The red color channel calculation could overflow into the sign bit,
which is undefined behavior. At least one compiler takes advantage of
this and assumes it cannot happen, resulting in incorrect results.
BltAlphaAdd looks similar, but does in fact not have this bug because it
shifts the color channel far enough that multiplication can't overflow.
This is required for glDrawElements() with a core profile. Furthermore, for
meshes that have a fixed face ordering (non-transparent meshes at 100%
completion), this puts more static data on the GPU that we don't have to
upload every frame.
For meshes with non-fixed face ordering, we still have to upload faces every
frame, since the ordering might change if the mesh rotates. We could still
improve this by figuring out if the order actually changed after the sort
step, and only update to the GPU if it has. In many cases it hasn't, so there
is some potential for more optimization there. But that's for later.
Since mesh instances can now be attached to attached definitions, attached
definitions need to denumerate pointers recursively to make sure that the
reference to the mesh instance is restored correctly.
Changing the mesh material to something that does not use alpha blending
restores the originial face order. This caused a crash for meshes with
Completion below 1, since all original faces were copied, but the buffer
in the mesh instance was only large enough to hold the number of faces of
the incompleted mesh. To fix this, simply run the standard
select-faces-for-a-given-completion-value procedure.
Replace the hardcoded VAI_ constants with that. The VAI constants are now
moved to C4DrawGL as C4SSA_ constants, similar to the C4SSU ones. This allows
to introduce other attributes to replace vertex positions, normals, colors
and texture coordinates with attributes in later commits. This, in turn, is
needed because the built-in attributes are no longer available in the OpenGL
core profile.
Also, while at it, cleanup C4Shader a bit. Use std::vector<> instead of
maintaining an own array of uniform names. Delete the vertex and fragment
objects after the full shader program has been linked. Make sure that
C4Shader::Init keeps the old program in place if the new one cannot be
compiled or linked.
The only use of C4RTF in its final moments was parsing out plain text
from RTF files anyway, so why even go to all the trouble instead of just
storing plain text in the beginning?
Instead, compute the projection, modelview and normal matrices explictly
and upload them as shader uniforms. This is one step towards using the
OpenGL 3 core profile.
The C++ standard library comes with perfectly fine implementations of
these functions, so there's no point in reimplementing them just for the
hell of it.
Using memset to initialize non-POD types doesn't work. Or rather, it may
work right now, but will fail when somebody adds a member that relies on
its constructor doing something (like for example any STL container).
Either way it's undefined behavior and needs to go. Furthermore, using
it to reinitialize an object also prevents any dtors from doing their
work when needed.
A new helper function InplaceReconstruct will take an object of nothrow-
default-constructible type, and call the dtor to properly clean up
before placement-new reconstructing the object in the same location.
This is still bad design, but unfortunately removing the Default/Clear
functions from every object currently using them is a herculean task.
This implements the proposal made in the forum for "shiny" materials -
material can now determine the angle at which the most light is reflected.
Shiny materials might set this lower to approximate a "reflection" effect,
and increase the "spottiness" at the same time. To compensate for the
lack of brightness without light, "emittance" can be used.
Not sure this is the most elegant way to model this - the "proper" way
here would be to have emittance, shading and specular as three separate
light parameters instead of molding one into the other and using the third
to compensate.
Furthermore, this reorganises shaders in a major way: We reduce the
number of shader files down to three, pushing a number of possible
configurations into preprocessor. I believe this should be easier to
understand, which for the moment trumps theoretical extensibility
benefits.
We already require support for std::unique_ptr, which itself requires
support for rvalue references. As such, we know we can use rvalue
references, and thus don't have to keep carrying dead code around.
In comparison to the old system, this is a downgrade - instead of being
able to set a full color mapping by gamma ramp, we now get just a value
per colour channel.
Upside is that we do not need to play around with the global gamma ramps
any more, which was arguably the wrong way to do it.
This commit will likely break everything that has been using gamma so far.
Instead of doing the transformation when drawing a mesh. This allows making
the OpenGL normal matrix more consistent, since it does not include the
Ogre-To-Clonk transformation, and so that the transformation does not need
to be inverted in the shader.
As a side effect, all Attach transformations were updated, since before
they were specified in the OGRE reference frame, not the Clonk reference
frame.
Nicolas Hake