Processing: Creative Coding and Computational Art

Accessing time
Figure 11-4. Collision Detection and Timeout sketch
The last sketch combined stuff you’ve looked at before. The collision detection block
worked identically to the previous single-object example, only of course using arrays and a
for loop. I did throw in two new function calls: millis() and noLoop().
millis() returns the number of milliseconds that have elapsed since the sketch began
running. In addition to returning milliseconds, Processing can also communicate with your
computer’s internal clock, accessing the current time with the six functions second(),
minute(), hour(), day(), month(), and year().
Processing’s noLoop() function immediately stops the draw() structure from looping.
There is also a companion loop() call that begins the draw() loop again. In the example, I
compared the total elapsed milliseconds with a user-defined variable, timeLimit, allowing
the draw() function to eventually stop after a certain amount of time had elapsed.
Adding some simple fading
The final modification I’ll make to the multirectangle sketch is the addition of a fade to the
white background, creating the illusion of some blur trails for the rectangles (shown in
Figure 11-5). The code should remain the same as in the last sketch, with the exception of
the replacement of the first line in the draw() function:
background(255);
MOTION
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