How to read the current graphics window
Jon Abbott (1421) 2598 posts |
You can set the graphics window with either OS_Plot,-24,X1,Y1,X2,Y2 or VDU 24,X1;Y1;X2;Y2; but how do you read the current graphics window? OS_ReadVduVariables doesn’t have a variable for it, only row equivalents (128..131) which are useless as they’re divided down, so are essentially MOD’d. |
Jeffrey Lee (213) 6046 posts |
Internally the OS stores the window coordinates in units of physical pixels; these are the coordinates that you can read back via OS_ReadVduVariables. VDU 24, on the other hand, specifies the coordinates in OS units. So to convert from OS_ReadVduVariables back to values which can be set via VDU 24 you need to left shift each value by the corresponding eigen value. |
Jon Abbott (1421) 2598 posts |
Ah..thanks…poorly worded manual then as it states row/column…which to me means text row/column. X,Y are normally referred to in terms of “coordinates” The following should return the bottom left X,Y then:
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