Declare loop variables inside for loop in C++ files.

PiperOrigin-RevId: 518852339 Change-Id: I0174d873d89e48f11b816d337728f213c2798248
2023-03-23 07:21:46 -07:00
parent 145fe7f354
commit 0e7e299bf6
11 changed files with 375 additions and 447 deletions
@@ -139,8 +139,6 @@ const char help_title[] =
 // init profiler figures
 void profilerinit(mj::Simulate* sim) {
  int i, n;
  // set figures to default
  mjv_defaultFigure(&sim->figconstraint);
  mjv_defaultFigure(&sim->figcost);
@@ -225,8 +223,8 @@ void profilerinit(mj::Simulate* sim) {
  sim->figtimer.range[1][1] = 0.4f;
  // init x axis on history figures (do not show yet)
-  for (n=0; n<6; n++)
+  for (int n=0; n<6; n++)
-    for (i=0; i<mjMAXLINEPNT; i++) {
+    for (int i=0; i<mjMAXLINEPNT; i++) {
      sim->figtimer.linedata[n][2*i] = -i;
      sim->figsize.linedata[n][2*i] = -i;
    }
@@ -234,11 +232,9 @@ void profilerinit(mj::Simulate* sim) {
 // update profiler figures
 void profilerupdate(mj::Simulate* sim) {
  int i, n;
  // update constraint figure
  sim->figconstraint.linepnt[0] = mjMIN(mjMIN(sim->d->solver_iter, mjNSOLVER), mjMAXLINEPNT);
-  for (i=1; i<5; i++) {
+  for (int i=1; i<5; i++) {
    sim->figconstraint.linepnt[i] = sim->figconstraint.linepnt[0];
  }
  if (sim->m->opt.solver==mjSOL_PGS) {
@@ -248,7 +244,7 @@ void profilerupdate(mj::Simulate* sim) {
  if (sim->m->opt.solver==mjSOL_CG) {
    sim->figconstraint.linepnt[4] = 0;
  }
-  for (i=0; i<sim->figconstraint.linepnt[0]; i++) {
+  for (int i=0; i<sim->figconstraint.linepnt[0]; i++) {
    // x
    sim->figconstraint.linedata[0][2*i] = i;
    sim->figconstraint.linedata[1][2*i] = i;
@@ -266,7 +262,7 @@ void profilerupdate(mj::Simulate* sim) {
  // update cost figure
  sim->figcost.linepnt[0] = mjMIN(mjMIN(sim->d->solver_iter, mjNSOLVER), mjMAXLINEPNT);
-  for (i=1; i<3; i++) {
+  for (int i=1; i<3; i++) {
    sim->figcost.linepnt[i] = sim->figcost.linepnt[0];
  }
  if (sim->m->opt.solver==mjSOL_PGS) {
@@ -274,7 +270,7 @@ void profilerupdate(mj::Simulate* sim) {
    sim->figcost.linepnt[2] = 0;
  }
-  for (i=0; i<sim->figcost.linepnt[0]; i++) {
+  for (int i=0; i<sim->figcost.linepnt[0]; i++) {
    // x
    sim->figcost.linedata[0][2*i] = i;
    sim->figcost.linedata[1][2*i] = i;
@@ -306,9 +302,9 @@ void profilerupdate(mj::Simulate* sim) {
  // update figtimer
  int pnt = mjMIN(201, sim->figtimer.linepnt[0]+1);
-  for (n=0; n<5; n++) {
+  for (int n=0; n<5; n++) {
    // shift data
-    for (i=pnt-1; i>0; i--) {
+    for (int i=pnt-1; i>0; i--) {
      sim->figtimer.linedata[n][2*i+1] = sim->figtimer.linedata[n][2*i-1];
    }
@@ -329,9 +325,9 @@ void profilerupdate(mj::Simulate* sim) {
  // update figsize
  pnt = mjMIN(201, sim->figsize.linepnt[0]+1);
-  for (n=0; n<6; n++) {
+  for (int n=0; n<6; n++) {
    // shift data
-    for (i=pnt-1; i>0; i--) {
+    for (int i=pnt-1; i>0; i--) {
      sim->figsize.linedata[n][2*i+1] = sim->figsize.linedata[n][2*i-1];
    }
@@ -542,7 +538,6 @@ void watch(mj::Simulate* sim) {
 // make physics section of UI
 void makephysics(mj::Simulate* sim, int oldstate) {
  int i;
  mjOption& opt = sim->m->opt;
  mjuiDef defPhysics[] = {
@@ -591,13 +586,13 @@ void makephysics(mj::Simulate* sim, int oldstate) {
    {mjITEM_CHECKINT,  "", 2, nullptr, ""},
    {mjITEM_END}
  };
-  for (i=0; i<mjNDISABLE; i++) {
+  for (int i=0; i<mjNDISABLE; i++) {
    mju::strcpy_arr(defFlag[0].name, mjDISABLESTRING[i]);
    defFlag[0].pdata = sim->disable + i;
    mjui_add(&sim->ui0, defFlag);
  }
  mjui_add(&sim->ui0, defEnableFlags);
-  for (i=0; i<mjNENABLE; i++) {
+  for (int i=0; i<mjNENABLE; i++) {
    mju::strcpy_arr(defFlag[0].name, mjENABLESTRING[i]);
    defFlag[0].pdata = sim->enable + i;
    mjui_add(&sim->ui0, defFlag);
@@ -611,8 +606,6 @@ void makephysics(mj::Simulate* sim, int oldstate) {
