Allow dcx::window struct to be subclassed step 2. This step renames and reconfigures window_create in window.cpp to be the main constructor. Also add a template constructor that allows an event handler that takes a subclass of window.
Allow dcx::window struct to be subclassed step 1. This step moves the definition for the window struct into window.h, keeping all member variables private and declaring the window related functions as 'friends'. This avoids changes to source files that use the window struct at this stage. Also moving some of the simpler functions in window.cpp into the struct definition to inline them. I would prefer to use class methods, so changing some of these to class methods as well.
Rename symbol OGL to DXX_USE_OGL to show that it is a DXX
symbol, not one inherited from a library. Move it to dxxsconf.h to
shorten the command line.
This is a mostly automated transform, but the changes to SConstruct were
manual.
git grep -lzw OGL -- '*.h' '*.cpp' | xargs -0 sed -i -e 's/\(\s*#\s*if\)def\s*OGL/\1 DXX_USE_OGL/' -e 's/\(\s*#\s*if\)ndef OGL/\1 !DXX_USE_OGL/' -e 's/\(\s*#\s*if !\?\)defined(OGL)/\1DXX_USE_OGL/'
