Add note describing required size information for image files.

diff --git a/doc/info/attrs.html b/doc/info/attrs.html
index 780411bad5792730b6f46f7e335b26e28b07e3bf..045566abe1574209cdaca38e2b7766cdfc4a0f1d 100644 (file)
--- a/doc/info/attrs.html
+++ b/doc/info/attrs.html
@@ -910,9 +910,23 @@ This field indicates which graph component uses the attribute.
 <DD>  Gives the name of a file containing an image to be displayed inside
   a node. The image file must be in one of the recognized 
   <A HREF=output.html#d:image_fmts>formats</A>,
-  typically JPEG, PNG, GIF or Postscript, and be able to be converted
+  typically JPEG, PNG, GIF, BMP, SVG or Postscript, and be able to be converted
   into the desired output format.
   <P>
+  The file must contain the image size information. This is usually trivially
+  true for the bitmap formats. For PostScript, the file must contain a
+  line starting with <TT>%%BoundingBox: </TT> followed by four integers
+  specifying the lower left x and y coordinates and the upper right x and y
+  coordinates of the bounding box for the image, the coordinates being in
+  points. An SVG image file must contain <TT>width</TT> and <TT>height</TT>
+  attributes, typically as part of the <TT>svg</TT> element.
+  The values for these should have the form of a floating point number,
+  followed by optional units, e.g., <TT>width="76pt"</TT>. 
+  Recognized units are <TT>in</TT>, <TT>px</TT>,
+  <TT>pc</TT>, <TT>pt</TT>, <TT>cm</TT> and <TT>mm</TT> for inches, pixels,
+  picas, points, centimeters and millimeters, respectively.
+  The default unit is points.
+  <P>
   Unlike with the <A HREF=#d:shapefile>shapefile</A> attribute,
   the image is treated as node
   content rather than the entire node. In particular, an image can

diff --git a/doc/infosrc/attrs b/doc/infosrc/attrs
index 5c28bb5cc23a83699c34ef91c931cff189aeccb3..a2b38634296c8f5051535a38ac8d5f0f3912a628 100644 (file)
--- a/doc/infosrc/attrs
+++ b/doc/infosrc/attrs
@@ -413,9 +413,23 @@ can include multiple image maps in the same document.
 Gives the name of a file containing an image to be displayed inside
 a node. The image file must be in one of the recognized 
 <A HREF=output.html#d:image_fmts>formats</A>,
-typically JPEG, PNG, GIF or Postscript, and be able to be converted
+typically JPEG, PNG, GIF, BMP, SVG or Postscript, and be able to be converted
 into the desired output format.
 <P>
+The file must contain the image size information. This is usually trivially
+true for the bitmap formats. For PostScript, the file must contain a
+line starting with <TT>%%BoundingBox: </TT> followed by four integers
+specifying the lower left x and y coordinates and the upper right x and y
+coordinates of the bounding box for the image, the coordinates being in
+points. An SVG image file must contain <TT>width</TT> and <TT>height</TT>
+attributes, typically as part of the <TT>svg</TT> element.
+The values for these should have the form of a floating point number,
+followed by optional units, e.g., <TT>width="76pt"</TT>. 
+Recognized units are <TT>in</TT>, <TT>px</TT>,
+<TT>pc</TT>, <TT>pt</TT>, <TT>cm</TT> and <TT>mm</TT> for inches, pixels,
+picas, points, centimeters and millimeters, respectively.
+The default unit is points.
+<P>
 Unlike with the <A HREF=#d:shapefile>shapefile</A> attribute,
 the image is treated as node
 content rather than the entire node. In particular, an image can