* src/groff/preproc/pic/lex.cpp (table): Add box attributes

`xslanted' and `yslanted'.

* src/groff/preproc/pic/object.cpp (object_spec::object_spec):
Initialize `xslanted' and `yslanted'.
(graphic_object): Add methods `set_xlanted' and `set_yslanted'.
(closed_object): Ditto.
Add members `xslanted' and `yslanted'.
(box_object::print): Use them.
(object_spec::make_object): Handle slant values.
 * src/groff/preproc/pic/object.h (IS_XSLANTED, IS_YSLANTED): New
constants.
(object_spec): Add members `xslanted' and `yslanted'.
* src/groff/preproc/pic/pic.y (XSLANTED, YSLANTED): New left-valued
tokens.
Add rules for them.

* src/groff/preproc/pic/pic.man, NEWS, doc/pic.ms: Document above
changes.

8 files changed, 152 insertions, 38 deletions

diff --git a/ChangeLog b/ChangeLog
index 156d0528..20a8f879 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,7 +1,29 @@
+2007-11-17  Heinz-Jürgen Oertel <hj.oertel@t-online.de>
+
+	* src/groff/preproc/pic/lex.cpp (table): Add box attributes
+	`xslanted' and `yslanted'.
+
+	* src/groff/preproc/pic/object.cpp (object_spec::object_spec):
+	Initialize `xslanted' and `yslanted'.
+	(graphic_object): Add methods `set_xlanted' and `set_yslanted'.
+	(closed_object): Ditto.
+	Add members `xslanted' and `yslanted'.
+	(box_object::print): Use them.
+	(object_spec::make_object): Handle slant values.
+ 	* src/groff/preproc/pic/object.h (IS_XSLANTED, IS_YSLANTED): New
+	constants.
+	(object_spec): Add members `xslanted' and `yslanted'.
+	* src/groff/preproc/pic/pic.y (XSLANTED, YSLANTED): New left-valued
+	tokens.
+	Add rules for them.
+	
+	* src/groff/preproc/pic/pic.man, NEWS, doc/pic.ms: Document above
+	changes.
+
 2007-11-16  Werner LEMBERG  <wl@gnu.org>
 
 	* tmac/hyphenex.pl: Generate copyright notice (this has been
-	approved By Barbara Beeton).
+	approved by Barbara Beeton).
 	* tmac/hyphenex.us: Updated.
 
 2007-11-10  Michail Vidiassov  <master@iaas.msu.ru>
diff --git a/NEWS b/NEWS
index deca0166..dea9b8ab 100644
--- a/NEWS
+++ b/NEWS
@@ -79,6 +79,10 @@ o int(x) now really behaves as documented: It truncates the non-integer part
 o Pic now supports up to 32 macro arguments (and up to 16 on EBCDIC
   platforms).
 
+o Heinz-Jürgen Örtel contributed code for two new keywords, `xslanted' and
+  `yslanted', which can change the shape of boxes into arbitrary
+  parallelograms.
+
 Eqn
 ---
 
