Morning Coffee: Fun Projects

Screen capture of a 230x130 section of the heightmap below.
the 126,161 blocks are instanced using a single opengl VBO

Just thought I would share some of the personal projects I have been dabbling with these days. I just started looking at the game Minecraft, and Dwarf Fortress. Some of you are probably wondering "where have you been". Well DF (Dwarf Fortress) was started during my college years and probably didn't gain popularity and stability in the game till I graduated so theres that, and Minecraft is a recent development and quiet popular.

They are very interesting concepts and my mind has been spinning since I was introduced to them by a guy at work. So my project is to make my own game based off these two games. I have always liked the idea of an infinite gameplay world where the player can build pretty much anything they want and create a completely unique experience for themselves. Basing things off a simple set of blocks seems like the easiest way to go. I could just play DF and Minecraft but there are too many things I know I would like to have or different ways I would have done things as it is with most games I play.

Oh that and the fact I am pretty broke atm, too many bills to speak of, darn economy. So paying for Minecraft didn't sound good at this point though I will probably give it a try when I have that extra $15. I have started playing DF but I'm afraid the game is really involved and will take me a while to get into it. I am slowly beginning to learn how to play. So I decided I'd start by using JOGL (hehehe).

634x427 Procedurally generated heightmap using perlin noise.
4 octaves and 0.205 persistence

I ran into some issues with the Depth Buffer not working correctly. I basically took a simple cube example from Nehe and fixed it up a bit. It was Lesson 05 and I had to fix up the code a little bit because of the changes to JOGL for the most recent aggregated build. And I used a perlin noise generator I wrote based off of pseudo code from an article on perlin noise. So the image above is the generated world, with only a small 250x130 section of the heightmap generating 842,456 blocks, and further reduced to only about 126,161 being drawn. Performance is pretty bad right now because I am drawing all 126,161, no fog or visibility culling. But then lighting isn't turned on which is my next task and will probably kill my Nvidia GeForce 8400 GS.

I also implemented the Quaternion Camera Class from the Nehe Lesson: Quaternion Camera Class. I had to implement the quaternion of course I was kind of surprised JOGL does not have an implementation for Quaternions. But then it's supposed to simply be Java bindings to opengl.

Angled View: All 126,161 also notice the cutout portion at the bottom.
Apparently the algorithm needs some work, I don't need the blocks
on the bottom, or on the sides.

Since I have done a couple implementations of terrain generators and various other land, maze generation it wasn't that hard to implement. I hope to provide from useful snippets for procedural map generation soon. Today's post was actually going to be about 2D map/level rendering, but I didn't have the snippet ready so I decided I'd write about this little side project instead. By next Tuesday I should have a series of snippets on 2D map and level rendering done. My plan is to go over ways to rendering 2D maps and levels drawing only the visible area, showing a really nice way to draw layers, and how to do smooth level scrolling. After that it's on to collision detection algorithms, and then after that I can finally get to the meat and reason for creating this blog and show the really interesting gameplay snippets and talk about the fun part of game programming.

Side-View: The removing the side and bottom layers of blocks
should reduce the amount of blocks even more

Ok that's enough rambling for this morning.

Angular Character Movement

So as you've probably noticed the past few posts have been about character movement, the first being Basic Character Movement where I went over briefly a few movement style options you have for making a game. This post is going to be another extension of the character movement snippets, where the character will only be moving forward but this time the right and left arrow keys will turn the character right or left. This gives you full 360 degree movement.

Implementation
The code changes are fairly minimal as we still are only interested in whether the up, left, or right arrow keys are pressed. We need to utilize some trigonometric functions sin and cos to determine the amount to move the characters position in the x and y directions, respectively. Here is the new update function:

// angular movement is based on a radian angle for direction

  if (right) {
   this.direction += -0.2; // angular turning speed
  }

  if (left) {
   this.direction += 0.2; // angular turning speed
  }

  if (up) {
   // the movement calculations, sin and cos are used to get the
   // distance in x and y directions respectively. We multiply by the
   // timed passed so that we get more accurate movement and then the
   // speed variable controls how fast the block moves. And it has
   // specific units which are pixels per second.
   basicBlock.x += Math.sin(direction) * dt * speed;
   basicBlock.y += Math.cos(direction) * dt * speed;
  }

As you can see it's not that many lines of code, the right and left arrow keys will change the direction angle which is in radians. You can put it in degrees if you want but radians gives us more precision.

Upgrades
You might want to play around with this snippet a little and try enhancing the turning speed. If you multiply the amount to turn the character by the time passed you can make movement a bit more smooth and consistent. You can also easily add in some basic collision detection and make a nice little game out of this snippet. Combine it with the Game State Machine and the Keyboard Input: Polling System in Java possibly the Toggle Fullscreen Mode and a few other snippets I've posted and you've got a decent basis for a nice little Java game. Then the only limitation is your creativity in gameplay.

So here is the snippet for you to play around with:

• AngularMovementSnippet.java

Next -> Mouse Movement