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2014/10/15 ¤U¤È 10:13:29

iphone Programming Glossary: rgba

Retrieving a pixel alpha value for a UIImage

http://stackoverflow.com/questions/1042830/retrieving-a-pixel-alpha-value-for-a-uiimage

of a pixel in a UIImageView. I have obtained the CGImage from UIImageView image and created a RGBA byte array from this. Alpha is premultiplied. CGImageRef image uiImage.CGImage NSUInteger width CGImageGetWidth..

How to get the RGB values for a pixel on an image on the iphone

http://stackoverflow.com/questions/144250/how-to-get-the-rgb-values-for-a-pixel-on-an-image-on-the-iphone

a read only reference to data . Method 1 Writable Pixel Information I defined constants #define RGBA 4 #define RGBA_8_BIT 8 In my UIImage subclass I declared instance variables size_t bytesPerRow size_t.. reference to data . Method 1 Writable Pixel Information I defined constants #define RGBA 4 #define RGBA_8_BIT 8 In my UIImage subclass I declared instance variables size_t bytesPerRow size_t byteCount size_t.. CGContextRef context CGColorSpaceRef colorSpace UInt8 pixelByteData A pointer to an array of RGBA bytes in memory RPVW_RGBAPixel pixelData The pixel struct with alpha in this version typedef struct..

underline text in UIlabel

http://stackoverflow.com/questions/2711297/underline-text-in-uilabel

CGContextSetRGBStrokeColor ctx 207.0f 255.0f 91.0f 255.0f 44.0f 255.0f 1.0f RGBA CGContextSetLineWidth ctx 1.0f CGContextMoveToPoint ctx 0 self.bounds.size.height 1 CGContextAddLineToPoint..

Retrieving a pixel alpha value for a UIImage

http://stackoverflow.com/questions/1042830/retrieving-a-pixel-alpha-value-for-a-uiimage

for a UIImage I am currently trying to obtain the alpha value of a pixel in a UIImageView. I have obtained the CGImage from UIImageView image and created a RGBA byte array from this. Alpha is premultiplied. CGImageRef image uiImage.CGImage NSUInteger width CGImageGetWidth image NSUInteger height CGImageGetHeight image CGColorSpaceRef..

How to get the RGB values for a pixel on an image on the iphone

http://stackoverflow.com/questions/144250/how-to-get-the-rgb-values-for-a-pixel-on-an-image-on-the-iphone

by previous posts and at the bottom of this post provides a read only reference to data . Method 1 Writable Pixel Information I defined constants #define RGBA 4 #define RGBA_8_BIT 8 In my UIImage subclass I declared instance variables size_t bytesPerRow size_t byteCount size_t pixelCount CGContextRef context CGColorSpaceRef.. posts and at the bottom of this post provides a read only reference to data . Method 1 Writable Pixel Information I defined constants #define RGBA 4 #define RGBA_8_BIT 8 In my UIImage subclass I declared instance variables size_t bytesPerRow size_t byteCount size_t pixelCount CGContextRef context CGColorSpaceRef colorSpace.. variables size_t bytesPerRow size_t byteCount size_t pixelCount CGContextRef context CGColorSpaceRef colorSpace UInt8 pixelByteData A pointer to an array of RGBA bytes in memory RPVW_RGBAPixel pixelData The pixel struct with alpha in this version typedef struct RGBAPixel byte red byte green byte blue byte alpha RGBAPixel..

underline text in UIlabel

http://stackoverflow.com/questions/2711297/underline-text-in-uilabel

method void drawRect CGRect rect CGContextRef ctx UIGraphicsGetCurrentContext CGContextSetRGBStrokeColor ctx 207.0f 255.0f 91.0f 255.0f 44.0f 255.0f 1.0f RGBA CGContextSetLineWidth ctx 1.0f CGContextMoveToPoint ctx 0 self.bounds.size.height 1 CGContextAddLineToPoint ctx self.bounds.size.width self.bounds.size.height 1..

Retrieving a pixel alpha value for a UIImage

http://stackoverflow.com/questions/1042830/retrieving-a-pixel-alpha-value-for-a-uiimage

obtain the alpha value of a pixel in a UIImageView. I have obtained the CGImage from UIImageView image and created a RGBA byte array from this. Alpha is premultiplied. CGImageRef image uiImage.CGImage NSUInteger width CGImageGetWidth image NSUInteger..

