// d3d9types.h

typedef enum _D3DBLEND {
  D3DBLEND_ZERO,
  D3DBLEND_ONE,
  D3DBLEND_SRCCOLOR,
  D3DBLEND_INVSRCCOLOR,
  D3DBLEND_SRCALPHA,
  D3DBLEND_INVSRCALPHA,
  D3DBLEND_DESTALPHA,
  D3DBLEND_INVDESTALPHA,
  D3DBLEND_DESTCOLOR,
  D3DBLEND_INVDESTCOLOR,
  D3DBLEND_SRCALPHASAT,
  D3DBLEND_BOTHSRCALPHA,
  D3DBLEND_BOTHINVSRCALPHA,
  D3DBLEND_BLENDFACTOR,
  D3DBLEND_INVBLENDFACTOR,
  D3DBLEND_SRCCOLOR2,
  D3DBLEND_INVSRCCOLOR2,
  D3DBLEND_FORCE_DWORD
} D3DBLEND;
View the official Windows Driver Kit DDI reference