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Filter_RegisterRectFilter
Programmer's Reference Manuals
» Part 7 - The Desktop
» The Filter Manager
» SWI Calls
» Filter_RegisterRectFilter
Filter_RegisterRectFilter
(SWI &42644)
| Entry | |
|---|---|
| R0 | Pointer to zero terminated filter name |
| R1 | Address of Pre Rectangle Filter Code |
| R2 | Value to be passed to R12 |
| R3 | Task handle of task to which filter is applied, or 0 for all tasks |
| Exit |
|---|
| All registers preserved |
Use
The purpose of this call is to add a new Wimp_GetRectangle filter to the list of pre-filters. This filter is called just before the drawing of a rectangle begins, before the window background has been filled, and before the VDU graphics window has been set up.
Notes
The address pointed to by R1 will be called whenever the task who’s handle is passed in R3 calls Wimp_GetRectangle with R12 equal to the value of R2 when this SWI is called.