1 extern Font* checkfont(Draw_Font*); 2 extern Image* checkimage(Draw_Image*); 3 extern Screen* checkscreen(Draw_Screen*); 4 extern Display* checkdisplay(Draw_Display*); 5 extern void freedrawdisplay(Heap*, int); 6 extern void freedrawfont(Heap*, int); 7 extern void freedrawimage(Heap*, int); 8 extern void freedrawscreen(Heap*, int); 9 extern Font* lookupfont(Draw_Font*); 10 extern Image* lookupimage(Draw_Image*); 11 extern Screen* lookupscreen(Draw_Screen*); 12 extern Draw_Image* mkdrawimage(Image*, Draw_Screen*, Draw_Display*, void*); 13