 // make rendering section of UI
 void makerendering(mj::Simulate* sim, int oldstate) {
  int i, j;
  mjuiDef defRendering[] = {
    {
      mjITEM_SECTION,
@@ -665,7 +658,7 @@ void makerendering(mj::Simulate* sim, int oldstate) {
  };
  // add model cameras, up to UI limit
-  for (i=0; i<mjMIN(sim->m->ncam, mjMAXUIMULTI-2); i++) {
+  for (int i=0; i<mjMIN(sim->m->ncam, mjMAXUIMULTI-2); i++) {
    // prepare name
    char camname[mjMAXUITEXT] = "\n";
    if (sim->m->names[sim->m->name_camadr[i]]) {
@@ -691,10 +684,10 @@ void makerendering(mj::Simulate* sim, int oldstate) {
    {mjITEM_CHECKBYTE,  "", 2, nullptr, ""},
    {mjITEM_END}
  };
-  for (i=0; i<mjNVISFLAG; i++) {
+  for (int i=0; i<mjNVISFLAG; i++) {
    // set name, remove "&"
    mju::strcpy_arr(defFlag[0].name, mjVISSTRING[i][0]);
-    for (j=0; j<strlen(mjVISSTRING[i][0]); j++)
+    for (int j=0; j<strlen(mjVISSTRING[i][0]); j++)
      if (mjVISSTRING[i][0][j]=='&') {
        mju_strncpy(
          defFlag[0].name+j, mjVISSTRING[i][0]+j+1, mju::sizeof_arr(defFlag[0].name)-j);
@@ -718,7 +711,7 @@ void makerendering(mj::Simulate* sim, int oldstate) {
  mjui_add(&sim->ui0, defTree);
  mjui_add(&sim->ui0, defOpenGL);
-  for (i=0; i<mjNRNDFLAG; i++) {
+  for (int i=0; i<mjNRNDFLAG; i++) {
    mju::strcpy_arr(defFlag[0].name, mjRNDSTRING[i][0]);
    if (mjRNDSTRING[i][2][0]) {
      mju::sprintf_arr(defFlag[0].other, " %s", mjRNDSTRING[i][2]);
@@ -788,7 +781,6 @@ void makegroup(mj::Simulate* sim, int oldstate) {
 // make joint section of UI
 void makejoint(mj::Simulate* sim, int oldstate) {
  int i;
  mjuiDef defJoint[] = {
    {mjITEM_SECTION, "Joint", oldstate, nullptr, "AJ"},
@@ -805,7 +797,7 @@ void makejoint(mj::Simulate* sim, int oldstate) {
  // add scalar joints, exit if UI limit reached
  int itemcnt = 0;
-  for (i=0; i<sim->m->njnt && itemcnt<mjMAXUIITEM; i++)
+  for (int i=0; i<sim->m->njnt && itemcnt<mjMAXUIITEM; i++)
    if ((sim->m->jnt_type[i]==mjJNT_HINGE || sim->m->jnt_type[i]==mjJNT_SLIDE)) {
      // skip if joint group is disabled
      if (!sim->vopt.jointgroup[mjMAX(0, mjMIN(mjNGROUP-1, sim->m->jnt_group[i]))]) {
@@ -838,8 +830,6 @@ void makejoint(mj::Simulate* sim, int oldstate) {
 // make control section of UI
 void makecontrol(mj::Simulate* sim, int oldstate) {
  int i;
  mjuiDef defControl[] = {
    {mjITEM_SECTION, "Control", oldstate, nullptr, "AC"},
    {mjITEM_BUTTON,  "Clear all", 2},
@@ -856,7 +846,7 @@ void makecontrol(mj::Simulate* sim, int oldstate) {
  // add controls, exit if UI limit reached (Clear button already added)
  int itemcnt = 1;
-  for (i=0; i<sim->m->nu && itemcnt<mjMAXUIITEM; i++) {
+  for (int i=0; i<sim->m->nu && itemcnt<mjMAXUIITEM; i++) {
    // skip if actuator group is disabled
    if (!sim->vopt.actuatorgroup[mjMAX(0, mjMIN(mjNGROUP-1, sim->m->actuator_group[i]))]) {
      continue;
@@ -886,11 +876,9 @@ void makecontrol(mj::Simulate* sim, int oldstate) {
 // make model-dependent UI sections
 void makesections(mj::Simulate* sim) {
  int i;
  // get section open-close state, UI 0
  int oldstate0[NSECT0];
-  for (i=0; i<NSECT0; i++) {
+  for (int i=0; i<NSECT0; i++) {
    oldstate0[i] = 0;
    if (sim->ui0.nsect>i) {
      oldstate0[i] = sim->ui0.sect[i].state;
@@ -899,7 +887,7 @@ void makesections(mj::Simulate* sim) {
  // get section open-close state, UI 1
  int oldstate1[NSECT1];
-  for (i=0; i<NSECT1; i++) {
+  for (int i=0; i<NSECT1; i++) {
    oldstate1[i] = 0;
    if (sim->ui1.nsect>i) {
      oldstate1[i] = sim->ui1.sect[i].state;
@@ -985,13 +973,11 @@ void copycamera(mj::Simulate* sim) {
 // update UI 0 when MuJoCo structures change (except for joint sliders)
 void updatesettings(mj::Simulate* sim) {
  int i;
  // physics flags
-  for (i=0; i<mjNDISABLE; i++) {
+  for (int i=0; i<mjNDISABLE; i++) {
