/* ScummVM - Scumm Interpreter
 * Copyright (C) 2004 The ScummVM project
 *
 * The ReInherit Engine is (C)2000-2003 by Daniel Balsom.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 *
 */
/*

 Description:   
 
    Font management and font drawing module

 Notes: 
*/

#include "reinherit.h"

#include "yslib.h"

/*
 * Uses the following modules:
\*--------------------------------------------------------------------------*/
#include "rscfile_mod.h"
#include "game_mod.h"

/*
 * Begin module
\*--------------------------------------------------------------------------*/
#include "font_mod.h"
#include "font.h"

namespace Saga {

static R_FONT_MODULE FontModule;

int FONT_Init(void)
{

	R_GAME_FONTDESC *gamefonts;
	int i;

	if (FontModule.init) {

		FontModule.err_str = "Font module already initialized.";

		return R_FAILURE;
	}

	/* Load font module resource context 
	 * \*------------------------------------------------------------ */
	if (GAME_GetFileContext(&FontModule.font_ctxt,
		R_GAME_RESOURCEFILE, 0) != R_SUCCESS) {

		FontModule.err_str = "Couldn't get resource context.";

		return R_FAILURE;
	}

	/* Allocate font table
	 * \*------------------------------------------------------------ */
	GAME_GetFontInfo(&gamefonts, &FontModule.n_fonts);

	assert(FontModule.n_fonts > 0);

	FontModule.fonts = (R_FONT **)malloc(FontModule.n_fonts *
	    sizeof *FontModule.fonts);
	if (FontModule.fonts == NULL) {

		FontModule.err_str = "Memory allocation failure.";

		return R_MEM;
	}

	for (i = 0; i < FontModule.n_fonts; i++) {

		FONT_Load(gamefonts[i].font_rn, gamefonts[i].font_id);
	}

	FontModule.init = 1;

	return R_SUCCESS;
}

int FONT_Shutdown(void)
{

//	int i;

	R_printf(R_STDOUT, "FONT_Shutdown(): Freeing fonts.\n");
/*
    for ( i = 0 ; i < R_FONT_COUNT ; i ++ ) {

        if ( FontModule.fonts[i] != NULL ) {

            if ( FontModule.fonts[i]->normal_loaded ) {
                free( FontModule.fonts[i]->normal->font_free_p );
                free( FontModule.fonts[i]->normal );
            }

            if ( FontModule.fonts[i]->outline_loaded ) {
                free( FontModule.fonts[i]->outline->font_free_p );
                free( FontModule.fonts[i]->outline );
            }
        }

        free( FontModule.fonts[i] );
    }
*/
	return R_SUCCESS;
}

int FONT_Load(ulong font_rn, int font_id)
{

	R_FONT_HEADER fh;
	R_FONT *font;
	R_FONT_STYLE *normal_font;

	uchar *fontres_p;
	size_t fontres_len;
	size_t remain;

	const uchar *read_p;

	int nbits;
	int c;

	if ((font_id < 0) || (font_id >= FontModule.n_fonts)) {
		return R_FAILURE;
	}

	/* Load font resource
	 * \*------------------------------------------------------------- */
	if (RSC_LoadResource(FontModule.font_ctxt,
		font_rn, &fontres_p, &fontres_len) != R_SUCCESS) {

		FontModule.err_str = "Couldn't load font resource.";

		return R_FAILURE;
	}

	if (fontres_len < R_FONT_DESCSIZE) {

		FontModule.err_str = "Invalid font length.";
	}

	read_p = fontres_p;
	remain = fontres_len;

	/* Create new font structure
	 * \*------------------------------------------------------------- */
	font = (R_FONT *)malloc(sizeof *font);
	if (font == NULL) {
		FontModule.err_str = "Memory allocation error.";

		return R_MEM;
	}

	/* Read font header
	 * \*------------------------------------------------------------- */
	fh.c_height = ys_read_u16_le(read_p, &read_p);
	fh.c_width = ys_read_u16_le(read_p, &read_p);
	fh.row_length = ys_read_u16_le(read_p, &read_p);

#if R_FONT_DBGLVL >= R_DEBUG_INFO
	R_printf(R_STDOUT, "FONT_Load(): Reading font resource...\n");
#endif

#if R_FONT_DBGLVL >= R_DEBUG_VERBOSE
	R_printf(R_STDOUT, "Character width:\t%d\n", fh.c_width);
	R_printf(R_STDOUT, "Character height:\t%d\n", fh.c_height);
	R_printf(R_STDOUT, "Row padding:\t%d\n", fh.row_length);
#endif

	/* Create normal font style
	 * \*------------------------------------------------------------- */
	normal_font = (R_FONT_STYLE *)malloc(sizeof *normal_font);
	if (normal_font == NULL) {

