Fills in a region of the graphics window containing the turtle and bounded by lines that have been drawn earlier. It fills using the current value of FLOODCOLOR.
fillmode is TRUE, then FILL fills until the current PENCOLOR is encountered.
fillmode is FALSE, then FILL fills while on same color.
fillmode is not given, it defaults to FALSE.
Fill can be used in PERSPECTIVE mode as long as the area to filled is bounded and you only fill what's in plain view. For example if you have a cube don't draw all 6 faces, only 3 at most can be in view, so draw just those faces and fill them.
; fill a square REPEAT 4 [FORWARD 100 RIGHT 90] RIGHT 45 PENUP FORWARD 20 FILL
; fill while on the same color SETFLOODCOLOR 4 SETPENCOLOR 1 CIRCLE 50 SETPENCOLOR 2 CIRCLE 100 FILL
; fill until the lines match PENCOLOR SETFLOODCOLOR 4 SETPENCOLOR 1 CIRCLE 50 SETPENCOLOR 2 CIRCLE 100 (FILL "TRUE)
; A 3D example TO SQUARE :color REPEAT 4 [FORWARD 100 RIGHT 90] PENUP RIGHT 45 FORWARD 50 SETFLOODCOLOR :color FILL BACK 50 LEFT 45 PENDOWN END PERSPECTIVE RIGHTROLL 45 DOWNPITCH 45 SQUARE 1 RIGHTROLL 90 SQUARE 2 UPPITCH 90 SQUARE 3