Use enum instead of NaNs for alternative orientation specification.

PiperOrigin-RevId: 627413508
Change-Id: I9f1a682a1533e1a3fa3cac0a462f28ce9b0fa192

src/xml/xml_base.cc

@@ -54,13 +54,25 @@ void mjXBase::SetModel(mjSpec* _model) {
 // read alternative orientation specification
 int mjXBase::ReadAlternative(XMLElement* elem, mjsOrientation& alt) {
   string text;
-  int read = (int)(elem->Attribute("quat") != 0) +
-             (ReadAttr(elem, "axisangle", 4, alt.axisangle, text) ? 1 : 0) +
-             (ReadAttr(elem, "xyaxes", 6, alt.xyaxes, text) ? 1 : 0) +
-             (ReadAttr(elem, "zaxis", 3, alt.zaxis, text) ? 1 : 0) +
-             (ReadAttr(elem, "euler", 3, alt.euler, text) ? 1 : 0);
-  if (read > 1) {
+  int numspec = (int)(elem->Attribute("quat") != 0);
+  if (ReadAttr(elem, "axisangle", 4, alt.axisangle, text)) {
+    numspec++;
+    alt.type = mjORIENTATION_AXISANGLE;
+  }
+  if (ReadAttr(elem, "xyaxes", 6, alt.xyaxes, text)) {
+    numspec++;
+    alt.type = mjORIENTATION_XYAXES;
+  }
+  if (ReadAttr(elem, "zaxis", 3, alt.zaxis, text)) {
+    numspec++;
+    alt.type = mjORIENTATION_ZAXIS;
+  }
+  if (ReadAttr(elem, "euler", 3, alt.euler, text)) {
+    numspec++;
+    alt.type = mjORIENTATION_EULER;
+  }
+  if (numspec > 1) {
     throw mjXError(elem, "multiple orientation specifiers are not allowed");
   }
-  return read;
+  return numspec;
 }

src/xml/xml_urdf.cc

@@ -635,6 +635,7 @@ void mjXURDF::Origin(XMLElement* origin_elem, double* pos, double* quat) {
     mjsOrientation alt;
     mjs_defaultOrientation(alt);
     if (ReadAttr(temp, "rpy", 3, alt.euler, text)) {
+      alt.type = mjORIENTATION_EULER;
       mjs_resolveOrientation(quat, 0, "XYZ", &alt);
     }
   }