Andy Li’s Blog - Processing

Setting up a Processing Android project in Eclipse

2013-04-25T04:32:00+08:00

Processing is written in Java, and it plays very well with the Android platform. Every serious programmer knows that the Processing IDE is far from being a proper IDE, and the official Android IDE is Eclipse, so we better stick to Eclipse.

To setup a Processing Android project in Eclipse, follow these steps:

Setup a normal Eclipse Android project, such that we can run a simple hello world with a blank activity, targeting Android API 10+.
Download Processing 2.0+.
Copy android-core.zip to the libs folder as android-core.jar inside our Eclipse Android project (Yes, rename to .jar).
The location of android-core.zip is:

For Processing 2.0 beta 9 and above, after installing the Android mode from within the Processing IDE, Documents/Processing/modes/AndroidMode/android-core.zip.
For Processing 2.0 beta 8 and below, inside the Processing folder, modes/android/android-core.zip. For Mac, the Processing folder can be found by right-clicking Processing.app, show package contents, /Contents/Resources/Java.

Right-click the Eclipse Android project, properties. Choose Java Build Path, under the Libraries tab, click Add JARs… button. Choose the android-core.jar we’ve copied in previous step.

Modify the MainActivity class such that it extends processing.core.PApplet instead of android.app.Activity:

package net.onthewings.android; //the package of MainActivity

import processing.core.*;

public class MainActivity extends PApplet { //PApplet in fact extends android.app.Activity
    public void setup() {
        /*...*/
    }

    public void draw() {
        /*...*/
    }
}

Run the project and you should see a blank full screen app :)

Notice that it is not even necessary to use additional Eclipse plug-in like proclipsing. By coding in plain Java, we can mix the Processing drawing API with the Android API easily. Additional Processing Android details can be found at http://wiki.processing.org/w/Android.

Javadoc2Haxe: Chrome extension that create a Java extern for Haxe in one-click

2012-04-18T00:19:00+08:00

Worldwide Haxe 2012(wwx) has just ended. The long awaited Haxe Java and C# targets by Cauê Waneck (@cwaneck) were pushed to the official Haxe trunk (For now you have to build the Haxe compiler from source in order to use it).

Cauê is kind enough to let me play with it before wwx and I coded two little Processing demos for him to shown during his talk. The Java target is very well designed such that using “native” Java class is extremely easy. It is very similar to creating externs for Haxe/JS. I used a little jQuery script to help me building extern from Javadoc pages (BTW @Dr_Emann, @razaina also had similar ideas). Later I think it would be fun and useful to create a Chrome extension for the script. Since there is already a Haxe extern of Chrome extension, it is pretty easy to implement it in Haxe.

Here it is from Chrome store

Go install Javadoc2Haxe from Chrome store.

How to use

Go to a Javadoc page (e.g. Processing’s). Select a class from the class menu and you should see a orange icon next to the class name:

Click on the button, see the magic:

Copy and paste the output to your project.

Edit it as you find appropriate, since the generated extern may contain unwanted methods(maybe referencing another Java type that you don’t want to create extern for it).

You’re more than welcome to fill issues, or even fork the extension from Github. Just beware of its quick and dirty code ;)

My first Processing work - BulletHell

2008-10-31T06:02:00+08:00

Here is my first Processing work, shown to you by the mighty processing.js.
It can’t be shown on IE.

Source code:

float[][] rocks = new float[50][4];
float[] ship = new float[2];
int lifetime = 0;
int gameStatus = 1; //0:playing, 1:pause, 2:end
int[] keyIsDown = new int[4]; //up, right, down, left
float addSpeed = 0;

PFont font;

void setup(){
  size(480,320);
  frameRate(30);
  smooth();
  noStroke();

  font = loadFont("Serif-48.vlw");

  init_var();

  //display instruction
  background(150);
  textFont(font, 22);
  text("Press r to start/restart", 10, height/2 - 30);
  text("Use your mouse to move", 10, height/2);
  text("Press P pause", 10, height/2 + 30);
}

void draw(){
  if (gameStatus == 0){
    background(0);

    lifetime++;

    //move ship
    ship[0]+=(mouseX-ship[0])*0.3;
    ship[1]+=(mouseY-ship[1])*0.3;

    ellipse(ship[0],ship[1],20,20);

    if (lifetime < 10000){
     addSpeed = lifetime;
     addSpeed = addSpeed/1000 +1;
    }

    //move rocks
    for(int i = 0;i<50;i++){
      rocks[i][0]+=rocks[i][2]*addSpeed;
      rocks[i][1]+=rocks[i][3]*addSpeed;
      ellipse(rocks[i][0],rocks[i][1],4,4);
      if(dist(rocks[i][0],rocks[i][1],ship[0],ship[1])<12){ //hit ship?
        gameStatus = 2;
      } else if (rocks[i][0]<-10 || rocks[i][1]<-10 || rocks[i][0]>width+10 || rocks[i][1]>height+10){//go away from screen area?
        rocks[i][0] = random(width);
        rocks[i][1] = random(-5);
      }
    }

  } else if (gameStatus == 2){//game end
    background(150);
    text("Game over. Your score: " + lifetime, 10, height/2);
    noLoop();
  }
}

void keyPressed(){
  //resume game?
  if (key == 'p'){
    if (gameStatus == 0){
      gameStatus = 1;
    } else if (gameStatus == 1){
      gameStatus = 0;
    }
  } else if (key == 'r'){
    gameStatus = 0;
    init_var();
    loop();
  }
}

void init_var(){
  lifetime = 0;

  ship[0] = width/2;
  ship[1] = height/2;

  for(int i = 0;i<50;i++){
    rocks[i][0] = random(width);
    rocks[i][1] = random(-5);
    rocks[i][2] = random(-5,5);
    rocks[i][3] = random(5);
  }
}