DexOS wrote:Is it possible to have the font background colour transparent, when using swi like
If so what are the SWI i should lookup.
If memory serves me right (not near my Pi at the minute !) using Fonts (as in Scalable Anti-aliased fonts) you need to use the Font_ module's SWI's. OS_Write0 is for purely text based output (am not sure if you can do that sort of blending with it).
In this particular case font blending is probably what you need (this is described in the PRMs and on the ROOL website - https://www.riscosopen.org/wiki/documen ... 20Blending
). RISC OS supports both standard blending and also Alpha/Supermacy (so you can have a RISC OS font "overlaying" a video source background).
Again (from memory) you use:
- to specify the font you want to use (something like Trinity, Homerton or whatever), that gives you a font handle
Follow the instructions in the Font Blending PRM note above.
is used to actually "display" the font.
When finished use Font_LoseFont
to free the font you specified (and have a handle for).
To get a list of Fonts <F12>
and type *FontCat
to list the fonts
Trinity would be a "Times like" serif font while Homerton would be "Helvetica" like - san serif, Corpus would be like "Courier" (a fixed spaced typewriter like font).
The relevant information is in:
https://www.riscosopen.org/wiki/documen ... Font_Paint
https://www.riscosopen.org/wiki/documen ... t_FindFont
https://www.riscosopen.org/wiki/documen ... t_LoseFont
Note that anti-aliased fonts can be plotted to the nearest pixel (the co-ordinates start at bottom left (0,0) and go to (1279,1023) top right on a MODE 15 screen) - on that screen you could plot at 640,512 for a point mid screen.
I hope that helps.