Fix type errors in engine and plugins.

- Preparation for a float32 build of MuJoCo.
- Fix use of `float`-typed `fabs` in `mju_eig3`.

PiperOrigin-RevId: 643804942
Change-Id: I89f64e8fd39f4e70e78d7607816283e217912383

doc/includes/references.h

@@ -1436,7 +1436,7 @@ struct mjpPlugin_ {
   void (*copy)(mjData* dest, const mjModel* m, const mjData* src, int instance);
 
   // called when an mjData is being reset (required)
-  void (*reset)(const mjModel* m, double* plugin_state, void* plugin_data, int instance);
+  void (*reset)(const mjModel* m, mjtNum* plugin_state, void* plugin_data, int instance);
 
   // called when the plugin needs to update its outputs (required)
   void (*compute)(const mjModel* m, mjData* d, int instance, int capability_bit);

include/mujoco/mjplugin.h

@@ -99,7 +99,7 @@ struct mjpPlugin_ {
   void (*copy)(mjData* dest, const mjModel* m, const mjData* src, int instance);
 
   // called when an mjData is being reset (required)
-  void (*reset)(const mjModel* m, double* plugin_state, void* plugin_data, int instance);
+  void (*reset)(const mjModel* m, mjtNum* plugin_state, void* plugin_data, int instance);
 
   // called when the plugin needs to update its outputs (required)
   void (*compute)(const mjModel* m, mjData* d, int instance, int capability_bit);

plugin/actuator/pid.cc

@@ -256,7 +256,7 @@ void Pid::RegisterPlugin() {
     delete reinterpret_cast<Pid*>(d->plugin_data[instance]);
     d->plugin_data[instance] = 0;
   };
-  plugin.reset = +[](const mjModel* m, double* plugin_state, void* plugin_data,
+  plugin.reset = +[](const mjModel* m, mjtNum* plugin_state, void* plugin_data,
                      int instance) {
     auto* pid = reinterpret_cast<Pid*>(plugin_data);
     pid->Reset(plugin_state);

plugin/sdf/sdf.cc

@@ -104,8 +104,8 @@ void SdfVisualizer::Visualize(const mjModel* m, const mjData* d,
         if (k == 0) {
           float rgba[4] = {static_cast<float>(j > 0), 0,
                            static_cast<float>(j == 0), 1};
-          mjtNum size[] = {.2*m->stat.meansize};
-          mjv_initGeom(thisgeom, mjGEOM_SPHERE, size, from, geom_xmat, rgba);
+          mjtNum size = 0.2 * m->stat.meansize;
+          mjv_initGeom(thisgeom, mjGEOM_SPHERE, &size, from, geom_xmat, rgba);
         } else {
           mjv_initGeom(thisgeom, mjGEOM_NONE, NULL, NULL, NULL, NULL);
           thisgeom->objtype = mjOBJ_UNKNOWN;

plugin/sensor/touch_grid.cc

@@ -432,15 +432,17 @@ void TouchGrid::Visualize(const mjModel* m, mjData* d, const mjvOption* opt,
         return;
       } else {
         // size
-        mjtNum size[3] = {dist*0.5*(x_edges[i+1]-x_edges[i]),
-                          dist*0.5*(y_edges[j+1]-y_edges[j]),
-                          dist*kRelativeThickness};
+        mjtNum size[3];
+        size[0] = dist*0.5*(x_edges[i+1]-x_edges[i]);
+        size[1] = dist*0.5*(y_edges[j+1]-y_edges[j]);
+        size[2] = dist*kRelativeThickness;
 
         // position
         mjtNum pos[3];
-        mjtNum aer[3] = {0.5*(x_edges[i+1]+x_edges[i]),
-                         0.5*(y_edges[j+1]+y_edges[j]),
-                         dist*(1-kRelativeThickness)};
+        mjtNum aer[3];
+        aer[0] = 0.5*(x_edges[i+1]+x_edges[i]);
+        aer[1] = 0.5*(y_edges[j+1]+y_edges[j]);
+        aer[2] = dist*(1-kRelativeThickness);
         SphericalToCartesian(aer, pos);
         mju_mulMatVec3(pos, site_mat, pos);
         mju_addTo3(pos, site_pos);
@@ -525,7 +527,7 @@ void TouchGrid::RegisterPlugin() {
   };
 
   // Reset callback.
-  plugin.reset = +[](const mjModel* m, double* plugin_state, void* plugin_data,
+  plugin.reset = +[](const mjModel* m, mjtNum* plugin_state, void* plugin_data,
                      int instance) {
     auto* TouchGrid = reinterpret_cast<class TouchGrid*>(plugin_data);
     TouchGrid->Reset(m, instance);

src/engine/engine_util_solve.c

@@ -707,7 +707,7 @@ void mju_solveLUSparse(mjtNum* res, const mjtNum* LU, const mjtNum* vec, int n,
 //--------------------------- eigen decomposition --------------------------------------------------
 
 // eigenvalue decomposition of symmetric 3x3 matrix
-static const mjtNum eigEPS = 1E-12;
+static const mjtNum eigEPS = mjMINVAL * 1000;
 int mju_eig3(mjtNum eigval[3], mjtNum eigvec[9], mjtNum quat[4], const mjtNum mat[9]) {
   mjtNum D[9], tmp[9];
   mjtNum tau, t, c;
@@ -730,11 +730,11 @@ int mju_eig3(mjtNum eigval[3], mjtNum eigvec[9], mjtNum quat[4], const mjtNum ma
     eigval[2] = D[8];
 
     // find max off-diagonal element, set indices
-    if (fabs(D[1]) > fabs(D[2]) && fabs(D[1]) > fabs(D[5])) {
+    if (mju_abs(D[1]) > mju_abs(D[2]) && mju_abs(D[1]) > mju_abs(D[5])) {
       rk = 0;     // row
       ck = 1;     // column
       rotk = 2;   // rotation axis
-    } else if (fabs(D[2]) > fabs(D[5])) {
+    } else if (mju_abs(D[2]) > mju_abs(D[5])) {
       rk = 0;
       ck = 2;
       rotk = 1;
@@ -745,7 +745,7 @@ int mju_eig3(mjtNum eigval[3], mjtNum eigvec[9], mjtNum quat[4], const mjtNum ma
     }
 
     // terminate if max off-diagonal element too small
-    if (fabs(D[3*rk+ck]) < eigEPS) {
+    if (mju_abs(D[3*rk+ck]) < eigEPS) {
       break;
     }
 
@@ -789,7 +789,7 @@ int mju_eig3(mjtNum eigval[3], mjtNum eigvec[9], mjtNum quat[4], const mjtNum ma
       eigval[j1+1] = t;
 
       // rotate quaternion
-      tmp[0] = 0.707106781186548;     // mju_cos(pi/4) = mju_sin(pi/4)
+      tmp[0] = 0.707106781186548;  // = cos(pi/4) = sin(pi/4)
       tmp[1] = tmp[2] = tmp[3] = 0;
       tmp[(j1+2)%3+1] = tmp[0];
       mju_mulQuat(quat, quat, tmp);

src/engine/engine_util_spatial.c

@@ -522,7 +522,7 @@ void mju_euler2Quat(mjtNum quat[4], const mjtNum euler[3], const char* seq) {
   }
 
   // init
-  double tmp[4] = {1, 0, 0, 0};
+  mjtNum tmp[4] = {1, 0, 0, 0};
 
   // loop over euler angles, accumulate rotations
   for (int i=0; i<3; i++) {