2015-03-04 09:41:41 +01:00

71 lines
1.9 KiB
Plaintext
Executable File

import processing.opengl.*;
import mathematik.*;
import teilchen.Particle;
import teilchen.Physics;
import teilchen.force.Spring;
/**
* this sketch shows
* 1 how to create a viscous drag to slow motion eventually down.
* 2 how to create a spring that connects two particles.
*/
Physics mPhysics;
Particle mRoot;
void setup() {
size(640, 480, OPENGL);
smooth();
frameRate(30);
/* create a particle system */
mPhysics = new Physics();
/* create a particle to which we will connect springs */
mRoot = mPhysics.makeParticle(width / 2, height / 2, 0.0);
/* we give the root particle a higher mass so it doesn t move as easily */
mRoot.mass(30);
}
void draw() {
/* create a particle at mouse position and connect it to the root particle through a spring */
if (mousePressed) {
Particle mParticle = mPhysics.makeParticle(mouseX, mouseY, 0);
Spring mSpring = mPhysics.makeSpring(mRoot, mParticle);
/* restlength defines the desired length of the spring. in this case it is the distance between the two particles. */
float mRestlength = mSpring.restlength();
/* we modify the restlength to add a bit of energy into the system */
mSpring.restlength(mRestlength * 1.5f);
}
/* update the particle system */
final float mDeltaTime = 1.0 / frameRate;
mPhysics.step(mDeltaTime);
/* draw particles and connecting line */
background(255);
/* draw springs */
noFill();
stroke(255, 0, 127, 64);
for (int i = 0; i < mPhysics.forces().size(); i++) {
if (mPhysics.forces().get(i) instanceof Spring) {
Spring mSSpring = (Spring)mPhysics.forces().get(i);
line(mSSpring.a().position().x, mSSpring.a().position().y,
mSSpring.b().position().x, mSSpring.b().position().y);
}
}
/* draw particles */
fill(245);
stroke(164);
for (int i = 0; i < mPhysics.particles().size(); i++) {
ellipse(mPhysics.particles().get(i).position().x,
mPhysics.particles().get(i).position().y,
12, 12);
}
}