Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
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stroke(0);
strokeWeight(2);
fill(225);
triangle(p[0].x, p[0].y, p[1].x, p[1].y, p[2].x, p[2].y);
}
Figure 9-6. Triangle sketch
The examples thus far in the chapter have been pretty dull, so we’ll do something a little
more interesting with the triangle() function. Also note that I used Java’s Point class
again, as I find it very convenient when plotting stuff. This class is not included in
Processing, so you won’t find it in the Processing reference. However, it’s in the Java API (see
http://java.sun.com/j2se/1.4.2/docs/api/java/awt/Point.html). Arrays in Processing
and Java can be declared of any data type. (Remember from Chapter 8 that a class is also
a data type.) Point is a class in Java and thus a valid data type. This allowed me to create a
Point array and to refer to each Point object in the array by a single index value (e.g.,
p[0] or p[1]). Since each Point object has an x and y property, this is a convenient data
type for keeping track of both components (x and y) at the same time. If I had just used
arrays of type float instead of the Point class, I’d need to use either two separate parallel
arrays—one for x and one for y—or I’d need to use a multidimensional array (p[][]).
I think using an array of Points is the simplest solution. Here’s a little variation on the
Triangle sketch (see Figure 9-7):
//Triangle Zoom
Point[]p = new Point[3];
float shift = 10;
void setup(){
size(400, 400);
background(190);
smooth();
p[0] = new Point(1, height-1);