Re: render texts to a buffer/drawable

[Ronald Bultje <rbultje ronald bitfreak net>]

Havoc Pennington wrote:

> Ronald Bultje <rbultje ronald bitfreak net> writes:
>
> > 		pixmap = gdk_pixmap_new(NULL, w, h, 24);
>
> Not sure if you are trying to be portable across machines, but this
> could easily fail, not all X servers have 24-bit.
Uhm... Never thought about that, really :-)
Is there any way to get a 24-bit drawable form the server on non-24-bit 
X-servers?

Is it possible at all to have 24-bit drawables on non-24-bit X-servers?

Or would I haev to use something else (client-side) for this? (like 
freetype, as John suggested).

> > 		for (y=0;y<h;y++)
> > 		{
> > 			for (x=0;x<w;x++)
> > 			{
> > 				pixel = gdk_image_get_pixel(image,x,y);
> > 				data[(y*w+x)*4] = pixel/(256^3);
> > 				data[(y*w+x)*4+1] = (pixel/(256^2))%256;
> > 				data[(y*w+x)*4+2] = (pixel/256)%(256^2);
> > 				data[(y*w+x)*4+3] = 255;
> > 			}
> > 		}
>
> Here you're assuming far more than you reasonably can about the image
> format. 
>
> gdk_pixbuf_get_from_drawable() does this for you and handles all the
> image formats and bit depths.
The problem I encountered with gdk_pixbuf_from_drawable is that it 
needed a colormap.
However, trying to get a colormap from the pixmap resulted in an error 
that it could not get a colormap from a pixmap....

Or should I use gdk_colormap_get_system() (which could be different from 
the colormap of the pixmap...)?

Regards,

Ronald