freetype.c

video linux conference

            for( y = 0, i_bitmap_offset = 0; y < p_glyph->bitmap.rows; y++ )
            {
                for( x = 0; x < p_glyph->bitmap.width; x++, i_bitmap_offset++ )
                {
                    if( p_glyph->bitmap.buffer[i_bitmap_offset] )
                        p_dst[i_offset+x] =
                         ((int)p_glyph->bitmap.buffer[i_bitmap_offset] + 8)/16;
                }
                i_offset += i_pitch;
            }
        }
    }

    /* Outlining (find something better than nearest neighbour filtering ?) */
    if( 1 )
    {
        uint8_t *p_dst = p_region->picture.Y_PIXELS;
        uint8_t *p_top = p_dst; /* Use 1st line as a cache */
        uint8_t left, current;

        for( y = 1; y < (int)fmt.i_height - 1; y++ )
        {
            memcpy( p_top, p_dst, fmt.i_width );
            p_dst += p_region->picture.Y_PITCH;
            left = 0;

            for( x = 1; x < (int)fmt.i_width - 1; x++ )
            {
                current = p_dst[x];
                p_dst[x] = ( 4 * (int)p_dst[x] + left + p_top[x] + p_dst[x+1] +
                             p_dst[x + p_region->picture.Y_PITCH]) / 8;
                left = current;
            }
        }
        memset( p_top, 0, fmt.i_width );
    }

    return VLC_SUCCESS;
}

/**
 * This function renders a text subpicture region into another one.
 * It also calculates the size needed for this string, and renders the
 * needed glyphs into memory. It is used as pf_add_string callback in
 * the vout method by this module
 */
static int RenderText( filter_t *p_filter, subpicture_region_t *p_region_out,
                       subpicture_region_t *p_region_in )
{
    filter_sys_t *p_sys = p_filter->p_sys;
    line_desc_t  *p_lines = 0, *p_line = 0, *p_next = 0, *p_prev = 0;
    int i, i_pen_y, i_pen_x, i_error, i_glyph_index, i_previous;
    uint32_t *psz_unicode, *psz_unicode_orig = 0, i_char, *psz_line_start;
    int i_string_length;
    char *psz_string;
    vlc_iconv_t iconv_handle = (vlc_iconv_t)(-1);
    int i_font_color, i_font_alpha, i_font_size, i_red, i_green, i_blue;

    FT_BBox line;
    FT_BBox glyph_size;
    FT_Vector result;
    FT_Glyph tmp_glyph;

    /* Sanity check */
    if( !p_region_in || !p_region_out ) return VLC_EGENERIC;
    psz_string = p_region_in->psz_text;
    if( !psz_string || !*psz_string ) return VLC_EGENERIC;

    i_font_color = __MAX( __MIN( p_region_in->i_text_color, 0xFFFFFF ), 0 );
    if( i_font_color == 0xFFFFFF ) i_font_color = p_sys->i_font_color;

    i_font_alpha = __MAX( __MIN( p_region_in->i_text_alpha, 255 ), 0 );
    if( !i_font_alpha ) i_font_alpha = 255 - p_sys->i_font_opacity;

    i_font_size  = __MAX( __MIN( p_region_in->i_text_size, 255 ), 0 );
    SetFontSize( p_filter, i_font_size );

    i_red   = ( i_font_color & 0x00FF0000 ) >> 16;
    i_green = ( i_font_color & 0x0000FF00 ) >>  8;
    i_blue  =   i_font_color & 0x000000FF;

    result.x =  result.y = 0;
    line.xMin = line.xMax = line.yMin = line.yMax = 0;

    psz_unicode = psz_unicode_orig =
        malloc( ( strlen(psz_string) + 1 ) * sizeof(uint32_t) );
    if( psz_unicode == NULL )
    {
        msg_Err( p_filter, "out of memory" );
        goto error;
    }
#if defined(WORDS_BIGENDIAN)
    iconv_handle = vlc_iconv_open( "UCS-4BE", "UTF-8" );
#else
    iconv_handle = vlc_iconv_open( "UCS-4LE", "UTF-8" );
#endif
    if( iconv_handle == (vlc_iconv_t)-1 )
    {
        msg_Warn( p_filter, "unable to do conversion" );
        goto error;
    }

