ColourTrans_ReturnFontColours
Programmer's Reference Manuals
» Part 8 - Non-kernel input/output
» ColourTrans
» SWI Calls
» ColourTrans_ReturnFontColours
ColourTrans_ ReturnFontColours
(SWI &4074E)
| Entry | |
|---|---|
| R0 | Font handle, or 0 for current font |
| R1 | Background palette entry |
| R2 | Foreground palette entry |
| R3 | Maximum foreground colour offset (0-14) |
| Exit | |
|---|---|
| R0 | Preserved |
| R1 | Background logical colour (preserved if in 256 colour mode) |
| R2 | Foreground logical colour |
| R3 | Maximum sensible colour offset (up to R3 on entry) |
Use
This purpose of this call is to return the maximum range of colour than can be sensibly used, given the background, foreground and number of anti-aliasing colour desired.
Notes
For any given palette entries passed in R1 and R2, it finds the best fit in the current palette, and then inspects the other available colours to deduce the maximum possible amount of anti-aliasing up to the limit passed in R3.
If anti-aliasing is desirable, R3 should equal 14 on entry, otherwise set to 0 for monochrome.
The values in R – R3 on exit are suitable for passing to Font_SetFontColours, or including in a font string in a command (18) sequence.
In 256 colour modes only 16 colours can be set before previously returned information becomes invalid – this is the source of the 16 colour change limitation in Font_Paint.
The 24-bit palette entries are in the &BBGGRR00 format.