Each texture unit now has its own texture transformation matrix stack.
Introduce a new texture unit configuration that is synced when changed.
Because we're no longer passing a silly `Vector` when drawing each
primitive, this results in a slightly improved frames per second :^)
This commit implements glClipPlane and its supporting calls, backed
by new support for user-defined clip planes in the software GPU clipper.
This fixes some visual bugs seen in the Quake III port, in which mirrors
would only reflect correctly from close distances.
Implement (anti)aliased point drawing and anti-aliased line drawing.
Supported through LibGL's `GL_POINTS`, `GL_LINES`, `GL_LINE_LOOP` and
`GL_LINE_STRIP`.
In order to support this, `LibSoftGPU`s rasterization logic was
reworked. Now, any primitive can be drawn by invoking `rasterize()`
which takes care of the quad loop and fragment testing logic. Three
callbacks need to be passed:
* `set_coverage_mask`: the primitive needs to provide initial coverage
mask information so fragments can be discarded early.
* `set_quad_depth`: fragments survived stencil testing, so depth values
need to be set so depth testing can take place.
* `set_quad_attributes`: fragments survived depth testing, so fragment
shading is going to take place. All attributes like color, tex coords
and fog depth need to be set so alpha testing and eventually,
fragment rasterization can take place.
As of this commit, there are four instantiations of this function:
* Triangle rasterization
* Points - aliased
* Points - anti-aliased
* Lines - anti-aliased
In order to standardize vertex processing for all primitive types,
things like vertex transformation, lighting and tex coord generation
are now taking place before clipping.
By setting the clip plane normals' W coordinate to 1, we can skip two
coordinate retrievals and three additions. This works because the
Vector `.dot()` operation multiplies the W coordinates of both vectors.
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)
