How to display Arabic word using print method?

[ahmedbahgat]

Hello all

I am trying to display Arabic words, like the Arabic names for the stars but I just don't know how, I know I have to use UTF-8 encoded characters but it is not working when I substitute the Arabic word with its UTF-8 encoded characters


Can you help me please with an example of displaying UTF-8 encoded characters using the print or the flash method?


Cheers

[jogad]

Hi,

It looks like arabic fonts in .txf format are missing in the celestia\fonts directories.
Maybe you can rebuild them following the method described here.
https://en.wikibooks.org/wiki/Celestia/Internationalization
(see "Building .txf font texture files" )
Change the "font_bold.ttf" in the description with a ttf police containing arabic characters.

celestia:print() uses the font "TitleFond" as declared in the celestia.cfg file.

I can't help too much because I am unable to write with this set of characters. (No arabic keyboard and above all zero knowledge of the language itself).

But I can test if you post a utf-8 encoded celx script with a valid celestia:print() statement containing arabic words.
- Please precise the default language of your computer and the language displayed in Celestia when you launch Celestia.

I fear there is also a problem in Celestia concerning the right to left management of the scripting.
In this case maybe you will have to write your text in reverse order

.

[carton]

Just had the same problem. Thank you for sharing.

[jogad]

.
Definitively, the arabic fonts are missing.

Here is a workaround to display arabic words in Celestia.
This is not the only way to do it, but maybe you find it useful.

1) Building the font for Celestia.

I have built a txf font with arabic characters (and also the latin ones, so you can use it to write any kind of text including special west-europeans letters with accents.

The base font is the simpo.ttf font that I found here.
https://cooltext.com/Fonts-Unicode-Arabic
I choosed this font because the latin characters in it match well withe the usual celestia fonts.
Of course another font is maybe better for arabic characters. Please tell me.

I gave the name simpo24_ar.txf to this font.
I got it withe this command :
ttf2txf -w 1048 -h 1048 -f codepoints_ar.txt -s 24 -o simpo24_ar.txf simpo.ttf

I join this font to this message.

2) copy this font in the fonts directory of Celestia.

3) In the celestia.cfg file, replace the sansbold20.txf with simpo24_ar.txf as TitleFont

Code: Select all

Font       "sans12.txf"
  LabelFont  "sans12.txf"
  # TitleFont  "sansbold20.txf"
  TitleFont  "simpo24_ar.txf"

Now you shoud be able to print arabic text using the celestia:print() or celestia:flash() functions.

But there is still a problem :
As I guessed, these functions don't manage the right to left order of arabic scripture and the text is written in reverse order.

To fix this issue, I have created a little lua function that reverse the order of a utf-8 text.

Here is a minimal script as exemple.

Code: Select all

local function utf8inverse(s)
   local inverse="";
   local i=1
   while (i <= string.len(s)) do
      local car,b
      b=string.byte(s,i)
      if b<128 then
         car = string.char(b);
         i=i+1
      elseif b<224 then
         car = string.sub(s,i,i+1)
         i=i+2
      elseif b<240 then
         car = string.sub(s,i,i+2)
         i=i+3
      else
         car = string.sub(s,i,i+3)
         i=i+4
      end
      inverse = car..inverse
   end
   return inverse
end

celestia:print(utf8inverse("هذا النجم الدبران") , 60,0,0,-12,-3)


And a screen copy of the result.
(click for a bigger view)

I Hope it make sense I used google to translate from French to Arab.

Download the font from here: