// Example 5-9: Simple Gravity float x = 00; // x location of square float y = 0; // y location of square float speed = 0; // speed of square int xspeed=5; //speed going across // A new variable, for gravity (i.e. acceleration). // We use a relatively small number (0.1) because this accelerations accumulates over time, increasing the speed. // Try changing this number to 2.0 and see what happens. float gravity = 1.0; void setup() { size(1280,1000); } void draw() { background(255); println("x is " + x); println("xspeed is " + xspeed); println("y= " +y); println("speed is " + speed); println(); // Display the image PImage b; b = loadImage("mad_200.jpg"); image(b, x, y); if (x>width-100 || x<0) { xspeed=xspeed*-1; } x=x+xspeed; y=y+speed; // Add gravity to speed. speed = speed + gravity; // If square reaches the bottom // Reverse speed if (y > height-200) { // Multiplying by -0.95 instead of -1 slows the square down each time it bounces (by decreasing speed). // This is known as a "dampening" effect and is a more realistic simulation of the real world (without it, a ball would bounce forever). speed = speed * -0.95; } }