Passing pointer as function parameter will now mean that it is possible
to pass `nullptr`. Some code examples now look like the parameter is
copied instead of referenced, which is misleading. Updated the
documentation to reflect that more clearly.
Advantages:
* The enums were large (600-800 lines) and they polluted the header,
now they are in separate files (except for BufferTexture, which has
the enum small enough to be left in the same file).
* Image classes now don't need to include OpenGL headers, as they were
needed only for the enum values. With advantage of C++11's forward
enum declarations there is no need to include the enum headers
anywhere in implementation, only when particular values are needed.
* The values are now less verbose:
AbstractTexture::InternalFormat::RGB8 // before
TextureFormat::RGB8 // now
* Resolved another "trivial choice" problem (thanks @JanDupal for
introducing this term to me): how to specify the format if there are
ten ways to do it (some being massively confusing):
Image2D::Format f = AbstractImage::Format::RGB; // too long...
Image2D::Format f = Image3D::Format::RGBA; // why 3D? this works?
Image2D::Format f = BufferImage1D::Format::RGBA; // wat?
It is even worse (and more verbose) with textures:
Texture2D::InternalFormat f =
CubeMapTextureArray::InternalFormat::RGB8; // this is allowed?
To have consistent naming this change was done also with
BufferTexture::InternalFormat (now BufferTextureFormat), although there
were no trivial choice issues and the enum isn't too large. But at least
it is now less typing.
Framebuffer::attach*() doesn't need the target at all (meaning the
attachment will be used for both reading and drawing), another
misunderstanding on my side.
Now the extension is used on all places where it can be used (except for
unimplemented features).
Got rid of InternalFormat class, now it is all in one big enum, as each
version (desktop, ES2, ES3) has different requirements and it can't be
done that way anymore (moreover that was terribly ugly solution).
Some target platforms supply their own OpenGL headers, thus we cannot
use our own from ES 3.0 and compilation fails.
On the other hand, this will be better for users as usage of unsupported
features will be catched right during compilation and not at runtime.
Desktop OpenGL and OpenGL ES 2 support can be switched using CMake
TARGET_GLES option. All functionality not supported in ES is marked in
documentation.
If targetting OpenGL ES, GLES2/gl2.h is included instead of GLEW.
Mesh class now uses VAOs only in desktop OpenGL, in ES the buffers are
bound on each draw call.
Vladimír Vondruš