Blender Git Loki

The long awaited Particle patch from Janne Karhu

http://www.blender3d.org/cms/New_Particle_options_a.721.0.html

There's no doubt this patch had a lot of good ideas for features, and I
want to compliment Janne again for getting it all to work even!
A more careful review of the features and code did show however quite some
flaws and bugs... partially because the current particle code was very much
polluted already, but also because of the implementation lacked quality.
However, the patch was too good to reject, so I've fixed and recoded the
parts that needed it most. :)

Here's a list of of most evident changes in the patch;

- Guides support recoded. It was implemented as a true 'force field',
checking all Curve path points for each particle to find the closest. Was
just far too slow, and didn't support looping or bends well.
The new implementation is fast (real time) and treats the paths as actual
trajectory for the particle.
- Guides didn't integrate in the physics/speed system either, was added as
exception. Now it's integrated and can be combined with other velocities
or forces
- Use of Fields was slow code in general, made it use a Cache instead.
- The "even" distribution didn't work for Jittered sample patterns.
- The "even" or "vertexgroup" code in the main loops were badly constructed,
giving too much cpu for a simple task. Instead of going over all faces
many times, it now only does it once.
Same part of the code used a lot of temporal unneeded mallocs.
- Use of DerivedMesh or Mesh was confused, didn't work for Subsurfs in all
cases
- Support for vertex groups was slow, evaluating vertexgroups too often
- When a vertexgroup failed to read, it was wrongly handled (set to zero).
VertexGroup support now is with a name.
- Split up the too huge build_particle() call in some parts (moving new code)
- The "texture re-timing" option failed for moving Objects. The old code used
the convention that particles were added with increasing time steps.
Solved by creating a object Matrix Cache.
Also: the texture coordinates had to be corrected to become "OrCo".
- The "Disp" option only was used to draw less particles. Changed it to
actually calculate fewer particles for 3D viewing, but render all still.
So now it can be used to keep editing realtime.

Removed;

The "speed threshold" and "Tight" features were not copied over. This
resembled too much to feature overkill. Needs re-evaluation.
Also the "Deform" option was not added, I prefer to first check if the
current particle system really works for the Modifier system.

And:

- Added integration for particle force fields in the dependency graph
- Added TAB completion for vertexgroup names!
- Made the 'wait cursor' only appear when particles take more than 0.5 sec
- The particle jitter table order now is randomized too, giving much
nicer emitting of particles in large faces.
- Vortex field didn't correctly use speed/forces, so it didn't work for
collisions.
- Triangle distribution was wrong
- Removed ancient bug that applied in a *very* weird way speed and forces.
(location changes got the half force, speed the full...???)

So much... might have forgotten some notes! :)