/*
    MACLIB:  A companion library to SDL for working with Macintosh (tm) data
    Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>

    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
*/

/* The Macintosh Font Server module */

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

#include "SDL_types.h"
#include "bitesex.h"
#include "Mac_FontServ.h"

#define copy_short(S, D)	memcpy(&S, D, 2); D += 2;
#define copy_long(L, D)		memcpy(&L, D, 4); D += 4;

/* The structure of the Macintosh 'FOND' resource */
struct Font_entry {
	Uint16	size;
	Uint16	style;
	Uint16	ID;
};
struct FOND {
	Uint16	flags;
	Uint16	ID;
	Uint16	firstCH;
	Uint16	lastCH;
	Uint16	MaxAscent;	/* Maximum Font Ascent */
	Uint16	MaxDescent;	/* Maximum Font Descent */
	Uint16	MaxLead;	/* Maximum Font Leading */
	Uint16	MaxWidth;	/* Maximum Font Glyph Width */
	Uint32	WidthOff;	/* Width table offset */
	Uint32	KernOff;	/* Kerning table offset */
	Uint32	StyleOff;	/* Style mapping table offset */
	Uint16	StyleProp[9];	/* 9 Style Properties */
	Uint32	Intl_info;	/* International script info */
	Uint16	Version;	/* The version of the FOND resource */

	/* The Font Association Table */
	Uint16	num_fonts;	/* Number of fonts in table - 1 */
#ifdef SHOW_VARLENGTH_FIELDS
	struct Font_entry nfnts[0];
#endif

	/* The Offset Table */
	/* The Bounding Box Table */
	/* The Glyph Width Table */
	/* The Style Mapping Table */
	/* The Kerning Table */
};


FontServ:: FontServ(const char *fontfile)
{
	fontres = new Mac_Resource(fontfile);
	text_allocated = 0;
	if ( fontres->Error() ) {
		SetError("Couldn't load resources from %s", fontfile);
		return;
	}
	if ( fontres->NumResources("FOND") == 0 ) {
		SetError("FontServ: No 'FOND' resources in %s", fontfile);
		return;
	}
	errstr = NULL;
}

FontServ:: ~FontServ()
{
	if ( text_allocated != 0 ) {
		fprintf(stderr,
			"FontServ: Warning: %d text surfaces extant\n",
							text_allocated);
	}
	delete fontres;
}


MFont *
FontServ:: NewFont(const char *fontname, int ptsize)
{
	Mac_ResData *fond;
	Uint8 *data;
	struct FOND Fond;
	struct Font_entry Fent;
	int nchars;		/* number of chars including 'missing char' */
	int nwords;		/* bit image size, in words */
	int i, swapfont;
	MFont *font;

	/* Get the font family */
	fond = fontres->Resource("FOND", fontname);
	if ( fond == NULL ) {
		SetError("Warning: Font family '%s' not found", fontname);
		return(NULL);
	}

	/* Find out what font ID we need */
	data = fond->data;
        copy_short(Fond.flags, data);
        copy_short(Fond.ID, data);
        copy_short(Fond.firstCH, data);
        copy_short(Fond.lastCH, data);
	copy_short(Fond.MaxAscent, data);
	copy_short(Fond.MaxDescent, data);
	copy_short(Fond.MaxLead, data);
	copy_short(Fond.MaxWidth, data);
	copy_long(Fond.WidthOff, data);
	copy_long(Fond.KernOff, data);
	copy_long(Fond.StyleOff, data);
	memcpy(Fond.StyleProp, data, 18); data += 18;
	copy_long(Fond.Intl_info, data);
	copy_short(Fond.Version, data);
	copy_short(Fond.num_fonts, data);
	bytesex16(Fond.num_fonts);
	++Fond.num_fonts;
	for (i=0; i<Fond.num_fonts; ++i, data += sizeof(struct Font_entry)) {
		memcpy(&Fent, data, sizeof(Fent));
		byteswap((Uint16 *)&Fent, 3);
		if ( (Fent.size == ptsize) && ! Fent.style )
			break;
	} 
	if ( i == Fond.num_fonts ) {
		SetError(
		"Warning: Font family '%s' doesn't have %d pt fonts",
							fontname, ptsize);
		return(NULL);
	}

	/* Now, Fent.ID is the ID of the correct NFNT resource */
	font = new MFont;
	font->nfnt = fontres->Resource("NFNT", Fent.ID);
	if ( font->nfnt == NULL ) {
		delete font;
		SetError(
"Warning: Can't find NFNT resource for %d pt %s font", ptsize, fontname);
		return(NULL);
	}

