[cairo] cairo+DevIL ?
john.ellson at comcast.net
Sat Aug 18 05:06:54 PDT 2007
Vladimir Vukicevic wrote:
> John Ellson wrote:
>> In a January 2007 posting
>> Vlad suggested that DevIL
>> would make a good backend for rendering other bitmap formats (gif,
>> jpeg, tga, ...) from cairo.
>> Is this still the best-practice recommendation? Is there any sample
>> code out there?
>> I've made an initial attempt to bind the two together. The problem
>> I'm having at the moment
>> is that the in-memory data formats seem to be incompatible:
>> CAIRO_FORMAT_ARGB32 v. IL_RGBA
>> Do I really have to byte-twiddle the image data just to transfer
>> between these two fine libraries?
> I'm not sure if there is a single best-practice recommendation; I've
> certainly had good experience using DevIL in the past, though I have
> never used it with cairo. It's interesting that DevIL only provides
> IL_RGBA and IL_BGRA; the documentation annoyingly states that these
> formats are "self explanatory", which they are not. Maybe IL_BGRA
> happens to be compatible, if they're talking about byte order?
> - Vlad
Both IL_BGRA and IL_RGBA result in black images. The size of my image
is right. I'm attempting
to transfer the image data using:
surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,120,60);
rc = ilTexImage(
cairo_image_surface_get_width(surface), // Width
1, // Depth
4, // Bpp
IL_BGRA, // Format
IL_UNSIGNED_BYTE, // Type
cairo_image_surface_get_data(surface) // Data
I'm just assuming my problem is byte-order, the DevIL documentation
isn't very clear, I'm going to have to dig deeper
into the code.
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