'===========================================================================
' Subject: VARYING WINDMILLS                 Date: 06-02-95 (21:50)       
' Author:  Ryan White                        Code: QB, QBasic, PDS        
' Origin:  BIGFOOT@SunBelt.Net             Packet: GRAPHICS.ABC
'===========================================================================
SCREEN 13
CLS
C = 16
E = 1
ON KEY(1) GOSUB ECH1
KEY(1) ON
ON KEY(2) GOSUB ECH2
KEY(2) ON

ST:
FOR X = 1 TO 80 STEP E
IF C >= 30 THEN C$ = "Y" ELSE IF C <= 16 THEN C$ = "N"
IF C$ = "Y" THEN C = C - 1 ELSE C = C + 1

LINE (X, 1)-(80 - X, 49), C
LINE (80 + X, 1)-(160 - X, 49), C
LINE (160 + X, 1)-(240 - X, 49), C
LINE (240 + X, 1)-(320 - X, 49), C

LINE (X, 50)-(80 - X, 99), C
LINE (80 + X, 50)-(160 - X, 99), C
LINE (160 + X, 50)-(240 - X, 99), C
LINE (240 + X, 50)-(320 - X, 99), C

LINE (X, 100)-(80 - X, 149), C
LINE (80 + X, 100)-(160 - X, 149), C
LINE (160 + X, 100)-(240 - X, 149), C
LINE (240 + X, 100)-(320 - X, 149), C

LINE (X, 149)-(80 - X, 199), C
LINE (80 + X, 149)-(160 - X, 199), C
LINE (160 + X, 149)-(240 - X, 199), C
LINE (240 + X, 149)-(320 - X, 199), C
NEXT X

FOR Y = 49 TO 1 STEP -E
IF C >= 30 THEN C$ = "Y" ELSE IF C <= 16 THEN C$ = "N"
IF C$ = "Y" THEN C = C - 1 ELSE C = C + 1

LINE (1, Y)-(80, 50 - Y), C
LINE (81, Y)-(160, 50 - Y), C
LINE (161, Y)-(240, 50 - Y), C
LINE (241, Y)-(320, 50 - Y), C

LINE (1, Y + 50)-(80, 100 - Y), C
LINE (81, Y + 50)-(160, 100 - Y), C
LINE (161, Y + 50)-(240, 100 - Y), C
LINE (241, Y + 50)-(320, 100 - Y), C

LINE (1, Y + 100)-(80, 150 - Y), C
LINE (81, Y + 100)-(160, 150 - Y), C
LINE (161, Y + 100)-(240, 150 - Y), C
LINE (241, Y + 100)-(320, 150 - Y), C

LINE (1, Y + 150)-(80, 200 - Y), C
LINE (81, Y + 150)-(160, 200 - Y), C
LINE (161, Y + 150)-(240, 200 - Y), C
LINE (241, Y + 150)-(320, 200 - Y), C
NEXT Y

IF INKEY$ = "" GOTO ST
END

ECH1:
IF E >= 1.1 THEN E = E - 1 ELSE E = E - .1
IF E <= .2 THEN E = 1
RETURN

ECH2:
E = E + 1
RETURN