This is to allow StretchRect to pass the texture filter to WineD3D.
DirectDraw sets the texture filter to WINED3DTEXF_NONE, simmilar to all
other functions which do not need filtering.
When using pbuffer or back buffer offscreen rendering the content of
the drawable will have been overwritten. Thus the texture has to be
written into the drawable. An exception is the (pretty common) case
that the whole render target is cleared before rendering to it.
The state handler binds index buffer 0 when a user pointer is used. Likewise the real index
buffer has to be restored when switching back to drawing from index buffers.
Previously the surfaces stored a flag if the system memory copy was
ahead of the gl copy(SFLAG_DIRTY) or the gl copy is
ahead(SFLAG_GLDIRTY). The pbuffer copy was 'managed' differently using
SFLAG_INPBUFFER and SFLAG_INTEXTURE.
This patch replaces them with 3 flags, INSYSMEM, INPBUFFER and
INTEXTURE which specify which copy contains the most up to date
copy. It is perfectly valid to have more than one of those flags
set. One must be set at least (except at init, when no content is in
the surface yet). When one copy is modified, the flags for the others
are removed.
The gl viewport origin is the lower left corner of the window, in d3d
it is the upper right corner. This is corrected when setting the
viewport. However, when we are doing offscreen rendering, this is
reversed. So do not flip the viewport origin when rendering offscreen.
Except with fbos, it is not possible to remove the depth stencil
buffer from the opengl frame buffer, so when the d3d app sets a NULL
depth stencil disable all states that work with the depth stencil
buffer.
It was incorrect to disable the scissor test for full surfaces in my
clear patch. With back buffer offscreen rendering the viewport does
not seem to restrict clearing, and with different sizes of depth
stencil and color buffer the final fantasy XI demo seems to expect the
clear to be restricted.
OpenGL AUX buffers provide a way for offscreen rendering which is very
similar to our back buffer "offscreen" rendering emulation. Not all
card support aux buffers, but if they are available they are a nice
present which is easy to use.
Index buffer creation changes the bound gl buffer, thus the state has to
be dirtified, similar to locking.
In an error case the function returned without calling LEAVE_GL().
