Added a new version (0.8.3) of FloatCanvas from Chris Barker. It's

now in a subpackage of wx.lib.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@27637 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/wx/lib/floatcanvas/__init__.py

@@ -0,0 +1,95 @@
+"""
+This is the floatcanvas package. It provides two primary modules, and a
+support module.
+
+FloatCanvas.py contains the main FloatCanvas class, and it's supporting
+classes.  NavCanvas.py contains a wrapper for the FloatCanvas that
+provides the canvas and a toolbar with tools that allow you to navigate
+the canvas (zooming, panning, etc.)  Resources.py is a module that
+contains a few resources required by the FloatCanvas (icons, etc)
+
+The FloatCanvas is a high level window for drawing maps and anything
+else in an arbitrary coordinate system.
+
+The goal is to provide a convenient way to draw stuff on the screen
+without having to deal with handling OnPaint events, converting to pixel
+coordinates, knowing about wxWindows brushes, pens, and colors, etc. It
+also provides virtually unlimited zooming and scrolling
+
+I am using it for two things:
+1) general purpose drawing in floating point coordinates
+2) displaying map data in Lat-long coordinates
+
+If the projection is set to None, it will draw in general purpose
+floating point coordinates. If the projection is set to 'FlatEarth', it
+will draw a FlatEarth projection, centered on the part of the map that
+you are viewing. You can also pass in your own projection function.
+
+It is double buffered, so re-draws after the window is uncovered by
+something else are very quick.
+
+It relies on NumPy, which is needed for speed (maybe, I haven't profiled
+it). It will also use numarray, if you don't have Numeric, but it is
+slower.
+
+Bugs and Limitations: Lots: patches, fixes welcome
+
+For Map drawing: It ignores the fact that the world is, in fact, a
+sphere, so it will do strange things if you are looking at stuff near
+the poles or the date line. so far I don't have a need to do that, so I
+havn't bothered to add any checks for that yet.
+
+Zooming: I have set no zoom limits. What this means is that if you zoom
+in really far, you can get integer overflows, and get weird results. It
+doesn't seem to actually cause any problems other than weird output, at
+least when I have run it.
+
+Speed: I have done a couple of things to improve speed in this app. The
+one thing I have done is used NumPy Arrays to store the coordinates of
+the points of the objects. This allowed me to use array oriented
+functions when doing transformations, and should provide some speed
+improvement for objects with a lot of points (big polygons, polylines,
+pointsets).
+
+The real slowdown comes when you have to draw a lot of objects, because
+you have to call the wx.DC.DrawSomething call each time. This is plenty
+fast for tens of objects, OK for hundreds of objects, but pretty darn
+slow for thousands of objects.
+
+If you are zoomed in, it checks the Bounding box of an object before
+drawing it. This makes it a great deal faster when there are a lot of
+objects and you are zoomed in so that only a few are shown.
+
+One solution is to be able to pass some sort of object set to the DC
+directly. I've used DC.DrawPointList(Points), and it helped a lot with
+drawing lots of points. However, when zoomed in, the Bounding boxes need
+to be checked, so I may some day write C++ code that does the loop and
+checks the BBs.
+
+Mouse Events:
+
+At this point, there are a full set of custom mouse events. They are
+just like the regular mouse events, but include an extra attribute:
+Event.GetCoords(), that returns the (x,y) position in world coordinates,
+as a length-2 NumPy vector of Floats.
+
+See the Demo for what it can do, and how to use it.
+
+Copyright: Christopher Barker
+
+License: Same as the version of wxPython you are using it with.
+
+Check for updates at:
+http://home.comcast.net/~chrishbarker/FloatCanvas/
+
+Please let me know if you're using this!!!
+
+Contact me at:
+
+Chris.Barker@noaa.gov
+
+"""
+
+__version__ = "0.8.3"
+
+