Processing: Creative Coding and Computational Art

type into the sketch. Although the 1 is a constant, it also expresses a state that is a constant.
There will always be one more column than the number of points when the points
are spaced out evenly using outer columns, and one less column than points if outer
columns aren’t used (see Figure 6-5).
Figure 6-5. Calculating columns based on number of objects
The float type keeps rounding errors from shifting the points during division in the for
loop. This is a subtle but very important point. For example, the simple expression 5 / 2
will not give the answer you might suspect; the answer, in Processing, is 2. This is because
two integers are divided together, which returns another integer. To get the right mathematical
answer (5.0 / 2 = 2.5), one of the operands needs to be a float.
In the sketch, change the float type to int, set totalPts to 30 or 60 points, and run the
sketch. Then, set totalPts to 29 or 59 points and run it again; the problem will go away,
as 29 + 1 and 59 + 1 yields an even multiple of 300. You can use other values to demonstrate
this as well. When steps is declared as type int, and you use it in the for loop (i.e.,
(width/steps)*i,), the answer gets rounded to an int. If you want to see the calculations,
try putting the statement println((width/steps)*i), within the for loop. You’ll
see that all the values are integers. Now switch steps type from int back to float, and the
output should be real numbers (numbers with fractional parts after the decimal point).
Creating organic form through randomization
OK, so you can draw a line with some points—no big deal, right? Well, there are some
interesting things you can do now that you have your line being described procedurally.
For example, to create a more organic or fuzzy line, you can use Processing’s random()
function within the loop (see Figure 6-6):
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