Re: Preliminary patch for preserving clip path lists - bug 686885

Index: src/gdevpdfd.c
===================================================================
RCS file: /cvs/ghostscript/gs/src/gdevpdfd.c,v
retrieving revision 1.34
diff -C2 -r1.34 gdevpdfd.c
*** src/gdevpdfd.c	14 Oct 2003 12:43:18 -0000	1.34
--- src/gdevpdfd.c	12 Nov 2003 08:30:40 -0000
***************
*** 260,263 ****
--- 260,286 ----
  }
  
+ /* Put a single element of a clipping path list. */
+ int
+ pdf_put_clip_path_list_elem(gx_device_pdf * pdev, gx_cpath_path_list *e, 
+ 	gs_path_enum *cenum, gdev_vector_dopath_state_t *state,
+ 	gs_fixed_point vs[3])
+ {   /* This recursive function provides a reverse order of the list elements. */
+     int pe_op;
+ 
+     if (e->next != NULL) {
+ 	int code = pdf_put_clip_path_list_elem(pdev, e->next, cenum, state, vs);
+ 
+ 	if (code != 0)
+ 	    return code;
+     }
+     gx_path_enum_init(cenum, &e->path);
+     while ((pe_op = gx_path_enum_next(cenum, vs)) > 0)
+ 	gdev_vector_dopath_segment(state, pe_op, vs);
+     pprints1(pdev->strm, "%s n\n", (e->rule <= 0 ? "W" : "W*"));
+     if (pe_op < 0)
+ 	return pe_op;
+     return 0;
+ }
+ 
  /* Put a clipping path on the output file. */
  int
***************
*** 308,312 ****
      if (new_id != pdev->no_clip_path_id) {
  	gdev_vector_dopath_state_t state;
- 	gs_cpath_enum cenum;
  	gs_fixed_point vs[3];
  	int pe_op;
--- 331,334 ----
***************
*** 318,321 ****
--- 340,346 ----
  	gdev_vector_dopath_init(&state, (gx_device_vector *)pdev,
  				gx_path_type_fill, NULL);
+ 	if (pcpath->path_list == NULL) {
+ 	    gs_cpath_enum cenum;
+ 
  	/*
  	 * We have to break 'const' here because the clip path
***************
*** 330,333 ****
--- 355,365 ----
  	if (pe_op < 0)
  	    return pe_op;
+ 	} else {
+ 	    gs_path_enum cenum;
+ 
+ 	    code = pdf_put_clip_path_list_elem(pdev, pcpath->path_list, &cenum, &state, vs);
+ 	    if (code < 0)
+ 		return code;
+ 	}
      }
      pdev->clip_path_id = new_id;
Index: src/gxcpath.c
===================================================================
RCS file: /cvs/ghostscript/gs/src/gxcpath.c,v
retrieving revision 1.8
diff -C2 -r1.8 gxcpath.c
*** src/gxcpath.c	8 Sep 2003 12:06:56 -0000	1.8
--- src/gxcpath.c	12 Nov 2003 08:30:40 -0000
***************
*** 40,51 ****
  public_st_device_clip();
  private_st_cpath_enum();
  
  /* GC procedures for gx_clip_path */
  private 
! ENUM_PTRS_WITH(clip_path_enum_ptrs, gx_clip_path *cptr) return ENUM_USING(st_path, &cptr->path, sizeof(cptr->path), index - 1);
  
  case 0:
! ENUM_RETURN((cptr->rect_list == &cptr->local_list ? 0 :
  	     cptr->rect_list));
  ENUM_PTRS_END
  private
--- 40,54 ----
  public_st_device_clip();
  private_st_cpath_enum();
+ private_st_cpath_path_list();
  
  /* GC procedures for gx_clip_path */
  private 
! ENUM_PTRS_WITH(clip_path_enum_ptrs, gx_clip_path *cptr) return ENUM_USING(st_path, &cptr->path, sizeof(cptr->path), index - 2);
  
  case 0:
! return ENUM_OBJ((cptr->rect_list == &cptr->local_list ? 0 :
  	     cptr->rect_list));
+ case 1:
+ return ENUM_OBJ(cptr->path_list);
  ENUM_PTRS_END
  private
***************
*** 54,57 ****
--- 57,61 ----
      if (cptr->rect_list != &cptr->local_list)
  	RELOC_VAR(cptr->rect_list);
+     RELOC_VAR(cptr->path_list);
      RELOC_USING(st_path, &cptr->path, sizeof(gx_path));
  }
***************
*** 95,98 ****
--- 99,103 ----
  private rc_free_proc(rc_free_cpath_list);
  private rc_free_proc(rc_free_cpath_list_local);
+ private rc_free_proc(rc_free_cpath_path_list);
  
  /*
***************
*** 117,120 ****
--- 122,126 ----
      null_rect.p.x = null_rect.p.y = null_rect.q.x = null_rect.q.y = 0;
      cpath_init_rectangle(pcpath, &null_rect);
+     pcpath->path_list = NULL;
  }
  private void
***************
*** 152,155 ****
--- 158,162 ----
  	rc_increment(pcpath->path.segments);
  	rc_increment(pcpath->rect_list);
+ 	rc_increment(pcpath->path_list);
      } else {
  	int code = cpath_alloc_list(&pcpath->rect_list, mem, cname);
***************
*** 206,209 ****
--- 213,218 ----
  	pcpath->rect_list = shared->rect_list;
  	rc_increment(pcpath->rect_list);
+ 	pcpath->path_list = shared->path_list;
+ 	rc_increment(pcpath->path_list);
  	cpath_share_own_contents(pcpath, shared);
      } else {
***************
*** 243,248 ****
--- 252,259 ----
  {
      rc_decrement(pcpath->rect_list, cname);
+     rc_decrement(pcpath->path_list, cname);
      /* Clean up pointers for GC. */
      pcpath->rect_list = 0;
+     pcpath->path_list = 0;
      {
  	gx_path_allocation_t alloc = pcpath->path.allocation;
***************
*** 323,326 ****
--- 334,367 ----
  }
  
