YAAB - Yet Another Actionscript Blog

After some playing around with various physics engines I decided to write a Verlet/Particle Physics Construction kit. Let people play around with building things out of not-so-steady materials. Anyway after some experimentation I ended up with something that played not unlike Tower of Goo (http://www.experimentalgameplay.com/game.php?g=17).

For some reason or other I decided to recreate the look and feel of Tower - mainly for the challenge of creating a native game into Flash/Actionscript.

The result is here:

http://www.100percentcode.com/ICK.html

See how high you can get!

If you like it the guys a 2D Boy are making a full games out their original - It also been entered into the IGF 2008 - good luck guys...

The latest demo of the engine & game can now always be found here:

http://home.planet.nl/%7Eborst595/Exile.html

Controls and Instructions can be found on the page. Its worth noting that this engine runs much faster with the latest Flash 9 Beta found here:

http://labs.adobe.com/technologies/flashplayer9/

This demo is running at 30fps.

Everything is the engine can now be destroyed (not the landscape thought) - some things are just tougher than others. At the moment the turrets and some of the doors only take a few hits - for test purposes.

Other improvements:

• New Weapon system + light rocket launcher implemented.
• Multi sampling between game objects (not landscape at the moment). This ensures high speed collisions always impact (the rocket should never tunnel through a door).
• Massive internal restructure. The code is now halfway into its release form.
• Improved Aiming
  

Additional keys:
1: Default blaster
4: Light rockets

Demo

I've switched track for a bit. This time working on the AI. This demo shows some line of sight testing. The code calculates 3 rays from an eye that intersect with the two limits and centre of an AABB. If the object is visible the the turret calculates a firing solution and fire. At the moment this is all done every frame (30fps). I'll spread this calculation out over a series of frames. The current enemy AI plan is:

1. Create a list of target candidates within range (1.5x the firing range of the turret)
   
2. Prioritize list
3. Lock target
4. Check visibility
5. Calculate firing solution and fire.
6. Reload
7. Goto 4

The controls are the same. WASD to move the player, click to fire in the direction of the mouse.

Demo

I wanted to get a version with source ready this weekend - unfortunately I didn't make that target. I did however fully incorporate the grid object cache (tested with 1000x1000 tiles), a new map definition method and a physics constraints system into the code base.

Demo

In order to manage the visible bitmap data in the tile engine, I wrote this 2D Circular Linked List Data Grid. Once initialized the grid can hold n x n data items. The grid can be shifted left, right, up and down. As the grid is shifted, the items that fall off once side are added to the other, and automatically updated with new information. This demo illustrates the code. The red rectangle simulates the scroll window of the Tile Engine. The black/grey 4x4 grid represents the Bitmap Data Grid (Each smaller square would be a super tile of, say 5x5 normal tiles). As you move the red rectangle around with the cursor keys, the grid updates correspondingly. The important thing here is that there is only ever 4x4 Bitmap and BitmapData objects that get rotated around, updated and recycled.

Source.

Big update:

• Completely new collision resolution code, much more stable.
• The physics system in much more flexible, it also includes mass in the calculations now.
• Projectile system improved. Projectiles die out after a certain time (with various effects). The system allows a great variety of weapons to be implemented using one class.
• Projectile explosions impart force on surrounding object (you can have fun with this and the boxes)
  
• First attempt at an Enemy AI gun turret. The turret uses a ballistics solver to calculate the two angles it can hit the player with, and then fires. I'll write an entry on this, I'm going to extend this to take into account relative velocities.
• The projector (.exe) version now uses the latest beta flash player.

Controls (focus window first):

• A,W,S,D : Thrust Player
• Left Click : Fire weapon in direction on mouse cursor
• CTRL Left CLick : Shoot ray
• SPACE : Add non-player 'boxes' to interact with
• ENTER : Add random force to boxes

Available here as:

.SWF
.EXE

Update:

• Particle system added
  
• Projectile system added

The controls have changes a little:

• A,W,S,D : Thrust Player
• Left Click : Fire weapon in directon on mouse cursor
• CTRL Left CLick : Shoot ray
• SPACE : Add non-player 'boxes' to interact with
• ENTER : Add random force to boxes
  

You can download a play the demo with the previous links. I've still not updated the source code, again its still in a bit of the mess.

If you try it out please let me know how it performs (cpu).

Thx

Major update:

• All AABB/Tile collision code done
• All ray/Tile/AABB code done (see keyboard instructions below)
• Scrolling! Level can be as big as you like (bound by the length of array). Because each tile in the map is only a reference to a single instance of that type the engine is very memory efficient.

The .SWF can be downloaded here.

The .EXE player version (incorporated the latest beta player) can be downloaded here.

The source can be found in a previous post.

Controls:

• Cursor: Move Player
• Space: Add/Reset boxes
• Enter: Apply random energy to boxes
• Left click: Shoot ray, intersects with tiles, affects boxes
• CTRL Left click: Place move player to mouse

To do:

• Some serious physics engine improvements
• Projectiles
• AI (pathfinding, flocking etc)
• Particle engine

Having played around with a few of my own ideas, I'm going to pursue a geometry based tile +physics engine initially based on the fabulous N tutorials found here. I'm currently working on porting the tutorials to AS3, and then adding the scrolling engine on top. A zip of the current build will be available here.

http://home.planet.nl/%7Eborst595/SeperationAxis.zip

This is the first demo of my new project - A 2D Tile Game Engine for AS3 - Glaze.

Features:
- Unlimited level size, the level builds as you transverse it
- Efficient pixel perfect collision detection between tiles and game objects
- Basic fast physics engine for a 2D sprite world
- Particle engine/effects
- Full level editor/sprite editor thanks to Tile Studio - an open source project that provides just that.

Planed features:
- Enhanced physics system (either Verlet or RK4 integrator)
- Line of sight functionality
- Common NPC AI (Pathfinding, flocking, communication)

If anybody tries the demo please let me know how it runs (outside a browser) - I'm interested in the spec of you machine a som idea of CPU usage.