FXC Define的使用方法

https://docs.microsoft.com/en-us/windows/desktop/direct3dtools/dx-graphics-tools-fxc-syntax

https://www.gamedev.net/forums/topic/667801-some-basic-help-on-fxc-compiling-shaders/

文档里说的很不清晰

fxc /T ps_3_0 /E VS_function /Fo comptst.fxc /D AMBIENT_HEMI /D FOGGING /D USENORMALMAP /D SPECULAR CR_ushader_v1.fx

还可以这样 

/D AMBIENT_HEMI =。。。。value