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

Maybe I am misunderstanding the question, but Quartz has the ability to fill rectangles:

void CGContextFillRect (CGContextRef c, CGRect rect);