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
