diff --git a/src/viewport.h b/src/viewport.h
--- a/src/viewport.h
+++ b/src/viewport.h
@@ -57,11 +57,11 @@ enum {
 
 void OffsetGroundSprite(int x, int y);
 
-void DrawGroundSprite(SpriteID image, SpriteID pal);
-void DrawGroundSpriteAt(SpriteID image, SpriteID pal, int32 x, int32 y, byte z);
-void AddSortableSpriteToDraw(SpriteID image, SpriteID pal, int x, int y, int w, int h, int dz, int z, bool transparent = false, int bb_offset_x = 0, int bb_offset_y = 0, int bb_offset_z = 0);
+void DrawGroundSprite(SpriteID image, SpriteID pal, const SubSprite *sub = NULL);
+void DrawGroundSpriteAt(SpriteID image, SpriteID pal, int32 x, int32 y, byte z, const SubSprite *sub = NULL);
+void AddSortableSpriteToDraw(SpriteID image, SpriteID pal, int x, int y, int w, int h, int dz, int z, bool transparent = false, int bb_offset_x = 0, int bb_offset_y = 0, int bb_offset_z = 0, const SubSprite *sub = NULL);
 void *AddStringToDraw(int x, int y, StringID string, uint64 params_1, uint64 params_2);
-void AddChildSpriteScreen(SpriteID image, SpriteID pal, int x, int y, bool transparent = false);
+void AddChildSpriteScreen(SpriteID image, SpriteID pal, int x, int y, bool transparent = false, const SubSprite *sub = NULL);
 
 
 void StartSpriteCombine();