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M 7. 3500
2) Straight line drawing
00000
0028
0001
0027
0050
VRAM 16 bit
structure
Example to draw a straight line from (X, Y) = (3, 1) to (X,
Y) = (635, 1).
Coordinates must be changed to absolute addresses.
(3, 1) - absolute address = 0028H
Dot address = 2H
Displacement between two points when the line draw
direction is OA (to the right): X = 635-3 = 632 (=278H),
Y=0
Whereas.
CSRW
TEXTW
VECTW
C
49H
PI
28H
P2 OOH
P3 20H
C
PI
78H
FF
P2 FF
HAD
I, , H
dAU
Kind of line (solid line)
C
PI
P2
P3
P4
P5
P6
P7
P8
P9
4 C H
OAH
7 8 H
0 2 H
88H
H>H
1 OH
FBH
O O H
O O H
} Drawing direction
}
\
1 AX I
1
f 2 ! AY 1 - I A x I
1
> 2 1 AY
1 -2
1 AX I
1
2 i AY !
W R I T E
C
23H
VECTE
C
6CH
[Explanation]
Specify the kind of line by TEXTW, using C for command
code and P for parameter, and specify the line drawing
direction using VECTW and above four values using X and
Y. The rest will be same the dot display It is also possible
to display a dot using the line drawing method for any line
drawing direction using X = Y = 0.
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