2014/10/15 下午 10:10:34

iphone Programming Glossary: inverted

Retrieving a pixel alpha value for a UIImage

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

for the alpha channel. Do I need to translate the co ordinates between UIKit and Core Graphics i.e is the y axis inverted Or have I misunderstood premultiplied alpha values Update @Nikolai Ruhe's suggestion was key to this. I did not in fact..

Flipped NSString drawing in CGContext

http://stackoverflow.com/questions/1252343/flipped-nsstring-drawing-in-cgcontext

share improve this question As describe here the coordinate system for a context within a UIView or its layer is inverted when compared to the normal Quartz drawing space. However when using Quartz to draw to an image this is no longer the case... case. The UIStringDrawing Cocoa Touch category on NSString that gives you the drawAtPoint withFont method assumes an inverted layout and that's why you're seeing the flipped text in your image. One way to work around this would be to save the graphics..

Get directory contents in date modified order

http://stackoverflow.com/questions/1523793/get-directory-contents-in-date-modified-order

NSDictionary dictionaryWithObjectsAndKeys file @ path modDate @ lastModDate nil sort using a block order inverted as we want latest date first NSArray sortedFiles filesAndProperties sortedArrayUsingComparator ^ id path1 id path2 ..

UISegmentedControl register taps on selected segment

http://stackoverflow.com/questions/1620972/uisegmentedcontrol-register-taps-on-selected-segment

how to order a list. Works fine. However I would like that when an already selected segment is tapped the order gets inverted. I have all the code in place but I don't know how to register the taps on those segments. It seems the only control event..

“Incorrect” frame / window size after re-orientation in iPhone

http://stackoverflow.com/questions/2686882/incorrect-frame-window-size-after-re-orientation-in-iphone

w 300.000000 h 480.000000 Rotation Portrait w 320.000000 h 460.000000 The values for w and h in Landscape seem inverted to me I was expecting that w 480 and h 300. What am I doing wrong The code I used to debug is below. void didRotateFromInterfaceOrientation..

drawing text using CGContextShowTextAtPoint but text shown is inverted,

http://stackoverflow.com/questions/2816659/drawing-text-using-cgcontextshowtextatpoint-but-text-shown-is-inverted

text using CGContextShowTextAtPoint but text shown is inverted void drawRect CGRect rect CGContextRef context UIGraphicsGetCurrentContext CGContextSelectFont context Arial 24 kCGEncodingMacRoman.. I am Rahul 7 I am trying to draw text as shown above I am Rahul but when i execute the code text gets shown but it is inverted why it is happening I am not getting help iphone share improve this question You can use this code CGContextSetTextMatrix..

Inner Shadow in UILabel

http://stackoverflow.com/questions/3231690/inner-shadow-in-uilabel

c uilabel share improve this question The answer by dmaclach is only suitable for shapes that can easily be inverted. My solution is a custom view that works with any shape and also text. It requires iOS 4 and is resolution independent...

Drawing app on iPad using OpenGL

http://stackoverflow.com/questions/4606680/drawing-app-on-ipad-using-opengl

for calling this function the above is in C this is in Obj C Invert the Y axis to conform the iPhone top down approach invertedYBegCoord self.bounds.size.height currentStroke objectAtIndex i CGPointValue .y invertedYEndCoord self.bounds.size.height.. the iPhone top down approach invertedYBegCoord self.bounds.size.height currentStroke objectAtIndex i CGPointValue .y invertedYEndCoord self.bounds.size.height currentStroke objectAtIndex i 1 CGPointValue .y invertedYThirdCoord self.bounds.size.height.. i CGPointValue .y invertedYEndCoord self.bounds.size.height currentStroke objectAtIndex i 1 CGPointValue .y invertedYThirdCoord self.bounds.size.height currentStroke objectAtIndex i 2 CGPointValue .y Figure our how many dots you need count..

Why is UIBezierPath faster than Core Graphics path?

http://stackoverflow.com/questions/6327817/why-is-uibezierpath-faster-than-core-graphics-path

to stroke each path so that I can see the time used by each path in Instruments. Below are typical results call tree inverted you can see that strokeContext takes 9.5 sec. while strokeUIBezierPath takes only 5 sec. Running Self Symbol Name 14638.0ms..

OpenGL ES 2.0 / MonoTouch: Texture is colorized red

http://stackoverflow.com/questions/7986153/opengl-es-2-0-monotouch-texture-is-colorized-red

imageSize.Height ctxt.DrawImage rect inImage.CGImage var data ctxt.Data return data I think the channels are inverted but maybe there is a way to invert the bitmap without some custom code. This is the image which is rendered ignore the fancy..

Draw glow around inside edge of multiple CGPaths

http://stackoverflow.com/questions/8480401/draw-glow-around-inside-edge-of-multiple-cgpaths

union of the paths. Instead make a bitmap. Fill each path on the bitmap. You'll use this as the mask. Next create an inverted image of the mask that has everything outside of the union area filled. You'll draw this to make CoreGraphics draw a shadow.. around the inner edge of the union. Finally set the mask as your CGContext mask set the shadow parameters and draw the inverted image. Ok that sounds complicated. But here's what it looks like Retina version on the right It's not perfect too light.. of the mask path union area. We can use UIKit functions to make this easier than a pure CoreGraphics approach UIImage invertedImageWithMask UIImage mask color UIColor color CGRect rect CGPointZero mask.size UIGraphicsBeginImageContextWithOptions rect.size..

How does the coordinate system in an CGContextRef look like?

http://stackoverflow.com/questions/868052/how-does-the-coordinate-system-in-an-cgcontextref-look-like

view layer and image drawing has 0 0 for its bottom left coordinate. The standard coordinate system on the iPhone is inverted with the upper left coordinate for a UIView being 0 0 . Its backing layer also has those flipped coordinates so drawing..

iPad modal view controller acting in portrait even though it's landscape

http://stackoverflow.com/questions/9583297/ipad-modal-view-controller-acting-in-portrait-even-though-its-landscape

over the text field. In order to do this i have to modify the frame.origin.x instead of y because the axis are inverted view is acting like portrait and this is causing a lot of issues. Edit If i change the modal presentation style on LoginViewController.. a way for this to properly work. It seems if you just create a new view controller and present that it will always be inverted. The fix i found was the put the view controller in a navigation controller. LoginViewController lvc LoginViewController..

How can you apply distortions to a UIImage using OpenGL ES?

http://stackoverflow.com/questions/9886843/how-can-you-apply-distortions-to-a-uiimage-using-opengl-es

I have in there are a convex bulge distortion using a GPUImageBulgeDistortionFilter a concave distortion using an inverted scale parameter to the previous filter a swirl distortion using the GPUImageSwirlFilter and finally a pinch distortion using..

Background ImageView is upside down(flipped) when I use CPTPGraphHostingView [Core plot]

http://stackoverflow.com/questions/9927031/background-imageview-is-upside-downflipped-when-i-use-cptpgraphhostingview-co

for this answer Core plot google group Related SO question I came to know that the whole CPTPGraphHostingView is inverted upside down to support both Mac OS and iOS. This is by design and is not a bug. So the solution from the given links is..