Similar to the change done in Corrade, see the commit for details:
878624ac36
Wow, this is probably the most backwards-compatibility code I've ever
written. Can't wait until I can drop all that.
As with Corrade, this is not exactly backwards compatible, but for
common use case without OBJECT libraries this should not be a problem.
In any case, recreate the build dir and update your copy of all
Find*.cmake modules to avoid weird things happening.
User-facing changes:
* Documentation of all Find*.cmake modules converted to
reStructuredText to follow official CMake guidelines.
* The newfangled way to use the libraries is to link to Magnum::Shaders
instead of adding ${MAGNUM_SHADERS_INCLUDE_DIRS} to include path and
linking to ${MAGNUM_SHADERS_LIBRARIES}.
* The old ${MAGNUM_*_LIBRARIES} are deprecated and now just expand to
Magnum::* target. Use the target directly. These are also enabled
only when building with MAGNUM_BUILD_DEPRECATED.
* The old ${MAGNUM_*_INCLUDE_DIRS} are removed as the Magnum::* targets
cover these too.
Internal changes:
* Global state such as include_directories() was replaced with
target-specific settings.
Each shader now has sample image, example mesh configuration and example
rendering setup. Also properly documented all attribute types and made
introductory chapter for whole Shaders namespace.
Less typing and less name duplication, but hides the actual load error
from the user. The error is printed on stdout anyway and the user
doesn't care anyway in 90% cases.