Re: [Chicken-users] I'm trying to use the cairo egg with the sdl2 egg but not making much progress. An

[Matt Welland]

With this I was able to get a sample page up. Thanks!

If Christian Kellermann, owner of cairo, sees this and would like to
add an sdl2 demo to the cairo egg please let me know.

On Mon, 2019-01-28 at 08:12 +0100, address@hidden wrote:
> Matt Welland <address@hidden> wrote:
> > Assuming it is possible, I'd like to use cairo to draw on sdl2
> > surfaces. I've read the demos and other available code but I'm not
> > yet
> > seeing how to bolt them together. Does anyone have some example
> > code
> > they can share to help me get going?
> 
> It is absolutly possible! I’ve done it countless times, with surfaces
> as well as textures (in the renderers API).
> 
> Here is the code I’ve wrote to use cairo on surfaces:
> It’s old code and I’ve not tested it in a whire though.
> 
> (define (sdl-colorspace->cairo bytes-per-pixel)
>   (case (* 8 bytes-per-pixel)
>     ((8) CAIRO_FORMAT_A8)
>     ((24) CAIRO_FORMAT_RGB24)
>     ((32) CAIRO_FORMAT_ARGB32)
>     (else CAIRO_FORMAT_ARGB32)))
> 
> (define (create-sdl2-cairo-context window)
>   (let-values
>     (((width height) (window-size window))
>      ((window-surface) (window-surface window))
>      ((cairo-surface)
>       (cairo-image-surface-create-for-data
>         (surface-pixels-raw window-surface)
>         (sdl-colorspace->cairo
>           (pixel-format-bytes-per-pixel (surface-format window-
> surface)))
>         width
>         height
>         (surface-pitch window-surface))))
>     (cairo-create cairo-surface)))