¡@
2014/10/15 ¤U¤È 10:11:35
iphone Programming Glossary: multipliedHow 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 bitmap memory. Releasing color space. CGColorSpaceRelease colorSpace return nil Create the bitmap context. Pre multiplied RGBA 8 bits per component. The source image format will be converted to the format specified here by CGBitmapContextCreate... void pixelData self.size.width self.size.height RGBA_8_BIT bytesPerRow colorSpace kCGImageAlphaPremultipliedLast Make sure we have our context if context free pixelData NSLog @ Context not created Draw the image to the bitmap..
How do I create/render a UIImage from a 3D transformed UIImageView? http://stackoverflow.com/questions/1949003/how-do-i-create-render-a-uiimage-from-a-3d-transformed-uiimageview the view transform. Basically it renders the original UIImageView into a UIImage. Then every pixel in the UIImage is multiplied by the inverse transform matrix to generate the transformed UIImage. RenderUIImageView.h #import UIKit UIKit.h #import QuartzCore.. context CGBitmapContextCreate inputData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big CGColorSpaceRelease colorSpace CGContextDrawImage context CGRectMake 0 0 width height imageRef.. context CGBitmapContextCreate outputData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big CGColorSpaceRelease colorSpace CGContextDrawImage context CGRectMake 0 0 width height imageRef..
http://stackoverflow.com/questions/262156/uiimage-rounded-corners example if we shrink an image by half scaleFactor will be 0.5. the scaledWidth and scaledHeight will be the original multiplied by the scaleFactor. IMPORTANT the targetHeight is the size of the space we're drawing into. The scaledHeight is the height.. mainViewContentContext CGBitmapContextCreate NULL targetSize.width targetSize.height 8 0 colorSpace kCGImageAlphaPremultipliedLast free the rgb colorspace CGColorSpaceRelease colorSpace if mainViewContentContext NULL return NULL CGContextSetFillColorWithColor..
OpenGL ES (IPhone) alpha blending looks weird http://stackoverflow.com/questions/4012035/opengl-es-iphone-alpha-blending-looks-weird height width 4 CGContextRef context CGBitmapContextCreate imageData width height 8 4 width colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big CGColorSpaceRelease colorSpace CGContextClearRect context CGRectMake 0 0 width height CGContextTranslateCTM.. on is that the pixel ordering in PNG image format files is converted from RGBA to BGRA and the color values are pre multiplied by the alpha channel value as well by a compression utility 'pngcrush' for device specific efficiency reasons when programming..
Setting anchor point for UIView layer http://stackoverflow.com/questions/4822457/setting-anchor-point-for-uiview-layer and adding to your view's center point the offset based on the difference between the initial and final anchorPoints multiplied by your view's width height or you could set the view's center to the initial touch point. Something like this perhaps void..
laying out images in UIScrollView automatically http://stackoverflow.com/questions/6488169/laying-out-images-in-uiscrollview-automatically from the left side of the screen leftInset . Then I add the distance from the left side of one image to the next image multiplied by the column imageNumber numPerRow . Y is calculated in a similar fashion but to calculate the row I use the imageNumber..
Using UIPinchGestureRecognizer to scale uiviews in single direction http://stackoverflow.com/questions/6759028/using-uipinchgesturerecognizer-to-scale-uiviews-in-single-direction x and y according to their relative variations. the scale factor delta is 1 gestureRecognizer.scale the delta is the multiplied by a factor so that it is somehow proportional to the displacement along the horizontal or vertical axis when the displacement..
http://stackoverflow.com/questions/8734078/ios-badge-number-live-update a new date that is from 1 to 64 days in the future by taking midnightToday and adding on the number of seconds per day multiplied by how many days in the future we want the date to be. We use this date to schedule the local notification. We also need..
Blur an UIImage on change of slider http://stackoverflow.com/questions/8758433/blur-an-uiimage-on-change-of-slider fail to create context CGColorSpaceRef colorSpace CGColorSpaceCreateDeviceRGB Create the bitmap context we want pre multiplied ARGB 8 bits per component CGContextRef bmContext CGBitmapContextCreate NULL width height 8 Bits per component bytesPerRow.. NULL width height 8 Bits per component bytesPerRow colorSpace kCGBitmapByteOrderDefault kCGImageAlphaPremultipliedFirst CGColorSpaceRelease colorSpace return bmContext UIImage blurredImageUsingGaussFactor NSUInteger gaussFactor andPixelRadius..
|