@hwnd%

[Richard Russell]

The obvious bit that stands out are the 2 single byte elements in the DEPTH_STENCIL_DESC, these are coded by the compiler in 32bit mode which ads the padding automatically (so AI says),

If your 32-bit structure is working that can't be right, because there's no 'automatic padding' in BBC BASIC - the structure members are always close-packed with whatever size you've declared them as (one byte in the case of depthStencilDesc.StencilReadMask&). Indeed, from the declarations you listed, the subsequent FrontFace{} and BackFace{} structures are not even 4-byte aligned.

That's probably quite significant, because if there isn't a requirement for 4-byte alignment in the 32-bit version it's probably the case that there's no requirement for 8-byte alignment (or even 4-byte alignment) in the 64-bit version! So maybe the AI is giving misleading information.

Indeed, from a quick glance, there's nothing in any of the structures you listed that would make me think you need to make any changes at all between 32-bit and 64-bit mode. I might be wrong, but the obvious candidates for changes being needed (pointers and handles - which are often pointers under the hood) don't seem to be present at all.

But it all comes down to how the structures are declared in C and whether the compiler's padding rules are set differently in the 32-bit amd 64-bit builds. If they are, all bets are off.

[Richard Russell]

Indeed, from a quick glance, there's nothing in any of the structures you listed that would make me think you need to make any changes at all between 32-bit and 64-bit mode.

I asked Gemini AI the direct question:

In respect of the Windows D3D11_DEPTH_STENCIL_DESC and D3D11_DEPTH_STENCIL_VIEW_DESC structures (and their sub-structures), are there any differences between 32-bit and 64-bit builds? Do any of the members change size or alignment?

and its answer was:

No, there are no functional differences in size or alignment for these specific structures between 32-bit (x86) and 64-bit (x64) builds.
Because these structures consist entirely of fixed-size types like UINT, BOOL, and enums (which are 4 bytes in the Windows C++ environment), they do not contain pointers or size_t members that vary by architecture.

As that agrees with my own analysis, it may be right.

[Ric]

Thanks Richard, it is a bit disappointing because I thought I was nearing the end of what the problem could be. I'll try AI with the same question for the rest of the structures and see what happens.