Mechanism to assign UIImages their own Rect inside a CALayer? - iphone

Question

I have one or more CALayers which represent/fill the whole screen.
I want to fill those CALayers from a grid structure, using a lot of small Rects with images.
What i tried was assigning each Rect its own CALayer and an UIImage.
With over 6000 CALayers the result was very slow. Now i am looking for a way not to use that much CALayer. Maybe only the top level ones.
So ist there a mechanism to assign UIImages their own Rect inside a CALayer ?
Slow / bad code Example:
- (void)createLayer{
CALayer *currentLayer = self.layer;
_layerArray = [[NSMutableArray alloc] initWithCapacity:WIDTH*HEIGHT];
int cellSize = self.bounds.size.width / WIDTH;
double xOffset = 0;
CGRect cellFrame = CGRectMake(0, 0, cellSize, cellSize);
NSUInteger cellIndex = 0;
cellFrame.origin.x = xOffset;
for (int i = 0; i < WIDTH; i++)
{
cellFrame.origin.y = 0;
for (int j = 0; j < HEIGHT; j++, cellIndex++)
{
if([[self.levelState.boardChanges objectAtIndex:(i*HEIGHT)+j] intValue]==1){
{
NSNumber *currentCell = [self.levelState.board objectAtIndex:cellIndex];
CALayer *sublayer = [CALayer layer];
sublayer.frame = cellFrame;
if (currentCell.intValue == 1)
{
[[_layerArray objectAtIndex:(i*HEIGHT)+j ] setContents:(id) [UIImage imageNamed:#"image1.png"].CGImage];
}
else if (currentCell.intValue == 0)
{
[[_layerArray objectAtIndex:(i*HEIGHT)+j ] setContents:(id) [UIImage imageNamed:#"image2.png"].CGImage];
}
[currentLayer addSublayer:sublayer];
[_layerArray addObject:sublayer];
}
}
cellFrame.origin.y += cellSize;
}
cellFrame.origin.x += cellSize;
}
}

Answer 1

I would recommend a very different approach.
subclass a uiview and use it as your background
in your uiview subclass, override
-(void)drawRect:(CGRect)rect
inside, you can draw your uiimages within rectangles you define
[[UIImage imageNamed:#"image1.png"]drawInRect:CGRectMake(0,0,10,10)]; //first square
[[UIImage imageNamed:#"image2.png"]drawInRect:CGRectMake(10,0,10,10)]; // and another right beside it
you can study core graphics more to get a better idea