I've got an algorithm,
which behaves a little strange since I've decided to use my function
to perform OR operation on all objects which belongs to one list. The
function I'm talking about looks like this:
"Entry list smaller than 2 elements!")
The lppA is a layer
purpose pair which is a defined global. I'm also using an empty CV to
perform the operation. From Cadence manual I figured out that this
function should perform OR operations on all shapes given on
shape_list. What I mean is operation which for overlapping regions of
shapes in shape_list returns this overlapping region only once.
And now the usage and the
limitations. My algorithm in pseudo code looks something like this:
And now some background.
Area(x) returns valid area of she list, which I've checked. In seed
at the beginning there are some shapes which do not overlap (I've
executed the or_shapes procedure). Oversize(x,k) oversizes all shapes
in x by the factor k. And the problem is that the out_area<in_area
(after_oversize>in_area), while it shouldn't be. In worst case the
out_area should be equal to in_area. Maybe the dbLayerOr function has
some limitations, or maybe I'm doing something else wrong. Any
suggestions would be much appreciated.
I'm not aware of any problems with dbLayerOr() - I'd be surprised. Most likely is something wrong with your Area code - I'd have thought it would be fairly obvious by looking at the layout at each step.
Perhaps you can contact me directly and then send me the code and data which shows the problem, and I'll try to take a quick look?
In reply to Andrew Beckett:
I found the solution to my
problem. While using leSizeShape procedure it turned up that, while
oversizing it is possible that the procedure returns more
than one shape. In my algorithm I was prepared for just one shape and
other shapes weren't taken into account in my algorithm. That's the
reason why the area was smaller. By the way I'm still quite surprised
that while oversizing one shape it is possible for procedures to
return shapes list (more then one shape in it). How is it possible?
In reply to ToMWUT:
If the resulting shape has too many vertices (more than 4000 if I remember rightly) then it will be split into multiple shapes. There's a maximum number of allowed vertices in a polygon in the database, so it has to do this.
That's the most likely explanation. I'm assuming shapes when oversized collide with other oversized shapes, and that could result in a shape with lots of vertices?