<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> <HTML VERSION="2.0"> <HEAD> <TITLE>Node Shapes</TITLE> </HEAD> <BODY BGCOLOR=white> <A NAME="top"></A> <H1 align=CENTER>Node Shapes</H1> <HR> The geometries of all node shapes are affected by the node attributes <A HREF=attrs.html#d:fixedsize><TT>fixedsize</TT></A>, <A HREF=attrs.html#d:fontname><TT>fontname</TT></A>, <A HREF=attrs.html#d:fontsize><TT>fontsize</TT></A>, <A HREF=attrs.html#d:height><TT>height</TT></A>, <A HREF=attrs.html#d:label><TT>label</TT></A>, <A HREF=#d:style><TT>style</TT></A> and <A HREF=attrs.html#d:width><TT>width</TT></A>. <H2><A NAME=polygon>Polygon-based Nodes</A></H2> The possible polygon-based shapes are displayed below. <TABLE ALIGN=CENTER> <TR ALIGN=CENTER> <TD><IMG SRC=box.gif> <TD><IMG SRC=polygon.gif> <TD><IMG SRC=ellipse.gif> <TD><IMG SRC=circle.gif> </TR> <TR ALIGN=CENTER> <TD><A NAME=d:box>box</A> <TD><A NAME=d:polygon>polygon</A> <TD><A NAME=d:ellipse>ellipse</A> <TD><A NAME=d:circle>circle</A> </TR> <TR ALIGN=CENTER> <TD><IMG SRC=point.gif> <TD><IMG SRC=egg.gif> <TD><IMG SRC=triangle.gif> <TD><IMG SRC=plaintext.gif> </TR> <TR ALIGN=CENTER> <TD><A NAME=d:point>point</A> <TD><A NAME=d:egg>egg</A> <TD><A NAME=d:triangle>triangle</A> <TD><A NAME=d:plaintext>plaintext</A> </TR> <TR ALIGN=CENTER> <TD><IMG SRC=diamond.gif> <TD><IMG SRC=trapezium.gif> <TD><IMG SRC=parallelogram.gif> <TD><IMG SRC=house.gif> </TR> <TR ALIGN=CENTER> <TD><A NAME=d:diamond>diamond</A> <TD><A NAME=d:trapezium>trapezium</A> <TD><A NAME=d:parallelogram>parallelogram</A> <TD><A NAME=d:house>house</A> </TR> <TR ALIGN=CENTER> <TD><IMG SRC=pentagon.gif> <TD><IMG SRC=hexagon.gif> <TD><IMG SRC=septagon.gif> <TD><IMG SRC=octagon.gif> </TR> <TR ALIGN=CENTER> <TD><A NAME=d:pentagon>pentagon</A> <TD><A NAME=d:hexagon>hexagon</A> <TD><A NAME=d:septagon>septagon</A> <TD><A NAME=d:octagon>octagon</A> </TR> <TR ALIGN=CENTER> <TD><IMG SRC=doublecircle.gif> <TD><IMG SRC=doubleoctagon.gif> <TD><IMG SRC=tripleoctagon.gif> <TD><IMG SRC=invtriangle.gif> </TR> <TR ALIGN=CENTER> <TD><A NAME=d:doublecircle>doublecircle</A> <TD><A NAME=d:doubleoctagon>doubleoctagon</A> <TD><A NAME=d:tripleoctagon>tripleoctagon</A> <TD><A NAME=d:invtriangle>invtriangle</A> </TR> <TR ALIGN=CENTER> <TD><IMG SRC=invtrapezium.gif> <TD><IMG SRC=invhouse.gif> <TD><IMG SRC=Mdiamond.gif> <TD><IMG SRC=Msquare.gif> </TR> <TR ALIGN=CENTER> <TD><A NAME=d:invtrapezium>invtrapezium</A> <TD><A NAME=d:invhouse>invhouse</A> <TD><A NAME=d:Mdiamond>Mdiamond</A> <TD><A NAME=d:Msquare>Msquare</A> </TR> <TR ALIGN=CENTER> <TD><IMG SRC=Mcircle.gif> <TD><IMG SRC=rect.gif> <TD><IMG SRC=rectangle.gif> </TR> <TR ALIGN=CENTER> <TD><A NAME=d:Mcircle>Mcircle</A> <TD><A NAME=d:rect>rect</A> <TD><A NAME=d:rectangle>rectangle</A> </TR> </TABLE> As the figures suggest, the shapes <TT>rect</TT> and <TT>rectangle</TT> are synonyms for <TT>box</TT>. Also, unlike the rest, we have shown the <TT>plaintext</TT> node without <TT>style=filled</TT> to indicate its normal use. If fill were turned on, the label text would appear in a filled rectangle. <P> The geometries of polygon-based shapes are also affected by the node attributes <A HREF=attrs.html#d:regular><TT>regular</TT></A>, <A