diff --git a/doc/pic.ms b/doc/pic.ms
index 9c0c3669..580bb744 100644
--- a/doc/pic.ms
+++ b/doc/pic.ms
@@ -31,7 +31,7 @@
 .\" Eric S. Raymond <esr@thyrsus.com> in August 1995.  It has been put
 .\" under the GPL in March 2006.
 .\"
-.\"	$Id: pic.ms,v 1.35 2007/03/21 13:30:59 wl Exp $	
+.\"	$Id: pic.ms,v 1.36 2007/11/19 09:28:44 wl Exp $	
 .
 .
 .\" Set a proper TeX and LaTeX
@@ -635,6 +635,24 @@ Radius values higher than half the minimum box dimension are silently
 truncated to that value.
 .
 .NH 2
+Slanted Boxes
+.PP
+GNU \fBgpic\fP supports slanted boxes:
+.KS
+.PS
+box wid 1.2 xslanted 0.1 "xslanted 0.1";
+move;
+box wid 1.2 yslanted -0.1 "yslanted -0.1";
+move;
+box wid 1.2 xslanted -0.2 yslanted 0.1 "xslanted -0.2" "yslanted 0.1";
+.PE
+.CE "4: Various slanted boxes.
+.PP
+The \fBxslanted\fP and \fByslanted\fP attributes specify the x and
+y\~offset, respectively, of the box's upper right corner from its default
+position.
+.
+.NH 2
 Arrowheads
 .PP
 Lines and arcs can be decorated as well.  Any line or arc (and any
@@ -644,7 +662,7 @@ as modifiers:
 .PS
 line <- ->
 .PE
-.CE "4: Double-headed line made with  \fBline <- ->\fP"
+.CE "5: Double-headed line made with  \fBline <- ->\fP"
 .PP
 In fact, the \fBarrow\fP command is just shorthand for \fBline ->\fP.  And
 there is a double-head modifier <->, so the figure above could have been made
@@ -710,7 +728,7 @@ values are darker; GNU \fBfillval\fP uses 0 for white and 1 for black.
 .PS
 circle fill; move; circle fill 0.4; move; circle fill 0.9;
 .PE
-.CE "5: \fBcircle fill; move; circle fill 0.4; move; circle fill 0.9;\fR"
+.CE "6: \fBcircle fill; move; circle fill 0.4; move; circle fill 0.9;\fR"
 .PP
 GNU \fBgpic\fP makes some additional guarantees.  A fill value greater
 than 1 can also be used: this means fill with the shade of gray that
@@ -735,7 +753,7 @@ suffix specifying the color.  Example:
 .PS
 box color "yellow"; arrow color "cyan"; circle shaded "green" outline "black";
 .PE
-.CE "6: \fBbox color ""yellow""; arrow color ""cyan""; \
+.CE "7: \fBbox color ""yellow""; arrow color ""cyan""; \
 circle shaded ""green"" outline ""black"";\fR"
 .PP
 Alternative spellings are \fBcolour\fP, \fBcolored\fP, \fBcoloured\fP,
@@ -2673,6 +2691,8 @@ direction on the block's bounding box.
   invis[ible]           \fR# make primitive invisible\fP
   solid                 \fR# make closed figure solid\fP
   fill[ed] [<expr>]     \fR# set fill density for figure\fP
+  xscaled <expr>        \fR# slant box into x direction\fP
+  yscaled <expr>        \fR# slant box into y direction\fP
   colo[u]r[ed] TEXT     \fR# set fill and outline color for figure\fP
   outline[d] TEXT       \fR# set outline color for figure\fP
   shaded TEXT           \fR# set fill color for figure\fP
diff --git a/src/preproc/pic/lex.cpp b/src/preproc/pic/lex.cpp
index 17357ac6..b286e0f0 100644
--- a/src/preproc/pic/lex.cpp
+++ b/src/preproc/pic/lex.cpp
@@ -1,6 +1,6 @@
 // -*- C++ -*-
-/* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2002, 2003, 2004, 2006
-     Free Software Foundation, Inc.
+/* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2002, 2003, 2004, 2006,
+     2007  Free Software Foundation, Inc.
      Written by James Clark (jjc@jclark.com)
 
 This file is part of groff.
@@ -557,6 +557,8 @@ int lookup_keyword(const char *str, int len)
     { "wid", WIDTH },
     { "width", WIDTH },
     { "with", WITH },
+    { "xslanted", XSLANTED },
+    { "yslanted", YSLANTED },
   };
   
   const keyword *start = table;
diff --git a/src/preproc/pic/object.cpp b/src/preproc/pic/object.cpp
index 2eeb9cde..f16ab40c 100644
--- a/src/preproc/pic/object.cpp
+++ b/src/preproc/pic/object.cpp
@@ -413,6 +413,8 @@ object_spec::object_spec(object_type t) : type(t)
   segment_is_absolute = 0;
   text = 0;
   shaded = 0;
+  xslanted = 0;
+  yslanted = 0;
   outlined = 0;
   with = 0;
   dir = RIGHT_DIRECTION;
@@ -565,6 +567,8 @@ public:
   void set_outline_color(char *);
   char *get_outline_color();
   virtual void set_fill(double);
+  virtual void set_xslanted(double);
+  virtual void set_yslanted(double);
   virtual void set_fill_color(char *);
 };
 
@@ -594,6 +598,14 @@ void graphic_object::set_fill(double)
 {
 }
 
+void graphic_object::set_xslanted(double)
+{
+}
+
+void graphic_object::set_yslanted(double)
+{
+}
+
 void graphic_object::set_fill_color(char *c)
 {
   color_fill = strsave(c);
@@ -701,14 +713,18 @@ public:
   closed_object(const position &);
   object_type type() = 0;
   void set_fill(double);
+  void set_xslanted(double);
+  void set_yslanted(double);
   void set_fill_color(char *fill);
 protected:
   double fill;			// < 0 if not filled
+  double xslanted;		// !=0 if x is slanted
+  double yslanted;		// !=0 if y is slanted
   char *color_fill;		// = 0 if not colored
 };
 
 closed_object::closed_object(const position &pos)
-: rectangle_object(pos), fill(-1.0), color_fill(0)
+: rectangle_object(pos), fill(-1.0), xslanted(0), yslanted(0), color_fill(0)
 {
 }
 
