Pause Drawing to show each triangle - Fractal

Discussion in 'Mac Programming' started by CMT, Nov 8, 2010.

  1. CMT
    macrumors member


    Aug 24, 2009
    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;
       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?

  2. macrumors 604

    Aug 9, 2009
    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.

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