Previously the number of textures in a packed texture atlas was
not limited. After some time the number of the textures could
grow quite a lot, however the first textures could contain very
little glyphs that are valid. In this commit we add a new method
ReduceTextureNumber which when called, reduces the number of
textures that are tracked by the texutre atlas to the specified
input number, and returnes the texture IDs that were removed so
the caller can now clean-up any invalid (OpenGLTexutre) objects.
Change-Id: I7790e8dddb4586167f860e0ecc81bda1f4dae21a
Reviewed-on: https://gerrit.libreoffice.org/24209
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
56c5a0ba77