[HarfBuzz] question about Mongolian text render

[Behdad Esfahbod]

On 14-11-28 08:57 PM, aron wrote:
> Thank you for your helping.
> I didn't compile with UCDN. If I did that, Do I have to make any changes in
> the HBDrawText function?

Nope.  No changes needed.

I should fix HB to either terminate compilation with an error if no Unicode
callbacks are configured, or automatically include UCDN.

> 
> 
> 2014-11-29 6:58 GMT+09:00 Behdad Esfahbod <behdad at behdad.org
> <mailto:behdad at behdad.org>>:
> 
>     Humm. Re the shaping issue, you most probably don't have any Unicode callbacks
>     set up.  Did you compile with UCDN?  You should.
> 
>     On 14-11-28 12:28 AM, aron wrote:
>     > Hi
>     > I use the latest version of HarfBuzz as a static library in VisualStudio,
>     > The Mongolian string can't be rendered as I expected in my program
>     > but rendered correctly in sh-view.exe. Could anyone tell me where is wrong in
>     > my program.
>     >
>     > I found that the vaule -- glyph_info[i].codepoint is less than real glyph
>     > index, the difference is always 87 in my case.What is the correct way to get
>     > glyph index?
>     >
>     > ​void HBDrawText(HDC dc, int x, int y)
>     > {
>     > const char*fontFilePath = "./MongolianWhite.ttf";
>     > const wchar_t*text = L"ᠺᠣᠮᠫᠢᠦ᠋ᠲ᠋ᠧᠷ";//Mongolian string for render
>     >
>     >
>     > FT_Libraryft_library;
>     > FT_Faceft_face;
>     >
>     > FT_Init_FreeType(&ft_library); /* initialize library */
>     > FT_New_Face(ft_library, fontFilePath, 0, &ft_face); /* create face object */
>     > FT_Set_Pixel_Sizes(ft_face, 0, 40); /* set character size */
>     >
>     > hb_font_t*font= hb_ft_font_create(ft_face, NULL);
>     > hb_buffer_t*buffer= hb_buffer_create();;
>     >
>     > //
>     > //set buffer
>     > //
>     > hb_buffer_add_utf16(buffer, (uint16_t *)text, lstrlen(text), 0, -1);
>     > hb_buffer_set_direction(buffer, HB_DIRECTION_TTB); /* or LTR */
>     > hb_buffer_set_script(buffer, HB_SCRIPT_MONGOLIAN); /* see hb-unicode.h */
>     > hb_buffer_guess_segment_properties(buffer);
>     > //
>     > //
>     > //
>     > hb_shape(font, buffer, NULL, 0);
>     >
>     > intglyph_count= hb_buffer_get_length(buffer);
>     > hb_glyph_info_t *glyph_info= hb_buffer_get_glyph_infos(buffer, 0);
>     >
>     > WCHARdbg_info[6];
>     > intpen_x= x;
>     > intyBaseLine= y;
>     > intglyphPosX= 0;
>     > intglyphPosY= 0;
>     >
>     > for (int i = 0; i < glyph_count; ++i)
>     > {
>     > FT_UInt glyph_index = glyph_info[i].codepoint;
>     > FT_Load_Glyph(ft_face, glyph_index, FT_LOAD_DEFAULT);
>     > wsprintf(dbg_info, L"%d,", glyph_index + 87);//*why + 87?*
>     > OutputDebugString(dbg_info);
>     >
>     > /* convert to an anti-aliased bitmap */
>     > FT_Render_Glyph(ft_face->glyph, FT_RENDER_MODE_NORMAL);
>     >
>     > FreeTypeDrawBitmap(dc, &ft_face->glyph->bitmap, pen_x +
>     > ft_face->glyph->bitmap_left,
>     > yBaseLine - ft_face->glyph->bitmap_top);
>     > pen_x += ft_face->glyph->advance.x >> 6;
>     > }
>     > hb_buffer_destroy(buffer);
>     > hb_font_destroy(font);
>     > FT_Done_Face(ft_face);
>     > FT_Done_FreeType(ft_library);
>     > }
>     >
>     > this is the glyph index list generated by this program(incorrect).
>     > 769,660,566,487,675,490,705
>     > hb-shape' s output(correct) is:
>     >  [769|660|566|484|678|492|705]
>     >
>     >
>     > --
>     > Aron
>     >
>     >
>     > _______________________________________________
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>     >
> 
>     --
>     behdad
>     http://behdad.org/
> 
> 
> 
> 
> -- 
> Aron
> 
> 
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-- 
behdad
http://behdad.org/