/* Copyright (C) 1989, 1990 Aladdin Enterprises.  All rights reserved.
   Distributed by Free Software Foundation, Inc.

This file is part of Ghostscript.

Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.  Refer
to the Ghostscript General Public License for full details.

Everyone is granted permission to copy, modify and redistribute
Ghostscript, but only under the conditions described in the Ghostscript
General Public License.  A copy of this license is supposed to have been
given to you along with Ghostscript so you can know your rights and
responsibilities.  It should be in a file named COPYING.  Among other
things, the copyright notice and this notice must be preserved on all
copies.  */

/* zchar.c */
/* Character operators for GhostScript */
#include "ghost.h"
#include "errors.h"
#include "oper.h"
#include "gxfixed.h"			/* for gstype1.h, gxfont1.h */
#include "gxmatrix.h"			/* for font.h */
#include "gschar.h"
#include "gstype1.h"
#include "gxdevice.h"			/* for gxfont.h */
#include "gxfont.h"
#include "gxfont1.h"
#include "gzpath.h"			/* for type1addpath: see below */
#include "gzstate.h"
#include "alloc.h"
#include "dict.h"
#include "font.h"
#include "estack.h"
#include "state.h"
#include "store.h"

/* All the character rendering operators use the execution stack */
/* for loop control -- see estack.h for details. */
/* The information pushed by these operators is as follows: */
/*	the enumerator (t_string, but points to a gs_show_enum); */
/*	a slot for the procedure for kshow, unused otherwise; */
/*	the procedure to be called at the end of the enumeration */
/*		(t_operator, but called directly, not by the interpreter); */
/*	the usual e-stack mark (t_null). */
#define snumpush 4
#define senum (gs_show_enum *)(esp->value.bytes)
#define sslot esp[-1]
#define seproc esp[-2]

/* Forward references */
private int setup_show(P2(ref *, op_proc_p));
private int show_continue(P1(ref *));
private int finish_show(P1(ref *));
private int finish_stringwidth(P1(ref *));
private gs_show_enum *find_show();
private void free_show();

/* show */
int
zshow(register ref *op)
{	int code = setup_show(op, finish_show);
	if ( code < 0 ) return code;
	if ( (code = gs_show_n_init(senum, igs, (char *)op->value.bytes, op->size)) < 0 )
	   {	free_show();
		return code;
	   }
	pop(1);  op--;
	return show_continue(op);
}

/* ashow */
int
zashow(register ref *op)
{	int code;
	float axy[2];
	if (	(code = num_params(op - 1, 2, axy)) < 0 ||
		(code = setup_show(op, finish_show)) < 0
	   )
		return code;
	if ( (code = gs_ashow_n_init(senum, igs, axy[0], axy[1], (char *)op->value.bytes, op->size)) < 0 )
	   {	free_show();
		return code;
	   }
	pop(3);  op -= 3;
	return show_continue(op);
}

/* widthshow */
int
zwidthshow(register ref *op)
{	int code;
	float cxy[2];
	check_type(op[-1], t_integer);
	if ( (ulong)(op[-1].value.intval) > 255 ) return e_rangecheck;
	if (	(code = num_params(op - 2, 2, cxy)) < 0 ||
		(code = setup_show(op, finish_show)) < 0
	   )
		return code;
	if ( (code = gs_widthshow_n_init(senum, igs, cxy[0], cxy[1],
					 (char)op[-1].value.intval,
					 (char *)op->value.bytes,
					 op->size)) < 0 )
	   {	free_show();
		return code;
	   }
	pop(4);  op -= 4;
	return show_continue(op);
}

