Doesn't build against projectM HEAD due to missing text-related helpers

[nzoschke]

https://github.com/projectM-visualizer/projectm/pull/652 removed parts of projectM this frontend uses.

The errors I get when building the frontend are

% make
Consolidate compiler generated dependencies of target projectMSDL
[ 11%] Building CXX object src/CMakeFiles/projectMSDL.dir/AudioCapture.cpp.o
[ 22%] Building CXX object src/CMakeFiles/projectMSDL.dir/ProjectMSDLApplication.cpp.o
[ 33%] Building CXX object src/CMakeFiles/projectMSDL.dir/ProjectMWrapper.cpp.o
[ 44%] Building CXX object src/CMakeFiles/projectMSDL.dir/RenderLoop.cpp.o
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:59:21: error: use of undeclared identifier 'projectm_is_text_input_active'
                if (projectm_is_text_input_active(_projectMHandle, true))
                    ^
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:70:22: error: use of undeclared identifier 'projectm_is_text_input_active'
                if (!projectm_is_text_input_active(_projectMHandle, true))
                     ^
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:85:21: error: use of undeclared identifier 'projectm_is_text_input_active'
                if (projectm_is_text_input_active(_projectMHandle, true))
                    ^
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:87:21: error: use of undeclared identifier 'projectm_set_search_text'; did you mean 'projectm_get_search_index'?
                    projectm_set_search_text(_projectMHandle, event.text.text);
                    ^~~~~~~~~~~~~~~~~~~~~~~~
                    projectm_get_search_index
/usr/local/include/libprojectM/projectM.h:822:30: note: 'projectm_get_search_index' declared here
PROJECTM_EXPORT unsigned int projectm_get_search_index(projectm_handle instance, const char* name);
                             ^
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:88:21: error: use of undeclared identifier 'projectm_populate_preset_menu'
                    projectm_populate_preset_menu(_projectMHandle);
                    ^
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:167:13: error: use of undeclared identifier 'projectm_set_toast_message'
            projectm_set_toast_message(_projectMHandle, aspectCorrectionEnabled ? "Aspect Correction Enabled"
            ^
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:196:17: error: use of undeclared identifier 'projectm_set_toast_message'
                projectm_set_toast_message(_projectMHandle, _audioCapture.AudioDeviceName().c_str());
                ^
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:234:13: error: use of undeclared identifier 'projectm_set_toast_message'
            projectm_set_toast_message(_projectMHandle, shuffleEnabled ? "Shuffle Enabled" : "Shuffle Disabled");
            ^
/Users/noah/src/frontend-sdl2/src/RenderLoop.cpp:340:13: error: use of undeclared identifier 'projectm_delete_search_text'
            projectm_delete_search_text(_projectMHandle);
            ^
9 errors generated.
make[2]: *** [src/CMakeFiles/projectMSDL.dir/RenderLoop.cpp.o] Error 1
make[1]: *** [src/CMakeFiles/projectMSDL.dir/all] Error 2
make: *** [all] Error 2

Workaround is to build projectM from and older version:

cd projectm
git reset --hard 62cecb36d6c796771f84511347a5772b48162960
cmake && make && make install

[nzoschke]

I assume any frontends should do their own text overlays going forward.

[kblaschke]

Lots of API changes going on now, e.g. splitting out playlist management and removing the built-in key handler, so this breakage is intentional. The frontend will be adapted to the changes when the API changes are finished, so the work has to be done only once instead of every push in the main repo.

For the future, I'll probably add a libprojectm Git submodule to this project, pointing to a known working commit in the upstream repo. This would make things easier for other devs to determine which commit of libprojectM still works.

[kblaschke]

It is now building against 4.0.0-rc1 in current master, plus a few additional fixes.