Particles' Collisions in TX2D: Nice and neat :)

I needed a flamethrower... no luck to get it with the engine as it is so... I rushed some code into it to get what I need, here's the very first unit test:



This has been added to the SVN repository (Commit Revision 28) ;)

- Particles' Collisions
- Ability to kill the particle on collision so to stop them when an obstacle is hit (see video)

The Unit Test shown in the video can be downloaded from LIVE here.

How to implement the collisions:

1. First of all recompile the game (with the engine!) because we need to update the schema (also the engine schema!)
2. open your level
3. define at least one level object type to identify what will collide with the particles
4. select the particle effect you want to use and add the component T2DParticleCollisionComponent
5. in the T2DParticleCollisionComponent write the name of the emitter that will generate the colliding particles, declare the target object type, check the Enabled checkbox (and also the KillOnCollision if you want to stop the particles when hit a target) and see if you want to have the Flip-Flop enabled.
6. In Visual Studio create a helper component to assign the SceneObject.Collision.OnParticleCollision delegate (or create the static delegate in your game events class if you want to avoid the helper component)
7. Select in the editor your target objects and add them the target object type and the helper component (or populate the OnParticleCollision in the Collision component if you are using a game event class).

Note on the Flip-Flop flag: to ease the CPU job if this flag is enabled the collisions are processed every 2 rendered particles. This is great if the particles are not too fast. In case you have fast particles and you notice that some collision is missed then disable the Flip-Flop flag.

The FrameInterval property is a more strong way to ease the CPU load: while the Flip-Flop skips half the live particles on each frame you can choose to skip them all, processing collision every <n> frames. this is good for slow particles which will be on the same location for many frames, still be aware that if a fast object goes through the particles within that interval then no collisions will be detected: this feature is to be used wisely.

Obviously put some code in the OnParticleCollision delegate if you want to do something on collision (besides killing the particle).

That's all folks!