Generic 2D Platformer

So, there are only 4 days left for me to finish "Beer Bottle Rocket Man". That's the game I'm submitting for the contest at the Slick forums.

How is that relevant to G2DP? Because I'm using the Generic 2D Platformer game library in Beer Bottle Rocket Man. As I use it, I see areas that could use improvement. And areas that are potentially broken and need some work done.

So tonight I've added a drawEntity method to the Camera class, which allows easy drawing of any entity, in addition to the player, so the developer no longer has to track the screen position of said entity. I had it in place for the player for a long time, but tonight it just made sense to add that functionality.

Yep, still doing. And still going.

It was difficult to continue working on G2DP without knowing how people might use it, and where it might need improvement and additional features. So I've created two other projects (one of them being a contest on the Slick forums) that use the library. I'm better able to see where improvements need to be made, etc.

Development continues.

I'm just messing around with the setColor method in Slick. It allows you to manipulate the color property (red, green, blue, alpha) of a corner.

The numbers, 0 through 3, represent the four different corners of a tile (as shown in the image). The combinations of corner manipulation with 100% transparency are indicated in the image.

I'm quite proud of what I've got to show off today.

Here we have the hero inside a "secret area". It's not so secret if you've been testing out the demo on a regular basis. It's the first room of the demo, just with a big rock placed onto the foreground layer.

Now the player can see where the hero is at when he's standing behind a tile.

The previous picture really doesn't show off the backdrop layer manager, so here's a video.

If you'd run the previous demo, you would have noticed that whenever you pressed jump, the hero would jump as high as he could, every time, no matter whether or not you held the jump key or simply tapped it. I've fixed that, so a tap results in a slight hop.

Edit: I finally found the link to the article that this effect is based on.

The backdrop layer manager is nearing completion. It's functional at the moment, but doesn't yet sort the background images in order of ascending width (important).

The following picture does not do it justice, but it shows off 4 images, layered accordingly.

So once again, I thought I'd work on the backdrop layer manager. I didn't get anything done with it. There's something about attempting to work on it (and I don't think it would be difficult to code), but there's something about it that makes me work hard on something else.

I had this little problem lurking around at the back of my mind. I wanted a simple way of specifying where our hero starts in the level. Up to now I had just been dropping him in the top left of the level (position 10,10).

Not any more. I'm using the Tiled editor's "group" layer, as you can see.

There's that "ACTORGROUP" layer, that holds the location of the Hero, and later on will tell G2DP where to create the NPCs. Notice the little orange box labelled "Player".

That gives us easy hero placement.

To avoid confusion with the term "background", I'm deciding to call the background image of G2DP a "backdrop". The potential for confusion is in regard to my naming convention of tiles in the Tiled map editor.

I have decided that the maps created in Tiled, and used in G2DP, require three layers. That is a requirement. One layer named "PLATFORMS", one layer named "FOREGROUND", and one layer named, you guessed it, "BACKGROUND".

You do not necessarily have to put any tiles in the foreground or the background. The map renderer just looks for it, and I think it's a good property for a two-dimensional platform map to have. Like a bald guy with "hair colour" on his drivers license.

The "background" of the Tiled map relates to just the individual tiles that the hero does not come in contact with. Therefore, "backdrop" refers to the screen's background. I'm not trying to step on any toes, but that seems less confusing for me.

Today started out with the intention of coding a backdrop layer manager, but the plan quickly diverted to fixing the hero's "wiggle walk". What is a wiggle walk, I hear you ask? Ever see a kid playing with paper cut-outs glued to a popsicle stick? That's what I'm calling a wiggle walk. I'm foregoing any player walking animations for a (more charming?) rotation of the hero's image. I can't make it work in print, so you'll have to see for yourself soon enough.

And in case I piqued any interest about the "backdrop layer manager", it's just a system of rendering layers of images in such a way that an illusion of depth is added to the background. It simulates the same sensation as when you are driving down a country road and, off in the distance, you see a barn slowly travel across your field of view. But along the side of the road, fence posts zoom by at the speed of the car.

There was a nice article and demonstration in Flash that I found a while back. I can't find it, though.

I'll leave you with a nice screenshot of what is the beginning of the backdrop layer manager.

I think I'm getting the hang of this WebStart thing.

What was holding me back was what seems to be a common problem with LWJGL. A "version mismatch" exception. I had no idea I had to package the native libraries myself, so that has now been addressed.

Here are the demos thus far:

• Test 0 – Pan around a level imported from the Tiled map editor. The demo focuses on displaying only the tiles that are within the view window. Arrow keys to navigate.
• Test 1 – Solid (static) bodies are in place for the platform tiles and some moveable bodies are dropped in for fun. 'R' to reset, 'B' to show the platform boundaries.
• Test 2 – Same as the previous post. Walk the hero around a level imported from a Tiled map editor that uses static bodies. Arrow keys to navigate. 'R' to reset, 'B' to show boundaries.

It took some doing (because I had never done it before) but I finally have a webstart demo working. I've tested it using 32bit Ubuntu 9.04. I have not tested it with Windows but I have compiled the libraries for it so it should work.

So here is the control test. It's simply an exercise in walking the hero around and pushing a box. 'Left' and 'Right' arrow keys move the hero left and right. 'Up' jumps. 'R' resets the app and 'B' shows the platform boundaries.

Other tests to come later.

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