    {
        char *p_in_buffer, *p_out_buffer;
        size_t i_in_bytes, i_out_bytes, i_out_bytes_left, i_ret;
        i_in_bytes = strlen( psz_string );
        i_out_bytes = i_in_bytes * sizeof( uint32_t );
        i_out_bytes_left = i_out_bytes;
        p_in_buffer = psz_string;
        p_out_buffer = (char *)psz_unicode;
        i_ret = vlc_iconv( iconv_handle, &p_in_buffer, &i_in_bytes,
                           &p_out_buffer, &i_out_bytes_left );

        vlc_iconv_close( iconv_handle );

        if( i_in_bytes )
        {
            msg_Warn( p_filter, "failed to convert string to unicode (%s), "
                      "bytes left %d", strerror(errno), i_in_bytes );
            goto error;
        }
        *(uint32_t*)p_out_buffer = 0;
        i_string_length = (i_out_bytes - i_out_bytes_left) / sizeof(uint32_t);
    }

#if defined(HAVE_FRIBIDI)
    {
        uint32_t *p_fribidi_string;
        FriBidiCharType base_dir = FRIBIDI_TYPE_ON;
        p_fribidi_string = malloc( (i_string_length + 1) * sizeof(uint32_t) );
        fribidi_log2vis( (FriBidiChar*)psz_unicode, i_string_length,
                         &base_dir, (FriBidiChar*)p_fribidi_string, 0, 0, 0 );
        free( psz_unicode_orig );
        psz_unicode = psz_unicode_orig = p_fribidi_string;
        p_fribidi_string[ i_string_length ] = 0;
    }
#endif

    /* Calculate relative glyph positions and a bounding box for the
     * entire string */
    if( !(p_line = NewLine( psz_string )) )
    {
        msg_Err( p_filter, "out of memory" );
        goto error;
    }
    p_lines = p_line;
    i_pen_x = i_pen_y = 0;
    i_previous = i = 0;
    psz_line_start = psz_unicode;

#define face p_sys->p_face
#define glyph face->glyph

    while( *psz_unicode )
    {
        i_char = *psz_unicode++;
        if( i_char == '\r' ) /* ignore CR chars wherever they may be */
        {
            continue;
        }

        if( i_char == '\n' )
        {
            psz_line_start = psz_unicode;
            if( !(p_next = NewLine( psz_string )) )
            {
                msg_Err( p_filter, "out of memory" );
                goto error;
            }
            p_line->p_next = p_next;
            p_line->i_width = line.xMax;
            p_line->i_height = face->size->metrics.height >> 6;
            p_line->pp_glyphs[ i ] = NULL;
            p_line->i_alpha = i_font_alpha;
            p_line->i_red = i_red;
            p_line->i_green = i_green;
            p_line->i_blue = i_blue;
            p_prev = p_line;
            p_line = p_next;
            result.x = __MAX( result.x, line.xMax );
            result.y += face->size->metrics.height >> 6;
            i_pen_x = 0;
            i_previous = i = 0;
            line.xMin = line.xMax = line.yMin = line.yMax = 0;
            i_pen_y += face->size->metrics.height >> 6;
#if 0
            msg_Dbg( p_filter, "Creating new line, i is %d", i );
#endif
            continue;
        }

        i_glyph_index = FT_Get_Char_Index( face, i_char );
        if( p_sys->i_use_kerning && i_glyph_index
            && i_previous )
        {
            FT_Vector delta;
            FT_Get_Kerning( face, i_previous, i_glyph_index,
                            ft_kerning_default, &delta );
            i_pen_x += delta.x >> 6;

        }
        p_line->p_glyph_pos[ i ].x = i_pen_x;
        p_line->p_glyph_pos[ i ].y = i_pen_y;
        i_error = FT_Load_Glyph( face, i_glyph_index, FT_LOAD_DEFAULT );
        if( i_error )
        {
            msg_Err( p_filter, "FT_Load_Glyph returned %d", i_error );
            goto error;
        }
        i_error = FT_Get_Glyph( glyph, &tmp_glyph );
        if( i_error )
        {
            msg_Err( p_filter, "FT_Get_Glyph returned %d", i_error );
            goto error;
        }
        FT_Glyph_Get_CBox( tmp_glyph, ft_glyph_bbox_pixels, &glyph_size );
        i_error = FT_Glyph_To_Bitmap( &tmp_glyph, ft_render_mode_normal, 0, 1);
        if( i_error ) continue;
        p_line->pp_glyphs[ i ] = (FT_BitmapGlyph)tmp_glyph;

