/*
 * --- public domain, no warranty.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>

/* FONTX2 header */
#define CODETYPE_ASCII	0
#define	CODETYPE_KANJI	1

/* common */
typedef struct {
	uint8_t	identifier[6];
	uint8_t	fontname[8];
	uint8_t	xsize;
	uint8_t	ysize;
	uint8_t	codetype;
} __attribute__((packed)) FONTX2_HEADER;

/* font data buffer */
#define	BUFFERSIZE	(4096)
static	uint8_t	Buf[BUFFERSIZE];

static	void	convert_ank(uint8_t *buf)
{
	int	i;
	uint8_t	d[14];
	FILE	*fp;
	FONTX2_HEADER	h;

	fp = fopen("tters7x14.fnt", "wb");
	if (fp == NULL) goto fin0;

 	/* header */
	strncpy(h.identifier, "FONTX2", sizeof(h.identifier));
	strncpy(h.fontname, "TEATERM ", sizeof(h.fontname));
	h.xsize = 7;
	h.ysize = 14;
	h.codetype = CODETYPE_ASCII;
	fwrite(&h, sizeof(h), 1, fp);

	/* 0x00-0x1f: blank */
	memset(d, 0, sizeof(d));
	for (i = 0x00; i < 0x20; i++) fwrite(d, sizeof(d), 1, fp);

	/* 0x20-0x7f */
	for (i = 0x20; i < 0x80; i++) {
		memcpy(d, &buf[(i - 0x20) * sizeof(d)], sizeof(d));
		fwrite(d, sizeof(d), 1, fp);
	}

	/* 0x80-0x9f: blank */
	memset(d, 0, sizeof(d));
	for (i = 0x80; i < 0xa0; i++) fwrite(d, sizeof(d), 1, fp);

	/* 0xa0-0xdf */
	for (i = 0xa0; i < 0xe0; i++) {
		memcpy(d, &buf[(i - 0xa0 + 0x60) * sizeof(d)], sizeof(d));
		fwrite(d, sizeof(d), 1, fp);
	}

	/* 0xe0-ff: blank */
	memset(d, 0, sizeof(d));
	for (i = 0xe0; i < 0x100; i++) fwrite(d, sizeof(d), 1, fp);

	fclose(fp);
fin0:
	return;
}

static	int	bload(char *filename, uint8_t *buf, int size)
{
	int	result;
	FILE	*fp;

	fp = fopen(filename, "rb");
	if (fp == NULL) {
		result = -1;
		goto fin0;
	}

	fread(buf, 1, size, fp);
	fclose(fp);

	result = 0;
fin0:
	return result;
}

int	main(int argc, char *argv[])
{
	if (bload("TTERS.FNT", Buf, 2304) < 0) {
		printf("TTERS.FNT not found\n");
		goto fin0;
	}
	convert_ank(Buf);

fin0:
	return 0;
}