REM set screen, set random, dimension wipe-pointsvariables

	CLS : SCREEN 12: CLS : RANDOMIZE TIMER

	DIM WX(4, 15), WY(4, 15)

	DIM WXX(4, 15), WYY(4, 15)



REM set various variables

	R = 5: RR = 4: Z = 2: ZZ = 3

	MAX1 = INT(RND * 50) + 50: MAX2 = INT(RND * 75) + 75

	COLOR1 = INT(RND * 7) + 9: COLOR2 = INT(RND * 7) + 9



REM set number of lines in polygon 1 (max 15)

	W = 15

REM set number of lines in polygon 2 (max 15)

	WW = 7



REM calculate vert. & horz. steps for all cornerpoints

	FOR I = 1 TO 4

		STAPX(I) = INT(RND * R) + Z: STAPY(I) = INT(RND * R) + Z

		X(I) = INT(RND * 640): Y(I) = INT(RND * 480)

		STAPXX(I) = INT(RND * RR) + ZZ: STAPYY(I) = INT(RND * RR) + ZZ

		XX(I) = INT(RND * 640): YY(I) = INT(RND * 480)

	NEXT



MAINLOOP:

	LINE (X(1), Y(1))-(X(2), Y(2)), COLOR1

	LINE (X(2), Y(2))-(X(3), Y(3)), COLOR1

	LINE (X(3), Y(3))-(X(4), Y(4)), COLOR1

	LINE (X(4), Y(4))-(X(1), Y(1)), COLOR1

       

	LINE (XX(1), YY(1))-(XX(2), YY(2)), COLOR2

	LINE (XX(2), YY(2))-(XX(3), YY(3)), COLOR2

	LINE (XX(3), YY(3))-(XX(4), YY(4)), COLOR2

	LINE (XX(4), YY(4))-(XX(1), YY(1)), COLOR2

       

REM swap all cornerpoints 1 step forward

	FOR J = 1 TO 4

		FOR I = 15 TO 2 STEP -1

			WX(J, I) = WX(J, I - 1)

			WY(J, I) = WY(J, I - 1)

			WXX(J, I) = WXX(J, I - 1)

			WYY(J, I) = WYY(J, I - 1)

	       

		NEXT

REM pick new corners for polygon 1

		WX(J, 1) = X(J): X(J) = X(J) + STAPX(J)

		IF X(J) > 639 THEN STAPX(J) = -(INT(RND * R) + Z)

		IF X(J) < 1 THEN STAPX(J) = INT(RND * R) + Z

		WY(J, 1) = Y(J): Y(J) = Y(J) + STAPY(J)

		IF Y(J) > 479 THEN STAPY(J) = -(INT(RND * R) + Z)

		IF Y(J) < 1 THEN STAPY(J) = INT(RND * R) + Z

	       

REM pick new corners for polygon 2

		WXX(J, 1) = XX(J): XX(J) = XX(J) + STAPXX(J)

		IF XX(J) > 639 THEN STAPXX(J) = -(INT(RND * RR) + XZ)

		IF XX(J) < 1 THEN STAPXX(J) = INT(RND * RR) + ZZ

		WYY(J, 1) = YY(J): YY(J) = YY(J) + STAPYY(J)

		IF YY(J) > 479 THEN STAPYY(J) = -(INT(RND * RR) + ZZ)

		IF YY(J) < 1 THEN STAPYY(J) = INT(RND * RR) + ZZ

       

	NEXT



REM wipe last polygon 1

	LINE (WX(1, W), WY(1, W))-(WX(2, W), WY(2, W)), 0

	LINE (WX(2, W), WY(2, W))-(WX(3, W), WY(3, W)), 0

	LINE (WX(3, W), WY(3, W))-(WX(4, W), WY(4, W)), 0

	LINE (WX(4, W), WY(4, W))-(WX(1, W), WY(1, W)), 0



REM wipe last polygon 2

	LINE (WXX(1, WW), WYY(1, WW))-(WXX(2, WW), WYY(2, WW)), 0

	LINE (WXX(2, WW), WYY(2, WW))-(WXX(3, WW), WYY(3, WW)), 0

	LINE (WXX(3, WW), WYY(3, WW))-(WXX(4, WW), WYY(4, WW)), 0

	LINE (WXX(4, WW), WYY(4, WW))-(WXX(1, WW), WYY(1, WW)), 0

	GOSUB COUNTER

GOTO MAINLOOP



COUNTER:    

	COUNTER1 = COUNTER1 + 1: IF COUNTER1 = MAX1 THEN GOSUB SETCOLOR1

	COUNTER2 = COUNTER2 + 1: IF COUNTER2 = MAX2 THEN GOSUB SETCOLOR2

	I$ = INKEY$: IF I$ <> "" THEN SCREEN 0: CLS : END

	RETURN



SETCOLOR1:

	COLOR1 = INT(RND * 7) + 9

	IF COLOR1 = COLOR2 THEN GOTO SETCOLOR1

	MAX1 = INT(RND * 50) + 50

	COUNTER1 = 1: RETURN



SETCOLOR2:

	COLOR2 = INT(RND * 7) + 9

	IF COLOR2 = COLOR1 THEN GOTO SETCOLOR2

	MAX2 = INT(RND * 75) + 75

	COUNTER2 = 1: RETURN