HREF=attrs.html#d:peripheries><TT>peripheries</TT></A> and <A HREF=attrs.html#d:orientation><TT>orientation</TT></A>. If <TT>shape="polygon"</TT>, the attributes <A HREF=attrs.html#d:sides><TT>sides</TT></A>, <A HREF=attrs.html#d:skew><TT>skew</TT></A> and <A HREF=attrs.html#d:distortion><TT>distortion</TT></A> are also used. If unset, they default to 4, 0.0 and 0.0, respectively. In addition, the 3 M* shapes support auxiliary labels using the <A HREF=attrs.html#d:toplabel><TT>toplabel</TT></A> and <A HREF=attrs.html#d:bottomlabel><TT>bottomlabel</TT></A> attributes. On the other hand, the point shape is special in that it is only affected by the <A HREF=attrs.html#d:peripheries><TT>peripheries</TT></A>, <A HREF=attrs.html#d:width><TT>width</TT></A> and <A HREF=attrs.html#d:height><TT>height</TT></A> attributes. <H2><A NAME=record>Record-based Nodes</A></H2> These are specified by shape values of "record" and "Mrecord". The structure of a record-based node is determined by its <A HREF=attrs.html#d:label><TT>label</TT></A>, which has the following schema: <TABLE> <TR><TD ALIGN=right><I>rlabel</I><TD>=<TD><I>field</I> ( '|' <I>field</I> )*</TR> <TR><TD ALIGN=right>where <I>field</I><TD>=<TD>fieldId</I> or '{' <I>rlabel</I> '}'</TR> <TR><TD ALIGN=right>and <I>fieldId</I><TD>=<TD> ( '<' <I>string</I> '>') ( <I>string</I> }</TR> </TABLE> Literal braces, vertical bars and angle brackets must be escaped. Spaces are interpreted as separators between tokens, so they must be escaped if you want spaces in the text. <P> The first string in <I>fieldId</I> gives a name to the field and can be combined with the node name to denote the end of an edge. The second string is used as the text for the field; it supports the usual <A HREF=attrs.html#d:label>escape sequences</A> \n, \l and \r. <P> Visually, a record is a box, with fields represented by alternating rows of horizontal or vertical subboxes. The Mrecord shape is identical to a record shape, except that the outermost box has rounded corners. Flipping between horizontal and vertical layouts is done by nesting fields in braces "{...}". The top-level orientation in a record is horizontal. Thus, a record with label "A | B | C | D" will have 4 fields oriented left to right, while "{A | B | C | D}" will have them from top to bottom and "A | { B | C } | D" will have "B" over "C", with "A" to the left and "D" to the right of "B" and "C". <P> As an example of a record node, the dot input <XMP> digraph structs { node [shape=record]; struct1 [label="<f0> left|<f1> mid\ dle|<f2> right"]; struct2 [label="<f0> one|<f1> two"]; struct3 [label="hello\nworld |{ b |{c|<here> d|e}| f}| g | h"]; struct1:f1 -> struct2:f0; struct1:f2 -> struct3:here; } </XMP> yields the figure<BR> <IMG SRC=record.gif> <P> If we change node <TT>struct1</TT> to have shape <TT>Mrecord</TT>, it then looks like:<BR> <IMG SRC=mrecord.gif> <H2><A NAME="d:style">Styles for Nodes</A></H2> The <A HREF=attrs.html#d:style><TT>style</TT></A> attribute can be used to modify the appearance of a node. At present, there are 4 style values recognized: <TT>filled</TT>, <TT>invisible</TT>, <TT>diagonals</TT> and <TT>rounded</TT>. <DL> <DT><A