Lecture 5 --- 6.837 Fall '98

lineDDA( ) Demonstration

Draw a line by clicking and dragging on the pixel grid shown with the left mouse button. An ideal line is displayed until the left button is released. Upon release a discrete approximation of the line is drawn on the display grid using the lineDDA() method described in the previous slide. An ideal line is then overlaid for comparison.

The lineDDA() method:

You should not see any difference in the lines generated by this method and the lineImproved( ) method mentioned previously.

Lecture 5

Slide 10

6.837 Fall '98

You should not see any difference in the lines generated by this method and the lineImproved( ) method mentioned previously. The main difference should only be speed, (I also made the method draw in a different color). When optimizing, it is important to verify at each step that the algorithm remains intact.