12 lines
523 B
Text
12 lines
523 B
Text
1500 REM === Draw a line. Ported from C version
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1510 REM Inputs are X1, Y1, X2, Y2: Destroys value of X1, Y1
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1520 DX = ABS(X2 - X1):SX = -1:IF X1 < X2 THEN SX = 1
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1530 DY = ABS(Y2 - Y1):SY = -1:IF Y1 < Y2 THEN SY = 1
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1540 ER = -DY:IF DX > DY THEN ER = DX
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1550 ER = INT(ER / 2)
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1560 PLOT X1,Y1:REM This command may differ depending on BASIC dialect
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1570 IF X1 = X2 AND Y1 = Y2 THEN RETURN
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1580 E2 = ER
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1590 IF E2 > -DX THEN ER = ER - DY:X1 = X1 + SX
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1600 IF E2 < DY THEN ER = ER + DX:Y1 = Y1 + SY
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1610 GOTO 1560
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