/* awidthshow */
int
zawidthshow(register ref *op)
{	int code;
	float cxy[2], axy[2];
	check_type(op[-3], t_integer);
	if ( (ulong)(op[-3].value.intval) > 255 ) return e_rangecheck;
	if (	(code = num_params(op - 4, 2, cxy)) < 0 ||
		(code = num_params(op - 1, 2, axy)) < 0 ||
		(code = setup_show(op, finish_show)) < 0
	   )
		return code;
	if ( (code = gs_awidthshow_n_init(senum, igs, cxy[0], cxy[1],
					  (char)op[-3].value.intval,
					  axy[0], axy[1],
					  (char *)op->value.bytes,
					  op->size)) < 0 )
	   {	free_show();
		return code;
	   }
	pop(6);  op -= 6;
	return show_continue(op);
}

/* kshow */
int
zkshow(register ref *op)
{	int code;
	check_proc(op[-1]);
	if ( (code = setup_show(op, finish_show)) < 0 ) return code;
	if ( (code = gs_kshow_n_init(senum, igs, (char *)op->value.bytes, op->size)) < 0 )
	   {	free_show();
		return code;
	   }
	sslot = op[-1];		/* save kerning proc */
	pop(2);  op -= 2;
	return show_continue(op);
}

/* Common finish procedure for all show operations. */
/* Doesn't have to do anything. */
private int
finish_show(ref *op)
{	return 0;
}

/* stringwidth */
int
zstringwidth(register ref *op)
{	int code = setup_show(op, finish_stringwidth);
	if ( code < 0 ) return code;
	if ( (code = gs_stringwidth_n_init(senum, igs, (char *)op->value.bytes, op->size)) < 0 )
	   {	free_show();
		return code;
	   }
	pop(1);  op--;
	return show_continue(op);
}
/* Finishing procedure for stringwidth. */
/* Pushes the accumulated width. */
private int
finish_stringwidth(register ref *op)
{	gs_point width;
	gs_show_width(senum, &width);
	push(2);
	make_real(op - 1, width.x);
	make_real(op, width.y);
	return 0;
}

/* charpath */
int
zcharpath(register ref *op)
{	int code;
	check_type(*op, t_boolean);
	code = setup_show(op - 1, finish_show);
	if ( code < 0 ) return code;
	if ( (code = gs_charpath_n_init(senum, igs, (char *)op[-1].value.bytes, op[-1].size, op->value.index)) < 0 )
	   {	free_show();
		return code;
	   }
	pop(2);  op -= 2;
	return show_continue(op);
}

/* setcachedevice */
int
zsetcachedevice(register ref *op)
{	float wbox[6];
	int npop = 6;
	gs_show_enum *penum = find_show();
	int code = num_params(op, 6, wbox);
	if ( penum == 0 ) return e_undefined;
	if ( code < 0 )
	   {	/* P*stScr*pt implementations apparently allow the */
		/* bounding box to be specified as a 4-element array. */
		/* Check for this here. */
		check_array(*op);
		if ( op->size != 4 ||
		     num_params(op - 1, 2, wbox) < 0 ||
		     num_params(op->value.refs + 3, 4, wbox + 2) < 0
		   )
			return code;
		npop = 3;
	   }
	if ( (code = gs_setcachedevice(penum, wbox[0], wbox[1], wbox[2], wbox[3], wbox[4], wbox[5])) < 0 )
		return code;
	pop(npop);
	return 0;
}

/* setcharwidth */
int
zsetcharwidth(register ref *op)
{	float width[2];
	gs_show_enum *penum = find_show();
	int code = num_params(op, 2, width);
	if ( penum == 0 ) return e_undefined;
	if (	code < 0 || 
		(code = gs_setcharwidth(penum, width[0], width[1])) < 0
	   )
		return code;
	pop(2);
	return 0;
}

