Fix precipitation

src/p_mobj.h

@@ -415,6 +415,7 @@ typedef struct precipmobj_s
 	UINT32 renderflags; // render flags
 	fixed_t spritexscale, spriteyscale;
 	fixed_t spritexoffset, spriteyoffset;
+	struct pslope_s *floorspriteslope; // The slope that the floorsprite is rotated by
 
 	struct mprecipsecnode_s *touching_sectorlist; // a linked list of sectors where this object appears