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/* Copyright (C) 1989, 2000 Aladdin Enterprises.  All rights reserved.

  This software is provided AS-IS with no warranty, either express or

  implied.

  This software is distributed under license and may not be copied,

  modified or distributed except as expressly authorized under the terms

  of the license contained in the file LICENSE in this distribution.

  For more information about licensing, please refer to

  http://www.ghostscript.com/licensing/. For information on

  commercial licensing, go to http://www.artifex.com/licensing/ or

  contact Artifex Software, Inc., 101 Lucas Valley Road #110,

  San Rafael, CA  94903, U.S.A., +1(415)492-9861.

*/

/* $Id: gscoord.c,v 1.9 2004/03/13 18:28:52 igor Exp $ */

/* Coordinate system operators for Ghostscript library */

#include "math_.h"

#include "gx.h"

#include "gserrors.h"

#include "gsccode.h"		/* for gxfont.h */

#include "gxfarith.h"

#include "gxfixed.h"

#include "gxmatrix.h"

#include "gxfont.h"		/* for char_tm */

#include "gxpath.h"		/* for gx_path_translate */

#include "gzstate.h"

#include "gxcoord.h"		/* requires gsmatrix, gsstate */

#include "gxdevice.h"

/* Choose whether to enable the rounding code in update_ctm. */

#define ROUND_CTM_FIXED 1

/* Forward declarations */

#ifdef DEBUG

#define trace_ctm(pgs) trace_matrix_fixed(&(pgs)->ctm)

private void trace_matrix_fixed(const gs_matrix_fixed *);

private void trace_matrix(const gs_matrix *);

#endif

/* Macro for ensuring ctm_inverse is valid */

#ifdef DEBUG

#  define print_inverse(pgs)\

     if ( gs_debug_c('x') )\

       dlprintf("[x]Inverting:\n"), trace_ctm(pgs), trace_matrix(&pgs->ctm_inverse)

#else

#  define print_inverse(pgs) DO_NOTHING

#endif

#define ensure_inverse_valid(pgs)\

	if ( !pgs->ctm_inverse_valid )\

	   {	int code = ctm_set_inverse(pgs);\

		if ( code < 0 ) return code;\

	   }

private int

ctm_set_inverse(gs_state * pgs)

{

    int code = gs_matrix_invert(&ctm_only(pgs), &pgs->ctm_inverse);

    print_inverse(pgs);

    if (code < 0)

	return code;

    pgs->ctm_inverse_valid = true;

    return 0;

}

/* Machinery for updating fixed version of ctm. */

/*

 * We (conditionally) adjust the floating point translation

 * so that it exactly matches the (rounded) fixed translation.

 * This avoids certain unpleasant rounding anomalies, such as

 * 0 0 moveto currentpoint not returning 0 0, and () stringwidth

 * not returning 0 0.

 */

#if ROUND_CTM_FIXED

#  define update_t_fixed(mat, t, t_fixed, v)\

    (set_float2fixed_vars((mat).t_fixed, v),\

     set_fixed2float_var((mat).t, (mat).t_fixed))

#else /* !ROUND_CTM_FIXED */

#  define update_t_fixed(mat, t, t_fixed, v)\

    ((mat).t = (v),\

     set_float2fixed_vars((mat).t_fixed, (mat).t))

#endif /* (!)ROUND_CTM_FIXED */

#define f_fits_in_fixed(f) f_fits_in_bits(f, fixed_int_bits)

#define update_matrix_fixed(mat, xt, yt)\

  ((mat).txy_fixed_valid = (f_fits_in_fixed(xt) && f_fits_in_fixed(yt) ?\

			    (update_t_fixed(mat, tx, tx_fixed, xt),\

			     update_t_fixed(mat, ty, ty_fixed, yt), true) :\

			    ((mat).tx = (xt), (mat).ty = (yt), false)))

#define update_ctm(pgs, xt, yt)\

  (pgs->ctm_inverse_valid = false,\

   pgs->char_tm_valid = false,\

   update_matrix_fixed(pgs->ctm, xt, yt))

/* ------ Coordinate system definition ------ */

int

gs_initmatrix(gs_state * pgs)

{

    gs_matrix imat;

    gs_defaultmatrix(pgs, &imat);

    update_ctm(pgs, imat.tx, imat.ty);

    set_ctm_only(pgs, imat);

#ifdef DEBUG

    if (gs_debug_c('x'))

	dlprintf("[x]initmatrix:\n"), trace_ctm(pgs);

#endif

    return 0;

}

int

gs_defaultmatrix(const gs_state * pgs, gs_matrix * pmat)

{

    gx_device *dev;

    if (pgs->ctm_default_set) {	/* set after Install */

	*pmat = pgs->ctm_default;

	return 1;

