/* Copyright (C) 1991, 1992, 1994, 1996, 1997, 1998 artofcode LLC.  All rights reserved.
  
  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.

*/

/*$Id: gsdps1.c,v 1.2.6.1.2.1 2003/01/17 00:49:02 giles Exp $ */
/* Display PostScript graphics additions for Ghostscript library */
#include "math_.h"
#include "gx.h"
#include "gserrors.h"
#include "gsmatrix.h"		/* for gscoord.h */
#include "gscoord.h"
#include "gspaint.h"
#include "gxdevice.h"
#include "gxfixed.h"
#include "gxmatrix.h"
#include "gspath.h"
#include "gspath2.h"		/* defines interface */
#include "gzpath.h"
#include "gzcpath.h"
#include "gzstate.h"

/*
 * Define how much rounding slop setbbox should leave,
 * in device coordinates.  Because of rounding in transforming
 * path coordinates to fixed point, the minimum realistic value is:
 *
 *      #define box_rounding_slop_fixed (fixed_epsilon)
 *
 * But even this isn't enough to compensate for cumulative rounding error
 * in rmoveto or rcurveto.  Instead, we somewhat arbitrarily use:
 */
#define box_rounding_slop_fixed (fixed_epsilon * 3)

/* ------ Graphics state ------ */

/* Set the bounding box for the current path. */
int
gs_setbbox(gs_state * pgs, floatp llx, floatp lly, floatp urx, floatp ury)
{
    gs_rect ubox, dbox;
    gs_fixed_rect obox, bbox;
    gx_path *ppath = pgs->path;
    int code;

    if (llx > urx || lly > ury)
	return_error(gs_error_rangecheck);
    /* Transform box to device coordinates. */
    ubox.p.x = llx;
    ubox.p.y = lly;
    ubox.q.x = urx;
    ubox.q.y = ury;
    if ((code = gs_bbox_transform(&ubox, &ctm_only(pgs), &dbox)) < 0)
	return code;
    /* Round the corners in opposite directions. */
    /* Because we can't predict the magnitude of the dbox values, */
    /* we add/subtract the slop after fixing. */
    if (dbox.p.x < fixed2float(min_fixed + box_rounding_slop_fixed) ||
	dbox.p.y < fixed2float(min_fixed + box_rounding_slop_fixed) ||
	dbox.q.x >= fixed2float(max_fixed - box_rounding_slop_fixed + fixed_epsilon) ||
	dbox.q.y >= fixed2float(max_fixed - box_rounding_slop_fixed + fixed_epsilon)
	)
	return_error(gs_error_limitcheck);
    bbox.p.x =
	(fixed) floor(dbox.p.x * fixed_scale) - box_rounding_slop_fixed;
    bbox.p.y =
	(fixed) floor(dbox.p.y * fixed_scale) - box_rounding_slop_fixed;
    bbox.q.x =
	(fixed) ceil(dbox.q.x * fixed_scale) + box_rounding_slop_fixed;
    bbox.q.y =
	(fixed) ceil(dbox.q.y * fixed_scale) + box_rounding_slop_fixed;
    if (gx_path_bbox(ppath, &obox) >= 0) {	/* Take the union of the bboxes. */
	ppath->bbox.p.x = min(obox.p.x, bbox.p.x);
	ppath->bbox.p.y = min(obox.p.y, bbox.p.y);
	ppath->bbox.q.x = max(obox.q.x, bbox.q.x);
	ppath->bbox.q.y = max(obox.q.y, bbox.q.y);
    } else {			/* empty path *//* Just set the bbox. */
	ppath->bbox = bbox;
    }
    ppath->bbox_set = 1;
    return 0;
}

/* ------ Rectangles ------ */

/* Append a list of rectangles to a path. */
int
gs_rectappend(gs_state * pgs, const gs_rect * pr, uint count)
{
    for (; count != 0; count--, pr++) {
	floatp px = pr->p.x, py = pr->p.y, qx = pr->q.x, qy = pr->q.y;
	int code;

	/* Ensure counter-clockwise drawing. */
	if ((qx >= px) != (qy >= py))
	    qx = px, px = pr->q.x;	/* swap x values */
	if ((code = gs_moveto(pgs, px, py)) < 0 ||
	    (code = gs_lineto(pgs, qx, py)) < 0 ||
	    (code = gs_lineto(pgs, qx, qy)) < 0 ||
	    (code = gs_lineto(pgs, px, qy)) < 0 ||
	    (code = gs_closepath(pgs)) < 0
	    )
	    return code;
    }
    return 0;
}