+ private void
+ rc_free_cpath_path_list(gs_memory_t * mem, void *vplist, client_name_t cname)
+ {
+     gx_cpath_path_list *plist = (gx_cpath_path_list *)vplist;
+     rc_decrement(plist->next, cname);
+     gx_path_free(&plist->path, cname);
+     gs_free_object(plist->path.memory, plist, cname);
+ }
+ 
+ /* Allocate a new clip path list node. The created node has a ref count
+    of 1, and "steals" the reference to next (i.e. does not increment
+    its reference count). */
+ private gx_cpath_path_list *
+ gx_cpath_path_list_new(gs_memory_t *mem, int rule, gx_path *ppfrom,
+ 		       gx_cpath_path_list *next)
+ {
+     int code;
+     client_name_t cname = "gx_cpath_path_list_new";
+     gx_cpath_path_list *pcplist = gs_alloc_struct(mem, gx_cpath_path_list,
+ 						  &st_cpath_path_list,
+ 						  cname);
+ 
+     if (pcplist == 0)
+ 	return 0;
+     rc_init_free(pcplist, mem, 1, rc_free_cpath_path_list);
+     code = gx_path_init_contained_shared(&pcplist->path, ppfrom, mem, cname);
+     pcplist->next = next;
+     return pcplist;
+ }
+ 
  /* ------ Clipping path accessing ------ */
  
***************
*** 500,504 ****
  	ppath = &fpath;
      }
!     /**************** SHOULD CHANGE THIS TO KEEP PATH ****************/
      if (gx_cpath_inner_box(pcpath, &old_box) &&
  	((code = gx_path_is_rectangle(ppath, &new_box)) ||
--- 541,545 ----
  	ppath = &fpath;
      }
! 
      if (gx_cpath_inner_box(pcpath, &old_box) &&
  	((code = gx_path_is_rectangle(ppath, &new_box)) ||
***************
*** 535,538 ****
--- 576,580 ----
  	}
  	/* Release the existing path. */
+ 	rc_decrement(pcpath->path_list, pcpath->path.memory);
  	gx_path_new(&pcpath->path);
  	ppath->bbox = new_box;
***************
*** 544,548 ****
  	}
      } else {
! 	/* Existing clip path is not a rectangle.  Intersect the slow way. */
  	bool path_valid =
  	    gx_cpath_inner_box(pcpath, &old_box) &&
--- 586,591 ----
  	}
      } else {
! 	/* New clip path is nontrivial.  Intersect the slow way. */
! 	gx_cpath_path_list *next = pcpath->path_list;
  	bool path_valid =
  	    gx_cpath_inner_box(pcpath, &old_box) &&
***************
*** 552,559 ****
--- 595,611 ----
  					new_box.q.x, new_box.q.y);
  
+ 	if (!path_valid && next == NULL) {
+ 	    gs_memory_t *mem = pcpath->path.memory;
+ 	    next = gx_cpath_path_list_new(mem, pcpath->rule,
+ 					  &pcpath->path, NULL);
+ 	}
  	code = gx_cpath_intersect_path_slow(pcpath, ppath, rule, pis);
  	if (code >= 0 && path_valid) {
  	    gx_path_assign_preserve(&pcpath->path, ppath_orig);
  	    pcpath->path_valid = true;
+ 	} else {
+ 	    gs_memory_t *mem = pcpath->path.memory;
+ 	    pcpath->path_list = gx_cpath_path_list_new(mem, rule, ppath_orig,
+ 						       next);
  	}
      }
Index: src/gzcpath.h
===================================================================
RCS file: /cvs/ghostscript/gs/src/gzcpath.h,v
retrieving revision 1.4
diff -C2 -r1.4 gzcpath.h
*** src/gzcpath.h	21 Feb 2002 22:24:53 -0000	1.4
--- src/gzcpath.h	12 Nov 2003 08:30:40 -0000
***************
*** 41,44 ****
--- 41,64 ----
      st_clip_list, list)
  
+ /*
+  * When the clip path consists of the intersection of two or more
+  * source paths, we maintain the complete list paths, so that it
+  * can be accurately output for high-level devices.
+  */
+ 
+ typedef struct gx_cpath_path_list_s gx_cpath_path_list;
+ 
+ struct gx_cpath_path_list_s {
+     gx_path path;
+     rc_header rc;
+     int rule;
+     gx_cpath_path_list *next;
+ };
+ 
+ #define private_st_cpath_path_list() 	/* in gxcpath.c */\
+   gs_private_st_suffix_add1(st_cpath_path_list, gx_cpath_path_list,\
+     "gs_cpath_list", cpath_path_list_enum_ptrs, cpath_path_list_reloc_ptrs,\
+     st_path, next)
+ 
  /* gx_clip_path is a 'subclass' of gx_path. */
  struct gx_clip_path_s {
***************
*** 55,58 ****
--- 75,79 ----
      gx_clip_rect_list *rect_list;
      bool path_valid;		/* path representation is valid */
+     gx_cpath_path_list *path_list;
      /* The id changes whenever the clipping region changes. */
      gs_id id;