/* Copyright (C) 1997 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU 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 GNU General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given to
  you along with GNU 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.
  
  Aladdin Enterprises is not affiliated with the Free Software Foundation or
  the GNU Project.  GNU Ghostscript, as distributed by Aladdin Enterprises,
  does not depend on any other GNU software.
*/

/* gdevpdfd.c */
/* Driver drawing procedures for PDF-writing driver */
#include "math_.h"
#include "gx.h"
#include "gxdevice.h"
#include "gxfixed.h"
#include "gxistate.h"
#include "gxpaint.h"
#include "gzpath.h"
#include "gzcpath.h"
#include "gdevpdfx.h"

/* ---------------- Drawing ---------------- */

/* Fill a rectangle. */
int
gdev_pdf_fill_rectangle(gx_device *dev, int x, int y, int w, int h,
  gx_color_index color)
{	gx_device_pdf *pdev = (gx_device_pdf *)dev;
	int code;

	/* Make a special check for the initial fill with white, */
	/* which shouldn't cause the page to be opened. */
	if ( color == 0xffffff && !is_in_page(pdev) )
	  return 0;
	code = pdf_open_page(pdev, pdf_in_stream);
	if ( code < 0 )
	  return code;
	/* Make sure we aren't being clipped. */
	pdf_put_clip_path(pdev, NULL);
	pdf_set_color(pdev, color, &pdev->fill_color, "rg");
	pprintd4(pdev->strm, "%d %d %d %d re f\n", x, y, w, h);
	return 0;
}

/* ---------------- Path drawing ---------------- */

/* ------ Utilities ------ */

/* Put a path on the output file.  If do_close is false and the last */
/* path component is a closepath, omit it and return 1. */
private int
pdf_put_path(gx_device_pdf *pdev, const gx_path *ppath, bool do_close,
  const gs_matrix *pmat)
{	stream *s = pdev->strm;
	gs_fixed_rect rbox;
	const subpath *next;
	gs_path_enum cenum;

	/* If do_close is false, we recognize rectangles specially. */
	if ( !do_close && ppath->subpath_count == 1 &&
	     ppath->curve_count == 0 &&
	     gx_subpath_is_rectangle(ppath->first_subpath, &rbox, &next) &&
             ppath->first_subpath->is_closed &&
	     (pmat == 0 || is_xxyy(pmat) || is_xyyx(pmat))
	   )
	  {	gs_point p, q;

		p.x = fixed2float(rbox.p.x), p.y = fixed2float(rbox.p.y);
		q.x = fixed2float(rbox.q.x), q.y = fixed2float(rbox.q.y);
		if ( pmat )
		  { gs_point_transform_inverse(p.x, p.y, pmat, &p);
		    gs_point_transform_inverse(q.x, q.y, pmat, &q);
		  }
		pprintg4(s, "%g %g %g %g re\n",
			 p.x, p.y, q.x - p.x, q.y - p.y);
		return 0;
	  }
	gx_path_enum_init(&cenum, ppath);
	for ( ; ; )
	  { gs_fixed_point vs[3];
	    gs_point vp[3];
	    const char *format;
	    int pe_op = gx_path_enum_next(&cenum, vs);

sw:	    switch ( pe_op )
	      {
	      case 0:		/* done */
		return 0;
	      case gs_pe_moveto:
		format = "%g %g m\n";
		goto do1;
	      case gs_pe_lineto:
		format = "%g %g l\n";
do1:		vp[0].x = fixed2float(vs[0].x), vp[0].y = fixed2float(vs[0].y);
		if ( pmat )
		  gs_point_transform_inverse(vp[0].x, vp[0].y, pmat, &vp[0]);
		pprintg2(s, format, vp[0].x, vp[0].y);
		break;
	      case gs_pe_curveto:
		vp[0].x = fixed2float(vs[0].x), vp[0].y = fixed2float(vs[0].y);
		vp[1].x = fixed2float(vs[1].x), vp[1].y = fixed2float(vs[1].y);
		vp[2].x = fixed2float(vs[2].x), vp[2].y = fixed2float(vs[2].y);
		if ( pmat )
		  { gs_point_transform_inverse(vp[0].x, vp[0].y, pmat, &vp[0]);
		    gs_point_transform_inverse(vp[1].x, vp[1].y, pmat, &vp[1]);
		    gs_point_transform_inverse(vp[2].x, vp[2].y, pmat, &vp[2]);
		  }
		pprintg6(s, "%g %g %g %g %g %g c\n",
			 vp[0].x, vp[0].y, vp[1].x, vp[1].y, vp[2].x, vp[2].y);
		break;
	      case gs_pe_closepath:
		if ( do_close )
		  { pputs(s, "h\n");
		    break;
		  }
		pe_op = gx_path_enum_next(&cenum, vs);
		if ( pe_op != 0 )
		  { pputs(s, "h\n");
		    goto sw;
		  }
		return 1;
	      }
	  }
}

