2014/10/15 下午 10:05:04

iphone Programming Glossary: cglayer

Optimizing a drawing (with finger touches) application for iPhone SDK

http://stackoverflow.com/questions/1123306/optimizing-a-drawing-with-finger-touches-application-for-iphone-sdk

touch events to draw a smooth path. Here's my current approach 1 I subclassed a UIView and added a poroperty to a CGLayer gets created lazily and is the same size as my UIView . 2 My UIView subclass responds to touch events by storing the current.. in the draw rect do the following draw a line from the previous touch location to the current touch location to the CGLayer draw the entire CGLayer to my views context in one go The main problem is when a user swipes fast I get relatively few touch.. following draw a line from the previous touch location to the current touch location to the CGLayer draw the entire CGLayer to my views context in one go The main problem is when a user swipes fast I get relatively few touch events so the lines..

What's the correct code to save a CGLayer as a PNG file?

http://stackoverflow.com/questions/4064470/whats-the-correct-code-to-save-a-cglayer-as-a-png-file

the correct code to save a CGLayer as a PNG file Please note that this question is about CGLayer which you typically use to draw offscreen it is not about.. the correct code to save a CGLayer as a PNG file Please note that this question is about CGLayer which you typically use to draw offscreen it is not about CALayer. In iOS what's the correct code to save a CGLayer as a.. CGLayer which you typically use to draw offscreen it is not about CALayer. In iOS what's the correct code to save a CGLayer as a PNG file Thanks Again that's CGLayer not CALayer. Note that you CAN NOT use UIGraphicsGetImageFromCurrentImageContext...

Render contents of UIView as an OpenGL texture

http://stackoverflow.com/questions/4118778/render-contents-of-uiview-as-an-opengl-texture

OpenGL texture Is there a way to render the contents of a UIView as a texture with OpenGL in iOS Or the contents of a CGLayer iphone uiview opengl es share improve this question You can use the view's layer property to get the CALayer and use..

Mysterious “progressive slowing” problem in run loop / drawRect

http://stackoverflow.com/questions/4786754/mysterious-progressive-slowing-problem-in-run-loop-drawrect

drawRect Here's a real mystery. Imagine you are doing the conventional process of drawing a complex image offscreen CGLayer and you are updating the image on to the screen intermittently as you draw. As you know the way to do this is run the large.. very strange behaviour from the OS. Later ... an astounding work around has been figured out by FELZ. Felz copies the CGLayer once each round. This completely stops the strange behaviour. However there is still no really clear understanding of what.. this one. Nice question and nice sample code. Here is my take on a possible answer The issue I see is the following. CGLayer are great for repeatedly painting because they cache their rendering into a flat image. The cache is invalidated when additional..