[SDL_TTF] internationalisation / Display arabic text

Hi

i new to this list

i have to display arabic text for a project that uses openGL

i discovered recently than sdl ttf can display unicode text

so i download the lib and the exemple called gl font

but i still can display arabic text correctly

for those of you who dont know, arabic is complex to display because the letter are joined together depending on the letter before and the letter after, so you have 2-3 different ways to write the same letter (with different unicode codes)

so i tried to display the text with the exact unicode string

for instance :

Uint16 unicode_text[]= {0x0628,0x0650,0x0633,0x0652,0x0645,0x0650,0x00};

text = TTF_RenderUNICODE_Blended(font,
(Uint16 *)unicode_text, *forecol);

it displays a text but the letter are not joined together so it is unreadable

did i make something wrong and / or how to fix it ?

Thanx in advance
Ibrahim