/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

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


#define GLYPH(n) glyphs[n]


int max_width = 0;

char inbuf[256];

typedef struct {
	int bytes;
	int width;
	unsigned char *bitmap;
} glyph_t;


unsigned int
invert_bits(unsigned int s, int bits) {
	unsigned int rv = 0;
	int i;
	for (i = 0; i < bits; i++)
		if (s & (1 << i))
			rv |= (1 << (bits - 1 - i));

	return rv;
}

void
read_single_glyph(FILE *in_file, glyph_t *dest, int index, int char_height) {
	int width = -1;
	int bytes = 0;
	int i;
	unsigned char *data
	= dest->bitmap = (unsigned char *) malloc(char_height * 4); /* Let's waste memory */

	do {
		unsigned int d = 0;

		fgets(inbuf, 255, in_file);

		if (char_height-- == -1) {
			fprintf(stderr, "Char 0x%02x is too long!\n", index);
			exit(1);
		}

		if (inbuf[0] == '.' || inbuf[0] == '#') {
			int cw;

			if (width == -1)
				width = strlen(inbuf) - 1;
			else if (strlen(inbuf) - 1 != width) {
				fprintf(stderr, "Char 0x%02x uses inconsistent width\n", index);
				exit(1);
			}

			for (i = 0; i < width; i++)
				if (inbuf[i] == '#')
					d |= (1 << i);

			d = invert_bits(d, ((width + 7) / 8) * 8);

			cw = width;
			do {
				*data = d & 0xff;
				d >>= 8;
				data++;
				cw -= 8;
				++bytes;
			} while (cw > 0);
		}

	} while (inbuf[0] == '.' || inbuf[0] == '#');

	if (char_height >= 0) {
		fprintf(stderr, "Char 0x%02x is too short (by %d)!\n", index, char_height);
		exit(1);
	}

	dest->width = width;
	if (width > max_width)
		max_width = width;

	dest->bytes = bytes;
}

glyph_t *
read_glyphs(FILE *in_file, int nr, int char_height) {
	int i;
	glyph_t *glyphs = (glyph_t *) calloc(sizeof(glyph_t), nr);

	for (i = 0; i < nr; i++)
		read_single_glyph(in_file, glyphs + i, i, char_height);

	return glyphs;
}

void
convert_font(FILE *in_file, char *structname, FILE *out_file) {
	int chars_nr;
	glyph_t *glyphs;
	int bytes_per_row;
	int line_height;
	int char_height = 0;
	int char_byte_size;
	int i;

	fscanf(in_file, "# %d %d\n", &chars_nr, &char_height);
	printf("Parsing %d characters at height %d\n", chars_nr, char_height);
	glyphs = read_glyphs(in_file, chars_nr, char_height);

	bytes_per_row = (max_width + 7) >> 3;
	line_height = char_height + 1;
	fclose(in_file);

	char_byte_size = bytes_per_row * char_height;

	fprintf(out_file, "/* Auto-generated by bdftofont.c */\n\n");

	fprintf(out_file, "#include <gfx_system.h>\n\n");

	fprintf(out_file, "static int %s_widths[] = {\n", structname);
	for (i = 0; i < chars_nr; i++) {
		int rw = GLYPH(i).width;
		fprintf(out_file, "\t%d%s\t/* 0x%02x */\n", rw,
		        (i < (chars_nr - 1)) ? "," : "", i);
	}
	fprintf(out_file, "};\n\n");

	fprintf(out_file, "static unsigned char %s_data[] = {\n", structname);
	for (i = 0; i < chars_nr; i++) {
		int rh = char_height;
		int rw = GLYPH(i).width;
		int xoff = 0;
		int yoff = 0;
		int j, k;

		int top_pad = yoff;
		int bot_pad = (char_height - rh) - top_pad;
		int bytes_to_read = (GLYPH(i).bytes) / rh;
		unsigned char *data = GLYPH(i).bitmap;

		if (bytes_to_read <= 0) {
			fprintf(stderr, "No bytes per row: bytes=%d, w=%d, h=%d\n",
			        GLYPH(i).bytes, rw, rh);
			exit(1);
		}

		if (bot_pad < 0) {
			fprintf(stderr, "Bottom padding <0: height=%d/%d, top_pad=%d\n",
			        rh, char_height, yoff);
			exit(1);
		}

		fprintf(out_file, "\t/* 0x%02x ('%c') */\n", i, ((i > 31) && (i < 0x7f)) ? i : '.');
		/* First, pad everything */
		for (j = 0; j < top_pad; j++) {
			fprintf(out_file, "\t");
			for (k = 0; k < bytes_per_row; k++)
				fprintf(out_file, "0x00, ");
			fprintf(out_file, "\n");
		}

		/* Write char data */
		for (j = 0; j < rh; j++) {
			unsigned int b = 0;
			unsigned int oldb;
			fprintf(out_file, "\t");
			for (k = 0; k < bytes_to_read; k++) {
				int shift_offset = 8 * (bytes_to_read - 1 - k);
				b |= (*data++ << shift_offset);
			}

			oldb = b;

			for (k = 0; k < bytes_per_row; k++) {
				fprintf(out_file, "0x%02x%s", (b & 0xff), (bot_pad || (i + 1 < chars_nr) || (j + 1 < rh) || (k + 1 < bytes_per_row)) ? ", " : "");
				b >>= 8;
			}
			fprintf(out_file, "\t/* ");
			for (k = 0; k < rw; k++)
				fprintf(out_file, (oldb & (1 << ((bytes_per_row * 8) - 1 - k))) ? "##" : "..");
			fprintf(out_file, " */");

			fprintf(out_file, "\n");
		}

		/* Pad bottom */
		for (j = 0; j < bot_pad; j++) {
			fprintf(out_file, "\t");
			for (k = 0; k < bytes_per_row; k++)
				fprintf(out_file, "0x00%s", ((i + 1 < chars_nr) || (j + 1 < bot_pad) || (k + 1 < bytes_per_row)) ? ", " : "");
			fprintf(out_file, "\n");
		}
	}
	fprintf(out_file, "};\n\n");

	fprintf(out_file, "gfx_bitmap_font_t %s = {\n", structname);
	fprintf(out_file, "\t-1, /* resource ID */\n");
	fprintf(out_file, "\t%d, /* # of characters */\n", chars_nr);
	fprintf(out_file, "\t%s_widths, /* Widths */\n", structname);
	fprintf(out_file, "\t%d, /* Bytes per row */\n", bytes_per_row);
	fprintf(out_file, "\t%d, /* Line height */\n", line_height);
	fprintf(out_file, "\t%d, /* Char height */\n", char_height);
	fprintf(out_file, "\t%d, /* Char size (occupied, in bytes) */\n", char_byte_size);
	fprintf(out_file, "\t%s_data /* Bulk data */\n", structname);
	fprintf(out_file, "};\n");

	fclose(out_file);
}


int
main(int argc, char **argv) {
	FILE *f = NULL;

	if (argc < 4) {
		fprintf(stderr, "Usage: %s <font.font> <structname> <outfile.c>\n ", argv[0]);
		exit(1);
	}

	f = fopen(argv[1], "r");
	if (f)
		convert_font(f, argv[2], fopen(argv[3], "w"));
	else
		perror(argv[1]);

}