/*
* Copyright (c) 2013, Oskar Veerhoek
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are those
* of the authors and should not be interpreted as representing official policies,
* either expressed or implied, of the FreeBSD Project.
*/
package episode_31;
import org.jbox2d.collision.shapes.PolygonShape;
import org.jbox2d.common.Vec2;
import org.jbox2d.dynamics.*;
import org.lwjgl.LWJGLException;
import org.lwjgl.input.Keyboard;
import org.lwjgl.input.Mouse;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import java.util.HashSet;
import java.util.Set;
import static org.lwjgl.opengl.GL11.*;
/**
* 30 pixels = 1 metre
*
* @author Oskar Veerhoek
*/
public class PhysicsDemo {
private static final String WINDOW_TITLE = "Physics in 2D!";
private static final int[] WINDOW_DIMENSIONS = {640, 480};
private static final World world = new World(new Vec2(0, -9.8f), false);
private static final Set<Body> bodies = new HashSet<Body>();
private static void render() {
glClear(GL_COLOR_BUFFER_BIT);
for (Body body : bodies) {
if (body.getType() == BodyType.DYNAMIC) {
glPushMatrix();
Vec2 bodyPosition = body.getPosition().mul(30);
glTranslatef(bodyPosition.x, bodyPosition.y, 0);
glRotated(Math.toDegrees(body.getAngle()), 0, 0, 1);
glRectf(-0.75f * 30, -0.75f * 30, 0.75f * 30, 0.75f * 30);
glPopMatrix();
}
}
}
private static void logic() {
world.step(1 / 60f, 8, 3);
}
private static void input() {
for (Body body : bodies) {
if (body.getType() == BodyType.DYNAMIC) {
if (Keyboard.isKeyDown(Keyboard.KEY_A) && !Keyboard.isKeyDown(Keyboard.KEY_D)) {
body.applyAngularImpulse(+0.01f);
} else if (Keyboard.isKeyDown(Keyboard.KEY_D) && !Keyboard.isKeyDown(Keyboard.KEY_A)) {
body.applyAngularImpulse(-0.01f);
}
if (Mouse.isButtonDown(0)) {
Vec2 mousePosition = new Vec2(Mouse.getX(), Mouse.getY()).mul(0.5f).mul(1 / 30f);
Vec2 bodyPosition = body.getPosition();
Vec2 force = mousePosition.sub(bodyPosition);
body.applyForce(force, body.getPosition());
}
}
}
}
private static void cleanUp(boolean asCrash) {
Display.destroy();
System.exit(asCrash ? 1 : 0);
}
private static void setUpMatrices() {
glMatrixMode(GL_PROJECTION);
glOrtho(0, 320, 0, 240, 1, -1);
glMatrixMode(GL_MODELVIEW);
}
private static void setUpObjects() {
BodyDef boxDef = new BodyDef();
boxDef.position.set(320 / 30 / 2, 240 / 30 / 2);
boxDef.type = BodyType.DYNAMIC;
PolygonShape boxShape = new PolygonShape();
boxShape.setAsBox(0.75f, 0.75f);
Body box = world.createBody(boxDef);
FixtureDef boxFixture = new FixtureDef();
boxFixture.density = 0.1f;
boxFixture.shape = boxShape;
box.createFixture(boxFixture);
bodies.add(box);
BodyDef groundDef = new BodyDef();
groundDef.position.set(0, 0);
groundDef.type = BodyType.STATIC;
PolygonShape groundShape = new PolygonShape();
groundShape.setAsBox(1000, 0);
Body ground = world.createBody(groundDef);
FixtureDef groundFixture = new FixtureDef();
groundFixture.density = 1;
groundFixture.restitution = 0.3f;
groundFixture.shape = groundShape;
ground.createFixture(groundFixture);
bodies.add(ground);
}
private static void update() {
Display.update();
Display.sync(60);
}
private static void enterGameLoop() {
while (!Display.isCloseRequested()) {
render();
logic();
input();
update();
}
}
private static void setUpDisplay() {
try {
Display.setDisplayMode(new DisplayMode(WINDOW_DIMENSIONS[0], WINDOW_DIMENSIONS[1]));
Display.setTitle(WINDOW_TITLE);
Display.create();
} catch (LWJGLException e) {
e.printStackTrace();
cleanUp(true);
}
}
public static void main(String[] args) {
setUpDisplay();
setUpObjects();
setUpMatrices();
enterGameLoop();
cleanUp(false);
}
}