NAME=d:filled><TT>filled</TT> <DD>This value indicates that the node's interior should be filled. The color used is the node's <TT>fillcolor</TT> or, if that's not defined, its <TT>color</TT>. For unfilled nodes, the interior of the node is transparent to whatever color is the current graph or cluster background color. Note that <TT>point</TT> shapes are always filled. <P> Thus, the code <XMP> digraph G { rankdir=LR node [shape=box, color=blue] node1 [style=filled] node2 [style=filled, fillcolor=red] node0 -> node1 -> node2 } </XMP> yields the figure<BR> <IMG SRC=fill.gif> <DT><A NAME=d:invisible><TT>invisible</TT> <DD>Setting this style causes the node not to be displayed at all. Note that the node is still used in laying out the graph. <DT><A NAME=d:diagonals><TT>diagonals</TT> <DD>The diagonals style causes small chords to be drawn near the vertices of the node's polygon or, in case of circles and ellipses, two chords near the top and the bottom of the shape. The special node shapes <A HREF=#d:Msquare><TT>Msquare</TT></A>, <A HREF=#d:Mcircle><TT>Mcircle</TT></A>, and <A HREF=#d:Mdiamond><TT>Mdiamond</TT></A> are simply an ordinary square, circle and diamond with the diagonals style set. <DT><A NAME=d:rounded><TT>rounded</TT> <DD>The rounded style causes the polygonal corners to be smoothed. Note that this style also applies to record-based nodes. Indeed, the <TT>Mrecord</TT> shape is simply shorthand for setting this style. At present, the rounded and filled styles are mutually exclusive. <P> As an example of rounding, dot uses the graph <XMP> digraph R { rankdir=LR node [style=rounded] node1 [shape=box] node2 [shape=diamond] node3 [shape=record, label="{ a | b | c }"] node1 -> node2 -> node3 } </XMP> to produce the figure<BR> <IMG SRC=round.gif> </DL> <P> Additional styles may be available with a specific code generator. <H2><A NAME=html>HTML-Like Labels</A></H2> <B>NOTE:</B><EM>This feature is only available on versions of Graphviz that are newer than mid-November 2003. In particular, it is not part of release 1.10.</EM> <P> If the value of a label attribute (<A HREF=attrs.html#d:label><TT>label</TT></A> for nodes, edges, clusters, and graphs, and the <A HREF=attrs.html#d:headlabel><TT>headlabel</TT></A> and <A HREF=attrs.html#d:taillabel><TT>taillabel</TT></A> attributes of an edge) is given as an <A HREF=lang.html#html>HTML string</A>, that is, delimited by <TT><...></TT> rather than <TT>"..."</TT>, the label is interpreted as an HTML description. At their simplest, such labels can describe multiple lines of variously aligned text as provided by ordinary <A HREF=attrs.html#k:escString>string labels</A>. More generally, the label can specify a table similar to those provided by HTML, with different graphical attributes at each level. <P> <B>NOTE:</B> The features and syntax supported by these labels is inspired by HTML. However, there are many aspects that are relevant to Graphviz labels that are not in HTML and, conversely, HTML allows various constructs which are meaningless in Graphviz. We will generally refer to these labels as "HTML labels" rather than the cumbersome "HTML-like labels" but the reader is warned that these are not really HTML. The