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