Linear \ Learning \ Processing.org

This example is for Processing version 1.1+. If you have a previous version, use the examples included with your software. If you see any errors or have suggestions, »please let us know.

Linear Motion.

Changing a variable to create a moving line. When the line moves off the edge of the window, the variable is set to 0, which places the line back at the bottom of the screen.

 
float a = 100;

void setup() 
{
  size(640, 200);
  stroke(255);
}

void draw() 
{
  background(51);
  a = a - 0.5;
  if (a < 0) { 
    a = height; 
  }
  line(0, a, width, a);  
}