/* type1addpath */
typedef struct {
	font_data *pfdata;
	fixed *osptr;			/* fake interpreter operand stack */
	fixed ostack[2];
} z1_data;
int
ztype1addpath(register ref *op)
{	int code;
	gs_show_enum *penum = find_show();
	gs_font *pfont = gs_currentfont(igs);
	font_data *pfdata = (font_data *)pfont->client_data;
	gs_type1_state *pis;
	fixed discard;
	gs_fixed_point spt, ept;
	int flex_path_was_open;
	gs_type1_data tdata;
	z1_data zdata;
	byte *charstring = 0;
	if ( penum == 0 ) return e_undefined;
	check_type(*op, t_string);
	tdata = pfdata->type1_data;
	zdata.pfdata = pfdata;
	zdata.osptr = zdata.ostack;
	tdata.proc_data = (char *)&zdata;
	if ( op->size <= tdata.lenIV )
	   {	/* String is empty, or too short.  Just ignore it. */
		pop(1);
		return 0;
	   }
	pis = (gs_type1_state *)alloc(1, gs_type1_state_sizeof, "type1addpath");
	if ( pis == 0 ) return e_VMerror;
	code = gs_type1_init(pis, penum,
			     gs_show_in_charpath(penum), pfont->paint_type,
			     op->value.bytes,
			     &tdata);
	if ( code < 0 )
	   {	alloc_free((char *)pis, 1, gs_type1_state_sizeof, "type1addpath");
		return code;
	   }
more:	code = gs_type1_interpret(pis, charstring);
	charstring = 0;
	if ( code > 0 )			/* seac or callothersubr */
	 { if ( code & 1)		/* seac */
	    {	ref *pcstr;
		code >>= 1;
		/* The restriction on seac seems to imply that */
		/* Adobe interpreters do something special about */
		/* StandardEncoding, but it seems just as easy for us */
		/* not to do anything special.... */
		if ( code >= pfdata->Encoding.size )
			return e_rangecheck;
		if ( dict_find(&pfdata->CharStrings,
			pfdata->Encoding.value.refs + code, &pcstr) <= 0 )
				return e_undefined;
		if ( r_type(pcstr) != t_string )
			return e_invalidfont;
		charstring = pcstr->value.bytes;
		goto more;
	    }
	  else				/* callothersubr */
	    {	/* We aren't prepared to call the interpreter here, */
		/* so we fake the Flex feature. */
		gx_path *ppath = igs->path;
		gs_type1_pop(pis, &discard);	/* pop # of args */
		switch ( (code >> 1) - 1 )
		   {
		case 0:
			/* We have to do something really sleazy here, */
			/* namely, make it look as though the rmovetos */
			/* never really happened, because we don't want */
			/* to interrupt the current subpath. */
			gx_path_current_point(ppath, &ept);
			gx_path_add_point(ppath, spt.x, spt.y);
			ppath->subpath_open = flex_path_was_open;
					/* ^--- sleaze */
			gx_path_add_line(ppath, ept.x, ept.y);
			/* Transfer endpoint coordinates to 'ostack' */
			gs_type1_pop(pis, &zdata.ostack[0]);
			gs_type1_pop(pis, &zdata.ostack[1]);
			gs_type1_pop(pis, &discard);
			zdata.osptr = &zdata.ostack[2];
			goto more;
		case 1:
			gx_path_current_point(ppath, &spt);
			flex_path_was_open = ppath->subpath_open;
					/* ^--- more sleaze */
			goto more;
		case 2:
			goto more;
		case 3:
			gs_type1_pop(pis, &discard);	/* pop subr# */
			zdata.ostack[0] = int2fixed(3);
			zdata.osptr = &zdata.ostack[1];
			goto more;
		   }
		/* Unrecognized othersubr */
		code = e_rangecheck;
	    }
	 }
	alloc_free((char *)pis, 1, gs_type1_state_sizeof, "type1addpath");
	if ( code >= 0 ) pop(1);
	return code;
}

/* type1imagepath */
int
ztype1imagepath(register ref *op)
{	float woxy[4];
	int code;
	check_type(op[-7], t_string);
	check_type(op[-6], t_integer);
	check_type(op[-5], t_integer);
	if ( (code = num_params(op - 1, 4, woxy)) < 0 ) return code;
	check_write_type(*op, t_string);
	code = gs_type1imagepath(igs, op[-7].value.bytes,
		(int)op[-6].value.intval, (int)op[-5].value.intval,
		woxy[0], woxy[1], woxy[2], woxy[3],
		op->value.bytes, op->size);
	if ( code < 0 ) return code;
	op[-7] = *op;
	op[-7].size = code;
	pop(7);
	return 0;
}