grammar below describes precisely what Graphviz will accept. <P> Although HTML labels are not strictly speaking a shape, they can be viewed as a generalization of the record shapes described above. In particular, if a node has set its <A HREF=attrs.html#k:shape><TT>shape</TT></A> attribute to <TT>plaintext</TT>, the HTML label will be the node's shape. On the other hand, if the node has any other shape (except <TT>point</TT>), the HTML label will be embedded within the node the same way an ordinary label would be. <P> The following is an abstract grammar for HTML labels. Terminals are shown in bold font and nonterminals in italics. Vertical bars | separate alternatives. <TABLE> <TR> <TD ALIGN=RIGHT><I>label</I></TD> <TD ALIGN=LEFT>:</TD> <TD ALIGN=LEFT><I>text</I></TD> </TR> <TR> <TD ALIGN=RIGHT></TD> <TD ALIGN=LEFT>|</TD> <TD ALIGN=LEFT><I>table</I></TD> </TR> <TR> <TD ALIGN=RIGHT><I>text</I></TD> <TD ALIGN=LEFT>:</TD> <TD ALIGN=LEFT><I>lines</I></TD> </TR> <TR> <TD ALIGN=RIGHT></TD> <TD ALIGN=LEFT>|</TD> <TD ALIGN=LEFT><I>lines</I> <I>string</I></TD> </TR> <TR> <TD ALIGN=RIGHT></TD> <TD ALIGN=LEFT>|</TD> <TD ALIGN=LEFT><I>string</I></TD> </TR> <TR> <TD ALIGN=RIGHT><I>lines</I></TD> <TD ALIGN=LEFT>:</TD> <TD ALIGN=LEFT><I>string</I> <B><BR/></B></TD> </TR> <TR> <TD ALIGN=RIGHT></TD> <TD ALIGN=LEFT>|</TD> <TD ALIGN=LEFT><I>lines</I> <I>string</I> <B><BR/></B></TD> </TR> <TR> <TD ALIGN=RIGHT><I>table</I></TD> <TD ALIGN=LEFT>:</TD> <TD ALIGN=LEFT><B><TABLE></B> <I>rows</I> <B></TABLE></B></TD> </TR> <TR> <TD ALIGN=RIGHT><I>rows</I></TD> <TD ALIGN=LEFT>:</TD> <TD ALIGN=LEFT><I>row</I></TD> </TR> <TR> <TD ALIGN=RIGHT></TD> <TD ALIGN=LEFT>|</TD> <TD ALIGN=LEFT><I>rows</I> <I>row</I></TD> </TR> <TR> <TD ALIGN=RIGHT><I>row</I></TD> <TD ALIGN=LEFT>:</TD> <TD ALIGN=LEFT><B><TR></B> <I>cells</I> <B></TR></B></TD> </TR> <TR> <TD ALIGN=RIGHT><I>cells</I></TD> <TD ALIGN=LEFT>:</TD> <TD ALIGN=LEFT><I>cell</I></TD> </TR> <TR> <TD ALIGN=RIGHT></TD> <TD ALIGN=LEFT>|</TD> <TD ALIGN=LEFT><I>cells</I> <I>cell</I></TD> </TR> <TR> <TD ALIGN=RIGHT><I>cell</I></TD> <TD ALIGN=LEFT>:</TD> <TD ALIGN=LEFT><B><TD></B> <I>label</I> <B></TD></B></TD> </TR> </TABLE> <P> Above, a <I>string</I> is any collection of printable characters, including all spaces. Note that outside of the body of a <TD> element, whitespace characters are ignored; within a <TD> element, spaces are preserved but all other white space characters are discarded. HTML comments are allowed within an HTML string. They can occur anywhere provided that if they contain part of an HTML element, they just contain the entire element. <P> Each of the HTML elements has a set of optional attributes. <PRE><TABLE ALIGN="CENTER|LEFT|RIGHT" BGCOLOR="<I>color</I>" BORDER="<I>value</I>" CELLBORDER="<I>value</I>" CELLPADDING="<I>value</I>" CELLSPACING="<I>value</I>" FIXEDSIZE="FALSE|TRUE" HEIGHT="<I>value</I>" HREF="<I>value</I>" PORT="<I>portName</I>" VALIGN="MIDDLE|BOTTOM|TOP" WIDTH="<I>value</I>" > </PRE> <P> <PRE><TD ALIGN="CENTER|LEFT|RIGHT" BGCOLOR="<I>color</I>" BORDER="<I>value</I>" CELLPADDING="<I>value</I>" CELLSPACING="<I>value</I>" COLSPAN="<I>value</I>" FIXEDSIZE="FALSE|TRUE" HEIGHT="<I>value</I>" HREF="<I>value</I>" PORT="<I>portName</I>" ROWSPAN="<I>value</I>" VALIGN="MIDDLE|BOTTOM|TOP" WIDTH="<I>value</I>" > </PRE> <P> <PRE><BR