    }

    dev = gs_currentdevice_inline(pgs);

    gs_deviceinitialmatrix(dev, pmat);

    /* Add in the translation for the Margins. */

    pmat->tx += dev->Margins[0] *

	dev->HWResolution[0] / dev->MarginsHWResolution[0];

    pmat->ty += dev->Margins[1] *

	dev->HWResolution[1] / dev->MarginsHWResolution[1];

    return 0;

}

int

gs_setdefaultmatrix(gs_state * pgs, const gs_matrix * pmat)

{

    if (pmat == NULL)

	pgs->ctm_default_set = false;

    else {

	pgs->ctm_default = *pmat;

	pgs->ctm_default_set = true;

    }

    return 0;

}

int

gs_currentmatrix(const gs_state * pgs, gs_matrix * pmat)

{

    *pmat = ctm_only(pgs);

    return 0;

}

/* Set the current transformation matrix for rendering text. */

/* Note that this may be based on a font other than the current font. */

int

gs_setcharmatrix(gs_state * pgs, const gs_matrix * pmat)

{

    gs_matrix cmat;

    int code = gs_matrix_multiply(pmat, &ctm_only(pgs), &cmat);

    if (code < 0)

	return code;

    update_matrix_fixed(pgs->char_tm, cmat.tx, cmat.ty);

    char_tm_only(pgs) = cmat;

#ifdef DEBUG

    if (gs_debug_c('x'))

	dlprintf("[x]setting char_tm:"), trace_matrix_fixed(&pgs->char_tm);

#endif

    pgs->char_tm_valid = true;

    return 0;

}

/* Read (after possibly computing) the current transformation matrix */

/* for rendering text.  If force=true, update char_tm if it is invalid; */

/* if force=false, don't update char_tm, and return an error code. */

int

gs_currentcharmatrix(gs_state * pgs, gs_matrix * ptm, bool force)

{

    if (!pgs->char_tm_valid) {

	int code;

	if (!force)

	    return_error(gs_error_undefinedresult);

	code = gs_setcharmatrix(pgs, &pgs->font->FontMatrix);

	if (code < 0)

	    return code;

    }

    if (ptm != NULL)

	*ptm = char_tm_only(pgs);

    return 0;

}

int

gs_setmatrix(gs_state * pgs, const gs_matrix * pmat)

{

    update_ctm(pgs, pmat->tx, pmat->ty);

    set_ctm_only(pgs, *pmat);

#ifdef DEBUG

    if (gs_debug_c('x'))

	dlprintf("[x]setmatrix:\n"), trace_ctm(pgs);

#endif

    return 0;

}

int

gs_imager_setmatrix(gs_imager_state * pis, const gs_matrix * pmat)

{

    update_matrix_fixed(pis->ctm, pmat->tx, pmat->ty);

    set_ctm_only(pis, *pmat);

#ifdef DEBUG

    if (gs_debug_c('x'))

	dlprintf("[x]imager_setmatrix:\n"), trace_ctm(pis);

#endif

    return 0;

}

int

gs_settocharmatrix(gs_state * pgs)

{

    if (pgs->char_tm_valid) {

	pgs->ctm = pgs->char_tm;

	pgs->ctm_inverse_valid = false;

	return 0;

    } else

	return_error(gs_error_undefinedresult);

}

int

gs_translate(gs_state * pgs, floatp dx, floatp dy)

{

    gs_point pt;

    int code;

    if ((code = gs_distance_transform(dx, dy, &ctm_only(pgs), &pt)) < 0)

	return code;

    pt.x += pgs->ctm.tx;

    pt.y += pgs->ctm.ty;

    update_ctm(pgs, pt.x, pt.y);

#ifdef DEBUG

    if (gs_debug_c('x'))

	dlprintf4("[x]translate: %f %f -> %f %f\n",

		  dx, dy, pt.x, pt.y),

	    trace_ctm(pgs);

#endif

    return 0;

}

int

gs_scale(gs_state * pgs, floatp sx, floatp sy)

{

    pgs->ctm.xx *= sx;

    pgs->ctm.xy *= sx;

    pgs->ctm.yx *= sy;

    pgs->ctm.yy *= sy;

    pgs->ctm_inverse_valid = false, pgs->char_tm_valid = false;

#ifdef DEBUG

    if (gs_debug_c('x'))

	dlprintf2("[x]scale: %f %f\n", sx, sy), trace_ctm(pgs);

#endif

    return 0;

}

int

gs_rotate(gs_state * pgs, floatp ang)

{

    int code = gs_matrix_rotate(&ctm_only(pgs), ang,

				&ctm_only_writable(pgs));

    pgs->ctm_inverse_valid = false, pgs->char_tm_valid = false;

#ifdef DEBUG

    if (gs_debug_c('x'))

	dlprintf1("[x]rotate: %f\n", ang), trace_ctm(pgs);

