Replace with forward declarations if needed and includes in .cpp that
now need them.
The idea here is to have our headers have the least amount of impact as
possible on our clients (e.g. compilation time).
In commit d955e73 we changed the default IBL from RGBM to RGB, but we
kept its internal format of RGBA8. Since the internal format is not
compatible with the data format, we see GL_INVALID_OPERATION during the
texture upload.
This is a single-pixel black texture, so the format does not really
matter, but this clears up a GL error seen on some platforms.
This class will not extend well to glTF so this cordons it off into the
filamesh namespace, which is an already-existing namespace that we use
for the things related to the filamesh file format.
For glTF we might create a new library with its own MeshReader so
this will mitigate confusion.
This is similar to its WebGL and Android counterparts, we simply did not
have a version for desktop. This uses resgen to package the model's
textures (albedo, normal, roughness, metallic, ao) into a library that
is linked only to this sample.
This is a good test because it applies multiple textures to the model.
Moreover Aaron was asking me for a C++ example that uses compressed
textures.
For now this selects the OpenGL backend. We can change it to use Vulkan
after we add support for 3-band formats to VulkanDriver.