@@ -718,6 +734,19 @@ void closed_object::set_fill(double f)
   fill = f;
 }
 
+/* accept positive and negative values */ 
+void closed_object::set_xslanted(double s)
+{
+  //assert(s >= 0.0);
+  xslanted = s;
+}
+/* accept positive and negative values */ 
+void closed_object::set_yslanted(double s)
+{
+  //assert(s >= 0.0);
+  yslanted = s;
+}
+
 void closed_object::set_fill_color(char *f)
 {
   color_fill = strsave(f);
@@ -775,10 +804,12 @@ void box_object::print()
   if (xrad == 0.0) {
     distance dim2 = dim/2.0;
     position vec[4];
-    vec[0] = cent + position(dim2.x, -dim2.y);
-    vec[1] = cent + position(dim2.x, dim2.y);
-    vec[2] = cent + position(-dim2.x, dim2.y);
-    vec[3] = cent + position(-dim2.x, -dim2.y);
+    /* error("x slanted %1", xslanted); */
+    /* error("y slanted %1", yslanted); */
+    vec[0] = cent + position(dim2.x, -(dim2.y - yslanted));	     /* lr */
+    vec[1] = cent + position(dim2.x + xslanted, dim2.y + yslanted);  /* ur */
+    vec[2] = cent + position(-(dim2.x - xslanted), dim2.y);	     /* ul */
+    vec[3] = cent + position(-(dim2.x), -dim2.y);		     /* ll */
     out->polygon(vec, 4, lt, fill);
   }
   else {
@@ -1896,6 +1927,10 @@ object *object_spec::make_object(position *curpos, direction *dirp)
     obj->set_thickness(th);
     if (flags & IS_OUTLINED)
       obj->set_outline_color(outlined);
+    if (flags & IS_XSLANTED)
+      obj->set_xslanted(xslanted);
+    if (flags & IS_YSLANTED)
+      obj->set_yslanted(yslanted);
     if (flags & (IS_DEFAULT_FILLED | IS_FILLED)) {
       if (flags & IS_SHADED)
 	obj->set_fill_color(shaded);
diff --git a/src/preproc/pic/object.h b/src/preproc/pic/object.h
index 9f7f4bc3..e87cc8bc 100644
--- a/src/preproc/pic/object.h
+++ b/src/preproc/pic/object.h
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-/* Copyright (C) 1989, 1990, 1991, 1992, 2002, 2004
+/* Copyright (C) 1989, 1990, 1991, 1992, 2002, 2004, 2007
    Free Software Foundation, Inc.
      Written by James Clark (jjc@jclark.com)
 
@@ -133,29 +133,31 @@ struct text_item {
   ~text_item();
 };
 
-const unsigned long IS_DOTTED = 01;
-const unsigned long IS_DASHED = 02;
-const unsigned long IS_CLOCKWISE = 04;
-const unsigned long IS_INVISIBLE = 020;
-const unsigned long HAS_LEFT_ARROW_HEAD = 040;
-const unsigned long HAS_RIGHT_ARROW_HEAD = 0100;
-const unsigned long HAS_SEGMENT = 0200;
-const unsigned long IS_SAME = 0400;
-const unsigned long HAS_FROM = 01000;
-const unsigned long HAS_AT = 02000;
-const unsigned long HAS_WITH = 04000;
-const unsigned long HAS_HEIGHT = 010000;
-const unsigned long HAS_WIDTH = 020000;
-const unsigned long HAS_RADIUS = 040000;
-const unsigned long HAS_TO = 0100000;
-const unsigned long IS_CHOPPED = 0200000;
-const unsigned long IS_DEFAULT_CHOPPED = 0400000;
-const unsigned long HAS_THICKNESS = 01000000;
-const unsigned long IS_FILLED = 02000000;
-const unsigned long IS_DEFAULT_FILLED = 04000000;
-const unsigned long IS_ALIGNED = 010000000;
-const unsigned long IS_SHADED = 020000000;
-const unsigned long IS_OUTLINED = 040000000;
+const unsigned long IS_DOTTED          =         01;
+const unsigned long IS_DASHED          =         02;
+const unsigned long IS_CLOCKWISE       =         04;
+const unsigned long IS_INVISIBLE       =        020;
+const unsigned long HAS_LEFT_ARROW_HEAD =       040;
+const unsigned long HAS_RIGHT_ARROW_HEAD =     0100;
+const unsigned long HAS_SEGMENT        =       0200;
+const unsigned long IS_SAME            =       0400;
+const unsigned long HAS_FROM           =      01000;
+const unsigned long HAS_AT             =      02000;
+const unsigned long HAS_WITH           =      04000;
+const unsigned long HAS_HEIGHT         =     010000;
+const unsigned long HAS_WIDTH          =     020000;
+const unsigned long HAS_RADIUS         =     040000;
+const unsigned long HAS_TO             =    0100000;
+const unsigned long IS_CHOPPED         =    0200000;
+const unsigned long IS_DEFAULT_CHOPPED =    0400000;
+const unsigned long HAS_THICKNESS      =   01000000;
+const unsigned long IS_FILLED          =   02000000;
+const unsigned long IS_DEFAULT_FILLED  =   04000000;
+const unsigned long IS_ALIGNED         =  010000000;
+const unsigned long IS_SHADED          =  020000000;
+const unsigned long IS_OUTLINED        =  040000000;
+const unsigned long IS_XSLANTED        = 0100000000;
+const unsigned long IS_YSLANTED        = 0200000000;
 