OpenGL ES 2d rendering into image

http://stackoverflow.com/questions/10455329/opengl-es-2d-rendering-into-image

outside of OpenGL ES you have two main options. The first is to simply render your scene and use glReadPixels to grab RGBA data for the scene and place it in a byte array like in the following GLubyte rawImagePixels GLubyte malloc totalBytesForImage.. GLubyte malloc totalBytesForImage glReadPixels 0 0 int currentFBOSize.width int currentFBOSize.height GL_RGBA GL_UNSIGNED_BYTE rawImagePixels Do something with the image free rawImagePixels The second and much faster way of doing.. kCFAllocatorDefault rawDataTextureCache renderTarget NULL texture attributes GL_TEXTURE_2D GL_RGBA opengl format int imageSize.width int imageSize.height GL_BGRA native iOS format GL_UNSIGNED_BYTE 0 renderTexture..

How to get the RGB values for a pixel on an image on the iphone

http://stackoverflow.com/questions/144250/how-to-get-the-rgb-values-for-a-pixel-on-an-image-on-the-iphone

of this post provides a read only reference to data . Method 1 Writable Pixel Information I defined constants #define RGBA 4 #define RGBA_8_BIT 8 In my UIImage subclass I declared instance variables size_t bytesPerRow size_t byteCount size_t pixelCount.. a read only reference to data . Method 1 Writable Pixel Information I defined constants #define RGBA 4 #define RGBA_8_BIT 8 In my UIImage subclass I declared instance variables size_t bytesPerRow size_t byteCount size_t pixelCount CGContextRef.. size_t pixelCount CGContextRef context CGColorSpaceRef colorSpace UInt8 pixelByteData A pointer to an array of RGBA bytes in memory RPVW_RGBAPixel pixelData The pixel struct with alpha in this version typedef struct RGBAPixel byte red byte..

OpenGL ES (iPhone) Touch Picking

http://stackoverflow.com/questions/2231433/opengl-es-iphone-touch-picking

is very hard to follow. I'm attempting to roll my own on iOS 5 with GLKView I've worked out how to touch detect pixel RGBA as I describe here now I'm trying to work out how to quickly change the colours of my scene objects to be unique to accompany..

underline text in UIlabel

http://stackoverflow.com/questions/2711297/underline-text-in-uilabel

ctx UIGraphicsGetCurrentContext CGContextSetRGBStrokeColor ctx 207.0f 255.0f 91.0f 255.0f 44.0f 255.0f 1.0f RGBA CGContextSetLineWidth ctx 1.0f CGContextMoveToPoint ctx 0 self.bounds.size.height 1 CGContextAddLineToPoint ctx self.bounds.size.width..

How to render to offscreen bitmap then blit to screen using Core Graphics

http://stackoverflow.com/questions/410313/how-to-render-to-offscreen-bitmap-then-blit-to-screen-using-core-graphics

to offscreen bitmap then blit to screen using Core Graphics I would like to render to an offscreen bitmap or array of RGBA values and then blit those to a UIView during in the view's drawRect function. I would prefer to do full 32 bit rendering..

Creating UIImage from raw RGBA data

http://stackoverflow.com/questions/4545237/creating-uiimage-from-raw-rgba-data

UIImage from raw RGBA data I have been trying to convert an array RGBA data int bytes into a UIImage. My code looks like as follows height and.. UIImage from raw RGBA data I have been trying to convert an array RGBA data int bytes into a UIImage. My code looks like as follows height and width are integers denoting the dimensions of the..

iOS - How to achieve emboss effect for the text on UILabel?

http://stackoverflow.com/questions/8467141/ios-how-to-achieve-emboss-effect-for-the-text-on-uilabel

You'll use this to make CoreGraphics draw a shadow around the inside edges of the string. This needs to be a full RGBA image. iOS doesn't seem to support grayscale alpha images. UIImage invertedMaskWithMask UIImage mask CGRect rect CGPointZero..

Record the drawing as a m4v video file - OpenGL

http://stackoverflow.com/questions/9661259/record-the-drawing-as-a-m4v-video-file-opengl

dictionaryWithObjectsAndKeys NSNumber numberWithBool YES kEAGLDrawablePropertyRetainedBacking kEAGLColorFormatRGBA8 kEAGLDrawablePropertyColorFormat nil context EAGLContext alloc initWithAPI kEAGLRenderingAPIOpenGLES1 if context EAGLContext.. Specify a 2D texture image providing the a pointer to the image data in memory glTexImage2D GL_TEXTURE_2D 0 GL_RGBA width height 0 GL_RGBA GL_UNSIGNED_BYTE brushData Release the image data it's no longer needed free brushData Set the.. image providing the a pointer to the image data in memory glTexImage2D GL_TEXTURE_2D 0 GL_RGBA width height 0 GL_RGBA GL_UNSIGNED_BYTE brushData Release the image data it's no longer needed free brushData Set the view's scale factor self.contentScaleFactor..