Three optimizations are applied:
1. If the list of vertices to clip is empty, return immediately after
clearing the output list.
2. Remember the previous vertex instead of recalculating whether it is
within the clip plane.
3. Instead of copying and swapping lists around, operate on the input
and output lists directly. This prevents a lot of `malloc`/`free`
traffic as a result of vector assignments.
This takes the clipping code CPU load from 3.9% down to 1.8% for
Quake 3 on my machine.
The `ClipPlane` enum is being looped over at run-time performing
run-time dispatch to determine the comparison operation in
`point_within_clip_plane`.
Change this `for` loop to be linear code which dispatches using a
template parameter. This allows for the `point_within_clip_plane`
function to do compile-time dispatch.
Note: This linear code can become a compile-time loop when static
reflection lands in C++2[y|z] allowing looping over the reflected
`enum class`.
The clipping logic is not DRY (Don't Repeat Yourself). The same logic
is repeated in multiple parts of an `if-else` statement. This can be
simplified to contain fewer branches and eliminate the redundant code.
Much of the `Clipper` class can be made free functions and their scope
limited.
The purpose of this is to prepare the interface for a change to more
compile-time dispatch.
We now have one set of texture coordinates per texture unit.
Texture coordinate generation and texture coordinate assignment is
currently only stubbed. This will be rectified in another commit.
This follows the OpenGL 1.5 spec much more closely. We need to store
the eye coordinates especially, since they are used in texture
coordinate generation and fog fragment depth calculation.
This introduces a new library, LibSoftGPU, that incorporates all
rendering related features that formerly resided within LibGL itself.
Going forward we will make both libraries completely independent from
each other allowing LibGL to load different, possibly accelerated,
rendering backends.
2021-12-24 05:10:28 -08:00
Renamed from Userland/Libraries/LibGL/Clipper.cpp (Browse further)