        /* Do rest */
        line.xMax = p_line->p_glyph_pos[i].x + glyph_size.xMax -
            glyph_size.xMin + ((FT_BitmapGlyph)tmp_glyph)->left;
        if( line.xMax > (int)p_filter->fmt_out.video.i_visible_width - 20 )
        {
            p_line->pp_glyphs[ i ] = NULL;
            FreeLine( p_line );
            p_line = NewLine( psz_string );
            if( p_prev ) p_prev->p_next = p_line;
            else p_lines = p_line;

            while( psz_unicode > psz_line_start && *psz_unicode != ' ' )
            {
                psz_unicode--;
            }
            if( psz_unicode == psz_line_start )
            {
                msg_Warn( p_filter, "unbreakable string" );
                goto error;
            }
            else
            {
                *psz_unicode = '\n';
            }
            psz_unicode = psz_line_start;
            i_pen_x = 0;
            i_previous = i = 0;
            line.xMin = line.xMax = line.yMin = line.yMax = 0;
            continue;
        }
        line.yMax = __MAX( line.yMax, glyph_size.yMax );
        line.yMin = __MIN( line.yMin, glyph_size.yMin );

        i_previous = i_glyph_index;
        i_pen_x += glyph->advance.x >> 6;
        i++;
    }

    p_line->i_width = line.xMax;
    p_line->i_height = face->size->metrics.height >> 6;
    p_line->pp_glyphs[ i ] = NULL;
    p_line->i_alpha = i_font_alpha;
    p_line->i_red = i_red;
    p_line->i_green = i_green;
    p_line->i_blue = i_blue;
    result.x = __MAX( result.x, line.xMax );
    result.y += line.yMax - line.yMin;

#undef face
#undef glyph

    p_region_out->i_x = p_region_in->i_x;
    p_region_out->i_y = p_region_in->i_y;

    Render( p_filter, p_region_out, p_lines, result.x, result.y );

    if( psz_unicode_orig ) free( psz_unicode_orig );
    FreeLines( p_lines );
    return VLC_SUCCESS;

 error:
    if( psz_unicode_orig ) free( psz_unicode_orig );
    FreeLines( p_lines );
    return VLC_EGENERIC;
}

static void FreeLine( line_desc_t *p_line )
{
    unsigned int i;
    for( i = 0; p_line->pp_glyphs[ i ] != NULL; i++ )
    {
        FT_Done_Glyph( (FT_Glyph)p_line->pp_glyphs[ i ] );
    }
    free( p_line->pp_glyphs );
    free( p_line->p_glyph_pos );
    free( p_line );
}

static void FreeLines( line_desc_t *p_lines )
{
    line_desc_t *p_line, *p_next;

    if( !p_lines ) return;

    for( p_line = p_lines; p_line != NULL; p_line = p_next )
    {
        p_next = p_line->p_next;
        FreeLine( p_line );
    }
}

static line_desc_t *NewLine( byte_t *psz_string )
{
    int i_count;
    line_desc_t *p_line = malloc( sizeof(line_desc_t) );

    if( !p_line ) return NULL;
    p_line->i_height = 0;
    p_line->i_width = 0;
    p_line->p_next = NULL;

    /* We don't use CountUtf8Characters() here because we are not acutally
     * sure the string is utf8. Better be safe than sorry. */
    i_count = strlen( psz_string );

    p_line->pp_glyphs = malloc( sizeof(FT_BitmapGlyph) * ( i_count + 1 ) );
    if( p_line->pp_glyphs == NULL )
    {
        free( p_line );
        return NULL;
    }
    p_line->pp_glyphs[0] = NULL;

    p_line->p_glyph_pos = malloc( sizeof( FT_Vector ) * i_count + 1 );
    if( p_line->p_glyph_pos == NULL )
    {
        free( p_line->pp_glyphs );
        free( p_line );
        return NULL;
    }

    return p_line;
}

static int SetFontSize( filter_t *p_filter, int i_size )
{
    filter_sys_t *p_sys = p_filter->p_sys;

    if( i_size && i_size == p_sys->i_font_size ) return VLC_SUCCESS;

    if( !i_size )
    {
        vlc_value_t val;

        if( !p_sys->i_default_font_size &&
            p_sys->i_display_height == (int)p_filter->fmt_out.video.i_height )
            return VLC_SUCCESS;

        if( p_sys->i_default_font_size )
        {
            i_size = p_sys->i_default_font_size;
        }
        else
        {
            var_Get( p_filter, "freetype-rel-fontsize", &val );
            i_size = (int)p_filter->fmt_out.video.i_height / val.i_int;
            p_filter->p_sys->i_display_height =
                p_filter->fmt_out.video.i_height;
        }
        if( i_size <= 0 )
        {
            msg_Warn( p_filter, "Invalid fontsize, using 12" );
            i_size = 12;
        }

        msg_Dbg( p_filter, "Using fontsize: %i", i_size );
    }

    p_sys->i_font_size = i_size;

    if( FT_Set_Pixel_Sizes( p_sys->p_face, 0, i_size ) )
    {
        msg_Err( p_filter, "couldn't set font size to %d", i_size );
        return VLC_EGENERIC;
    }

    return VLC_SUCCESS;
}