Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
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The create() method includes a nested for loop that is a bit dense to untangle. I needed
an algorithm that would run through the vertices array and treat each individual face as a
self-contained quadrangle (composed of four points). Notice that the beginShape() and
endShape() functions are nested within the outer for loop as well, allowing each face to
be drawn as a separate unit. This structure will also allow you to easily customize the color
of each face, which we’ll look at shortly. However, before getting into that, I’ll show you
how to use the two classes just created to generate a cube.
Here’s some runnable code. (Please note that I didn’t repeat the code from the Point3D
and Cube classes shown previously. Just make sure you add the two classes beneath the following
code, or put each class in its own tab.)
Cube c1;
void setup(){
size(400, 400, P3D);
c1 = new Cube(200, 200, 200);
c1.create();
}
// Don't forget to add the Point3D and Cube classes code
I also want to translate the cube to the middle of the drawing space, or at least have
it move around some. I’ll use Processing’s translate() and rotate() functions in
conjunction with the classes to achieve this. In addition, I’ll create an overloaded
create(color[]quadBG) method for customizing the color of each quad face.
You may remember that an overloaded method is an object-oriented concept
meaning that more than one method with the same name exists in a class. What
differentiates the same named methods is the number and type of parameters
between the parentheses in the head of the method. You can read more about
overloaded methods and other object-oriented concepts in Chapter 8.
The next example, shown in Figure 13-8, creates two cubes, using the two overloaded create()
methods. Since I added an additional create() method to the Cube class, I’ve
included the updated class code in the following example. I didn’t repeat the Point3D
class, which you’ll need as well to run the example; simply paste it below the Cube class or
put it into its own tab.
// Two Rotating Custom Cubes
// custom Cube reference variables
Cube c1, c2;
// array to hold different face colors
color[]quadBG = new color[6];
void setup(){
size(400, 400, P3D);
quadBG[0] = color(175, 30, 30, 150);
quadBG[1] = color(30, 175, 30, 150);