hermes.physics
Class Physics

java.lang.Object
  hermes.physics.Physics

public class Physics
extends java.lang.Object

A utility class for physics.

Constructor Summary

Physics()

Method Summary

static PVector	calculateImpulse(MassedBeing being1, MassedBeing being2, float elasticity, PVector normal) Calculates the impulse from a collision between Massed Beings, without accounting for rotation.
static PVector	calculateImpulse(PVector v1, PVector v2, float m1, float m2, float elasticity, PVector normal) Calculates the impulse from a collision between objects, without accounting for rotation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Physics

public Physics()

Method Detail

calculateImpulse

public static PVector calculateImpulse(PVector v1,
                                       PVector v2,
                                       float m1,
                                       float m2,
                                       float elasticity,
                                       PVector normal)

Calculates the impulse from a collision between objects, without accounting for rotation.

Parameters:

v1 - the velocity of the first object

v2 - the velocity of the second object

m1 - the mass of the first object

m2 - the mass of the second object

elasticity - the elasticity of collision, 1.0 is perfectly elastic (objects will bounce, all energy is conserved), 0.0 is completely inelastic (they will stop, no conservation of kinetic energy)

normal - vector pointing from body 1 into body 2 along the axis of collision does NOT need to be of unit length (use the projection vector)

Returns:

the impulse from body 1 on body 2 (impulse from 2 on 1 is merely the reverse of this) this is calculated by the equation:

-(1-e)(v2 - v1) . n
j = -----------------------------------
n . n(1/m1 + 1/m2)

where e is elasticity and n is the normal

calculateImpulse

public static PVector calculateImpulse(MassedBeing being1,
                                       MassedBeing being2,
                                       float elasticity,
                                       PVector normal)

Calculates the impulse from a collision between Massed Beings, without accounting for rotation.

Parameters:

being1 - the first being

being2 - the second being

elasticity - the elasticity of collision, 1.0 is perfectly elastic (objects will bounce, all energy is conserved), 0.0 is completely inelastic (they will stop, no conservation of kinetic energy)

normal - vector pointing from being1 to being2 along the axis of collision (use the projection vector between their shapes)

Returns:

impulse from being1 on being2