[ros-dev] Problem with out current NtGdiExtGetObjectW implementation

[Timo Kreuzer]

Hi,

although I like the way NtGdiExtGetObjectW is using the union, we will 
get a problem with it.
We don't know how many styles an extpen has, so we cannot statically 
allocate a kmode buffer that is big enough.

I can currently think of 3 possible solutions:

1. Add a big additional hack for GDI_OBJECT_TYPE_EXTPEN in 
NtGdiExtGetObjectW, that will copy the styles, wich seems to be a bad idea.

2. Use the old method of first calling IntGdiExtGetObjectW to get the 
needed buffer size then allocate a kernelmode buffer then call 
IntGdiExtGetObjectW again to tranfer the data then copy to usermode. 
This is slower and needs extra memory.

3. Move the copying to usermode to the XXX_GetObject functions. This 
would remove the need for an extra kernelmode buffer and we wouldn't 
really need IntGdiExtGetObjectW anymore. But it doesn't match the rest 
of our call chain design.

Comments appreciated.
Timo