How do i rotate a Polygon programmaticly?

[Anonymous User]

Original User: mmoles

I know the toolbar has a rotate option, but how can i rotate polygons programmaticly.

There must be some rotate function  like rotate(myPolygon, deg, centerPoint) somewhere in there.  If not, i guess i will need to write one myself =(

[JianHuang]

Unfortunately, we didn't make it as an API.
You need to check dojox/gfx/matrix library. Here is the short but essential code:

var tx = matrix.rotategAt(angle, anchor);
graphic.getDojoShape().setTransform(tx);

[Anonymous User]

Original User: mmoles

Unfortunately, we didn't make it as an API.
You need to check dojox/gfx/matrix library. Here is the short but essential code:

var tx = matrix.rotategAt(angle, anchor);
graphic.getDojoShape().setTransform(tx);

Sadly this wont work for me.   The command just modifies the svg and not the polygon ring.  I also wanted to use the geographic mercator system to define the location, which is probably still possible to do by creating a point in that coordinate or some other command.   The next issue that I run into is that, when i would zoom out, it then refreshes the layer which removes my changes because its just a graphical change and not the object itself.

I guess i will need to start doing some math =(

[JianHuang]

That code snippet is what we are using in the API to rotate the shape. Once it's done, you need to call graphic.setGeometry() to make it permanent.
There are a lot math going on, but still gfx library can do a lot heavy lifting part.

[Anonymous User]

Original User: mmoles

That code snippet is what we are using in the API to rotate the shape. Once it's done, you need to call graphic.setGeometry() to make it permanent.
There are a lot math going on, but still gfx library can do a lot heavy lifting part.

Is it better to do it this way, or to modify the object and having it redraw?

I was using the mercator system and i was trying var tx = dojox.gfx.matrix.rotategAt(45, -10372784, 3316853)  which sadly doesnt work.   So, how can i convert a geo point to a browser coordinate?

Aaaand, last question... setGeometry(geometry)   .... whats geometry do i pass in?  The tempGraphicsLayer.graphics[2].getDojoShape() object that i did the transformation says it has no getExtent method.

[JianHuang]

Please take a look:
https://developers.arcgis.com/javascript/jsapi/map-amd.html#toscreen

[Anonymous User]

Original User: mmoles

awesome, i knew that was in there somewhere.  I also edited my post after your reply asking 1 last question.

setGeometry(geometry) .... whats geometry do i pass in? The tempGraphicsLayer.graphics[2].getDojoShape() object that i did the transformation says it has no getExtent method.  Same goes with trying to pass in  tempGraphicsLayer.graphics[2].geometry funny enough.