    sim->disable[i] = ((sim->m->opt.disableflags & (1<<i)) !=0);
  }
-  for (i=0; i<mjNENABLE; i++) {
+  for (int i=0; i<mjNENABLE; i++) {
    sim->enable[i] = ((sim->m->opt.enableflags & (1<<i)) !=0);
  }
@@ -1094,7 +1080,6 @@ void uiEvent(mjuiState* state) {
  mj::Simulate* sim = static_cast<mj::Simulate*>(state->userdata);
  mjModel* m = sim->m;
  mjData* d = sim->d;
  int i;
  char err[200];
  // call UI 0 if event is directed to it
@@ -1202,22 +1187,25 @@ void uiEvent(mjuiState* state) {
      case 5:             // Adjust key
      case 6:             // Load key
-        i = sim->key;
+      {
        int i = sim->key;
        d->time = m->key_time[i];
-        mju_copy(d->qpos, m->key_qpos+i*m->nq, m->nq);
+        mju_copy(d->qpos, m->key_qpos + i * m->nq, m->nq);
-        mju_copy(d->qvel, m->key_qvel+i*m->nv, m->nv);
+        mju_copy(d->qvel, m->key_qvel + i * m->nv, m->nv);
-        mju_copy(d->act, m->key_act+i*m->na, m->na);
+        mju_copy(d->act, m->key_act + i * m->na, m->na);
-        mju_copy(d->mocap_pos, m->key_mpos+i*3*m->nmocap, 3*m->nmocap);
+        mju_copy(d->mocap_pos, m->key_mpos + i * 3 * m->nmocap, 3 * m->nmocap);
-        mju_copy(d->mocap_quat, m->key_mquat+i*4*m->nmocap, 4*m->nmocap);
+        mju_copy(d->mocap_quat, m->key_mquat + i * 4 * m->nmocap,
-        mju_copy(d->ctrl, m->key_ctrl+i*m->nu, m->nu);
+                 4 * m->nmocap);
        mju_copy(d->ctrl, m->key_ctrl + i * m->nu, m->nu);
        mj_forward(m, d);
        profilerupdate(sim);
        sensorupdate(sim);
        updatesettings(sim);
-        break;
+      } break;
      case 7:             // Save key
-        i = sim->key;
+      {
        int i = sim->key;
        m->key_time[i] = d->time;
        mju_copy(m->key_qpos+i*m->nq, d->qpos, m->nq);
        mju_copy(m->key_qvel+i*m->nv, d->qvel, m->nv);
@@ -1225,7 +1213,7 @@ void uiEvent(mjuiState* state) {
        mju_copy(m->key_mpos+i*3*m->nmocap, d->mocap_pos, 3*m->nmocap);
        mju_copy(m->key_mquat+i*4*m->nmocap, d->mocap_quat, 4*m->nmocap);
        mju_copy(m->key_ctrl+i*m->nu, d->ctrl, m->nu);
-        break;
+      } break;
      }
    }
@@ -1233,14 +1221,14 @@ void uiEvent(mjuiState* state) {
    else if (it && it->sectionid==SECT_PHYSICS) {
      // update disable flags in mjOption
      m->opt.disableflags = 0;
-      for (i=0; i<mjNDISABLE; i++)
+      for (int i=0; i<mjNDISABLE; i++)
        if (sim->disable[i]) {
          m->opt.disableflags |= (1<<i);
        }
      // update enable flags in mjOption
      m->opt.enableflags = 0;
-      for (i=0; i<mjNENABLE; i++)
+      for (int i=0; i<mjNENABLE; i++)
        if (sim->enable[i]) {
          m->opt.enableflags |= (1<<i);
        }
@@ -122,11 +122,9 @@ bool mjCComposite::AddDefaultJoint(char* error, int error_sz) {
 // set defaults, after reading top-level info and skin
 void mjCComposite::SetDefault(void) {
  int i;
  // determine dimensionality
  int tmpdim = 0;
-  for (i=0; i<3; i++) {
+  for (int i=0; i<3; i++) {
    if (count[i]>1) {
      tmpdim++;
    }
@@ -149,7 +147,7 @@ void mjCComposite::SetDefault(void) {
      type==mjCOMPTYPE_LOOP       ||
      type==mjCOMPTYPE_CABLE      ||
      (type==mjCOMPTYPE_GRID && tmpdim==1)) {
-    for (i=0; i<mjNCOMPKINDS; i++) {
+    for (int i=0; i<mjNCOMPKINDS; i++) {
      def[i].geom.group = 0;
      def[i].tendon.group = 0;
    }
@@ -196,7 +194,7 @@ void mjCComposite::SetDefault(void) {
    AdjustSoft(solrefsmooth, solimpsmooth, 1);
    // soft fix everywhere
-    for (i=0; i<mjNCOMPKINDS; i++) {
+    for (int i=0; i<mjNCOMPKINDS; i++) {
      AdjustSoft(def[i].equality.solref, def[i].equality.solimp, 1);
    }
@@ -1173,7 +1171,6 @@ void mjCComposite::BoxProject(double* pos) {
 // make 3d box, ellipsoid or cylinder
 bool mjCComposite::MakeBox(mjCModel* model, mjCBody* body, char* error, int error_sz) {
