Mainly adding 'wire' suffix to wire/distance drawing func and shader.
Also, match wire vertex shader behavior with solid one regarding
head/tail only drawing (i.e. alwas expect head bone mat, never tail one,
and assume that if a radius is negative, then we only draw on the other
end of the bone).
Envelope bones are now pretty much identical to old drawing code.
Note that currently new DwM drawing code does not seem to care about
wire/solid drawing modes at all, guess this is still TODO... For now we
hence just get both wire and solid for envelope bones, this can be
refined later.
This is not complete, it does not implement 3D solid drawing of
envelope bones. 2D wire is hence always drawn for now.
Some notes:
I did not try to implement the 'capsule' approach suggested by @fclem, because:
1. I spent enough time on this already, and finally got something working.
2. I managed to get rid of geometry shader completely.
3. Current approach allows us to use same shader for
distance outline and envelope wire.
It's working fine, except for one glitch - superpositions of envelope
outlines do not work as expected, not sure what's wrong here, tried to
disable zbuff, enable GL_BLEND, no luck so far...
I think we need our own 'background' drawpass to get them working (also
to avoid them drawing over the wire lines).
Changing states didn't properly reset between shading groups
causing the GL state to be wrong based on draw order.
States are now only set when changed.
All engines are now called by the draw manager. Engines are separate entities that cannot interfer with each others.
Also separated draw_mode_pass.c into the mode engines.
