Re: [Freeciv-Dev] xpm, gif, png & map view!

[Markus Linnala <maage@xxxxxxxxx>]

Lalo Martins <lalo@xxxxxxxxxx> writes:

> IMHO png would be the "right thing to do"; but if there is
> opposition, xpm.gz might do the trick.

I want these things from freeciv graphic system:
- good looking graphics at 8-bit and also at 24-bit graphics system
- handling (edit, load, save) graphics should be easy
- compiletime options to use external libraries to handle
  graphics
- and 2 sets of graphics, one (64 colours) for systems without
  external libs and one (24-bit) for systems with

I blurred tiles.xpm and units.xpm with gimp and saved them as
PNG and XPM (both have 15 bit colours). After that I measured
how much time it takes to load a picture.

Original:
 721 -rw-r--r--   1 maage    maage      733254 Mar  7 02:56 tiles.xpm
 122 -rw-r--r--   1 maage    maage      123054 Mar  1 15:06 units.xpm

PNG:
-rw-r--r--   1 maage    maage      896940 Mar  7 14:33 tiles2.png
xv: 5.02s real (2.63s:0.22s)=56% %KK (%MK)
ee: 8.29s real (3.44s:0.42s)=46% %KK (%MK)
-rw-r--r--   1 maage    maage      149163 Mar  7 03:10 units2.png
xv: 2.72s real (0.79s:0.14s)=34% %KK (%MK)
ee: 5.65s real (1.33s:0.29s)=28% %KK (%MK)

XPM:
-rw-r--r--   1 maage    maage     2719219 Mar  7 14:31 tiles2.xpm
xv: 37.61s real (31.90s:0.43s)=85% %KK (%MK)
ee: 1536.41s real (866.43s:8.08s)=56% %KK (%MK)
-rw-r--r--   1 maage    maage      852369 Mar  7 03:10 units2.xpm
xv: 5.71s real (3.58s:0.26s)=67% %KK (%MK)
ee: 265.52s real (209.02s:10.46s)=82% %KK (%MK)

XPM (compressed):
-rw-r--r--   1 maage    maage      741433 Mar  7 14:35 tiles2.xpm.gz
-rw-r--r--   1 maage    maage      265748 Mar  7 14:32 units2.xpm.gz

My conclusion is that if we want to use 24-bit pictures we
should skip XPM and choose PNG. 

PNG pros: 
    - quite fast and simple to process
    - alphachannel
    - 24-bit
    - natively compressed
    cons: 
    - need extra libraries

XPM pros:
    - easy to edit when you have ~64 colours
    - no need for extra libraries
    cons:
    - can only have 15-bit colours(?)
    - without packing, files are big
    - files with many colours need much processing power to load

Also, imlib (ee) is very slow on loading xpm:s with many colours
compared to native libpng (xv).

-- 
//Markus