/* calculate the overall length of the font, only used to create the picture for the google wiki */
size_t u8g2_GetFontSize(const uint8_t *font_arg)
{
uint16_t e;
const uint8_t *font = font_arg;
font += U8G2_FONT_DATA_STRUCT_SIZE;
for(;;)
{
if ( u8x8_pgm_read( font + 1 ) == 0 )
break;
font += u8x8_pgm_read( font + 1 );
}
/* continue with unicode section */
font += 2;
/* skip unicode lookup table */
font += u8g2_font_get_word(font, 0);
for(;;)
{
e = u8x8_pgm_read( font );
e <<= 8;
e |= u8x8_pgm_read( font + 1 );
if ( e == 0 )
break;
font += u8x8_pgm_read( font + 2 );
}
return (font - font_arg) + 2;
}
/* new font format */
void u8g2_read_font_info(u8g2_font_info_t *font_info, const uint8_t *font)
{
/* offset 0 */
font_info->glyph_cnt = u8g2_font_get_byte(font, 0);
font_info->bbx_mode = u8g2_font_get_byte(font, 1);
font_info->bits_per_0 = u8g2_font_get_byte(font, 2);
font_info->bits_per_1 = u8g2_font_get_byte(font, 3);
/* offset 4 */
font_info->bits_per_char_width = u8g2_font_get_byte(font, 4);
font_info->bits_per_char_height = u8g2_font_get_byte(font, 5);
font_info->bits_per_char_x = u8g2_font_get_byte(font, 6);
font_info->bits_per_char_y = u8g2_font_get_byte(font, 7);
font_info->bits_per_delta_x = u8g2_font_get_byte(font, 8);
/* offset 9 */
font_info->max_char_width = u8g2_font_get_byte(font, 9);
font_info->max_char_height = u8g2_font_get_byte(font, 10);
font_info->x_offset = u8g2_font_get_byte(font, 11);
font_info->y_offset = u8g2_font_get_byte(font, 12);
/* offset 13 */
font_info->ascent_A = u8g2_font_get_byte(font, 13);
font_info->descent_g = u8g2_font_get_byte(font, 14);
font_info->ascent_para = u8g2_font_get_byte(font, 15);
font_info->descent_para = u8g2_font_get_byte(font, 16);
/* offset 17 */
font_info->start_pos_upper_A = u8g2_font_get_word(font, 17);
font_info->start_pos_lower_a = u8g2_font_get_word(font, 19);
/* offset 21 */
#ifdef U8G2_WITH_UNICODE
font_info->start_pos_unicode = u8g2_font_get_word(font, 21);
#endif
}
/*
Description:
Find the starting point of the glyph data.
Args:
encoding: Encoding (ASCII or Unicode) of the glyph
Return:
Address of the glyph data or NULL, if the encoding is not avialable in the font.
*/
const uint8_t *u8g2_font_get_glyph_data(u8g2_t *u8g2, uint16_t encoding)
{
const uint8_t *font = u8g2->font;
font += U8G2_FONT_DATA_STRUCT_SIZE;
if ( encoding <= 255 )
{
if ( encoding >= 'a' )
{
font += u8g2->font_info.start_pos_lower_a;
}
else if ( encoding >= 'A' )
{
font += u8g2->font_info.start_pos_upper_A;
}
for(;;)
{
if ( u8x8_pgm_read( font + 1 ) == 0 )
break;
if ( u8x8_pgm_read( font ) == encoding )
{
return font+2; /* skip encoding and glyph size */
}
font += u8x8_pgm_read( font + 1 );
}
}
#ifdef U8G2_WITH_UNICODE
else
{
uint16_t e;
const uint8_t *unicode_lookup_table;
// removed, there is now the new index table
//#ifdef __unix__
// if ( u8g2->last_font_data != NULL && encoding >= u8g2->last_unicode )
// {
// font = u8g2->last_font_data;
// }
// else
//#endif
font += u8g2->font_info.start_pos_unicode;
unicode_lookup_table = font;
/* issue 596: search for the glyph start in the unicode lookup table */
do
{
font += u8g2_font_get_word(unicode_lookup_table, 0);
e = u8g2_font_get_word(unicode_lookup_table, 2);
unicode_lookup_table+=4;
} while( e < encoding );
for(;;)
{
e = u8x8_pgm_read( font );
e <<= 8;
e |= u8x8_pgm_read( font + 1 );
// removed, there is now the new index table
//#ifdef __unix__
// if ( encoding < e )
// break;
//#endif
if ( e == 0 )
break;
if ( e == encoding )
{
// removed, there is now the new index table
//#ifdef __unix__
// u8g2->last_font_data = font;
// u8g2->last_unicode = encoding;
//#endif
return font+3; /* skip encoding and glyph size */
}
font += u8x8_pgm_read( font + 2 );
}
}
#endif
return NULL;
}
