/**
* Detect if two bodies are crashing into each other If they are, then create and return the
* resultant body, if they aren't, then return a null value. *
*/
private static Body crash(Body m1, Body m2) {
// Distance formula to determine if two bodies are touching
if (StrictMath.sqrt(
StrictMath.pow((m2.getposx() - m1.getposx()), 2)
+ StrictMath.pow((m2.getposy() - m1.getposy()), 2))
< (m1.getSize() + m2.getSize())) {
int mass, size;
double vX, vY, pX, pY;
Color color;
mass = (m1.getMass() + m2.getMass());
size = ((m1.getSize() + m2.getSize()));
color = combineColor(m1, m2);
// Get the resultant velocities with the inelastic collisions equation:
// V = (M1*V1 + M2*V2)/(M1+M2)
vX =
((m1.getvelx() * m1.getMass() + m2.getvelx() * m2.getMass())
/ (m1.getMass() + m2.getMass()));
vY =
((m1.getvely() * m1.getMass() + m2.getvely() * m2.getMass())
/ (m1.getMass() + m2.getMass()));
// Whichever body is bigger absorbs the other body
if (m1.getMass() > m2.getMass()) {
pX = m1.getposx();
pY = m1.getposy();
} else {
pX = m2.getposx();
pY = m2.getposy();
}
return (new Body(mass, size, color, vX, vY, pX, pY));
} else return null;
}
/** Change the position to the new position * */
private static void posChanges(Body b) {
b.setposx(b.getposx() + b.getvelx());
b.setposy(b.getposy() + b.getvely());
}
private static double calculateGravity(Body m1, Body m2, boolean returnX) {
/**
* *** Newton's universal law of gravitation with the distance formula substituted for r^2 ***
*/
double force =
((G * m1.getMass() * m2.getMass())
/ (StrictMath.pow((m2.getposx() - m1.getposx()), 2)
+ StrictMath.pow((m2.getposy() - m1.getposy()), 2)));
double angle = Math.atan((m2.getposy() - m1.getposy()) / (m2.getposx() - m1.getposx()));
if (returnX) // If we want the X component of the force.
if (m2.getposx() < m1.getposx() && m2.getposy() > m1.getposy()
|| m2.getposx() < m1.getposx() && m2.getposy() < m1.getposy())
// Flip the force to the correct direction.
force = force * Math.cos(angle) * -1;
else force = force * Math.cos(angle);
else // Else, we want the Y component of the force.
if (m2.getposx() < m1.getposx() && m2.getposy() > m1.getposy()
|| m2.getposx() < m1.getposx() && m2.getposy() < m1.getposy())
// Flip the force to the correct direction.
force = force * Math.sin(angle) * -1;
else force = force * Math.sin(angle);
return force;
}