/* ------ Auxiliary procedures for type 1 fonts ------ */

int
z1_subr_proc(gs_type1_data *pdata, int index, byte **pstr)
{	font_data *pfdata = ((z1_data *)(pdata->proc_data))->pfdata;
	ref *psubr;
	if ( index < 0 || index >= pfdata->Subrs.size )
		return e_rangecheck;
	psubr = pfdata->Subrs.value.refs + index;
	check_type(*psubr, t_string);
	*pstr = psubr->value.bytes;
	return 0;
}

int
z1_pop_proc(gs_type1_data *pdata, fixed *pf)
{	*pf = *--(((z1_data *)(pdata->proc_data))->osptr);
	return 0;
}

/* ------ Initialization procedure ------ */

void
zchar_op_init()
{	static op_def my_defs[] = {
		{"3ashow", zashow},
		{"6awidthshow", zawidthshow},
		{"2charpath", zcharpath},
		{"2kshow", zkshow},
		{"3setcachedevice", zsetcachedevice},
		{"2setcharwidth", zsetcharwidth},
		{"1show", zshow},
		{"1stringwidth", zstringwidth},
		{"1type1addpath", ztype1addpath},
		{"8type1imagepath", ztype1imagepath},
		{"4widthshow", zwidthshow},
		op_def_end
	};
	z_op_init(my_defs);
}

/* ------ Internal routines ------ */

/* Set up for a show operator. */
/* The top stack element must be the string to be scanned. */
/* The caller has already done all other argument checking. */
private int
setup_show(ref *op, op_proc_p endproc /* end procedure */)
{	gs_show_enum *penum;
	check_read_type(*op, t_string);
	check_estack(snumpush + 2);
	if ( (penum = (gs_show_enum *)alloc(1, gs_show_enum_sizeof, "setup_show")) == 0 )
		return e_VMerror;
	mark_estack(es_show);
	push_op_estack(endproc);
	++esp;
	make_tv(esp, t_null, index, 0);		/* reserve slot */
	++esp;
	make_tasv(esp, t_string, 0, gs_show_enum_sizeof, bytes, (byte *)penum);
	return o_check_estack;
}

/* Continuation operator for character rendering. */
private int
show_continue(register ref *op)
{	gs_show_enum *penum = senum;
	int code = gs_show_next(penum);
	switch ( code )
	   {
	case 0:				/* all done */
		code = (*seproc.value.opproc)(op);
		free_show();
		return (code >= 0 ? o_check_estack : code);
	case gs_show_kern:
	   {	ref *pslot = &sslot;
		push(2);
		make_int(op - 1, gs_kshow_previous_char(penum));
		make_int(op, gs_kshow_next_char(penum));
		push_op_estack(show_continue);		/* continue after kerning */
		*++esp = *pslot;	/* kerning procedure */
	   }
		return o_check_estack;
	case gs_show_render:
	   {	font_data *pfont = (font_data *)gs_currentfont(igs)->client_data;
		push(2);
		op[-1] = pfont->dict;	/* push the font */
		make_int(op, gs_show_current_char(penum));
		push_op_estack(show_continue);
		*++esp = pfont->BuildChar;
	   }
		return o_check_estack;
	default:			/* error */
		free_show();
		return code;
	   }
}

/* Find the current show enumerator on the e-stack. */
private gs_show_enum *
find_show()
{	ref *ep = esp;
	while ( !(r_type(ep) == t_null && ep->value.index == es_show) )
	   {	if ( --ep < estack ) return 0;	/* no mark */
	   }
	return (gs_show_enum *)ep[snumpush - 1].value.bytes;
}

/* Discard the show record (after an error, or at the end). */
private void
free_show()
{	alloc_free((char *)senum, 1, gs_show_enum_sizeof, "free_show");
	esp -= snumpush;
}