/* Test whether we will need to put the clipping path. */
bool
pdf_must_put_clip_path(gx_device_pdf *pdev, const gx_clip_path *pcpath)
{	if ( pcpath == NULL )
	  return pdev->clip_path_id != pdev->no_clip_path_id;
	if ( pdev->clip_path_id == pcpath->id )
	  return false;
	if ( gx_cpath_includes_rectangle(pcpath, fixed_0, fixed_0,
					 int2fixed(pdev->width),
					 int2fixed(pdev->height))
	   )
	  return pdev->clip_path_id != pdev->no_clip_path_id;
	return true;
}

/* Put a clipping path on the output file. */
int
pdf_put_clip_path(gx_device_pdf *pdev, const gx_clip_path *pcpath)
{	stream *s = pdev->strm;

	if ( pcpath == NULL ) {
	  if ( pdev->clip_path_id == pdev->no_clip_path_id )
	    return 0;
	  pputs(s, "Q\nq\n");
	  pdev->clip_path_id = pdev->no_clip_path_id;
	} else {
	  if ( pdev->clip_path_id == pcpath->id )
	    return 0;
	  if ( gx_cpath_includes_rectangle(pcpath, fixed_0, fixed_0,
					   int2fixed(pdev->width),
					   int2fixed(pdev->height))
	     ) {
	    if ( pdev->clip_path_id == pdev->no_clip_path_id )
	      return 0;
	    pputs(s, "Q\nq\n");
	    pdev->clip_path_id = pdev->no_clip_path_id;
	  } else {
	    pputs(s, "Q\nq\nW\n");
	    if ( pcpath->segments_valid )
	      pdf_put_path(pdev, &pcpath->path, true, NULL);
	    else
	      { /* Write out the rectangles. */
		const gx_clip_rect *prect = pcpath->list.head;

		if ( prect == 0 )
		  prect = &pcpath->list.single;
		for ( ; prect != 0; prect = prect->next )
		  if ( prect->xmax > prect->xmin && prect->ymax > prect->ymin )
		    pprintg4(s, "%g %g %g %g re\n",
			     prect->xmin, prect->ymin,
			     prect->xmax - prect->xmin,
			     prect->ymax - prect->ymin);
	      }
	    pputs(s, "n\n");
	    pdev->clip_path_id = pcpath->id;
	  }
	}
	pdev->text.font = 0;
	if ( pdev->context == pdf_in_text )
	  pdev->context = pdf_in_stream;
	pdf_reset_graphics(pdev);
	return 0;
}

/* ------ Driver procedures ------ */

/* Fill a path. */
int
gdev_pdf_fill_path(gx_device *dev, const gs_imager_state *pis, gx_path *ppath,
  const gx_fill_params *params,
  const gx_drawing_color *pdcolor, const gx_clip_path *pcpath)
{	gx_device_pdf *pdev = (gx_device_pdf *)dev;
	int code;
	/*
	 * HACK: we fill an empty path in order to set the clipping path
	 * and the color for writing text.  If it weren't for this, we
	 * could detect and skip empty paths before putting out the clip
	 * path or the color.  We also clip with an empty path in order
	 * to advance currentpoint for show operations without actually
	 * drawing anything.
	 */
	bool have_path;

	/*
	 * Check for an empty clipping path.
	 */
	if ( pcpath ) {
	  gs_fixed_rect box;

	  gx_cpath_outer_box(pcpath, &box);
	  if ( box.p.x >= box.q.x || box.p.y >= box.q.y )
	    return 0;		/* empty clipping path */
	}
	if ( !gx_dc_is_pure(pdcolor) )
	  return gx_default_fill_path(dev, pis, ppath, params, pdcolor,
				      pcpath);
	/*
	 * Make a special check for the initial fill with white,
	 * which shouldn't cause the page to be opened.
	 */
	if ( gx_dc_pure_color(pdcolor) == 0xffffff && !is_in_page(pdev) )
	  return 0;
	have_path = !gx_path_is_void(ppath);
	if ( have_path || pdev->context == pdf_in_none ||
	     pdf_must_put_clip_path(pdev, pcpath)
	   )
	  { code = pdf_open_page(pdev, pdf_in_stream);
	    if ( code < 0 )
	      return code;
	  }
	pdf_put_clip_path(pdev, pcpath);
	pdf_set_color(pdev, gx_dc_pure_color(pdcolor), &pdev->fill_color, "rg");
	if ( have_path )
	  { stream *s = pdev->strm;

	    if ( params->flatness != pdev->flatness )
	      { pprintg1(s, "%g i\n", params->flatness);
	        pdev->flatness = params->flatness;
	      }
	    pdf_put_path(pdev, ppath, false, NULL);
	    pputs(s, (params->rule < 0 ? "f\n" : "f*\n"));
	  }
	return 0;
}

/* Compare two dash patterns. */
private bool
pdf_dash_pattern_eq(const float *stored, const gx_dash_params *set, float scale)
{	int i;
	for ( i = 0; i < set->pattern_size; ++i )
	  if ( stored[i] != (float)(set->pattern[i] * scale) )
	    return false;
	return true;
}

