Fast Horizontal Line Draw Routine (changes)
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Programmer's VDU Reference Variables Manuals
» Fast Horizontal Line Draw RoutinePart 15 – SWI Calls
» OS
» OS_ReadVduVariables
» VDU Variables
» Fast Horizontal Line Draw Routine
Fast Horizontal Line Draw Routine
(VDU variable #166)
| Entry | |
|---|---|
| R0 | Left x coordinate of end of line |
| R1 | Y co-odinade of line |
| R2 | Right x co-ordinate of end of line |
| R3 | 0 = plot with no action (do nothing!) |
| 1 = plot with foreground colour and action | |
| 2 = invert current screen colour | |
| 3 = plot with background colour and action | |
| >3 pointer to aligned ECF block | |
| R14 | Return address |
| Exit | |
|---|---|
| All registers preserved | |
Notes
This must be called in SVC mode. The caller should is responsible for temporarily disabling the text cursor usingOS_RemoveCursors before calling, andOS_RestoreCursors afterwards. as appropriate. All coordinates are internal coordinates, and the line is plotted as specified by R3, clipped to the current graphics window.
See also
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