	/* Now that we have the resource, fiddle with the font structure
	   so we can use it.  (Code taken from 'mac2bdf' -- Thanks! :)
	 */
	font->header = (struct FontHdr *)(font->nfnt)->data;
	if ( ((font->header->fontType & ~3) != PROPFONT) &&
			((font->header->fontType & ~3) != FIXEDFONT) ) {
		swapfont = 1;
	} else {
		swapfont = 0;
	}
	if ( swapfont ) {
		byteswap((Uint16 *)font->header,
				sizeof(struct FontHdr)/sizeof(Uint16));
	}

	/* Check magic number.
	   The low two bits are masked off; newer versions of the Font Manager
	   use these to indicate the presence of optional 'width' and 'height'
	   tables, which are for fractional character spacing (unused).
	 */
	if ( ((font->header->fontType & ~3) != PROPFONT) &&
			((font->header->fontType & ~3) != FIXEDFONT) ) {
		SetError("Warning: Bad font Magic number: 0x%04x", 
						(font->header)->fontType);
		delete font;
		return(NULL);
	}
	nchars= ((font->header)->lastChar - (font->header)->firstChar + 1) + 1;
		/* One extra for "missing character image" */
	nwords= (font->header)->rowWords * (font->header)->fRectHeight;
	
	/* Read the tables.  They follow sequentially in the resource */
	font->bitImage = (Uint16 *)((font->nfnt)->data+sizeof(*font->header));
	font->locTable = (Uint16 *)(font->bitImage+nwords);
	font->owTable = (Sint16 *)(font->locTable+nchars+1);
	
	/* Note -- there may be excess data at the end of the resource
	   (the optional width or height tables) */
	
	/* Byteswap the tables */
	if ( swapfont ) {
		byteswap(font->bitImage, nwords);
		byteswap(font->locTable, nchars+1);
		byteswap((Uint16 *)font->owTable, nchars);
	}
	return(font);
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#define HiByte(word)		((word>>8)&0xFF)
#define LoByte(word)		(word&0xFF)

/* The width of the specified text in pixels when displayed with the 
   specified font and style.
*/
Uint16
FontServ:: TextWidth(const char *text, MFont *font, Uint8 style)
{
	int nchars, i;
	int space_width;	/* The width of the whole character */
	int extra_width;	/* Stylistic width */
	Uint16 Width;

	switch (style) {
		case STYLE_NORM:	extra_width = 0;
					break;
		case STYLE_BOLD:	extra_width = 1;
					break;
		case STYLE_ULINE:	extra_width = 0;
					break;
		default:		return(0);
	}
	nchars = strlen(text);

	Width = 0;
	for ( i = 0; i < nchars; ++i ) {
		/* check to see if this character is defined */
		if (font->owTable[(Uint8)text[i]] <= 0)
			continue;
		
		space_width = LoByte(font->owTable[(Uint8)text[i]]);
#ifdef WIDE_BOLD
		Width += (space_width+extra_width);
#else
		Width += space_width;
#endif
	}
	return(Width);
}
Uint16
FontServ:: TextHeight(MFont *font)
{
	return((font->header)->fRectHeight);
}

/* Get/Set bit i of a scan line */
#define GETBIT(scanline, i) \
		((scanline[(i)/16] >> (15 - (i)%16)) & 1)
#define SETBIT(scanline, i, bit) \
		(scanline[(i)/8] |= bit << (7 - (i)%8))

SDL_Surface *
FontServ:: TextImage(const char *text, MFont *font, Uint8 style,
			SDL_Color foreground, SDL_Color background)
{
	Uint16 width, height;
	SDL_Surface *image;
	Uint8 *bitmap;
	int nchars;
	int bit_offset;		/* The current bit offset into a scanline */
	int space_width;	/* The width of the whole character */
	int space_offset;	/* The offset into the character of glyph */
	int glyph_line_offset;	/* The offset into scanline of glyph */
	int glyph_width;	/* The width of brushed glyph */
	int bold_offset, boldness;
	int ascii, i, y;
	int bit;

	switch (style) {
		case STYLE_NORM:	bold_offset = 0;
					break;
		case STYLE_BOLD:	bold_offset = 1;
					break;
		case STYLE_ULINE:	bold_offset = 0;
					break;
		case STYLE_ITALIC:	SetError(
					"FontServ: Italics not implemented!");
					return(NULL);
		default:		SetError(
					"FontServ: Unknown text style!");
					return(NULL);
	}

	/* Notes on the tables.
	