		FontModule.err_str = "Memory allocation error.";
		free(font);

		return R_MEM;
	}

	normal_font->font_free_p = fontres_p;
	normal_font->hdr.c_height = fh.c_height;
	normal_font->hdr.c_width = fh.c_width;
	normal_font->hdr.row_length = fh.row_length;

	for (c = 0; c < R_FONT_CHARCOUNT; c++) {
		normal_font->fce[c].index = ys_read_u16_le(read_p, &read_p);
	}

	for (c = 0; c < R_FONT_CHARCOUNT; c++) {
		nbits = normal_font->fce[c].width =
		    ys_read_u8(read_p, &read_p);
		normal_font->fce[c].byte_width = GetByteLen(nbits);
	}

	for (c = 0; c < R_FONT_CHARCOUNT; c++) {
		normal_font->fce[c].flag = ys_read_u8(read_p, &read_p);
	}

	for (c = 0; c < R_FONT_CHARCOUNT; c++) {
		normal_font->fce[c].tracking = ys_read_u8(read_p, &read_p);
	}

	if ((read_p - fontres_p) != R_FONT_DESCSIZE) {

		R_printf(R_STDERR, "Invalid font resource size.\n");
		return R_FAILURE;
	}

	normal_font->font_p = fontres_p + R_FONT_DESCSIZE;

	font->normal = normal_font;
	font->normal_loaded = 1;

	/* Create outline font style
	 * \*------------------------------------------------------------- */
	font->outline = FONT_CreateOutline(normal_font);
	font->outline_loaded = 1;

	/* Set font data 
	 * \*------------------------------------------------------------- */

	FontModule.fonts[font_id] = font;

	return R_SUCCESS;
}

int FONT_GetHeight(int font_id)
{

	R_FONT *font;

	if (!FontModule.init) {
		return R_FAILURE;
	}

	if ((font_id < 0) ||
	    (font_id >= FontModule.n_fonts) ||
	    (FontModule.fonts[font_id] == NULL)) {

		FontModule.err_str = "Invalid font id.";

		return R_FAILURE;
	}

	font = FontModule.fonts[font_id];

	return font->normal->hdr.c_height;
}

static R_FONT_STYLE *FONT_CreateOutline(R_FONT_STYLE * src_font)
{

	R_FONT_STYLE *new_font;
	unsigned char *new_font_data;
	size_t new_font_data_len;

	int s_width = src_font->hdr.c_width;
	int s_height = src_font->hdr.c_height;

	int new_row_len = 0;
	int row;
	int i;

	int index;
	size_t index_offset = 0;

	int new_byte_width;
	int old_byte_width;

	int current_byte;

	unsigned char *base_ptr;
	unsigned char *src_ptr;
	unsigned char *dest_ptr1;
	unsigned char *dest_ptr2;
	unsigned char *dest_ptr3;

	unsigned char c_rep;

	/* Create new font style structure
	 * \*------------------------------------------------------------- */
	new_font = (R_FONT_STYLE *)malloc(sizeof *new_font);

	if (new_font == NULL) {
		FontModule.err_str = "Memory allocation error.";

		return NULL;
	}

	memset(new_font, 0, sizeof *new_font);

	/* Populate new font style character data 
	 * \*------------------------------------------------------------- */
	for (i = 0; i < R_FONT_CHARCOUNT; i++) {

		new_byte_width = 0;
		old_byte_width = 0;

		index = src_font->fce[i].index;
		if ((index > 0) || (i == R_FONT_FIRSTCHAR)) {
			index += index_offset;
		}

		new_font->fce[i].index = index;
		new_font->fce[i].tracking = src_font->fce[i].tracking;
		new_font->fce[i].flag = src_font->fce[i].flag;

		if (src_font->fce[i].width != 0) {

			new_byte_width =
			    GetByteLen(src_font->fce[i].width + 2);
			old_byte_width = GetByteLen(src_font->fce[i].width);

			if (new_byte_width > old_byte_width) {
				index_offset++;
			}
		}

		new_font->fce[i].width = src_font->fce[i].width + 2;
		new_font->fce[i].byte_width = new_byte_width;
		new_row_len += new_byte_width;
	}

#if R_FONT_DBGLVL >= R_DEBUG_VERBOSE
	R_printf(R_STDOUT, "New row length: %d\n", new_row_len);
#endif

	new_font->hdr.c_width = s_width + 2;
	new_font->hdr.c_height = s_height + 2;
	new_font->hdr.row_length = new_row_len;

	/* Allocate new font representation storage 
	 * \*------------------------------------------------------------- */
	new_font_data_len = new_row_len * (s_height + 2);
	new_font_data = (unsigned char *)malloc(new_font_data_len);

	if (new_font_data == NULL) {
		FontModule.err_str = "Memory allocation error.";

		return NULL;
	}

	memset(new_font_data, 0, new_font_data_len);

	new_font->font_free_p = new_font_data;
	new_font->font_p = new_font_data;

