Update documentation to reflect that Prism is now the default overlap removal algorithm,

as of 2.28.

diff --git a/doc/info/attrs.html b/doc/info/attrs.html
index 5b798b2d9eba08e2cdf9d8291531bd9aa31f48aa..c60931f6e974753423955d183ae584ccd53e3f39 100644 (file)
--- a/doc/info/attrs.html
+++ b/doc/info/attrs.html
@@ -1193,15 +1193,9 @@ This field indicates which graph component uses the attribute.
   enlarged using the <A HREF=#d:sep><B>sep</B></A> attribute.
   If "true" , overlaps are retained.
   If the value is "scale", overlaps are removed by uniformly scaling in x and y.
-  If the value converts to "false", node overlaps are removed by a
-  Voronoi-based technique.
-  If the value is "scalexy", x and y are separately
-  scaled to remove overlaps.
-  <P>
-  If sfdp is available, one can set overlap to "prism" to use a 
-  proximity graph-based algorithm for overlap removal. 
-  This is the preferred technique,
-  though "scale" and "false" can work well with small graphs.
+  If the value converts to "false", and it is available, Prism, a proximity graph-based algorithm, is
+  used to remove node overlaps.
+  This can also be invoked explicitly with "overlap=prism".
   This technique starts with a
   small scaling up, controlled by the 
   <A HREF="#d:overlap_scaling"><TT>overlap_scaling</TT></A> attribute,
@@ -1212,6 +1206,12 @@ This field indicates which graph component uses the attribute.
   <TT>overlap="prism1000"</TT>. Setting <TT>overlap="prism0"</TT>
   causes only the scaling phase to be run.
   <P>
+  If Prism is not available, or the version of Graphviz is earlier than 2.28, "overlap=false"
+  uses a Voronoi-based technique.
+  <P>
+  If the value is "scalexy", x and y are separately
+  scaled to remove overlaps.
+  <P>
   If the value is "compress", the layout will be scaled down as much as
   possible without introducing any overlaps, obviously assuming there are
   none to begin with.
@@ -1242,12 +1242,12 @@ This field indicates which graph component uses the attribute.
   N.B. At present, this only supports one level of clustering.
   <P>
   Except for fdp and sfdp, the layouts assume <TT>overlap="true"</TT> as the default.
-  Fdp first uses a number of passes using built-in, force-directed technique
-  to remove overlaps. Thus, fdp accepts <B>overlap</B> with an integer
+  Fdp first uses a number of passes using a built-in, force-directed technique
+  to try to remove overlaps. Thus, fdp accepts <B>overlap</B> with an integer
   prefix followed by a colon, specifying the number of tries. If there is
   no prefix, no initial tries will be performed. If there is nothing following
   a colon, none of the above methods will be attempted. By default, fdp
-  uses <TT>overlap="9:portho"</TT>. Note that <TT>overlap="true"</TT>,
+  uses <TT>overlap="9:prism"</TT>. Note that <TT>overlap="true"</TT>,
   <TT>overlap="0:true"</TT> and <TT>overlap="0:"</TT> all turn off all overlap
   removal.
   <P>

diff --git a/doc/infosrc/attrs b/doc/infosrc/attrs
index eefd6bf9063db2b28a5e33caeaf5a45f956a93fb..dbcf75276fec8ad07d21fe08da1e26c01800890b 100644 (file)
--- a/doc/infosrc/attrs
+++ b/doc/infosrc/attrs
@@ -674,15 +674,9 @@ Determines if and how node overlaps should be removed. Nodes are first
 enlarged using the <A HREF=#d:sep><B>sep</B></A> attribute.
 If "true" , overlaps are retained.
 If the value is "scale", overlaps are removed by uniformly scaling in x and y.
-If the value converts to "false", node overlaps are removed by a
-Voronoi-based technique.
-If the value is "scalexy", x and y are separately
-scaled to remove overlaps.
-<P>
-If sfdp is available, one can set overlap to "prism" to use a 
-proximity graph-based algorithm for overlap removal. 
-This is the preferred technique,
-though "scale" and "false" can work well with small graphs.
+If the value converts to "false", and it is available, Prism, a proximity graph-based algorithm, is
+used to remove node overlaps.
+This can also be invoked explicitly with "overlap=prism".
 This technique starts with a
 small scaling up, controlled by the 
 <A HREF="#d:overlap_scaling"><TT>overlap_scaling</TT></A> attribute,
@@ -693,6 +687,12 @@ removal. By default, <TT>overlap="prism"</TT> is equivalent to
 <TT>overlap="prism1000"</TT>. Setting <TT>overlap="prism0"</TT>
 causes only the scaling phase to be run.
 <P>
+If Prism is not available, or the version of Graphviz is earlier than 2.28, "overlap=false"
+uses a Voronoi-based technique.
+<P>
+If the value is "scalexy", x and y are separately
+scaled to remove overlaps.
+<P>
 If the value is "compress", the layout will be scaled down as much as
 possible without introducing any overlaps, obviously assuming there are
 none to begin with.
@@ -723,12 +723,12 @@ incorporated into the layout algorithm itself.
 N.B. At present, this only supports one level of clustering.
 <P>
 Except for fdp and sfdp, the layouts assume <TT>overlap="true"</TT> as the default.
-Fdp first uses a number of passes using built-in, force-directed technique
-to remove overlaps. Thus, fdp accepts <B>overlap</B> with an integer
+Fdp first uses a number of passes using a built-in, force-directed technique
+to try to remove overlaps. Thus, fdp accepts <B>overlap</B> with an integer
 prefix followed by a colon, specifying the number of tries. If there is
 no prefix, no initial tries will be performed. If there is nothing following
 a colon, none of the above methods will be attempted. By default, fdp
-uses <TT>overlap="9:portho"</TT>. Note that <TT>overlap="true"</TT>,
+uses <TT>overlap="9:prism"</TT>. Note that <TT>overlap="true"</TT>,
 <TT>overlap="0:true"</TT> and <TT>overlap="0:"</TT> all turn off all overlap
 removal.
 <P>