On Mac it happens that when a context is bound to a pbuffer
and you want to bind it to a window (NSView) instead you must
release it from the pbuffer before binding the window by calling
clearDrawable handle of NSOpenGLContext.
This change added an override of NSOpenGLContext in order to track
to which drawable type the context was previously bound and
call clearDrawable when necessary.
Change-Id: Iece5ab16a46aa0d107ccb773986a6b280d09d181
The following enables the renderer build on darwin.
Moved platform specific type declarations from render_api.h
to render_api_platform_types.h so it can be included from the
objective c code.
Fixed subwindow to use EmuGLView which overrides NSView to prevent
background drawing of the view.
The application provides the window handle to which the
OpenglRenderer should render to however only a sub-region of
this window needs to be rendered. This change adds this functionality
by creating a native child subwindow into which rendering will happen.
