Update: This project has been merged into Monogame Extended. I'm currently not working on a project that needs this engine, but if I need it in the future I'll probably write up an editor for effects and maybe a renderer that hands out some work to the GPU (not sure about performance right now, but a faster renderer is definitely possible).
This is a version of the Mercury Particle Engine usable with MonoGame. Basically to use the MPE all that's needed is a renderer that uses the MonoGame SpriteBatch and functions to convert HSL color to RGB. I made some other changes however, that made the engine more convenient to use IMO.
Structure
Let's see how this all works! :) We start out with a ParticleEffect. A ParticleEffect has one or more Emitters. An emitter shoots out particles whenever the parent effect is triggered. The initial properties of a particle are determined by the Profile of the emitter and the ReleaseParameters of the emitter. The Texture that the particles use is specified in their Emitter.
Profiles
The Profile can be seen as the shape of the emitter. It determines where particles are released and what direction they go to. For example a Point profile sends out particles with a random direction from the center off the emitter, while a ring profile creates particles at a certain distance from the center and makes them go either towards the center or away from it.
ReleaseParameters
The ReleaseParameters of an emitter determine the initial properties of the particles. Most of these are ranges from which a value gets picked randomly on releasing a particle. The number of particles released when the emitter is triggered is also set in here. Parameters specify initial Velocity (note: not direction, that's handled by the profile), Colour (which are HSL colors, I stuck with the original naming), Opacity, Scale, Rotation and Mass (for force modifiers).
Modifiers
Of course that's not very flexible, so to actually do something with the particles we use Modifiers. An Emitter has a list of modifiers. When an effect is updated, it updates all it's emitters which then move all their particles and update all Modifiers. When updated a Modifier can change particle properties. The Modifier names pretty much speak for themselves.
Example
A Game wich draws a simple particle effect to the screen can be found here.
Changes to original MPE
Modifications
- Made the particle buffer circular. (it copied over particles at every reclaim)
- Made an iterator for the particle buffer.
- Changed particle to use structs rather than using arrays of floats (so you can say particle->Position.X instead of particle->Position[0])
- Made scale a vector for separate x and y scaling.
Additions
- As mentioned before I added a ColorHelper class to convert colors.
- New container modifiers