Textures are stored in a global hashtable. Each mesh pipeline has access
to a single texture. The texture may be used as an atlas by creating
meshes with different texture coordinates. The current system should be
fine for text glyphs. However, if you have an atlas where each
subdivision is equal in its dimensions, the use of layers and the
VK_IMAGE_VIEW_TYPE_2D_ARRAY view type would be best. Some preliminary
code for this was completed, but for now inserting textures into the
hashmap defaults to VK_IMAGE_VIEW_TYPE_2D.
