Processing: Creative Coding and Computational Art

Note that the if statement around the two incrementation lines just keeps the
triangle from endlessly spinning when the mouse stops moving.
The last step is damping the accelX and accelY values, which occurs in the final two lines:
// slow down springing
accelX *= damping;
accelY *= damping;
As always, I suggest playing with these values. Although it is relatively easy to implement
the springing, it’s not easy to fully grasp how/why it’s working. Playing with the values will
help you to better understand the principle.
There is so much more that can be done with both the following/easing and springing
code. One really fun and interesting thing to try is to put a number of springy forms
together in a series. In this next example (shown in Figure 11-12), I’ll create a worm composed
of 60 overlapping springy ellipses that follow an invisible moving food source. The
springing for the initial ellipse will be calculated based on the position of the food source;
while the springing for each of the other 59 ellipses will be based on the position of the
preceding ellipse—forming a reactive chain.
/* Worm
demonstrates springs in a series */
// for worm
int segments = 60;
float[] x = new float[segments];
float[] y = new float[segments];
float[] accelX = new float[segments];
float[] accelY = new float[segments];
float[] springing = new float[segments];
float[] damping = new float[segments];
// for food
float fx, fy;
float fCntrX, fCntrY;
float fAngle, fSpeedX = .25, fSpeedY = .5;
void setup(){
size(400, 400);
smooth();
// initialize array values
for (int i=0; i