  int ix, iy, iz;
  char txt[100];
  // check dim
@@ -1199,9 +1196,9 @@ bool mjCComposite::MakeBox(mjCModel* model, mjCBody* body, char* error, int erro
  ten->name = txt;
  // create bodies, geoms and joints: outside shell only
-  for (ix=0; ix<count[0]; ix++) {
+  for (int ix=0; ix<count[0]; ix++) {
-    for (iy=0; iy<count[1]; iy++) {
+    for (int iy=0; iy<count[1]; iy++) {
-      for (iz=0; iz<count[2]; iz++) {
+      for (int iz=0; iz<count[2]; iz++) {
        if (ix==0 || ix==count[0]-1 ||
            iy==0 || iy==count[1]-1 ||
            iz==0 || iz==count[2]-1) {
@@ -1297,11 +1294,10 @@ bool mjCComposite::MakeBox(mjCModel* model, mjCBody* body, char* error, int erro
 // add shear tendons to 2D
 void mjCComposite::MakeShear(mjCModel* model) {
  int ix, iy;
  char txt[100], txt1[100], txt2[100];
-  for (ix=0; ix<count[0]-1; ix++) {
+  for (int ix=0; ix<count[0]-1; ix++) {
-    for (iy=0; iy<count[1]-1; iy++) {
+    for (int iy=0; iy<count[1]-1; iy++) {
      // recover site names
      mju::sprintf_arr(txt1, "%sS%d_%d", prefix.c_str(), ix, iy);
      mju::sprintf_arr(txt2, "%sS%d_%d", prefix.c_str(), ix+1, iy+1);
@@ -2188,12 +2184,11 @@ void mjCComposite::MakeSkin3(mjCModel* model) {
 // make one face of 3D skin, box
 void mjCComposite::MakeSkin3Box(mjCSkin* skin, int c0, int c1, int side,
                                int& vcnt, const char* format) {
  int i0, i1;
  char txt[100];
  // loop over bodies/vertices of specified face
-  for (i0=0; i0<c0; i0++) {
+  for (int i0=0; i0<c0; i0++) {
-    for (i1=0; i1<c1; i1++) {
+    for (int i1=0; i1<c1; i1++) {
      // vertex
      skin->vert.push_back(0);
      skin->vert.push_back(0);
@@ -2248,12 +2243,11 @@ void mjCComposite::MakeSkin3Box(mjCSkin* skin, int c0, int c1, int side,
 // make one face of 3D skin, smooth
 void mjCComposite::MakeSkin3Smooth(mjCSkin* skin, int c0, int c1, int side,
                                   const std::map<string, int>& vmap, const char* format) {
  int i0, i1;
  char txt00[100], txt01[100], txt10[100], txt11[100];
  // loop over bodies/vertices of specified face
-  for (i0=0; i0<c0; i0++) {
+  for (int i0=0; i0<c0; i0++) {
-    for (i1=0; i1<c1; i1++) {
+    for (int i1=0; i1<c1; i1++) {
      // body names
      mju::sprintf_arr(txt00, format, prefix.c_str(), i0, i1);
      mju::sprintf_arr(txt01, format, prefix.c_str(), i0, i1+1);
@@ -387,8 +387,6 @@ double* mjCMesh::GetQuatPtr(mjtMeshType type) {
 // set geom size to match mesh
 void mjCMesh::FitGeom(mjCGeom* geom, double* meshpos) {
  int i;
  // copy mesh pos into meshpos
  mjuu_copyvec(meshpos, GetPosPtr(geom->typeinertia), 3);
@@ -438,7 +436,7 @@ void mjCMesh::FitGeom(mjCGeom* geom, double* meshpos) {
    case mjGEOM_SPHERE:
      // find maximum distance
      geom->size[0] = 0;
-      for (i=0; i<nvert; i++) {
+      for (int i=0; i<nvert; i++) {
        double v[3] = {vert[3*i], vert[3*i+1], vert[3*i+2]};
        double dst = mjuu_dist3(v, cen);
        geom->size[0] = mjMAX(geom->size[0], dst);
@@ -450,7 +448,7 @@ void mjCMesh::FitGeom(mjCGeom* geom, double* meshpos) {
      // find maximum distance in XY, separately in Z
      geom->size[0] = 0;
      geom->size[1] = 0;
-      for (i=0; i<nvert; i++) {
+      for (int i=0; i<nvert; i++) {
        double v[3] = {vert[3*i], vert[3*i+1], vert[3*i+2]};
        double dst = sqrt((v[0]-cen[0])*(v[0]-cen[0]) +
                          (v[1]-cen[1])*(v[1]-cen[1]));
@@ -464,7 +462,7 @@ void mjCMesh::FitGeom(mjCGeom* geom, double* meshpos) {
      // special handling of capsule: consider curved cap
      if (geom->type==mjGEOM_CAPSULE) {
        geom->size[1] = 0;
-        for (i=0; i<nvert; i++) {
+        for (int i=0; i<nvert; i++) {
          // get distance in XY and Z
          double v[3] = {vert[3*i], vert[3*i+1], vert[3*i+2]};