 struct segment {
   int is_absolute;
@@ -189,6 +191,8 @@ struct object_spec {
   double end_chop;
   double thickness;
   double fill;
+  double xslanted;
+  double yslanted;
   char *shaded;
   char *outlined;
   direction dir;
diff --git a/src/preproc/pic/pic.man b/src/preproc/pic/pic.man
index c54cfbef..9242d656 100644
--- a/src/preproc/pic/pic.man
+++ b/src/preproc/pic/pic.man
@@ -1,5 +1,6 @@
 .ig
-Copyright (C) 1989-2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+Copyright (C) 1989-2000, 2001, 2002, 2003, 2004, 2007
+  Free Software Foundation, Inc.
 
 Permission is granted to make and distribute verbatim copies of
 this manual provided the copyright notice and this permission notice
@@ -735,6 +736,17 @@ has a value of\ 0.
 A box with rounded corners can be dotted or dashed.
 .
 .LP
+Boxes can have slanted sides.
+This effectively changes the shape of a box from a rectangle to an
+arbitrary parallelogram.
+The
+.B xslanted
+and
+.B yslanted
+attributes specify the x and y\~offset of the box's upper right corner
+from its default position.
+.
+.LP
 The
 .B .PS
 line can have a second argument specifying a maximum height for
@@ -818,7 +830,7 @@ variable, nor by the width or height given in the
 line.
 .
 .LP
-Boxes (including boxes with rounded corners),
+Boxes (including boxes with rounded corners or slanted sides),
 circles and ellipses can be filled by giving them an attribute of
 .BR fill [ ed ].
 This takes an optional argument of an expression with a value between
diff --git a/src/preproc/pic/pic.y b/src/preproc/pic/pic.y
index 2f838da3..2f0b31f9 100644
--- a/src/preproc/pic/pic.y
+++ b/src/preproc/pic/pic.y
@@ -197,6 +197,8 @@ char *do_sprintf(const char *form, const double *v, int nv);
 %token COLORED
 %token OUTLINED
 %token SHADED
+%token XSLANTED
+%token YSLANTED
 %token ALIGNED
 %token SPRINTF
 %token COMMAND
@@ -221,6 +223,7 @@ box "foo" above ljust == box ("foo" above ljust)
 precedence than left and right, so that eg `line chop left'
 parses properly. */
 %left CHOP SOLID DASHED DOTTED UP DOWN FILL COLORED OUTLINED
+%left XSLANTED YSLANTED
 %left LABEL
 
 %left VARIABLE NUMBER '(' SIN COS ATAN2 LOG EXP SQRT K_MAX K_MIN INT RAND SRAND LAST 
@@ -935,6 +938,18 @@ object_spec:
 		  $$->flags |= IS_FILLED;
 		  $$->fill = $3;
 		}
+	| object_spec XSLANTED expr
+		{
+		  $$ = $1;
+		  $$->flags |= IS_XSLANTED;
+		  $$->xslanted = $3;
+		}
+	| object_spec YSLANTED expr
+		{
+		  $$ = $1;
+		  $$->flags |= IS_YSLANTED;
+		  $$->yslanted = $3;
+		}
 	| object_spec SHADED text
 		{
 		  $$ = $1;