[Freeciv-Dev] Re: (PR#12111) Re: Xaw3d client startup problem(png problem)

["Egor Vyscrebentsov" <evyscr@xxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=12111 >

On Thu, 17 Feb 2005 05:11:01 -0800
Vijay Kiran Kamuju <infyquest@xxxxxxxxx> wrote:

VKK>i think in the next beta u might keep this line xaw-client is currently 
broken.
VKK>
VKK>i am new to XWindows coding, i am trying to understand the code.
VKK>
VKK>the code thats affecting is in the graphics.c file in client/gui-xaw

Yes

VKK>the function thats affecting is loadgfxfile()

Yes

VKK>in the function we are trying to get the palette infomation only with
VKK>out checking whether the file is a paletted png file or a rgba png
VKK>file.
VKK>
VKK>i could make that much only,
VKK>
VKK>i could not understand the rest of the code.

Me too...

VKK>if the file is a palettd png file, can you please explain what we are doing.

Well, we get a palette. (This mean we create an array of colors.)
Next, we get a png row (array of bytes, byte is a number of color in palette).
Next, we assign pixels in sprite, which will be returned by function.

VKK>i tring to port the code in the gui-win32 for the gui-xaw.

Hm, don't know if this will give good results. Main idea of xaw-client use 
paletted
images is paletted displays (at least, i have listened this from other people).
What i want is allow gui-xaw to use both types of images.

VKK>when i tried google, for conversion of paletted png images i could get
VKK>only links for libgd, where i could find no info regarding it.

http://www.libpng.org/pub/png/apps/pngquant.html
This tool allow to make paletted (not only 256 colors) pngs from color RGBA.
I use this tool (with some my patches) to get colormap tilesets (and working 
gui-xaw :).
(I even think about including these two c-files into gui-xaw.)

`man libpng` has a good info about all(?) libpng functions.

Thanks, evyscr.