SmileBASIC does not provide a native method of drawing sprite hitboxes, but this is really easy to implement.
DEF SHOW_HITBOX ID%, COL%
VAR X%,Y%,W%,H%,XX%,YY%,S%,SX%=1,SY%=1
SPOFS ID% OUT XX%,YY%
SPCOL ID% OUT X%,Y%,W%,H%,S%
IF S% THEN SPSCALE ID% OUT SX%,SY%
GBOX XX%+X%*SX%,YY%+Y%*SY%,XX%+(X%*SX%+W%*SX%-1),YY%+(Y%*SY%+H%*SY%-1)
END
Usage:
SHOW_HITBOX Management number, drawing color
Example:
SPSET 0,0
SPCOL 0,1
SHOW_HITBOX 0,#GREEN
SPOFS 0,200,120
SHOW_HITBOX 0,#RED
You should see a small green box at the top-left corner, and a big red box somewhat at the center of the screen.
If you are going to run this in a loop, I suggest clearing the graphics screen every frame.