#endif

    return code;

}

int

gs_concat(gs_state * pgs, const gs_matrix * pmat)

{

    gs_matrix cmat;

    int code = gs_matrix_multiply(pmat, &ctm_only(pgs), &cmat);

    if (code < 0)

	return code;

    update_ctm(pgs, cmat.tx, cmat.ty);

    set_ctm_only(pgs, cmat);

#ifdef DEBUG

    if (gs_debug_c('x'))

	dlprintf("[x]concat:\n"), trace_matrix(pmat), trace_ctm(pgs);

#endif

    return code;

}

/* ------ Coordinate transformation ------ */

#define is_skewed(pmat) (!(is_xxyy(pmat) || is_xyyx(pmat)))

int

gs_transform(gs_state * pgs, floatp x, floatp y, gs_point * pt)

{

    return gs_point_transform(x, y, &ctm_only(pgs), pt);

}

int

gs_dtransform(gs_state * pgs, floatp dx, floatp dy, gs_point * pt)

{

    return gs_distance_transform(dx, dy, &ctm_only(pgs), pt);

}

int

gs_itransform(gs_state * pgs, floatp x, floatp y, gs_point * pt)

{				/* If the matrix isn't skewed, we get more accurate results */

    /* by using transform_inverse than by using the inverse matrix. */

    if (!is_skewed(&pgs->ctm)) {

	return gs_point_transform_inverse(x, y, &ctm_only(pgs), pt);

    } else {

	ensure_inverse_valid(pgs);

	return gs_point_transform(x, y, &pgs->ctm_inverse, pt);

    }

}

int

gs_idtransform(gs_state * pgs, floatp dx, floatp dy, gs_point * pt)

{				/* If the matrix isn't skewed, we get more accurate results */

    /* by using transform_inverse than by using the inverse matrix. */

    if (!is_skewed(&pgs->ctm)) {

	return gs_distance_transform_inverse(dx, dy,

					     &ctm_only(pgs), pt);

    } else {

	ensure_inverse_valid(pgs);

	return gs_distance_transform(dx, dy, &pgs->ctm_inverse, pt);

    }

}

int

gs_imager_idtransform(const gs_imager_state * pis, floatp dx, floatp dy,

		      gs_point * pt)

{

    return gs_distance_transform_inverse(dx, dy, &ctm_only(pis), pt);

}

/* ------ For internal use only ------ */

/* Set the translation to a fixed value, and translate any existing path. */

/* Used by gschar.c to prepare for a BuildChar or BuildGlyph procedure. */

int

gx_translate_to_fixed(register gs_state * pgs, fixed px, fixed py)

{

    double fpx = fixed2float(px);

    double fdx = fpx - pgs->ctm.tx;

    double fpy = fixed2float(py);

    double fdy = fpy - pgs->ctm.ty;

    fixed dx, dy;

    int code;

    if (pgs->ctm.txy_fixed_valid) {

	dx = float2fixed(fdx);

	dy = float2fixed(fdy);

	code = gx_path_translate(pgs->path, dx, dy);

	if (code < 0)

	    return code;

	if (pgs->char_tm_valid && pgs->char_tm.txy_fixed_valid)

	    pgs->char_tm.tx_fixed += dx,

		pgs->char_tm.ty_fixed += dy;

    } else {

	if (!gx_path_is_null(pgs->path))

	    return_error(gs_error_limitcheck);

    }

    pgs->ctm.tx = fpx;

    pgs->ctm.tx_fixed = px;

    pgs->ctm.ty = fpy;

    pgs->ctm.ty_fixed = py;

    pgs->ctm.txy_fixed_valid = true;

    pgs->ctm_inverse_valid = false;

    if (pgs->char_tm_valid) {	/* Update char_tm now, leaving it valid. */

	pgs->char_tm.tx += fdx;

	pgs->char_tm.ty += fdy;

    }

#ifdef DEBUG

    if (gs_debug_c('x')) {

	dlprintf2("[x]translate_to_fixed %g, %g:\n",

		  fixed2float(px), fixed2float(py));

	trace_ctm(pgs);

	dlprintf("[x]   char_tm:\n");

	trace_matrix_fixed(&pgs->char_tm);

    }

#endif

    gx_setcurrentpoint(pgs, fixed2float(pgs->ctm.tx_fixed), fixed2float(pgs->ctm.ty_fixed));

    pgs->current_point_valid = true;

    return 0;

}

/* Scale the CTM and character matrix for oversampling. */

int

gx_scale_char_matrix(register gs_state * pgs, int sx, int sy)

