Split portal-related code to its own source files.
Most of the 2-line-specific setup has been moved to the function which adds a 2-line case. The portals should render as they used to so far, anyway.
Other notes:
* Renamed all new functions to have HWR_ prefix instead of gld_, for consistency
* HWR_FrustrumSetup and HWR_SphereInFrustum are disabled and require HAVE_SPHEREFRUSTRUM. This is because 1) SRB2CB did not need the code, so presumably neither will we, and 2) there are some OpenGL API functions used there that due to our way of using OpenGL we don't use outside of r_opengl.c, which makes dealing with HWR_FrustrumSetup complicated in theory
* The new clipping functions are not added to OpenGL's "main" rendering code itself just yet, they're just available to use now once hw_clip.h is included
CMake: Fix nasm Linux builds
When compiling under Linux with CMake and nasm/yasm enabled, the operation would fail during linking with undefined symbols related to the tmap files.
This commit adds support for passing flags to the assembler and passes ```-DLINUX``` in order to compile.
After this change, binaries are successfully compiled with either nasm or yasm on Linux systems.
Tested on Ubuntu.
See merge request !153
Basically, it manually sets *_FOUND, *_INCLUDE_DIRS and *_LIBRARIES instead of using find_package. Frankly I have no idea how well what I've done works currently though, not even sure if I've set the _LIBRARIES variables correctly. Again, it's WIP work, this can probably be fixed eventually I suppose.
Also updated any relevant project files that I can think of to include the new files, as well as the makefile of course. Some of the other project files haven't been touched in years so I'll leave those alone ...unless someone objects
Core code has too many #define dependencies on interface-specific
defines. This means that it's currently not possible to safely
separate the core and interface code into different contexts. The
core code should be refactored to accomadate for this because we
should not have any interface-specific code in core in the first
place.
This reverts the static library SRB2Core from a7135094 and instead
adds the core sources to the SRB2SDL2 target directly.
So frustrating...
Core and SDL2 are two separate targets now. Core is a static library
that is linked into SRB2SDL2. The sources for both are separated.
When using an IDE like Visual Studio or Xcode, the source code
organized into groups that explain what that group of sources does.
In the future, "Main" could be split into a few more groups based on
file prefixes, but I think the way it is set up works for now.
Makefile targets are not affected by source_groups and typing `make`
will automatically compile both the "Core" library and SRB2SDL2
itself.
