeftInputTextureCoordinate).r;
float upperRightIntensity = texture2D(inputImageTexture, upperRightInputTextureCoordinate).r;
float lowerLeftIntensity = texture2D(inputImageTexture, lowerLeftInputTextureCoordinate).r;
float lowerRightIntensity = texture2D(inputImageTexture, lowerRightInputTextureCoordinate).r;
gl_FragColor = vec4(upperLeftIntensity, upperRightIntensity, lowerLeftIntensity, lowerRightIntensity);
}
);
#else
NSString *const kGPUImageColorPackingFragmentShaderString = SHADER_STRING
(
uniform sampler2D inputImageTexture;
uniform mat3 convolutionMatrix;
varying vec2 outputTextureCoordinate;
varying vec2 upperLeftInputTextureCoordinate;
varying vec2 upperRightInputTextureCoordinate;
varying vec2 lowerLeftInputTextureCoordinate;
varying vec2 lowerRightInputTextureCoordinate;
void main()
{
float upperLeftIntensity = texture2D(inputImageTexture, upperLeftInputTextureCoordinate).r;
float upperRightIntensity = texture2D(inputImageTexture, upperRightInputTextureCoordinate).r;
float lowerLeftIntensity = texture2D(inputImageTexture, lowerLeftInputTextureCoordinate).r;
float lowerRightIntensity = texture2D(inputImageTexture, lowerRightInputTextureCoordinate).r;
gl_FragColor = vec4(upperLeftIntensity, upperRightIntensity, lowerLeftIntensity, lowerRightIntensity);
}
);
#endif
@implementation GPUImageColorPackingFilter
#pragma mark -
#pragma mark Initialization and teardown
- (id)init;
{
if (!(self = [super initWithVertexShaderFromString:kGPUImageColorPackingVertexShaderString fragmentShaderFromString:kGPUImageColorPackingFragmentShaderString]))
{
return nil;
}
texelWidthUniform = [filterProgram uniformIndex:@"texelWidth"];
texelHeightUniform = [filterProgram uniformIndex:@"texelHeight"];
return self;
}
- (void)setupFilterForSize:(CGSize)filterFrameSize;
{
texelWidth = 0.5 / inputTextureSize.width;
texelHeight = 0.5 / inputTextureSize.height;
runSynchronouslyOnVideoProcessingQueue(^{
[GPUImageContext setActiveShaderProgram:filterProgram];
glUniform1f(texelWidthUniform, texelWidth);
glUniform1f(texelHeightUniform, texelHeight);
});
}
#pragma mark -
#pragma mark Managing the display FBOs
- (CGSize)sizeOfFBO;
{
CGSize outputSize = [self maximumOutputSize];
if ( (CGSizeEqualToSize(outputSize, CGSizeZero)) || (inputTextureSize.width < outputSize.width) )
{
CGSize quarterSize;
quarterSize.width = inputTextureSize.width / 2.0;
quarterSize.height = inputTextureSize.height / 2.0;
return quarterSize;
}
else
{
return outputSize;
}
}
#pragma mark -
#pragma mark Rendering
- (CGSize)outputFrameSize;
{
CGSize quarterSize;
quarterSize.width = inputTextureSize.width / 2.0;
quarterSize.height = inputTextureSize.height / 2.0;
return quarterSize;
}
@end