I
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270 '
280'Subroutine to draw a line from Xl,Yl to X2,Y2.
290'
300 | XL = x2 - xl | : YL = Y2 - Yl |
310 | NX = ABS(XL*LXFAC) : NY = ABS(YL*LYFAC) | |
320 | IF NX < NY THEN NX = NY | |
330NS% = INT(NX+l)
340 DX = XL/NS% | : DY = YL/NS% | |
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350FOR 1% = 1 TO NS%
360 | Xl = Xl + DX | : Yl = Yl + DY | - |
370 | GOSUB 400 |
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380 | NEXT 1% | - |
390 RETURN |
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400 | ’ | ~- |
410 'Subroutine to plot a point at Xl,Yl. |
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42Q | ' | - |
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430xx = Xl * LXFAC : YY = Yl * LYFAC
440COL% = INT(XX) + 1
450 ROW% = INT(YY/G) | - |
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460XIT% = INT(YY - ROW% * 6) + 1
470BIT%(COL%,ROW%) = BIT%(COL%,ROW%) OR MASK%(XIT%)
480RETURN
600’
619' Subroutine to plot a circle.
620'
630RAD = 9
644) | xl = 19 | : Yl = 10 | - | |
6541FOR ANG% = Q TO 360 STEP 10 | ||||
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660 | RANG = ANG%"6.28/360 | - | ||
670 X2 = RAD*COS(RANG)+lQ : Y2 = RAD*SIN(RANG)+lQ | ||||
680 | GOSUB 270 |
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690 NEXT ANG% |
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700 RETURN
If you are using with the IBM mode. change the following lines | - |
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to the program given above. |
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160 LPRINT CHR$(27) "A" CHR$(6) CHR$(27) "2" |
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250 LPRINT CHR$(27) "A" CHR$(12) CHR$(27) "2" |
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n How the program works |
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In the program above, we’ve created an array called BIT%, |
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which is dimensioned in line 50. You’ll note that instead of using |
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numeric constants to dimension the array, we used the variables |
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MAXCOL% and MAXROW%. This way, if your computer |
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has enough memory and you want to plot a larger image, all |
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112
