Looks like if you create a symbol with json , the angle rotates counter clockwise. Tested on 3.10 and 3.11 =(
function arrowSMS(angle)
{
//Works but rotates backwards.
var symbol = new esri.symbol.SimpleMarkerSymbol({
"color": [0, 0, 0, 1],
"size": 12,
"path": "m280,10l271,541l-271,-117.12372l-271,117.12372l271,-541z",
"angle": angle,
"xoffset": 0,
"yoffset": 0,
"type": "esriSMS",
"style": "esriSMSPath"
});
//// Works Properly
// var symbol = new esri.symbol.SimpleMarkerSymbol()
// symbol.setPath("m280,10l271,541l-271,-117.12372l-271,117.12372l271,-541z");
// symbol.setColor(new dojo.Color([0, 0, 0, 1]));
// symbol.setAngle(angle);
return symbol;
}