Allow `Matrix::inverse()` to return an error and deal with those in
LibGL. Also use this opportunity to more efficiently calculate the
transpose of the model view matrix for the normal transformation.
Context parameters are LibGL's way of centrally defining all parameters
that can be retrieved through `glGetBoolean*`, `glGetInteger*`, etc.
The spec describes that capabilities such as `GL_LIGHTING` can also be
retrieved through these methods, but it should not be possible to
retrieve random boolean parameters through `glIsEnabled`. For example,
`GL_UNPACK_LSB_FIRST` can only be retrieved through `glGet*`.
This moves reading of capabilities to `::get_context_parameter` and
implements its use in `::gl_is_enabled`.
Texture coordinate generation is the concept of automatically
generating vertex texture coordinates instead of using the provided
coordinates (i.e. `glTexCoord`).
This commit implements support for:
* The `GL_TEXTURE_GEN_Q/R/S/T` capabilities
* The `GL_OBJECT_LINEAR`, `GL_EYE_LINEAR`, `GL_SPHERE_MAP`,
`GL_REFLECTION_MAP` and `GL_NORMAL_MAP` modes
* Object and eye plane coefficients (write-only at the moment)
This changeset allows Tux Racer to render its terrain :^)
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.
* LibGL now supports the `GL_NORMALIZE` capability
* LibSoftGPU transforms and normalizes the vertices' normals
Normals are heavily used in texture coordinate generation, to be
implemented in a future commit.
The `GL_LINEAR` param was erroneously not picked up on. Also implement
support for `GL_FOG_START` and `GL_FOG_END`, and make sure that the
`gl_fog*` family of functions are optionally registered with the active
list.
These stubs are largely implemented the same: their API is exposed, but
they print to the debug console and sometimes `TODO()`. These changes
allow GLU and Tux Racer to build.
Methods stubbed:
* `glTexImage1D`
* `glTexImage3D`
* `glTexCoord2d(v)`
* `glNormalPointer`
* `glTexGen(d|f|i)`
* `glTexGenfv`
Previously, if the client supplied `GL_STENCIL_BUFFER_BIT`, `glClear`
would return an error. Since it is a valid parameter, we now continue
and report that this parameter is unimplemented instead.
This adds a method `info()` to SoftGPU that returns the name of the
hardware vendor and device name, as well as the number of texture untis.
LibGL uses the returned texture unit count to initialize its internal
texture unit array.
Replaces the GLenum used in RasterizerConfig to select the draw buffer
with a simple boolean that disabled color output when the draw buffer
is set to GL_NONE on the OpenGL side.
We now sample textures from the device owned image samplers.
Passing of enabled texture units has been simplified by only passing a
list of texture unit indices.
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.
This is a deprecated feature that is still in use in some older games,
most notably Grim Fandango in ScummVM makes heavy use of it.
Luckily, since you can only draw convex polygons, the end result is
exactly the same as when you would have used `glBegin(GL_TRIANGLE_FAN)`
- so we just reuse that code as-is.
Implement support for the `GL_TEXTURE` matrix mode, the texture matrix
stack and texture coordinate matrix transformation.
Also, an unused `m_current_matrix` was removed to make room for
`m_texture_matrix`.
In OpenGL, texture coordinates can have up to 4 values. This change
will help with easy application of texture coordinate matrix
transformations in the future.
Additionally, correct the initial value for texture coordinates to
`{ 0.f, 0.f, 0.f, 1.f}`.
Before, `SoftwareRasterizer` was iterating over all 32 possible texture
units for each fragment and checking each if they're bound to a texture.
After this change, an intrusive list containing only texture units with
bound textures is passed to the rasterizer. In GLQuake, this results in
a performance improvement of ~30% (from 12 to 16 FPS in the first demo)
on my machine.
If an unsupported drawing mode was configured, `glEnd` would not reach
the line where `m_in_draw_state` was set to `false`. This caused all
subsequent invocations to `glBegin` to fail.
