flipper_cyrillic_example/font/bdfconv/bdf_kern.c
2023-05-02 21:01:20 +03:00

218 lines
6.2 KiB
C

/*
bdf_kern.c
*/
#include "bdf_font.h"
#include <assert.h>
#define BDF_KERNING_MAX (1024*60)
/* the following tables contain the first encodings if they do contain any kernings */
uint16_t bdf_first_table_cnt;
uint16_t bdf_first_encoding_table[BDF_KERNING_MAX];
uint16_t bdf_index_to_second_table[BDF_KERNING_MAX];
/* the index from bdf_index_to_second_table can be used to jump into the following table */
uint16_t bdf_second_table_cnt;
uint16_t bdf_second_encoding_table[BDF_KERNING_MAX];
uint8_t bdf_kerning_values[BDF_KERNING_MAX];
/*
struct u8g2_kerning
{
uint16_t first_table_cnt;
uint16_t second_table_cnt;
uint16_t *first_encoding_table;
uint16_t *index_to_second_table;
uin16_t *second_encoding_table;
uint8_t *kerning_values;
}
*/
static void bdf_write_uint16_array(FILE *fp, const char *pre, const char *post, uint16_t cnt, const uint16_t *a)
{
uint16_t i;
fprintf(fp, "static const uint16_t %s_%s[%u] = {\n ", pre, post, cnt);
for( i = 0; i < cnt; i++ )
{
fprintf(fp, "%u", a[i]);
if ( i+1 < cnt )
{
fprintf(fp, ", ");
if ( i % 16 == 0 && i > 0 )
{
fprintf(fp, "\n ");
}
}
}
fprintf(fp, "};\n");
}
static void bdf_write_uint8_array(FILE *fp, const char *pre, const char *post, uint16_t cnt, const uint8_t *a)
{
uint16_t i;
fprintf(fp, "static const uint8_t %s_%s[%u] = {\n ", pre, post, cnt);
for( i = 0; i < cnt; i++ )
{
fprintf(fp, "%u", a[i]);
if ( i+1 < cnt )
{
fprintf(fp, ", ");
if ( i % 16 == 0 && i > 0 )
{
fprintf(fp, "\n ");
}
}
}
fprintf(fp, "};\n");
}
void bdf_write_kerning_file(const char *kernfile, const char *name)
{
FILE *fp;
fp = fopen(kernfile, "w");
fprintf(fp, "/* %s, Size: %u Bytes */\n", name, bdf_first_table_cnt*4 + bdf_second_table_cnt*3 + 4 + 8); // size calculation for 16 bit controller
bdf_write_uint16_array(fp, name, "first_encoding_table", bdf_first_table_cnt, bdf_first_encoding_table);
bdf_write_uint16_array(fp, name, "index_to_second_table", bdf_first_table_cnt, bdf_index_to_second_table);
bdf_write_uint16_array(fp, name, "second_encoding_table", bdf_second_table_cnt, bdf_second_encoding_table);
bdf_write_uint8_array(fp, name, "kerning_values", bdf_second_table_cnt, bdf_kerning_values);
fprintf(fp, "u8g2_kerning_t %s_k = {\n", name);
fprintf(fp, " %u, %u,\n", bdf_first_table_cnt, bdf_second_table_cnt);
fprintf(fp, " %s_%s,\n", name, "first_encoding_table");
fprintf(fp, " %s_%s,\n", name, "index_to_second_table");
fprintf(fp, " %s_%s,\n", name, "second_encoding_table");
fprintf(fp, " %s_%s};\n\n", name, "kerning_values");
fclose(fp);
}
/*
assumes
tga_set_font(font);
and
tga_init((tga_get_char_width()+16)*3, ((tga_get_char_height()+8)*2));
is called before
*/
static int bdf_is_glyph_overlap(uint8_t *font, uint16_t e1, uint16_t e2, uint8_t kerning_test, int is_save)
{
unsigned int x, y;
tga_clear();
x = 8;
y = tga_get_char_height();
