PDA

View Full Version : Pause Drawing to show each triangle - Fractal




CMT
Nov 8, 2010, 03:42 PM
For studying purposes (on recursion), I build a simple NSView subclass capable of drawing a Sierpiński triangle.

The class has 2 helper methods to draw triangles and the fractal itself. The former is quite simple, draws triangles given start point, height and width. The latter, also simple, is called inside -drawRect and looks like:


void drawFractal x,y,w,h {
if (h < {predefined value} || w < {...}) {
drawTriangle x,y,w,h;
return;
}
drawFractal x,y,w/2,h/2 // for lower left Triangle
drawFractal ... // for top
drawFractal ... // for lower right
}


The question is:
Is it possible to "pause" after each call to -drawTriangle say for 0.25 second and redisplay the view, so I can see each triangle being draw?

Thanks!



chown33
Nov 8, 2010, 03:47 PM
Not possible.

If you want a pause between images, you need to think of it as an animation: a series of individual frames, each of which appears for a fixed time interval.