Processing: Creative Coding and Computational Art

set initial button background colors
color pencilBg = buttonSelected;
color brushBg = buttonUp;
color eraserBg = buttonUp;
// button booleans
boolean isPencilSelected = true;
boolean isBrushSelected = false;
boolean isEraserSelected = false;
As in the last example, I created up, over, and selected states for each of the buttons, as
well as Boolean values to hold the specific button states. For example, I initialized the
sketch by making the pencil active and the other tools inactive. Thus, I set
isPencilSelected to true and isBrushSelected and isEraserSelected to false.
// slider
float[] sliderBar, sliderHandle;
boolean isSliderMovable = false;
color sliderHandleUp = color(255, 127, 0);
color sliderHandleOver = color(255, 200, 0);
color sliderHandleBg = sliderHandleUp;
float sliderValue = 0;
//clear button
float[]clearBtn;
color clearBtnOver = color(50, 50, 150);
color clearBtnUp = color(0, 0);
color clearBtnBg = clearBtnUp;
The slider and the clear button were handled very similarly to the tool buttons. I could
have encapsulated this more and removed some of the redundant structures, but the code
would have become denser and more inscrutable. I could have also used an objectoriented
structure—building a base widget class and having each specific interactive
element extend (inherit) it and then add its own specific properties/methods. This OOP
approach would be an excellent exercise to try on your own.
After declaring all the global variables, I then initialized many of them in the setup()
function.
void setup(){
size(600, 400);
background(canvasBg);
frameRate(30);
// create fonts
titleFont = createFont("Arial", 11);
clearFont = createFont("Arial", 10);
INTERACTIVITY
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