x += tga_draw_glyph(x, y, e1, 0);
x -= kerning_test;
tga_clear_pixel_intersection();
x += tga_draw_glyph(x, y, e2, 0);
if ( is_save )
{
//char buf[64];
//sprintf(buf, "glyph_intersection_%u_%u_%u.tga", e1, e2, kerning_test);
//tga_save(buf);
}
return tga_is_pixel_intersection();
}
unsigned bdf_calculate_kerning(uint8_t *font, uint16_t e1, uint16_t e2, uint8_t min_distance_in_per_cent_of_char_width)
{
uint8_t upper_bound;
uint8_t kerning;
uint8_t min_distance_in_pixel;
tga_set_font(font);
tga_init((tga_get_char_width()+16)*3, ((tga_get_char_height()+8)*2));
min_distance_in_pixel = ((unsigned)tga_get_char_width()*(unsigned)min_distance_in_per_cent_of_char_width) / 100;
upper_bound = tga_get_char_width();
for( kerning = 0; kerning < upper_bound; kerning++ )
{
if ( bdf_is_glyph_overlap(font, e1, e2, kerning, 0) != 0 )
break;
}
if ( kerning >= upper_bound )
kerning = 0; /* maybe "." compared against "-" */
if ( kerning < min_distance_in_pixel )
kerning = 0;
else
kerning -= min_distance_in_pixel;
if ( kerning != 0 )
{
bdf_is_glyph_overlap(font, e1, e2, kerning, 1);
//printf("bdf_calculate_kerning %u %u ", e1, e2);
//printf("result: %d\n", kerning);
}
return kerning;
}
void bdf_calculate_all_kerning(bf_t *bf, const char *filename, const char *fontname, uint8_t min_distance_in_per_cent_of_char_width)
{
int first, second;
bg_t *bg_first;
bg_t *bg_second;
uint8_t kerning;
int is_first_encoding_added;
bdf_first_table_cnt = 0;
bdf_second_table_cnt = 0;
for( first= 0; first < bf->glyph_cnt; first++ )
{
is_first_encoding_added = 0;
bg_first = bf->glyph_list[first];
if ( bg_first->target_data != NULL && bg_first->is_excluded_from_kerning == 0 )
{
for( second= 0; second < bf->glyph_cnt; second++ )
{
bg_second = bf->glyph_list[second];
if ( bg_second->target_data != NULL && bg_second->is_excluded_from_kerning == 0 )
{
kerning = bdf_calculate_kerning(bf->target_data, bg_first->encoding, bg_second->encoding, min_distance_in_per_cent_of_char_width);
if ( kerning > 1 )
{
if ( is_first_encoding_added == 0 )
{
bdf_first_encoding_table[bdf_first_table_cnt] = bg_first->encoding;
bdf_index_to_second_table[bdf_first_table_cnt] = bdf_second_table_cnt;
bdf_first_table_cnt++;
if (bdf_first_table_cnt > BDF_KERNING_MAX)
{
fprintf(stderr, "Kerning calculation aborted: bdf_first_table_cnt > BDF_KERNING_MAX\n");
return;
}
is_first_encoding_added = 1;
}
bdf_second_encoding_table[bdf_second_table_cnt] = bg_second->encoding;
bdf_kerning_values[bdf_second_table_cnt] = kerning;
bdf_second_table_cnt++;
if (bdf_second_table_cnt > BDF_KERNING_MAX)
{
fprintf(stderr, "Kerning calculation aborted: bdf_second_table_cnt > BDF_KERNING_MAX\n");
return;
}
}
}
}
}
}
/* add a final entry for more easier calculation in u8g2 */
bdf_first_encoding_table[bdf_first_table_cnt] = 0x0ffff;
bdf_index_to_second_table[bdf_first_table_cnt] = bdf_second_table_cnt;
bdf_first_table_cnt++;
bdf_write_kerning_file(filename, fontname);
}