{

#define scale_cxy(s, vx, vy)\

  if ( s != 1 )\

   {	pgs->ctm.vx *= s;\

	pgs->ctm.vy *= s;\

	pgs->ctm_inverse_valid = false;\

	if ( pgs->char_tm_valid )\

	{	pgs->char_tm.vx *= s;\

		pgs->char_tm.vy *= s;\

	}\

   }

    scale_cxy(sx, xx, yx);

    scale_cxy(sy, xy, yy);

#undef scale_cxy

    if_debug2('x', "[x]char scale: %d %d\n", sx, sy);

    return 0;

}

/* Compute the coefficients for fast fixed-point distance transformations */

/* from a transformation matrix. */

/* We should cache the coefficients with the ctm.... */

int

gx_matrix_to_fixed_coeff(const gs_matrix * pmat, register fixed_coeff * pfc,

			 int max_bits)

{

    gs_matrix ctm;

    int scale = -10000;

    int expt, shift;

    ctm = *pmat;

    pfc->skewed = 0;

    if (!is_fzero(ctm.xx)) {

	discard(frexp(ctm.xx, &scale));

    }

    if (!is_fzero(ctm.xy)) {

	discard(frexp(ctm.xy, &expt));

	if (expt > scale)

	    scale = expt;

	pfc->skewed = 1;

    }

    if (!is_fzero(ctm.yx)) {

	discard(frexp(ctm.yx, &expt));

	if (expt > scale)

	    scale = expt;

	pfc->skewed = 1;

    }

    if (!is_fzero(ctm.yy)) {

	discard(frexp(ctm.yy, &expt));

	if (expt > scale)

	    scale = expt;

    }

    /*

     * There are two multiplications in fixed_coeff_mult: one involves a

     * factor that may have max_bits significant bits, the other may have

     * fixed_fraction_bits (_fixed_shift) bits.  Ensure that neither one

     * will overflow.

     */

    if (max_bits < fixed_fraction_bits)

	max_bits = fixed_fraction_bits;

    scale = sizeof(long) * 8 - 1 - max_bits - scale;

    shift = scale - _fixed_shift;

    if (shift > 0) {

	pfc->shift = shift;

	pfc->round = (fixed) 1 << (shift - 1);

    } else {

	pfc->shift = 0;

	pfc->round = 0;

	scale -= shift;

    }

#define SET_C(c)\

  if ( is_fzero(ctm.c) ) pfc->c = 0;\

  else pfc->c = (long)ldexp(ctm.c, scale)

    SET_C(xx);

    SET_C(xy);

    SET_C(yx);

    SET_C(yy);

#undef SET_C

#ifdef DEBUG

    if (gs_debug_c('x')) {

	dlprintf6("[x]ctm: [%6g %6g %6g %6g %6g %6g]\n",

		  ctm.xx, ctm.xy, ctm.yx, ctm.yy, ctm.tx, ctm.ty);

	dlprintf6("   scale=%d fc: [0x%lx 0x%lx 0x%lx 0x%lx] shift=%d\n",

		  scale, pfc->xx, pfc->xy, pfc->yx, pfc->yy,

		  pfc->shift);

    }

#endif

    pfc->max_bits = max_bits;

    return 0;

}

/*

 * Handle the case of a large value or a value with a fraction part.

 * See gxmatrix.h for more details.

 */

fixed

fixed_coeff_mult(fixed value, long coeff, const fixed_coeff *pfc, int maxb)

{

    int shift = pfc->shift;

    /*

     * Test if the value is too large for simple long math.

     */

    if ((value + (fixed_1 << (maxb - 1))) & (-fixed_1 << maxb)) {

	/* The second argument of fixed_mult_quo must be non-negative. */

	return

	    (coeff < 0 ?

	     -fixed_mult_quo(value, -coeff, fixed_1 << shift) :

	     fixed_mult_quo(value, coeff, fixed_1 << shift));

    } else {

	/*

	 * The construction above guarantees that the multiplications

	 * won't overflow the capacity of an int.

	 */

        return (fixed)

	    arith_rshift(fixed2int_var(value) * coeff

			 + fixed2int(fixed_fraction(value) * coeff)

			 + pfc->round, shift);

    }

}

/* ------ Debugging printout ------ */

#ifdef DEBUG

/* Print a matrix */

private void

trace_matrix_fixed(const gs_matrix_fixed * pmat)

{

    trace_matrix((const gs_matrix *)pmat);

    if (pmat->txy_fixed_valid) {

	dprintf2("\t\tt_fixed: [%6g %6g]\n",

		 fixed2float(pmat->tx_fixed),

		 fixed2float(pmat->ty_fixed));

    } else {

	dputs("\t\tt_fixed not valid\n");

    }

}

private void

trace_matrix(register const gs_matrix * pmat)

{

    dlprintf6("\t[%6g %6g %6g %6g %6g %6g]\n",

	      pmat->xx, pmat->xy, pmat->yx, pmat->yy, pmat->tx, pmat->ty);

}

#endif