float dicke = 2;

void setup () {
	size(640, 480);
	background(255);
}

void draw() {
	if (mousePressed) {
	strokeWeight(dicke);
	line(pmouseX, pmouseY, mouseX, mouseY);
	}
}

void keyPressed() {
	switch(key) {
	case 'l': //loeschen
	background(255);
	break;
case '+': //dicker
	dicke = constrain(dicke * 1.1, 0.5, 100);
	break;
case '-': //duenner
	dicke = constrain(dicke * 0.9, 0.5, 100);
	break;
case 'r': //rot
	stroke(255, 0, 0);
	break;
case 'g': //gruen
	stroke(0, 255, 0);
	break;
case 'b': //blau
	stroke(0, 0, 255);
	break;
case 's': //schwarz
	stroke(0);
	break;
case 'w': //weiss
	stroke(255);
	break;
case 'd': //speichern
	save("mein_bild.png");
	break;
default:
	break;
	}
}