Fix shader_dxbc.h compiling on linux with vulkan

[L3nn0x]

On linux when trying to build with vulkan on and opengl off, shader_dxbc.h is included after Xlib.h which includes X.h which in turn #define None 0. Undefining so we can properly compile the file.

[mcourteaux]

This should probably be wrapped in an #ifdef None ... #endif.

[bkaradzic]

I'm not getting this error when building on Linux with D3D11 and D3D12 only.

Env var: BGFX_CONFIG is set to "RENDERER_DIRECT3D11=1 RENDERER_DIRECT3D12=1"

[L3nn0x]

I haven't tried with D3D11 nor D3D12. What I observed is that the vulkan header includes Xlib.h which causes the define issue. Looking at the D3D code, I don't see any Xlib.h include.
Building bgfx with only vulkan support seems to cause the issue, because if I build with both vulkan and openGL support, I do not get the issue.

[bkaradzic]

../../../src/bgfx.cpp (1613): BGFX Supported renderer backends (2):
../../../src/bgfx.cpp (1616): BGFX 	 - Noop
../../../src/bgfx.cpp (1616): BGFX 	 - Vulkan

Just built with VK only and still don't get the issue...

[L3nn0x]

I'm so sorry, I completely forgot to mention that I'm building the amalgamated version of bgfx.
The order of includes is as follow:

• renderer_vk.cpp
• renderer_vk.h (because BGFX_CONFIG_RENDERER_VULKAN is set)
• vulkan-local/vulkan.h
• X11/Xlib.h (because VK_USE_PLATFORM_XLIB_KHR is set, I'm using the Kronos version from the 3rdparty in bgfx)
• X11/X.h -> contains #define None 0
• shader_dbxbc.cpp
• shader_dbxbc.h -> contains DxbcOperandModifier::None which gets pre-processed to DxbcOperandModifier::0 because of the define higher up

One other possibility would be to put renderer_vk.cpp after shader_dbxbc.cpp in the amalgamated source.

Hopefully that helps diagnose the issue.

[bkaradzic]

Ok lets try like this...

I modify src/config.h near top of the file:

#define BGFX_CONFIG_RENDERER_VULKAN 1

And then I run this:

genie --with-combined-examples --with-amalgamated --gcc=linux-gcc gmake
make --no-print-directory -C .build/projects/gmake-linux-gcc config=debug64 -j 6 examples

I get no issues.

[mcourteaux]

@L3nn0x You should try to figure out what it is on your system that causes this to not work:

bgfx/src/renderer_vk.h

Lines 35 to 38 in a37185e

	// vulkan.h pulls X11 crap...
	#if defined(None)
	# undef None
	#endif // defined(None)

This #undef is already there, so something seems off...

[L3nn0x]

I'll try to figure out what's wrong with my system and if I can repro I'll reopen. Thank you for your time both 😄