Render UIView into byte-buffer

[paul84]

Hello,

I'd like to display the contents of an UIView-subclass (such as UITableView or UITextView) on the surface of an OpenGL-object (a cube). Therefore I need to render the tableView (textView respectively) into my own context.

I experimented with UIGraphicsPushContext(...) and UIGraphicsPopContext() hoping that subviews like the tableView would render themself into the alternative context (which is my texture), but they didn't. Here's my code to create the texture:

...
size_t TEXTURE_WIDTH = 256;
size_t TEXTURE_HEIGHT = 256;
GLubyte *textureData = (GLubyte*)malloc(TEXTURE_WIDTH * TEXTURE_HEIGHT * 4);
CGContextRef textureContext = CGBitmapContextCreate(textureData,
	TEXTURE_WIDTH, TEXTURE_HEIGHT, 8, TEXTURE_WIDTH * 4,
	CGColorSpaceCreateDeviceRGB(), kCGImageAlphaPremultipliedLast);
// Try to render tableView on texture
UIGraphicsPushContext(textureContext);
[tableView drawRect:CGRectMake(0, 0, 193, 138)];
UIGraphicsPopContext();
...

Any suggestions preventing me from adopting the lookalike of the ready-existing views all by myself , will be much appreciated.

Thanks in advance,
Paul

[Mehuge]

Originally Posted by paul84

Hello,

I'd like to display the contents of an UIView-subclass (such as UITableView or UITextView) on the surface of an OpenGL-object (a cube). Therefore I need to render the tableView (textView respectively) into my own context.

I experimented with UIGraphicsPushContext(...) and UIGraphicsPopContext() hoping that subviews like the tableView would render themself into the alternative context (which is my texture), but they didn't. Here's my code to create the texture:

...
size_t TEXTURE_WIDTH = 256;
size_t TEXTURE_HEIGHT = 256;
GLubyte *textureData = (GLubyte*)malloc(TEXTURE_WIDTH * TEXTURE_HEIGHT * 4);
CGContextRef textureContext = CGBitmapContextCreate(textureData,
	TEXTURE_WIDTH, TEXTURE_HEIGHT, 8, TEXTURE_WIDTH * 4,
	CGColorSpaceCreateDeviceRGB(), kCGImageAlphaPremultipliedLast);
// Try to render tableView on texture
UIGraphicsPushContext(textureContext);
[tableView drawRect:CGRectMake(0, 0, 193, 138)];
UIGraphicsPopContext();
...

Any suggestions preventing me from adopting the lookalike of the ready-existing views all by myself , will be much appreciated.

Thanks in advance,
Paul

I too would be interested to know how to do this.

Found this http://www.iphonedevsdk.com/forum/ip...ot-uiview.html
going to have a play.

[Mehuge]

[view.layer renderInContext:UIGraphicsGetCurrentContext()];

Did the trick for me. I created a version of the Flow Cover sample code that renders a view instead of an image with a few simple changes.

In the imageToTextureUIImage*)image method which I renamed to viewToTextureUIView*)view I replaced the middle section of that code which sized and scaled the image and rendered the image in the graphic context with a the above call.