Descend collision was broken because of two reasons - one complicated and
one easy. Firstly, we would not re-visit beams after eliminations if they
were closer to the light source than the remaining beam. Especially nasty
because the comments claimed the opposite. Secondly, the coordinates
passed to find_cross were actually flipped.
I took the opportunity to clean up the control structure a bit, update
the comments (brr), and fix the bug in one swoop.
While none of the mismatches were having a side-effect, this silences a
number of -Wreorder warnings which were drowning out potentially
important diagnostics.
This should improve cache coherency by having all surface tiles adjacent
instead of strewn across the heap. This will also remove an indirection
in the common case of only using one tile.
- Increase light fade-in/fade-out quite a bit (4 times stronger)
- Fixed normal jump when multiple lights intersect (will make things a
little less nice with only one light, but this takes priority)
- Don't draw objects without light in light-debug mode
The "b" value returned by the new find_cross function had basically
nothing to do with what the old version did (it was for the other
pair of coordinates *and* sign-switched). This is not cosmetical - the
algorithm depends quite a bit on this being consistent.
Additionally, most of the list modifications in CalculateTriangles were
wrong (didn't reprocess last triangle for ascend shadowing, and the descend
case was removing the wrong triangle). I admit the old code was probably a
bit too tricky with how it handled "i", so I attempted to refactor it to
make it less easy to screw up in future.
With this change, an additional rectangle is stored in C4FoWRegion that
represents the area covered by the viewport in fractional floating point
coordinates. This allows the light texture to be created for an arbitrary
portion of the landscape, and the coordinate transformations for the
shaders will still work.
Also, since the additional rectangle uses floating point precision, the
computed coordinate transformations do now give the exact same result as for
the landscape pixel-by-pixel, and there should not be any offsets left.
I also hope that this change improves or fixes the single-pixel-lines of sky
that are sometimes seen at the edges of the viewport.
This gets rid of GL state changes for questionable gain. It also fixes drawing
of fade sky backgrounds in global viewports (where, for some reason, the shade
model was set to GL_FLAT instead of GL_SMOOTH).
There were two problems with the previous transforms:
1) For inverting the Y axis for the ambient map, the total height of the
output window is needed, not only the viewport region.
2) The Y offset to only use the part of the light texture that is being
rendered to was not applied.
In order to keep the transformations more readable, a new lightweight class
C4FragTransform has been introduced which can only handle translations
and scales in x and y.
This gives a more consistent normal distribution across directions.
I actually had to make the "normal region" of the light bigger, because
now the Clonk's face would be all dark otherwise. In the end,
everything looks smoother and less flashy now, which is probably as
it should be.
Also slight refactoring.
Now we use the shader to do a proper blend - this avoids some artefacts
that were visible before. Also after some hair-pulling the coordinate
transformation now seems to be more correct than before. Maybe even
with zoom. We'll see.
Peter Wortmann