          double dst = sqrt((v[0]-cen[0])*(v[0]-cen[0]) +
@@ -515,13 +513,12 @@ quicksortfunc(vertcompare, context, el1, el2) {
 // remove repeated vertices
 void mjCMesh::RemoveRepeated() {
  int i, j;
  int repeated = 0;
  // allocate sort and redirection indices, set to identity
  auto index = std::unique_ptr<int[]>(new int[nvert]);
  auto redirect = std::unique_ptr<int[]>(new int[nvert]);
-  for (i=0; i < nvert; i++) {
+  for (int i=0; i < nvert; i++) {
    index[i] = redirect[i] = i;
  }
@@ -529,7 +526,7 @@ void mjCMesh::RemoveRepeated() {
  mjQUICKSORT(index.get(), nvert, sizeof(int), vertcompare, vert);
  // find repeated vertices, set redirect
-  for (i=1; i < nvert; i++) {
+  for (int i=1; i < nvert; i++) {
    if (vert[3*index[i]] == vert[3*index[i-1]] &&
        vert[3*index[i]+1] == vert[3*index[i-1]+1] &&
        vert[3*index[i]+2] == vert[3*index[i-1]+2]) {
@@ -541,8 +538,8 @@ void mjCMesh::RemoveRepeated() {
  // compress vertices, change face data
  if (repeated) {
    // track redirections until non-redirected vertex, set
-    for (i=0; i<nvert; i++) {
+    for (int i=0; i<nvert; i++) {
-      j = i;
+      int j = i;
      while (redirect[j]!=j) {
        j = redirect[j];
      }
@@ -550,8 +547,8 @@ void mjCMesh::RemoveRepeated() {
    }
    // find good vertices, compress, reuse index to save compressed position
-    j = 0;
+    int j = 0;
-    for (i=0; i<nvert; i++) {
+    for (int i=0; i<nvert; i++) {
      if (redirect[i]==i) {
        index[i] = j;
        memcpy(vert+3*j, vert+3*i, 3*sizeof(float));
@@ -562,7 +559,7 @@ void mjCMesh::RemoveRepeated() {
    }
    // recompute face data to reflect compressed vertices
-    for (i=0; i<3*nface; i++) {
+    for (int i=0; i<3*nface; i++) {
      face[i] = index[redirect[face[i]]];
      // sanity check, SHOULD NOT OCCUR
@@ -908,9 +905,8 @@ void mjCMesh::LoadMSH(const mjVFS* vfs) {
  // rearange face data if left-handed scaling
  if (nface && !righthand) {
-    int i, tmp;
+    for (int i=0; i<nface; i++) {
-    for (i=0; i<nface; i++) {
+      int tmp = face[3*i+1];
      tmp = face[3*i+1];
      face[3*i+1] = face[3*i+2];
      face[3*i+2] = tmp;
    }
@@ -932,7 +928,6 @@ void mjCMesh::Process() {
    double area = 0;
    double inert[6] = {0, 0, 0, 0, 0, 0};
    int i, j;
    double nrm[3];
    double cen[3];
@@ -943,7 +938,7 @@ void mjCMesh::Process() {
        float rp[3] = {(float)refpos[0], (float)refpos[1], (float)refpos[2]};
        // process vertices
-        for (i=0; i<nvert; i++) {
+        for (int i=0; i<nvert; i++) {
          vert[3*i] -= rp[0];
          vert[3*i+1] -= rp[1];
          vert[3*i+2] -= rp[2];
@@ -959,7 +954,7 @@ void mjCMesh::Process() {
        mju_quat2Mat(mat, quat);
        // process vertices
-        for (i=0; i<nvert; i++) {
+        for (int i=0; i<nvert; i++) {
          mjtNum p1[3], p0[3] = {vert[3*i], vert[3*i+1], vert[3*i+2]};
          mju_rotVecMatT(p1, p0, mat);
          vert[3*i] = (float) p1[0];
@@ -968,7 +963,7 @@ void mjCMesh::Process() {
        }
        // process normals
-        for (i=0; i<nnormal; i++) {
+        for (int i=0; i<nnormal; i++) {
          mjtNum n1[3], n0[3] = {normal[3*i], normal[3*i+1], normal[3*i+2]};
          mju_rotVecMatT(n1, n0, mat);
          normal[3*i] = (float) n1[0];
@@ -979,13 +974,13 @@ void mjCMesh::Process() {
      // scale
      if (scale[0]!=1 || scale[1]!=1 || scale[2]!=1) {
-        for (i=0; i<nvert; i++) {
+        for (int i=0; i<nvert; i++) {
          vert[3*i] *= scale[0];
          vert[3*i+1] *= scale[1];
          vert[3*i+2] *= scale[2];
        }
-        for (i=0; i<nnormal; i++) {
+        for (int i=0; i<nnormal; i++) {
          normal[3*i] *= scale[0];
          normal[3*i+1] *= scale[1];
          normal[3*i+2] *= scale[2];
@@ -993,7 +988,7 @@ void mjCMesh::Process() {