ALIGN="CENTER|LEFT|RIGHT" > </PRE> <P> <B><I><FONT SIZE=-1>ALIGN</FONT> </I></B> <BLOCKQUOTE> specifies horizontal placement. When an object is allocated more space than required, this value determines where the extra space is placed left and right of the object. <P> <ul> <LI>CENTER aligns the object in the center. (Default) </LI> <LI>LEFT aligns the object on the left.</LI> <LI>RIGHT aligns the object on the right. </LI> </ul> </BLOCKQUOTE> <B><I><FONT SIZE=-1>BGCOLOR="color"</FONT></I></B> <BLOCKQUOTE> sets the color of the background. This color can be overridden by a <B><I>BGCOLOR</I></B> attribute in descendents. </BLOCKQUOTE> <B><I><FONT SIZE=-1>BORDER="value"</FONT></I></B> <BLOCKQUOTE> specifies the width of the border around the object in points. A value of zero indicates no border. The default is 1. If set in a table, and <B><I>CELLBORDER</I></B> is not set, this value is also used for all cells in the table. It can be overridden by a <B><I>BORDER</I></B> tag in a cell. </BLOCKQUOTE> <B><I><FONT SIZE=-1>CELLBORDER="value"</FONT></I></B> <BLOCKQUOTE> specifies the width of the border for all cells in a table. It can be overridden by a <B><I>BORDER</I></B> tag in a cell. </BLOCKQUOTE> <B><I><FONT SIZE=-1>CELLPADDING="value"</FONT></I></B> <BLOCKQUOTE> specifies the space, in points, between a cell's border and its content. The default is 2. </BLOCKQUOTE> <B><I><FONT SIZE=-1>CELLSPACING="value"</FONT></I></B> <BLOCKQUOTE> specifies the space, in points, between cells in a table and between a cell and the table's border. The default is 2. </BLOCKQUOTE> <B><I><FONT SIZE=-1>COLSPAN="value"</FONT></I></B> <BLOCKQUOTE> specifies the number of columns spanned by the cell. The default is 1. </BLOCKQUOTE> <B><I><FONT SIZE=-1>FIXEDSIZE</FONT> </I></B> <BLOCKQUOTE> specifies whether the values given by the <B><I>WIDTH</I></B> and <B><I>HEIGHT</I></B> attributes are enforced. <P> <ul> <LI>FALSE allows the object to grow so that all its contents will fit. (Default) </LI> <LI>TRUE fixes the object size to its given <B><I>WIDTH</I></B> and <B><I>HEIGHT</I></B>. Both of these attributes must be supplied.</LI> </ul> </BLOCKQUOTE> <B><I><FONT SIZE=-1>HEIGHT="value"</FONT></I></B> <BLOCKQUOTE> specifies the mininum height, in points, of the object. The height includes the contents, any spacing and the border. Unless <B><I>FIXEDSIZE</I></B> is true, the height will be expanded to allow the contents to fit. </BLOCKQUOTE> <B><I><FONT SIZE=-1>HREF="value"</FONT></I></B> <BLOCKQUOTE> attaches a URL to the object. </BLOCKQUOTE> <B><I><FONT SIZE=-1>PORT="value"</FONT></I></B> <BLOCKQUOTE> attaches a port name to the object. This can be used to modify the head or tail of an edge, so that the end attaches directly to the object. </BLOCKQUOTE> <B><I><FONT SIZE=-1>ROWSPAN="value"</FONT></I></B> <BLOCKQUOTE> specifies the number of rows spanned by the cell. The default is 1. </BLOCKQUOTE> <P> <B><I><FONT SIZE=-1>VALIGN</FONT> </I></B> <BLOCKQUOTE> specifies vertical placement. When an object is allocated more space than required, this value determines where the extra space is placed above and below the object. <P> <ul> <LI>MIDDLE aligns the object in the center. (Default) </LI> <LI>LEFT aligns the object on the left.