	/* Generate outline font representation
	 * \*------------------------------------------------------------- */
	for (i = 0; i < R_FONT_CHARCOUNT; i++) {

		for (row = 0; row < s_height; row++) {

			for (current_byte = 0;
			    current_byte < new_font->fce[i].byte_width;
			    current_byte++) {

				base_ptr =
				    new_font->font_p + new_font->fce[i].index +
				    current_byte;

				dest_ptr1 =
				    base_ptr + new_font->hdr.row_length * row;
				dest_ptr2 =
				    base_ptr +
				    new_font->hdr.row_length * (row + 1);
				dest_ptr3 =
				    base_ptr +
				    new_font->hdr.row_length * (row + 2);

				if (current_byte > 0) {

					/* Get last two columns from previous byte */
					src_ptr = src_font->font_p +
					    src_font->hdr.row_length * row +
					    src_font->fce[i].index +
					    (current_byte - 1);

					c_rep = *src_ptr;
					*dest_ptr1 |=
					    ((c_rep << 6) | (c_rep << 7));
					*dest_ptr2 |=
					    ((c_rep << 6) | (c_rep << 7));
					*dest_ptr3 |=
					    ((c_rep << 6) | (c_rep << 7));
				}

				if (current_byte < src_font->fce[i].byte_width) {

					src_ptr = src_font->font_p +
					    src_font->hdr.row_length * row +
					    src_font->fce[i].index +
					    current_byte;

					c_rep = *src_ptr;
					*dest_ptr1 |=
					    c_rep | (c_rep >> 1) | (c_rep >>
					    2);
					*dest_ptr2 |=
					    c_rep | (c_rep >> 1) | (c_rep >>
					    2);
					*dest_ptr3 |=
					    c_rep | (c_rep >> 1) | (c_rep >>
					    2);
				}
			}
		}

		/* "Hollow out" character to prevent overdraw */
		for (row = 0; row < s_height; row++) {

			for (current_byte = 0;
			    current_byte < new_font->fce[i].byte_width;
			    current_byte++) {

				dest_ptr2 = new_font->font_p +
				    new_font->hdr.row_length * (row + 1) +
				    new_font->fce[i].index + current_byte;

				if (current_byte > 0) {

					/* Get last two columns from previous byte */
					src_ptr = src_font->font_p +
					    src_font->hdr.row_length * row +
					    src_font->fce[i].index +
					    (current_byte - 1);

					*dest_ptr2 &=
					    ((*src_ptr << 7) ^ 0xFFU);
				}

				if (current_byte < src_font->fce[i].byte_width) {

					src_ptr = src_font->font_p +
					    src_font->hdr.row_length * row +
					    src_font->fce[i].index +
					    current_byte;

					*dest_ptr2 &=
					    ((*src_ptr >> 1) ^ 0xFFU);
				}
			}
		}
	}

	return new_font;

}

static int GetByteLen(int num_bits)
{

	int byte_len;

	byte_len = num_bits / 8;

	if (num_bits % 8) {
		byte_len++;
	}

	return byte_len;
}

int
FONT_GetStringWidth(int font_id,
    const char *test_str, size_t test_str_ct, int flags)
/*--------------------------------------------------------------------------*\
 * Returns the horizontal length in pixels of the graphical representation
 *  of at most 'test_str_ct' characters of the string 'test_str', taking
 *  into account any formatting options specified by 'flags'.
 * If 'test_str_ct' is 0, all characters of 'test_str' are counted.
\*--------------------------------------------------------------------------*/
{

	R_FONT *font;
	size_t ct;
	int width = 0;
	int ch;
	const uchar *txt_p;

	if (!FontModule.init) {
		return R_FAILURE;
	}

	if ((font_id < 0) ||
	    (font_id >= FontModule.n_fonts) ||
	    (FontModule.fonts[font_id] == NULL)) {

		FontModule.err_str = "Invalid font id.";

		return R_FAILURE;
	}

	font = FontModule.fonts[font_id];
	assert(font != NULL);

	txt_p = (const uchar *) test_str;

	for (ct = test_str_ct;
	    *txt_p && (!test_str_ct || ct > 0); txt_p++, ct--) {

		ch = *txt_p & 0xFFU;

		/* Translate character */
		ch = CharMap[ch];
		assert(ch < R_FONT_CHARCOUNT);

		width += font->normal->fce[ch].tracking;
	}

	if ((flags & FONT_BOLD) || (flags & FONT_OUTLINE)) {
		width += 1;
	}

	return width;
}

int
FONT_Draw(int font_id,
    R_SURFACE * ds,
    const char *draw_str,
    size_t draw_str_ct,
    int text_x, int text_y, int color, int effect_color, int flags)
{

