Forces With Vectors
/**
* Forces (Gravity and Fluid Resistance) with Vectors
* by Daniel Shiffman.
*
* Demonstration of multiple forces acting on bodies.
* Bodies experience gravity continuously and fluid
* resistance when in "water".
*/
Array<Mover*> movers(10);
Liquid* liquid;
void reset();
void setup() {
size(640, 360);
reset();
liquid = new Liquid(0, height/2, width, height/2, 0.1);
}
void draw() {
background(0);
liquid->display();
for (Mover* mover : movers) {
// Is the Mover in the liquid?
if (liquid->contains(mover)) {
// Calculate drag force
PVector drag = liquid->drag(mover);
// Apply drag force to Mover
mover->applyForce(drag);
}
// Gravity is scaled by mass here!
PVector gravity(0, 0.1*mover->mass);
// Apply gravity
mover->applyForce(gravity);
// Update and display
mover->update();
mover->display();
mover->checkEdges();
}
fill(255);
text("click mouse to reset", 10, 30);
}
void mousePressed() {
reset();
}
// Restart all the Mover objects randomly
void reset() {
for (int i = 0; i < movers.length(); i++) {
movers[i] = new Mover(random(0.5, 3), 40+i*70, 0);
}
}