/* Clip to a list of rectangles. */
int
gs_rectclip(gs_state * pgs, const gs_rect * pr, uint count)
{
    int code;
    gx_path save;

    gx_path_init_local(&save, pgs->memory);
    gx_path_assign_preserve(&save, pgs->path);
    gs_newpath(pgs);
    if ((code = gs_rectappend(pgs, pr, count)) < 0 ||
	(code = gs_clip(pgs)) < 0
	) {
	gx_path_assign_free(pgs->path, &save);
	return code;
    }
    gx_path_free(&save, "gs_rectclip");
    gs_newpath(pgs);
    return 0;
}

/* Fill a list of rectangles. */
/* We take the trouble to do this efficiently in the simple cases. */
int
gs_rectfill(gs_state * pgs, const gs_rect * pr, uint count)
{
    const gs_rect *rlist = pr;
    gx_clip_path *pcpath;
    uint rcount = count;
    int code;

    gx_set_dev_color(pgs);
    if ((is_fzero2(pgs->ctm.xy, pgs->ctm.yx) ||
	 is_fzero2(pgs->ctm.xx, pgs->ctm.yy)) &&
	gx_effective_clip_path(pgs, &pcpath) >= 0 &&
	clip_list_is_rectangle(gx_cpath_list(pcpath)) &&
	gs_state_color_load(pgs) >= 0 &&
	(*dev_proc(pgs->device, get_alpha_bits)) (pgs->device, go_graphics)
	<= 1
	) {
	uint i;
	gs_fixed_rect clip_rect;

	gx_cpath_inner_box(pcpath, &clip_rect);
	for (i = 0; i < count; ++i) {
	    gs_fixed_point p, q;
	    gs_fixed_rect draw_rect;
	    int x, y, w, h;

	    if (gs_point_transform2fixed(&pgs->ctm, pr[i].p.x, pr[i].p.y, &p) < 0 ||
	    gs_point_transform2fixed(&pgs->ctm, pr[i].q.x, pr[i].q.y, &q) < 0
		) {		/* Switch to the slow algorithm. */
		goto slow;
	    }
	    draw_rect.p.x = min(p.x, q.x) - pgs->fill_adjust.x;
	    draw_rect.p.y = min(p.y, q.y) - pgs->fill_adjust.y;
	    draw_rect.q.x = max(p.x, q.x) + pgs->fill_adjust.x;
	    draw_rect.q.y = max(p.y, q.y) + pgs->fill_adjust.y;
	    rect_intersect(draw_rect, clip_rect);
	    x = fixed2int_pixround(draw_rect.p.x);
	    y = fixed2int_pixround(draw_rect.p.y);
	    w = fixed2int_pixround(draw_rect.q.x) - x;
	    h = fixed2int_pixround(draw_rect.q.y) - y;
	    if (w > 0 && h > 0) {
		if (gx_fill_rectangle(x, y, w, h, pgs->dev_color, pgs) < 0)
		    goto slow;
	    }
	}
	return 0;
      slow:rlist = pr + i;
	rcount = count - i;
    } {
	bool do_save = !gx_path_is_null(pgs->path);

	if (do_save) {
	    if ((code = gs_gsave(pgs)) < 0)
		return code;
	    gs_newpath(pgs);
	}
	if ((code = gs_rectappend(pgs, rlist, rcount)) < 0 ||
	    (code = gs_fill(pgs)) < 0
	    )
	    DO_NOTHING;
	if (do_save)
	    gs_grestore(pgs);
	else if (code < 0)
	    gs_newpath(pgs);
    }
    return code;
}

/* Stroke a list of rectangles. */
/* (We could do this a lot more efficiently.) */
int
gs_rectstroke(gs_state * pgs, const gs_rect * pr, uint count,
	      const gs_matrix * pmat)
{
    bool do_save = pmat != NULL || !gx_path_is_null(pgs->path);
    int code;

    if (do_save) {
	if ((code = gs_gsave(pgs)) < 0)
	    return code;
	gs_newpath(pgs);
    }
    if ((code = gs_rectappend(pgs, pr, count)) < 0 ||
	(pmat != NULL && (code = gs_concat(pgs, pmat)) < 0) ||
	(code = gs_stroke(pgs)) < 0
	)
	DO_NOTHING;
    if (do_save)
	gs_grestore(pgs);
    else if (code < 0)
	gs_newpath(pgs);
    return code;
}