[Gzz-commits] manuscripts/xupdf article.rst

[Tuomas J. Lukka]

CVSROOT:        /cvsroot/gzz
Module name:    manuscripts
Changes by:     Tuomas J. Lukka <address@hidden>        03/02/14 14:30:23

Modified files:
        xupdf          : article.rst 

Log message:
        Buoy discussion

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/xupdf/article.rst.diff?tr1=1.107&tr2=1.108&r1=text&r2=text

Patches:
Index: manuscripts/xupdf/article.rst
diff -u manuscripts/xupdf/article.rst:1.107 manuscripts/xupdf/article.rst:1.108
--- manuscripts/xupdf/article.rst:1.107 Fri Feb 14 12:12:16 2003
+++ manuscripts/xupdf/article.rst       Fri Feb 14 14:30:21 2003
@@ -342,36 +342,27 @@
 and if the buoy would be inside this ellipse, its position
 and size is calculated differently.
 
-The size falls 
+The position is calculated by *projecting* the anchor to the circle
+from the leftmost point of the ellipse.
+This places the buoys in a predictable and comprehensible way:
+the human eye is good at understanding pencils of lines, due to perspective.
+The size of the projected buoys
+falls linearly with the distance of the anchor from the 
+center up to the edge of the ellipse,
+
+For left-link-end buoys the preceding discussion should
+be reversed.
+
+..  Thus, the buoys are equally close to the focus, matching 
+    the fisheye focus shape.
+    Additionally, a circle arc provides more area for the buoys than,
+    e.g., a straight line.
 
-The buoys are placed on an ellipse with diameter little less 
-than the screen heighand tcentered at the focus.
-Thus, the buoys are equally close to the focus, matching 
-the fisheye focus shape.
-Additionally, a circle arc provides more area for the buoys than,
-e.g., a straight line.
-
-The position of a right-end buoy on the circle is obtained by 
-projecting a line from a constant point on the left side of the view
-through the anchor point and to the circle, and similarly
-for the left-end buoys.
 The resulting layout placed the buoys close to the anchor
 while maintaining the left-right orientation.
-Also, such line projections are easy to perceive for humans,
-because it is analogous to 3D perspective.
-
-The buoy scale is chosen to be relative to the anchor's distance 
-from the circle. That is, a buoy anchored at the center of the focus
-is large and gets linearly smaller as it approaches the circle.
-
-Because the documents, even with the fisheye-distortion, can be larger 
-than the buoy circle, buoys anchored far from the focus are drawn 
-near the anchor instead (while maintaining the link direction).
-This is needed to prevent awkward view-cutting 
-long lines and to yield more space for the layout of buoys anchored 
-close to the focus.
-Furthermore, the final positions of the buoys may need be adjusted 
-to prevent too much overlap.
+If buoy anchors coincide or are very close to each other 
+in the focused node,
+the final positions of the buoys need be adjusted to prevent.
 
 .. how does this interact with the perception of the projection?
 
@@ -381,18 +372,13 @@
    
    Buoy layout geometry: XXX
 
-The above design produces good results and is very simple if not 
-the simplest way to meet the layout requirements.
-
-
-
 
 
 Paper
 -----
 
-Although the silhuettes of the buoys are different,
-the fragments of the documents still seem quite similar.
+The fragments of nodes seen in buoys are 
+generally very similar in appearance.
 The user could identify the related documents by
 reading the text of a fragment, but that requires attention.