Explicitly specify actdim on PID plugin actuators, to allow them to be used with keyframes.

Support actdim attribute on plugin actuators.

Remove the actuator_actdim callback. This callback leads to crashes when loading keyframes for models that have a stateful plugin.

PiperOrigin-RevId: 650649505
Change-Id: I40d1994d02ae4e20ce631b2702a984766cf2628e

src/user/user_model.cc

@@ -1343,7 +1343,7 @@ void mjCModel::SetSizes() {
   // nu, na
   for (int i=0; i<actuators_.size(); i++) {
     nu++;
-    na += actuators_[i]->actdim + actuators_[i]->plugin_actdim;
+    na += actuators_[i]->actdim;
   }
 
   // nbvh, nbvhstatic, nbvhdynamic
@@ -2639,7 +2639,7 @@ void mjCModel::CopyObjects(mjModel* m) {
     m->actuator_biastype[i] = pac->biastype;
     m->actuator_trnid[2*i] = pac->trnid[0];
     m->actuator_trnid[2*i+1] = pac->trnid[1];
-    m->actuator_actnum[i] = pac->actdim + pac->plugin_actdim;
+    m->actuator_actnum[i] = pac->actdim;
     m->actuator_actadr[i] = m->actuator_actnum[i] ? adr : -1;
     pac->actadr_ = m->actuator_actadr[i];
     pac->actnum_ = m->actuator_actnum[i];
@@ -3535,13 +3535,6 @@ void mjCModel::TryCompile(mjModel*& m, mjData*& d, const mjVFS* vfs) {
           this->nsensordata += nsensordata;
         }
       }
-      if ((plugin->capabilityflags & mjPLUGIN_ACTUATOR) && plugin->actuator_actdim) {
-        for (int actuator_id : plugin_to_actuators[i]) {
-          int plugin_actdim = plugin->actuator_actdim(m, i, actuator_id);
-          actuators_[actuator_id]->plugin_actdim = plugin_actdim;
-          this->na += plugin_actdim;
-        }
-      }
     }
     m->npluginstate = stateadr;
   }

src/user/user_objects.cc

@@ -5208,14 +5208,16 @@ void mjCActuator::Compile(void) {
   }
 
   // check and set actdim
-  if (actdim > 1 && dyntype != mjDYN_USER) {
-    throw mjCError(this, "actdim > 1 is only allowed for dyntype 'user' in actuator");
-  }
-  if (actdim == 1 && dyntype == mjDYN_NONE) {
-    throw mjCError(this, "invalid actdim 1 in stateless actuator");
-  }
-  if (actdim == 0 && dyntype != mjDYN_NONE) {
-    throw mjCError(this, "invalid actdim 0 in stateful actuator");
+  if (!plugin.active) {
+    if (actdim > 1 && dyntype != mjDYN_USER) {
+      throw mjCError(this, "actdim > 1 is only allowed for dyntype 'user' in actuator");
+    }
+    if (actdim == 1 && dyntype == mjDYN_NONE) {
+      throw mjCError(this, "invalid actdim 1 in stateless actuator");
+    }
+    if (actdim == 0 && dyntype != mjDYN_NONE) {
+      throw mjCError(this, "invalid actdim 0 in stateful actuator");
+    }
   }
 
   // set actdim

src/xml/xml_native_reader.cc

@@ -423,10 +423,11 @@ const char* MJCF[nMJCF][mjXATTRNUM] = {
             "lmin", "lmax", "vmax", "fpmax", "fvmax"},
         {"adhesion", "*", "9", "name", "class", "group",
             "forcelimited", "ctrlrange", "forcerange", "user", "body", "gain"},
-        {"plugin", "*", "24", "name", "class",  "plugin", "instance", "group",
+        {"plugin", "*", "25", "name", "class",  "plugin", "instance", "group",
             "ctrllimited", "forcelimited", "actlimited", "ctrlrange", "forcerange", "actrange",
             "lengthrange", "gear", "cranklength", "joint", "jointinparent",
-            "site", "dyntype", "dynprm", "tendon", "cranksite", "slidersite", "user", "actearly"},
+            "site", "actdim", "dyntype", "dynprm", "tendon", "cranksite", "slidersite", "user",
+            "actearly"},
         {"<"},
           {"config", "*", "2", "key", "value"},
         {">"},
@@ -2234,6 +2235,7 @@ void mjXReader::OneActuator(XMLElement* elem, mjsActuator* pact) {
       pact->actearly = (n==1);
     }
     ReadAttr(elem, "dynprm", mjNDYN, pact->dynprm, text, false, false);
+    ReadAttrInt(elem, "actdim", &pact->actdim);
   }
 
   else {          // SHOULD NOT OCCUR

src/xml/xml_native_writer.cc

@@ -757,6 +757,13 @@ void mjXWriter::OneActuator(XMLElement* elem, const mjCActuator* pact, mjCDef* d
   WriteAttr(elem, "cranklength", 1, &pact->cranklength, &def->Actuator().cranklength);
   WriteAttrKey(elem, "actearly", bool_map, 2, pact->actearly,
                def->Actuator().actearly);
+  // special handling of actdim which has default value of -1
+  if (writingdefaults) {
+    WriteAttrInt(elem, "actdim", pact->actdim, def->Actuator().actdim);
+  } else {
+    int default_actdim = pact->dyntype == mjDYN_NONE ? 0 : 1;
+    WriteAttrInt(elem, "actdim", pact->actdim, default_actdim);
+  }
   WriteAttrKey(elem, "dyntype", dyn_map, dyn_sz, pact->dyntype, def->Actuator().dyntype);
   WriteAttr(elem, "dynprm", mjNDYN, pact->dynprm, def->Actuator().dynprm);
 
@@ -767,13 +774,6 @@ void mjXWriter::OneActuator(XMLElement* elem, const mjCActuator* pact, mjCDef* d
 
   // non-plugins: write actuator parameters
   else {
-    // special handling of actdim which has default value of -1
-    if (writingdefaults) {
-      WriteAttrInt(elem, "actdim", pact->actdim, def->Actuator().actdim);
-    } else {
-      int default_actdim = pact->dyntype == mjDYN_NONE ? 0 : 1;
-      WriteAttrInt(elem, "actdim", pact->actdim, default_actdim);
-    }
     WriteAttrKey(elem, "gaintype", gain_map, gain_sz, pact->gaintype, def->Actuator().gaintype);
     WriteAttrKey(elem, "biastype", bias_map, bias_sz, pact->biastype, def->Actuator().biastype);
     WriteAttr(elem, "gainprm", mjNGAIN, pact->gainprm, def->Actuator().gainprm, true);