Examples

04 - Add interaction

Last example showed how to add force. Now we will link add force to keyboard interaction.

Applet

Code

//Import all Phys2D libraries
import pphys2d.bodies.*;
import pphys2d.joints.*;
import pphys2d.shapes.*;
import pphys2d.phys2d.raw.collide.*;
import pphys2d.phys2d.raw.strategies.*;
import pphys2d.phys2d.raw.forcesource.*;
import pphys2d.phys2d.util.*;
import pphys2d.phys2d.raw.shapes.*;
import pphys2d.*;

//Create a PPhys2D world
PPWorld world = new PPWorld();

//Create a PPhys2D Box
PPBox myBox;

//Create a PPhys2D Circle
PPCircle myCircle;

//Create an Array to hold keys
boolean[] keyIsPressed = new boolean[512];

void setup () {

  //Set size and framerate
  frameRate(30);
  size(500,500);

  //Set a standard world gravity
  world.setGravity(0, 200);

  //Add a box to the world
  myBox = new PPBox(50, 90);
  myBox.setPosition(250, 100);
  myBox.setStrokeWidth(1);
  myBox.setFillColor(new Color(40,40,100));
  myBox.setStrokeColor(new Color(40,40,40));
  world.add(myBox);

  //Add a static circle to the world
  myCircle = new PPCircle(50);
  myCircle.setPosition(220, 250);
  myCircle.setStrokeWidth(1);
  myCircle.setStaticBody(true);
  myCircle.setFillColor(new Color(100,20,20));
  myCircle.setStrokeColor(new Color(40,40,40));
  world.add(myCircle);

  //Set world edges in dark gray
  world.setEdges(this, new Color (40, 40, 40));
}

void draw () {
  //Clear screen
  background(255);
  //Draw world
  world.draw(this);
  //Check if a key has been pressed add add force
  checkKey();
}

void keyPressed() {
  //Set presed key code
  keyIsPressed[keyCode] = true;
}

void keyReleased() {
  //Set presed key code
  keyIsPressed[keyCode] = false;
}

void checkKey() {
  if(keyIsPressed[38])myBox.addForce(0, -80000); //UP
  if(keyIsPressed[40])myBox.addForce(0, 80000); //DOWN
  if(keyIsPressed[37])myBox.addForce(-80000, 0); //LEFT
  if(keyIsPressed[39])myBox.addForce(80000, 0); //RIGHT
}