imccrum / canviz

Automatically exported from code.google.com/p/canviz
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Large graph viewing #22

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
Drawing the graph to a single canvas is fine for small and medium-sized graphs, 
but if the graph is 
thousands of pixels tall and/or wide, the computer slows to a crawl as the 
browser tries to allocate 
the tons of virtual memory it needs to make such a huge canvas. One solution 
might be to slice the 
graph into fixed-size tiles of say a few hundred pixels square, where each tile 
is a canvas, and 
create only those canvases necessary to draw the visible portion of the graph. 
As you scroll around 
to reveal other portions of the graph, those canvases get created and drawn, 
while the canvases you 
scrolled off the screen get deleted. This would be similar to the method Google 
Maps appears to 
employ.

Original issue reported on code.google.com by ryandesi...@gmail.com on 16 Oct 2008 at 8:11

GoogleCodeExporter commented 9 years ago
That would be awesome. I had a graph file with around 6000 nodes (and many more 
edges) and the only way I have managed to put it online was by rendering a huge 
PNG which is sliced in to multiple bitmap images for Seadragon. (example here: 
http://peterkrantz.com/v11n/rfc/). But that method will always have problems 
with interactivity. 

Multiple canvases would be very interesting to explore.

Original comment by peter.kr...@gmail.com on 26 Aug 2011 at 8:50

GoogleCodeExporter commented 9 years ago
I am also interested in this functionality (dragging around a small subsection 
to explore the graph). What's the best way to work on this since I'm new to the 
project?

Clearly there's another separate but related functionality for zoom (changing 
the scale) via scrolling. Should this be opened as a new issue? 

Original comment by ben.is.l...@gmail.com on 20 Feb 2013 at 2:52