      }
      // normalize normals
-      for (i=0; i<nnormal; i++) {
+      for (int i=0; i<nnormal; i++) {
        // compute length
        float len = normal[3*i]*normal[3*i] + normal[3*i+1]*normal[3*i+1] + normal[3*i+2]*normal[3*i+2];
@@ -1011,9 +1006,9 @@ void mjCMesh::Process() {
      }
      // find centroid of faces
-      for (i=0; i<nface; i++) {
+      for (int i=0; i<nface; i++) {
        // check vertex indices
-        for (j=0; j<3; j++) {
+        for (int j=0; j<3; j++) {
          if (face[3*i+j]<0 || face[3*i+j]>=nvert) {
            throw mjCError(this, "vertex index out of range in %s (index = %d)", name.c_str(), i);
          }
@@ -1023,7 +1018,7 @@ void mjCMesh::Process() {
        double a = _triangle(nrm, cen, vert+3*face[3*i], vert+3*face[3*i+1], vert+3*face[3*i+2]);
        // accumulate
-        for (j=0; j<3; j++) {
+        for (int j=0; j<3; j++) {
          facecen[j] += a*cen[j];
        }
        area += a;
@@ -1036,14 +1031,14 @@ void mjCMesh::Process() {
      }
      // finalize centroid of faces
-      for (j=0; j<3; j++) {
+      for (int j=0; j<3; j++) {
        facecen[j] /= area;
      }
    }
    // compute CoM and volume from pyramid volumes
    GetVolumeRef(type) = 0;
-    for (i=0; i<nface; i++) {
+    for (int i=0; i<nface; i++) {
      // get area, normal and center
      double a = _triangle(nrm, cen, vert+3*face[3*i], vert+3*face[3*i+1], vert+3*face[3*i+2]);
@@ -1058,7 +1053,7 @@ void mjCMesh::Process() {
      // add pyramid com
      GetVolumeRef(type) += vol;
-      for (j=0; j<3; j++) {
+      for (int j=0; j<3; j++) {
        CoM[j] += vol*(cen[j]*3.0/4.0 + facecen[j]/4.0);
      }
    }
@@ -1070,15 +1065,15 @@ void mjCMesh::Process() {
    }
    // finalize CoM, save as mesh center
-    for (j=0; j<3; j++) {
+    for (int j=0; j<3; j++) {
      CoM[j] /= GetVolumeRef(type);
    }
    mjuu_copyvec(GetPosPtr(type), CoM, 3);
    // re-center mesh at CoM
    if (type==mjVOLUME_MESH) {
-      for (i=0; i<nvert; i++) {
+      for (int i=0; i<nvert; i++) {
-        for (j=0; j<3; j++) {
+        for (int j=0; j<3; j++) {
          vert[3*i+j] -= CoM[j];
        }
      }
@@ -1088,7 +1083,7 @@ void mjCMesh::Process() {
    const int k[6][2] = {{0, 0}, {1, 1}, {2, 2}, {0, 1}, {0, 2}, {1, 2}};
    double P[6] = {0, 0, 0, 0, 0, 0};
    GetVolumeRef(type) = 0;
-    for (i=0; i<nface; i++) {
+    for (int i=0; i<nface; i++) {
      float* D = vert+3*face[3*i];
      float* E = vert+3*face[3*i+1];
      float* F = vert+3*face[3*i+2];
@@ -1104,7 +1099,7 @@ void mjCMesh::Process() {
      // apply formula, accumulate
      GetVolumeRef(type) += vol;
-      for (j=0; j<6; j++) {
+      for (int j=0; j<6; j++) {
        P[j] += def->geom.density*vol /
                  (type==mjSHELL_MESH ? 12 : 20) * (
                  2*(D[k[j][0]] * D[k[j][1]] +
@@ -1153,7 +1148,7 @@ void mjCMesh::Process() {
    boxsz[2] = sqrt(6*(eigval[0]+eigval[1]-eigval[2])/mass)/2;
    // copy quat
-    for (j=0; j<4; j++) {
+    for (int j=0; j<4; j++) {
      GetQuatPtr(type)[j] = type == mjVOLUME_MESH ? quattmp[j] : GetQuatPtr(mjVOLUME_MESH)[j];
    }
@@ -1162,12 +1157,12 @@ void mjCMesh::Process() {
      double neg[4] = {quattmp[0], -quattmp[1], -quattmp[2], -quattmp[3]};
      double mat[9];
      mjuu_quat2mat(mat, neg);
-      for (i=0; i<nvert; i++) {
+      for (int i=0; i<nvert; i++) {
        // vertices
        const double vec[3] = {vert[3*i], vert[3*i+1], vert[3*i+2]};
        double res[3];
        mjuu_mulvecmat(res, vec, mat);
-        for (j=0; j<3; j++) {
+        for (int j=0; j<3; j++) {
          vert[3*i+j] = (float) res[j];
          // axis-aligned bounding box
@@ -1175,12 +1170,12 @@ void mjCMesh::Process() {
          aabb[j+3] = mjMAX(aabb[j+3], res[j]);
        }
      }
