teamSize++ and Other Things

Lots of things to say today: the biggest is that I'm no longer working alone. My roommate has joined me. He's a pretty awesome programmer and really good at math.

Quicksand Fix:

We decided to fix my engine instead of using someone else's. I fixed the quicksand (for real this time) by adding the non impact force to the impact force (if impact is true). Here is the new snippet:


protected Vector calcContactForce(float theta) {
    if(impact) {                              
        if_contact = new Vector(theta, (float) (mass * velocity.magProj(new Vector((float) (theta + Math.PI), 1)) / dt)).add(new Vector(theta, sumForce.magProj(new Vector((float) (theta + Math.PI), 1))));
            // impact plus notImpact
        }
        else {
            f_contact = new Vector(theta, sumForce.magProj(new Vector((float) (theta + Math.PI), 1)));
        }
        return f_contact;
    }
}

I was so happy when I finally got this.

Zooming and Cropping:

The view now moves with the player and scales with velocity according to a Gompertz Curve.

Redoing Collision:

My roommate is redoing the collision system to make it more general (so that it can support more shapes and maybe even rotated shapes down the line). It's not done yet though.

Size Update:

justin@agartha:src$ wc -l *.java

   21 AirBlock.java

   31 Block.java

    7 CanDraw.java

    5 CanMove.java

   32 GroundBlock.java

   57 KromFrame.java

   42 KromGenericLine.java

   61 KromLine.java

  175 KromPanel.java

   39 KromPoint.java

  114 KromRectangle.java

    9 KromShape.java

   64 KromXLine.java

   59 KromYLine.java

  105 Map.java

  160 Physics.java

   37 Player.java

   87 SlantBlock.java

   69 Vector.java

 1174 total

justin@agartha:src$ wc -c ../bin/*.class

  775 ../bin/AirBlock.class

 1200 ../bin/Block.class

  173 ../bin/CanDraw.class

  251 ../bin/CanMove.class

 1122 ../bin/GroundBlock.class

 2474 ../bin/KromFrame.class

 1632 ../bin/KromGenericLine.class

 1541 ../bin/KromLine.class

 6910 ../bin/KromPanel.class

 1474 ../bin/KromPoint.class

 4054 ../bin/KromRectangle.class

  423 ../bin/KromShape.class

 1302 ../bin/KromXLine.class

 1302 ../bin/KromYLine.class

 4327 ../bin/Map.class

 5169 ../bin/Physics.class

 1551 ../bin/Player.class

 1944 ../bin/SlantBlock.class

 2315 ../bin/Vector.class

39939 total

Huge size increases. We passed 1000 lines. Woohoo! Almost 40KB too.

Git is Magical:

We are using git for version control. The subheading sums it up.

I think that's it. I'll be showing a video of all the recent changes whenever the new collision system is working.

Unity is better for 3d. All I need is a physics engine.

I've decided to use http://www.jbox2d.org/ as my physics engine. I suggest you play with this: http://gwtbox2d.appspot.com/

This engine was used in Angry Birds and others, It is free and open source (zlib license). I've decided to stick with java because it is cross platform by default and a port to android wouldn't be too hard.

Thinking about switching to Unity

So, that solution to the quicksand I stumbled upon wasn't a solution at all. It looked like it fixed the problem but the character was actually just bouncing a tiny bit. I knew the problem was still there because I could still push the character through walls.

I think at this point it is fair to say that my physics engine is broken. I don't know if it is worth the effort to go back and fix the entire engine. I've been thinking about using Unity instead. They've promised support for GNU/Linux with Unity 4. I assume this will include an editor too.

I've been wanting to learn C++ anyway and I don't want to give up on Kromapoka just because I made some mistakes in my physics engine that I can't find.

A friend of mine recently told me that I should be a lazier programmer. I realized that I should stand on the shoulders of giants instead of trying to right every line of code myself. The people that make these engines are much better than me and are asking coders to use their engine.

I just have to wait for unity 4. I will not boot into windows to code. That just seems so backwards to me.

EDIT: Just found out that the port is only for the publisher. Maybe Wine will have to do. Also, my comment about C++ might be incorrect. I think it's C#. O well, pretty close anyway.