Previously the API didn't encourage the user to set up and activate
shader before drawing the meshes, leading to unintuitive behavior:
// Can I just call draw() or do I have to fully understand the
// meaning of the universe before?
mesh.draw();
Now the draw() needs the shader passed explicitly as parameter, which
should hint that the shader must be set up somehow:
// Right, so this needs just a shader and that's all. Expecting this
// I fortunately *did* configure all the uniforms before this call.
mesh.draw(shader);
It is also possible to pass the shader as rvalue, in case the drawing is
just a one-off thing and is already fully configured.
mesh.draw(MyShader{});
As usual, the original API is kept, is marked as deprecated and will be
removed in some future release.
Also added (currently disabled) ES implementation (provided by
EXT_separate_shader_objects). Unfortunately it's not possible to reduce
the function count, because ARB_separate_shader_objects and
EXT_direct_state_access are completely independent. Also double uniforms
are supported since GL 4.0 and SSO are since 4.1, so we can't omit
old glUniform*() calls for doubles either.
It now defaults to magnum/ subdirectory of dir where main Magnum library
was found. It was *annoying* to change /usr/local/lib/magnum to
/usr/lib/magnum _every time_.
The previous way was half-working at best, as it handled array textures
improperly. Now there is overload for each texture type. The old way
with attachTexture*D() is marked as deprecated and will be removed in
future release.
Each texture has slightly different usage requirements and having
everything under one generic class is not worth the additional runtime
checks and whatnot. The current way with Texture::Target enum
(hopefully not too widely used) is now deprecated and will be removed in
some future release. However general Texture1D/2D/3D usage is not
changed in any way.
Don't do anything to respond to viewport size by default, as the window
has fixed size in most cases anyway (always fullscreen, canvas of fixed
size in browser etc.). Makes the initial implementation requirements
much simpler and shorter.