-      for (i=0; i<nnormal; i++) {
+      for (int i=0; i<nnormal; i++) {
        // normals
        const double nrm[3] = {normal[3*i], normal[3*i+1], normal[3*i+2]};
        double res[3];
        mjuu_mulvecmat(res, nrm, mat);
-        for (j=0; j<3; j++) {
+        for (int j=0; j<3; j++) {
          normal[3*i+j] = (float) res[j];
        }
      }
@@ -1225,7 +1220,7 @@ double& mjCMesh::GetVolumeRef(mjtMeshType type) {
 // make graph describing convex hull
 void mjCMesh::MakeGraph(void) {
-  int i, adr, ok, curlong, totlong, exitcode;
+  int adr, ok, curlong, totlong, exitcode;
  double* data;
  facetT* facet, **facetp;
  vertexT* vertex, *vertex1, **vertex1p;
@@ -1241,7 +1236,7 @@ void mjCMesh::MakeGraph(void) {
  if (!data) {
    throw mjCError(this, "could not allocate data for qhull");
  }
-  for (i=0; i<3*nvert; i++) {
+  for (int i=0; i<3*nvert; i++) {
    data[i] = (double)vert[i];
  }
@@ -1282,7 +1277,7 @@ void mjCMesh::MakeGraph(void) {
    int* face_globalid = graph + 2 + 3*numvert + 3*numface;
    // fill in graph data
-    i = adr = 0;
+    int i = adr = 0;
    ok = 1;
    FORALLvertices {
      // point id of this vertex, check
@@ -1380,9 +1375,10 @@ void mjCMesh::MakeGraph(void) {
    }
    // replace global ids with local ids in edge data
-    for (i=0; i<numvert+3*numface; i++) {
+    for (int i=0; i<numvert+3*numface; i++) {
      if (edge_localid[i]>=0) {
        // search vert_globalid for match
        int adr;
        for (adr=0; adr<numvert; adr++) {
          if (vert_globalid[adr]==edge_localid[i]) {
            edge_localid[i] = adr;
@@ -1428,10 +1424,9 @@ void mjCMesh::CopyGraph(void) {
  face = (int*) mju_malloc(3*nface*sizeof(int));
  // copy faces
-  int i, j;
+  for (int i=0; i<nface; i++) {
  for (i=0; i<nface; i++) {
    // address in graph
-    j = 2 + 3*numvert + 3*nface + 3*i;
+    int j = 2 + 3*numvert + 3*nface + 3*i;
    // copy
    face[3*i] = graph[j];
@@ -1444,8 +1439,6 @@ void mjCMesh::CopyGraph(void) {
 // compute vertex normals
 void mjCMesh::MakeNormal(void) {
  int i, j, k;
  // only if normal data is missing
  if (normal) {
    return;
@@ -1462,16 +1455,16 @@ void mjCMesh::MakeNormal(void) {
  }
  // loop over faces, accumulate vertex normals
-  for (i=0; i<nface; i++) {
+  for (int i=0; i<nface; i++) {
    // get vertex ids
    int vertid[3];
-    for (j=0; j<3; j++) {
+    for (int j=0; j<3; j++) {
      vertid[j] = face[3*i+j];
    }
    // get triangle edges
    mjtNum vec01[3], vec02[3];
-    for (j=0; j<3; j++) {
+    for (int j=0; j<3; j++) {
      vec01[j] = vert[3*vertid[1]+j] - vert[3*vertid[0]+j];
      vec02[j] = vert[3*vertid[2]+j] - vert[3*vertid[0]+j];
    }
@@ -1482,8 +1475,8 @@ void mjCMesh::MakeNormal(void) {
    mjtNum area = mju_normalize3(nrm);
    // add normal to each vertex with weight = area
-    for (j=0; j<3; j++) {
+    for (int j=0; j<3; j++) {
-      for (k=0; k<3; k++) {
+      for (int k=0; k<3; k++) {
        normal[3*vertid[j]+k] += nrm[k]*area;
      }
      facenormal[3*i+j] = vertid[j];
@@ -1497,16 +1490,16 @@ void mjCMesh::MakeNormal(void) {
    memset(nremove, 0, 3*nnormal*sizeof(float));
    // remove contributions from faces at large angles with vertex normal
-    for (i=0; i<nface; i++) {
+    for (int i=0; i<nface; i++) {
      // get vertex ids
      int vertid[3];
-      for (j=0; j<3; j++) {
+      for (int j=0; j<3; j++) {
        vertid[j] = face[3*i+j];
      }
      // get triangle edges
      mjtNum vec01[3], vec02[3];
-      for (j=0; j<3; j++) {
+      for (int j=0; j<3; j++) {
        vec01[j] = vert[3*vertid[1]+j] - vert[3*vertid[0]+j];
        vec02[j] = vert[3*vertid[2]+j] - vert[3*vertid[0]+j];
      }
@@ -1517,14 +1510,14 @@ void mjCMesh::MakeNormal(void) {
      mjtNum area = mju_normalize3(nrm);
      // compare to vertex normal, subtract contribution if dot product too small
