Mac OS Cocoa: Draw a simple pixel on a canvas

Question

I wish I would find an answer for this. I have searched and searched and couldn\'t the right answer. Here is my situation:

In a Mac OS Cocoa Application, I want to draw

Answer 1

Here's a quick way to draw pixels on OS X:

- (void)drawRect:(NSRect)dirtyRect {
    [super drawRect:dirtyRect];

    NSBitmapImageRep *rep = [[NSBitmapImageRep alloc]
                             initWithFocusedViewRect:dirtyRect];

    for (int x = 0; x < [rep pixelsWide]; x++) {
        for (int y = 0; y < [rep pixelsHigh]; y++) {
            NSUInteger pixel[4] = { 0, 255, 0, 255 };
            [rep setPixel:pixel atX:x y:y];
        }
    }

    [rep drawInRect:dirtyRect];
}