This example is for Processing 2+. 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.
Continuous Lines.
Click and drag the mouse to draw a line.
void setup() {
size(640, 360);
background(102);
}
void draw() {
stroke(255);
if (mousePressed == true) {
line(mouseX, mouseY, pmouseX, pmouseY);
}
}