Loading bitmaps

SDL Development
1

Greetings,

I have this vague recollection of either stumbling across a post, or someone
posting to this list, a patch for SDL that allowed it to load 32bpp bitmaps.
Am I having some kind of mental breakdown, or does that ring a bell for
anyone?

Todd Lang

2

I remember something about someone needing an alpha channel in their bitmap.

I think the suggestion was to have a greyscale bitmap with the alpha
information and a normal bitmap

Load the two surfaces and create a third with alpha which combines the two.

  • Tom>Greetings,

I have this vague recollection of either stumbling across a post, or someone
posting to this list, a patch for SDL that allowed it to load 32bpp bitmaps.
Am I having some kind of mental breakdown, or does that ring a bell for
anyone?

Todd Lang

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

3

Hi,

Some graphics packages do support outputting .bmp files with alpha
channel in the unused channel at 32 bit. (I use GraphicConverter.)

I have some code that operates with a very similar interface to the
SDL LoadBMP and it uses RWops as the input (i.e. files or memory).
I’d be willing to open source license if it’s any use.

Regards,
Rob>Greetings,

I have this vague recollection of either stumbling across a post, or someone
posting to this list, a patch for SDL that allowed it to load 32bpp bitmaps.
Am I having some kind of mental breakdown, or does that ring a bell for
anyone?

Todd Lang

4

Actually, I found the post I was thinking of that linked to a patch put
forth about March last year that enables the alpha channel on the bitmaps
the SDL library loads. It was about 10 lines to change. I just made the
changes and recompiled SDL. Works great! I’m surprised it’s not part of
the main CVS.

Todd Lang> ----- Original Message -----

From: sdl-bounces+todd.lang=kiyote.ca@libsdl.org
[mailto:sdl-bounces+todd.lang=kiyote.ca at libsdl.org] On Behalf Of Rob Probin
Sent: March 4, 2005 4:10 PM
To: sdl at libsdl.org
Subject: [SDL] Loading bitmaps

Hi,

Some graphics packages do support outputting .bmp files with alpha channel
in the unused channel at 32 bit. (I use GraphicConverter.)

I have some code that operates with a very similar interface to the SDL
LoadBMP and it uses RWops as the input (i.e. files or memory). I’d be
willing to open source license if it’s any use.

Regards,
Rob

Greetings,

I have this vague recollection of either stumbling across a post, or someone
posting to this list, a patch for SDL that allowed it to load 32bpp bitmaps.
Am I having some kind of mental breakdown, or does that ring a bell for
anyone?

Todd Lang