	   Table 'bits' contains a bitmap image of the entire font.
	   There are fRectHeight rows, each rowWords long.
	   The high bit of a word is leftmost in the image.
	   The characters are placed in this image in order of their
	   ASCII value.  The last image is that of the "missing
	   character"; every Mac font must have such an image
	   (traditionally a maximum-sized block).
	   
	   The location table (loctab) and offset/width table (owtab)
	   have one entry per character in the range firstChar..lastChar,
	   plus two extra entries: one for the "missing character" image
	   and a terminator.  They describe, respectively, where to
	   find the character in the bitmap and how to interpret it with
	   respect to the "character origin" (pen position on the base
	   line).
	   
	   The location table entry for a character contains the bit (!)
	   offset of the start of its image data in the font's bitmap.
	   The image data's width is computed by subtracting the start
	   from the start of the next character (hence the terminator).
	   
	   The offset/width table contains -1 for undefined characters;
	   for defined characters, the high byte contains the character
	   offset (distance between left of character image and
	   character origin), and the low byte contains the character
	   width (distance between the character origin and the origin
	   of the next character on the line).
	 */
	
	/* Figure out how big the text image will be */
	width = TextWidth(text, font, style);
	if ( width == 0 ) {
		SetError("No text to convert");
		return(NULL);
	}
	height = (font->header)->fRectHeight;

	/* Allocate the text bitmap image */
	image = SDL_CreateRGBSurface(SDL_SWSURFACE, width, height, 1, 0,0,0,0);
	if ( image == NULL ) {
		SetError("Unable to allocate bitmap: %s", SDL_GetError());
		return(NULL);
	}
	bitmap = (Uint8 *)image->pixels;

	/* Print the individual characters */
	/* Note: this could probably be optimized.. eh, who cares. :) */
	nchars = strlen(text);
	for ( boldness=0; boldness <= bold_offset; ++boldness ) {
		bit_offset=0;
		for ( i = 0; i < nchars; ++i ) {
			/* check to see if this character is defined */
			/* According to the above comment, we should */
			/* check if the table contains -1, but this  */
			/* change seems to fix a SIGSEGV that would  */
			/* otherwise occur in some cases.            */
			if (font->owTable[(Uint8)text[i]] <= 0)
				continue;

			space_width = LoByte(font->owTable[(Uint8)text[i]]);
			space_offset = HiByte(font->owTable[(Uint8)text[i]]);
			ascii = (Uint8)text[i] - (font->header)->firstChar;
			glyph_line_offset = font->locTable[ascii]; 
			glyph_width = (font->locTable[ascii+1] -
							font->locTable[ascii]);
			for ( y=0; y<height; ++y ) {
				int     dst_offset;
				Uint16 *src_scanline;
			
				dst_offset = (y*image->pitch*8+
						bit_offset+space_offset);
				src_scanline = font->bitImage + 
						y*(font->header)->rowWords;
				for ( bit = 0; bit<glyph_width; ++bit ) {
					SETBIT(bitmap, dst_offset+bit+boldness, 
				  		GETBIT(src_scanline, glyph_line_offset+bit));
				}
			}
#ifdef WIDE_BOLD
			bit_offset += (space_width+bold_offset);
#else
			bit_offset += space_width;
#endif
		}
	}
	if ( (style&STYLE_ULINE) == STYLE_ULINE ) {
		y = (height-(font->header)->descent+1);
		bit_offset = (y*image->pitch*8);
		for ( bit=0; bit<width; ++bit )
			SETBIT(bitmap, bit_offset+bit, 0x01);
	}

	/* Map the image and return */
	SDL_SetColorKey(image, SDL_TRUE, 0);
	image->format->palette->colors[0] = background;
	image->format->palette->colors[1] = foreground;
	++text_allocated;
	return(image);
}
void
FontServ:: FreeText(SDL_Surface *text)
{
	--text_allocated;
	SDL_FreeSurface(text);
}
int
FontServ:: InvertText(SDL_Surface *text)
{
	SDL_Color colors[2];

	/* Only works on bitmap images */
	if ( text->format->BitsPerPixel != 1 ) {
		SetError("Not a text bitmap");
		return(-1);
	}

	/* Swap background and foreground colors */
	colors[0] = text->format->palette->colors[1];
	colors[1] = text->format->palette->colors[0];
	SDL_SetPaletteColors(text->format->palette, colors, 0, 2);
	return(0);
}