CGContextRef Initialisierung.m

// Größe
int viewHeight = 800;
int viewWidth = 800;

// Initialisieren des CGContext nach Dokumentation
int bitmapBytesPerRow = (pixelsWide * 4);
int bitmapByteCount = (bitmapBytesPerRow * pixelsHigh);
	
CGColorSpaceRef colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
void *bitmapData = malloc( bitmapByteCount );
	
if (bitmapData == NULL)
	NSLog(@"Memory not allocated!");

CGContextRef contextRef = CGBitmapContextCreate(bitmapData,
						pixelsWide,
						pixelsHigh,
						8,
						bitmapBytesPerRow,
						colorSpace,
						(CGBitmapInfo)kCGImageAlphaPremultipliedFirst);
	
if (contextRef == NULL)
{
	free(bitmapData);
	NSLog(@"Context could not be created!");
}
	
CGColorSpaceRelease(colorSpace);