</LI> <LI>RIGHT aligns the object on the right. </LI> </ul> </BLOCKQUOTE> <B><I><FONT SIZE=-1>WIDTH="value"</FONT></I></B> <BLOCKQUOTE> specifies the mininum width, in points, of the object. The width includes the contents, any spacing and the border. Unless <B><I>FIXEDSIZE</I></B> is true, the width will be expanded to allow the contents to fit. </BLOCKQUOTE> <P> There is some inheritance among the attributes. If a table specifies a <I><B>CELLPADDING</B></I>, <I><B>CELLBORDER</B></I> or <I><B>BORDER</B></I> value, this value is used by the table's cells unless overridden. If a cell or table specifies a BGCOLOR, this will be the background color for all of its descendents. Of course, if a background or fill color is specified for the graph object owning the label, this will be the original background for the label. Finally, the pencolor or color of the graph object will be used as the border color, and the object's fontname, fontcolor and fontsize attributes are used for drawing text. <P> Because of certain limitations in handling tables in a device-independent manner, when <I><B>BORDER</B></I> is 1 and both table and cell borders are on and <I><B>CELLSPACING</B></I> is less than 2, anomalies can arise in the output, such as gaps between sides of borders which should be abutting or even collinear. The user can usual get around this by increasing the border size or the spacing, or turning off the table border. <P> As an example of HTML labels, the dot input <XMP> digraph structs { node [shape=plaintext] struct1 [label=< <TABLE BORDER="0" CELLBORDER="1" CELLSPACING="0"> <TR><TD>left</TD><TD PORT="f1">mid dle</TD><TD PORT="f2">right</TD></TR> </TABLE>>]; struct2 [label=< <TABLE BORDER="0" CELLBORDER="1" CELLSPACING="0"> <TR><TD PORT="f0">one</TD><TD>two</TD></TR> </TABLE>>]; struct3 [label=< <TABLE BORDER="0" CELLBORDER="1" CELLSPACING="0" CELLPADDING="4"> <TR> <TD ROWSPAN="3">hello<BR/>world</TD> <TD COLSPAN="3">b</TD> <TD ROWSPAN="3">g</TD> <TD ROWSPAN="3">h</TD> </TR> <TR> <TD>c</TD><TD PORT="here">d</TD><TD>e</TD> </TR> <TR> <TD COLSPAN="3">f</TD> </TR> </TABLE>>]; struct1:f1 -> struct2:f0; struct1:f2 -> struct3:here; } </XMP> produces the HTML analogue of the record example above<BR> <IMG SRC=html1.gif> <P> As usual, an HTML specification is more verbose. On the other hand, HTML labels are much more general, as the following example shows: <P> <IMG SRC=html2.gif> <P> The source for this graph can be found <A HREF=html2.dot>here</A>. <H2><A NAME=epsf>User-defined Nodes</A></H2> There is a third type of node shape which is specified by the user. Typically, these shapes rely on the details of a concrete graphics format. At present, shapes can be described using PostScript, via a file or add-on library, for use in PostScript output, or shapes can be specified by a bitmap-image file for use with SVG or bitmap (jpeg, gif, etc.) output. More information can be found on the page <A HREF=http://www.research.att.com/sw/tools/graphviz/shapehowto.html>How to create custom shapes</A>. </BODY> </HTML>