Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
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As the deltaX and deltaY values become farther apart, the line visually approaches either
a vertical or horizontal line. The most diagonal line (if there is such a thing) is when deltaX
and deltaY are equal, or the change in x and the change in y are equal. As you might have
guessed, this is also when the slope is 1. Slope is a very important property in describing
motion, which I’ll cover in Chapter 11. Speed is the rate at which position is changing.
When you plot a diagonal line as a function of distance and time, as shown in Figure 7-5,
the slope of the plotted line is speed.
Figure 7-5. Speed plot
Creating your first curve
Without acceleration, speed is a constant and will always generate a straight line, as the
rate of change will be constant. Starting with different constant values of speed, you can
change the steepness, or slope, of the line, as the previous example showed, but you can
never get a curve if you keep the speed (or slope) constant. Thus, it would seem logical, if
you wanted to generate a curve, to use a changing speed value—which is precisely what
you’ll do next. This is also the reason why curves, with regard to motion, describe acceleration,
or the change in speed. This next sketch (shown in Figure 7-6) is a curve plot:
/*
Curve I
Ira Greenberg, December 3, 2005
*/
size(200, 200);
background(255);