/* Stroke a path. */
int
gdev_pdf_stroke_path(gx_device *dev, const gs_imager_state *pis,
  gx_path *ppath, const gx_stroke_params *params,
  const gx_drawing_color *pdcolor, const gx_clip_path *pcpath)
{	gx_device_pdf *pdev = (gx_device_pdf *)dev;
	stream *s;
	int code;
	int pattern_size = pis->line_params.dash.pattern_size;
	double scale;
	bool set_ctm;
	gs_matrix mat;
	const gs_matrix *pmat;
	int i;

	if ( gx_path_is_void(ppath) )
	  return 0;		/* won't mark the page */
	if ( !gx_dc_is_pure(pdcolor) )
	  return gx_default_stroke_path(dev, pis, ppath, params, pdcolor,
					pcpath);
	code = pdf_open_page(pdev, pdf_in_stream);
	if ( code < 0 )
	  return code;
	/*
	 * If the CTM is not uniform, stroke width depends on angle.
	 * We'd like to avoid resetting the CTM, so we check for uniform
	 * CTMs explicitly.  Note that in PDF, unlike PostScript, it is
	 * the CTM at the time of the stroke operation, not the CTM at
	 * the time the path was constructed, that is used for transforming
	 * the points of the path; so if we have to reset the CTM, we must
	 * do it before constructing the path, and inverse-transform all
	 * the coordinates.
	 */
	if ( pis->ctm.xy == 0 && pis->ctm.yx == 0 )
	  { scale = fabs(pis->ctm.xx);
	    set_ctm = fabs(pis->ctm.yy) != scale;
	  }
	else if ( pis->ctm.xx == 0 && pis->ctm.yy == 0 )
	  { scale = fabs(pis->ctm.xy);
	    set_ctm = fabs(pis->ctm.yx) != scale;
	  }
	else if ( (pis->ctm.xx == pis->ctm.yy && pis->ctm.xy == -pis->ctm.yx)||
		  (pis->ctm.xx == -pis->ctm.yy && pis->ctm.xy == pis->ctm.yx)
		)
	  { scale = hypot(pis->ctm.xx, pis->ctm.xy);
	    set_ctm = false;
	  }
	else
	  set_ctm = true;
	if ( set_ctm ) {
	  scale = 1;
	  mat.xx = pis->ctm.xx / pdev->scale.x;
	  mat.xy = pis->ctm.xy / pdev->scale.y;
	  mat.yx = pis->ctm.yx / pdev->scale.x;
	  mat.yy = pis->ctm.yy / pdev->scale.y;
	  mat.tx = mat.ty = 0;
	  pmat = &mat;
	} else {
	  pmat = 0;
	}
	    
	pdf_put_clip_path(pdev, pcpath);
	pdf_set_color(pdev, gx_dc_pure_color(pdcolor), &pdev->stroke_color, "RG");
	s = pdev->strm;
	if ( (float)(pis->line_params.dash.offset * scale) != pdev->line_params.dash.offset ||
	     pattern_size != pdev->line_params.dash.pattern_size ||
	     pattern_size > max_dash ||
	     (pattern_size != 0 &&
	      !pdf_dash_pattern_eq(pdev->dash_pattern, &pis->line_params.dash,
				   scale))
	   )
	  { pputs(s, "[ ");
	    pdev->line_params.dash.pattern_size = pattern_size;
	    for ( i = 0; i < pattern_size; ++i )
	      { float element = pis->line_params.dash.pattern[i] * scale;
		if ( i < max_dash )
		  pdev->dash_pattern[i] = element;
		pprintg1(s, "%g ", element);
	      }
	    pdev->line_params.dash.offset =
	      pis->line_params.dash.offset * scale;
	    pprintg1(s, "] %g d\n", pdev->line_params.dash.offset);
	  }
	if ( params->flatness != pdev->flatness )
	  { pprintg1(s, "%g i\n", params->flatness);
	    pdev->flatness = params->flatness;
	  }
	if ( (float)(pis->line_params.half_width * scale) != pdev->line_params.half_width )
	  { pdev->line_params.half_width = pis->line_params.half_width * scale;
	    pprintg1(s, "%g w\n", pdev->line_params.half_width * 2);
	  }
	if ( pis->line_params.miter_limit != pdev->line_params.miter_limit )
	  { pprintg1(s, "%g M\n", pis->line_params.miter_limit);
	    gx_set_miter_limit(&pdev->line_params,
			       pis->line_params.miter_limit);
	  }
	if ( pis->line_params.cap != pdev->line_params.cap )
	  { pprintd1(s, "%d J\n", pis->line_params.cap);
	    pdev->line_params.cap = pis->line_params.cap;
	  }
	if ( pis->line_params.join != pdev->line_params.join )
	  { pprintd1(s, "%d j\n", pis->line_params.join);
	    pdev->line_params.join = pis->line_params.join;
	  }
	if ( set_ctm )
	  pdf_put_matrix(pdev, "q ", &mat, "cm\n");
	code = pdf_put_path(pdev, ppath, false, pmat);
	if ( code < 0 )
	  return code;
	pputs(s, (code ? "s" : "S"));
	pputs(s, (set_ctm ? " Q\n" : "\n"));
	return 0;
}