	R_FONT *font;

	if (!FontModule.init) {
		FontModule.err_str = "Font Module not initialized.";

		return R_FAILURE;
	}

	if ((font_id < 0) ||
	    (font_id >= FontModule.n_fonts) ||
	    (FontModule.fonts[font_id] == NULL)) {

		FontModule.err_str = "Invalid font id.";

		return R_FAILURE;
	}

	font = FontModule.fonts[font_id];

	if (flags & FONT_OUTLINE) {

		FONT_Out(font->outline,
		    ds,
		    draw_str,
		    draw_str_ct, text_x - 1, text_y - 1, effect_color);

		FONT_Out(font->normal,
		    ds, draw_str, draw_str_ct, text_x, text_y, color);
	} else if (flags & FONT_SHADOW) {

		FONT_Out(font->normal,
		    ds,
		    draw_str,
		    draw_str_ct, text_x - 1, text_y + 1, effect_color);

		FONT_Out(font->normal,
		    ds, draw_str, draw_str_ct, text_x, text_y, color);
	} else {		/* FONT_NORMAL */

		FONT_Out(font->normal,
		    ds, draw_str, draw_str_ct, text_x, text_y, color);
	}

	return R_SUCCESS;
}

int
FONT_Out(R_FONT_STYLE * draw_font,
    R_SURFACE * ds,
    const char *draw_str,
    size_t draw_str_ct, int text_x, int text_y, int color)
{

	const uchar *draw_str_p;

	uchar *c_data_ptr;
	int c_code;

	int char_row;

	uchar *output_ptr;
	uchar *output_ptr_min;
	uchar *output_ptr_max;

	int row;
	int row_limit;

	int c_byte_len;
	int c_byte;
	int c_bit;

	int ct;

	if ((text_x > ds->buf_w) || (text_y > ds->buf_h)) {
		/* Output string can't be visible */
		return R_SUCCESS;
	}

	draw_str_p = (const uchar *) draw_str;
	ct = draw_str_ct;

	/* Draw string one character at a time, maximum of 'draw_str'_ct 
	 * characters, or no limit if 'draw_str_ct' is 0 */
	for (; *draw_str_p && (!draw_str_ct || ct); draw_str_p++, ct--) {

		c_code = *draw_str_p & 0xFFU;

		/* Translate character */
		c_code = CharMap[c_code];
		assert(c_code < R_FONT_CHARCOUNT);

		/* Check if character is defined */
		if ((draw_font->fce[c_code].index == 0) &&
		    (c_code != R_FONT_FIRSTCHAR)) {

#           if R_FONT_SHOWUNDEFINED

			if (c_code == R_FONT_CH_SPACE) {
				text_x += draw_font->fce[c_code].tracking;
				continue;
			}
			c_code = R_FONT_CH_QMARK;

#           else

			/* Character code is not defined, but advance tracking
			 * ( Not defined if offset is 0, except for 33 ('!') which
			 *   is defined ) */
			text_x += draw_font->fce[c_code].tracking;
			continue;

#endif
		}

		/* Get length of character in bytes */
		c_byte_len = ((draw_font->fce[c_code].width - 1) / 8) + 1;

		row_limit = (ds->buf_h < (text_y + draw_font->hdr.c_height))
		    ? ds->buf_h : text_y + draw_font->hdr.c_height;

		char_row = 0;

		for (row = text_y; row < row_limit; row++, char_row++) {

			/* Clip negative rows */
			if (row < 0) {
				continue;
			}

			output_ptr = ds->buf + (ds->buf_pitch * row) + text_x;

			output_ptr_min = ds->buf + (ds->buf_pitch * row) +
			    (text_x > 0 ? text_x : 0);

			output_ptr_max = output_ptr + (ds->buf_pitch - text_x);

			/* If character starts off the screen, jump to next character */
			if (output_ptr < output_ptr_min) {
				break;
			}

			c_data_ptr = draw_font->font_p +
			    char_row * draw_font->hdr.row_length +
			    draw_font->fce[c_code].index;

			for (c_byte = 0; c_byte < c_byte_len;
			    c_byte++, c_data_ptr++) {

				/* Check each bit, draw pixel if bit is set */
				for (c_bit = 7;
				    c_bit >= 0
				    && (output_ptr < output_ptr_max);
				    c_bit--) {

					if ((*c_data_ptr >> c_bit) & 0x01) {
						*output_ptr = (uchar) color;
					}
					output_ptr++;

				}	/* end per-bit processing */

			}	/* end per-byte processing */

		}		/* end per-row processing */

		/* Advance tracking position */
		text_x += draw_font->fce[c_code].tracking;

	}			/* end per-character processing */

	return R_SUCCESS;
}

} // End of namespace Saga