In mac osx (cocoa), It is very easy to make a blank image of a specific size and draw to it off screen:
NSImage* image = [[NSImage alloc] initWithSize:NSMakeSize(64,64)];
[image lockFocus];
/* drawing code here */
[image unlockFocus];
However, in iOS (cocoa touch) there does not seem to be equivalent calls for UIImage. I want to use UIImage (or some other equivalent class) to do the same thing. That is, I want to make an explicitly size, initially empty image to which I can draw using calls like UIRectFill(...)
and [UIBezierPath stroke]
.
How would I do this?
CoreGraphics is needed here, as UIImage does not have high level functions like what you explained..
UIGraphicsBeginImageContext(CGSizeMake(64,64));
CGContextRef context = UIGraphicsGetCurrentContext();
// drawing code here (using context)
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
You can do that as follows:
UIGraphicsBeginImageContext(CGSizeMake(64, 64));
//Drawing code here
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Here is Apple's Graphics and Drawing reference.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With