// d3d9types.h

typedef enum _D3DTEXTUREOP {
  D3DTOP_DISABLE,
  D3DTOP_SELECTARG1,
  D3DTOP_SELECTARG2,
  D3DTOP_MODULATE,
  D3DTOP_MODULATE2X,
  D3DTOP_MODULATE4X,
  D3DTOP_ADD,
  D3DTOP_ADDSIGNED,
  D3DTOP_ADDSIGNED2X,
  D3DTOP_SUBTRACT,
  D3DTOP_ADDSMOOTH,
  D3DTOP_BLENDDIFFUSEALPHA,
  D3DTOP_BLENDTEXTUREALPHA,
  D3DTOP_BLENDFACTORALPHA,
  D3DTOP_BLENDTEXTUREALPHAPM,
  D3DTOP_BLENDCURRENTALPHA,
  D3DTOP_PREMODULATE,
  D3DTOP_MODULATEALPHA_ADDCOLOR,
  D3DTOP_MODULATECOLOR_ADDALPHA,
  D3DTOP_MODULATEINVALPHA_ADDCOLOR,
  D3DTOP_MODULATEINVCOLOR_ADDALPHA,
  D3DTOP_BUMPENVMAP,
  D3DTOP_BUMPENVMAPLUMINANCE,
  D3DTOP_DOTPRODUCT3,
  D3DTOP_MULTIPLYADD,
  D3DTOP_LERP,
  D3DTOP_FORCE_DWORD
} D3DTEXTUREOP;
View the official Windows Driver Kit DDI reference