#DEFINE WM_LBUTTONDOWN 513
#DEFINE WM_CLOSE 16

FBSLSETTEXT(ME, "Before Flood Fill") ' Set form caption
FBSLSETFORMCOLOR(ME, RGB(0, 255, 255)) ' Cyan: persistent background color
FBSL.GETDC(ME) ' Use volatile FBSL.GETDC below to avoid extra assignments

RESIZE(ME, 0, 0, 220, 220)
CENTER(ME)
SHOW(ME)

DIM Breadth AS INTEGER, Height AS INTEGER
FBSL.GETCLIENTRECT(ME, 0, 0, Breadth, Height)

DrawCircles() ' Initialize circles

BEGIN EVENTS
	SELECT CASE CBMSG
		CASE WM_LBUTTONDOWN: FillCircles() ' Flood fill circles
		CASE WM_CLOSE: FBSL.RELEASEDC(ME, FBSL.GETDC) ' Clean up
	END SELECT
END EVENTS

SUB FillCircles()
	FILL(FBSL.GETDC, Breadth / 2, Height / 2, &HFFFF) ' Yellow: flood fill using intrinsics
	FOR DIM x = 0 TO Breadth / 2 ' Red: flood fill iteratively
		FOR DIM y = 0 TO Height / 2
			IF NOT POINT(FBSL.GETDC, x, y) THEN PSET(FBSL.GETDC, x, y, &HFF)
		NEXT
	NEXT
	FBSLSETTEXT(ME, "After Flood Fill") ' Reset form caption
END SUB

SUB DrawCircles() ' Concatenate function calls
	CIRCLE(FBSL.GETDC, Breadth / 2, Height / 2, 85, &HFFFFFF, 0, 360, 1, TRUE) _ ' White
	(FBSL.GETDC, Breadth / 3, Height / 3, 30, 0, 0, 360, 1, TRUE) ' Black
END SUB