Processing: Creative Coding and Computational Art

easy. The benefit of internally recording the coordinate data is that the data can be plotted
based on different drawing algorithms. Using different mode arguments within the
beginShape() and endShape() functions, Processing can use the same vertex() data to
draw different types of geometry.
As a little example of how this internal recording process works, the following sketch
(shown in Figure 6-32) re-creates some of the functionality of vertex(), using the point()
and line() functions already covered. Although this may seem like an exercise in futility, I
think it is helpful to have a sense of what’s happening internally, before you rely on these
higher-level commands. In addition, you’ll see that by going a little lower level, other interesting
creative possibilities arise. Afterward, we’ll look at similar functionality, the easy way.
/*
Point Recorder/Plotter
Ira Greenberg, November 23, 2005
*/
void setup(){
size(300, 300);
background(0);
// create arrays to hold x, y coords
float[]x = new float[4];
float[]y = new float[4];
// create a convenient 2 dimensional
// array to hold x, y arrays
float[][]xy = {x, y};
//record points
//x positions
xy[0][0] = 50;
xy[0][1] = 250;
xy[0][2] = 250;
xy[0][3] = 50;
//y positions
xy[1][0] = 50;
xy[1][1] = 50;
xy[1][2] = 250;
xy[1][3] = 250;
// call plotting function
makeRect(xy);
}
void makeRect(float[][]pts){
stroke(255);
smooth();
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