Thursday, August 23rd, 2007
Dojo 0.9: Dissected, Fast, and 3D
There has been a flurry of activity now that 0.9 is out of the door for Dojo:
James Burke wrote about Dissecting 0.9's dojo.js file, which differs from the old "dojo.js could mean anything" view, and now is a base platform. The post also dives into the internals of Dojo 0.9's dojo.js, and break down the features and their relative sizes. After reading this it is easier to easier to compare the stand-alone dojo.js with the features and file sizes of other "one file" basic libraries like jQuery and Prototype.
Dojo 0.9 in 30 seconds is a sprint by Alex that shows you examples of dojo.js, such as how to make elements on a page fade out when clicked:
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dojo.query(".fadeHandle").onclick(function(e){
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dojo.fadeOut({ node: e.target.parentNode }).play();
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});
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Finally we have Bar3d, proudly powered by dojox.gfx3d, which is inspired by the Microsoft Excel's canonical bar3d graphics, and features:
- Multiple-series are supported
- Lighting
- Rotation, of course you can, but you need to be aware how difficult to find the right angles
- Animation, check calibration section
- User-interactivity, theoretically if we could figure out how to interpret the mouse movement.
No demo on the site of the 3d charts, just a PNG screenshot?
The 3D charts are pretty neat. I don’t think 3D is good for most charts, but impressive none the less.
What engine does the actual rendering here? Is this done in Canvas or SVG? Can’t seem to find much documentation or specifics…
I guess is canvas.
One that i made (few weeks ago actually) was in canvas, take a look
http://dragan.yourtree.org/code/canvas-3d-graph/
“User-interactivity, theoretically if we could figure out how to interpret the mouse movement.”
my idea was to place div above canvas (absolute positioning) and in that div place small divs that will interact on mouse events, not really elegant solution, but i can’t see any other.
Dragan: It’s not canvas, it’s the portable 2D drawing API (dojox.gfx) that can render down to whatever’s available (SVG, VML, Silverlight, etc.). The 3D scene graph engine is the result of Kun Xi’s excellent SoC work, and the charting work is Neil Joshi’s SoC contribution. The screenshot represents a successful merge of their efforts and is a major milestone.
Adam: I agree about most 3D charts not being useful, but this does also lay the groundwork for letting us visualize data for which the 3rd dimension is meaningful. Hopefully once we’re a bit further along we can do examples of that kind of data set.
Regards