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Font_ScanString
Programmer's Reference Manuals
» Part 8 - Non-kernel input/output
» The Font Manager
» SWI Calls
» Font_ScanString
Font_ScanString
(SWI &400A1)
| Entry | |
|---|---|
| R0 | Initial font handle, or 0 for current |
| R1 | Pointer to string |
| R2 | Flags |
| R3 | X co-ordinate of mouse click, or width of string |
| R4 | Y co-ordinate of mouse click, or height of string |
| R5 | Pointer to block |
| R6 | Pointer to Font Transformation Matrix |
| R7 | Length of string |
| Exit | |
|---|---|
| R1 | Pointer to where scan ended |
| R2 | Preserved |
| R3 | X of where scan ended |
| R4 | Y of where scan ended |
| R5 | Preserved |
| R6 | Preserved |
| R7 | Number of split characters in scanned part of string |
Use
This purpose of this call is to return information on a string.
Notes
How to use the call:
How wide is a string?
Use large values for R3, R4 and no split character.
Given width, how much of a string will fit?
Use correct width in R3, large value in R4 and (if needed) a split character in the buffer at R5.
Address of a mouse click?
Use correct width in R3, large value in R4 and (if needed) a split character in the buffer at R5.
Graphical position of a caret?
Set R7 to offset into string, use huge values for R3 and R4, and no split.
The flags in R2 determine how this call is used. Registers R0, R5, R6 and R7 are only used if bits 5, 6, 7 and 8 are set in flags in R2.
Unlike Font_Paint, this call only allows millipoints for all co-ordinates.