Use AbstractObject<dimensions, T> like before and add two kinds of
aliases instead of only one:
AbstractBasicObject2D<T>/AbstractBasicObject3D<T> for abstract type and
AbstractObject2D/AbstractObject2D for Float.
Makes it easier to use AbstractObject in templates of fixed dimensions
(e.g. Bullet integration, where it can now be written as
`AbstractBasicObject2D<btScalar>` instead of potentially confusing
`AbstractBasicObject<2, btScalar>`).
Partially reverts commit cfd405c32c.
This allows to use those nice aliases even on GCC <= 4.6 without
resorting to verbose full name. Double and other types can be then
typedef'd as e.g. Camera3Dd or Camera3Di.
Calling functions directly on Object will result in non-virtual calls,
calling functions on AbstractObject will result in virtual calls. Also
removed now unneeded "hacks" like `sceneObject()` and properly hiding
unsafe functions taking `AbstractObject*` with safe functions taking
`Object*`. Also hide `isScene()` from public documentation, as it is
sort-of hack too.
Also updated all dependent classes to follow the change, such as Color
and Rectangle. Backwards compatibility for GCC 4.6 (with lack of support
for delegating constructors) will be done as non-constexpr constructor
using operator=().
* Camera is now templated also on underlying floating-point type.
* Drawable objects can be split into groups (e.g. for separated
rendering of transparent objects)
* Added (long time missing) test for draw() function.
Vladimír Vondruš