-      for (j=0; j<3; j++) {
+      for (int j=0; j<3; j++) {
        // normalized vertex normal
        mjtNum vnrm[3] = {normal[3*vertid[j]], normal[3*vertid[j]+1], normal[3*vertid[j]+2]};
        mju_normalize3(vnrm);
        // dot too small: remove
        if (mju_dot3(nrm, vnrm)<0.8) {
-          for (k=0; k<3; k++) {
+          for (int k=0; k<3; k++) {
            nremove[3*vertid[j]+k] += nrm[k]*area;
          }
        }
@@ -1532,14 +1525,14 @@ void mjCMesh::MakeNormal(void) {
    }
    // apply removal, free nremove
-    for (i=0; i<3*nnormal; i++) {
+    for (int i=0; i<3*nnormal; i++) {
      normal[i] -= nremove[i];
    }
    mju_free(nremove);
  }
  // normalize normals
-  for (i=0; i<nnormal; i++) {
+  for (int i=0; i<nnormal; i++) {
    // compute length
    float len = sqrtf(normal[3*i]*normal[3*i] +
                      normal[3*i+1]*normal[3*i+1] +
@@ -1547,7 +1540,7 @@ void mjCMesh::MakeNormal(void) {
    // divide by length
    if (len>mjMINVAL)
-      for (j=0; j<3; j++) {
+      for (int j=0; j<3; j++) {
        normal[3*i+j] /= len;
      } else {
        normal[3*i] = normal[3*i+1] = 0;
@@ -1608,7 +1601,6 @@ mjCSkin::~mjCSkin() {
 // compiler
 void mjCSkin::Compile(const mjVFS* vfs) {
  size_t i, j;
  // load file
  if (!file.empty()) {
@@ -1678,7 +1670,7 @@ void mjCSkin::Compile(const mjVFS* vfs) {
  // resolve body names
  bodyid.resize(nbone);
-  for (i=0; i<nbone; i++) {
+  for (int i=0; i<nbone; i++) {
    mjCBase* pbody = model->FindObject(mjOBJ_BODY, bodyname[i]);
    if (!pbody) {
      throw mjCError(this, "unknown body '%s' in skin", bodyname[i].c_str());
@@ -1701,7 +1693,7 @@ void mjCSkin::Compile(const mjVFS* vfs) {
  fill(vw.begin(), vw.end(), 0.0f);
  // accumulate vertex weights from all bones
-  for (i=0; i<nbone; i++) {
+  for (int i=0; i<nbone; i++) {
    // make sure bone has vertices and sizes match
    size_t nbv = vertid[i].size();
    if (vertweight[i].size()!=nbv || nbv==0) {
@@ -1709,7 +1701,7 @@ void mjCSkin::Compile(const mjVFS* vfs) {
    }
    // accumulate weights in global array
-    for (j=0; j<nbv; j++) {
+    for (int j=0; j<nbv; j++) {
      // get index and check range
      int jj = vertid[i][j];
      if (jj<0 || jj>=nvert) {
@@ -1722,21 +1714,21 @@ void mjCSkin::Compile(const mjVFS* vfs) {
  }
  // check coverage
-  for (i=0; i<nvert; i++) {
+  for (int i=0; i<nvert; i++) {
    if (vw[i]<=mjMINVAL) {
      throw mjCError(this, "vertex %d must have positive total weight in skin", NULL, i);
    }
  }
  // normalize vertex weights
-  for (i=0; i<nbone; i++) {
+  for (int i=0; i<nbone; i++) {
-    for (j=0; j<vertid[i].size(); j++) {
+    for (int j=0; j<vertid[i].size(); j++) {
      vertweight[i][j] /= vw[vertid[i][j]];
    }
  }
  // normalize bindquat
-  for (i=0; i<nbone; i++) {
+  for (int i=0; i<nbone; i++) {
    mjtNum quat[4] = {
      (mjtNum)bindquat[4*i],
      (mjtNum)bindquat[4*i+1],
@@ -181,29 +181,27 @@ mjCModel::mjCModel() {
 // destructor
 mjCModel::~mjCModel() {
  unsigned int i;
  // delete kinematic tree and all objects allocated in it
  delete bodies[0];
  // delete objects allocated in mjCModel
-  for (i=0; i<meshes.size(); i++) delete meshes[i];
+  for (int i=0; i<meshes.size(); i++) delete meshes[i];
-  for (i=0; i<skins.size(); i++) delete skins[i];
+  for (int i=0; i<skins.size(); i++) delete skins[i];
-  for (i=0; i<hfields.size(); i++) delete hfields[i];
+  for (int i=0; i<hfields.size(); i++) delete hfields[i];
-  for (i=0; i<textures.size(); i++) delete textures[i];
+  for (int i=0; i<textures.size(); i++) delete textures[i];
-  for (i=0; i<materials.size(); i++) delete materials[i];
+  for (int i=0; i<materials.size(); i++) delete materials[i];
-  for (i=0; i<pairs.size(); i++) delete pairs[i];
+  for (int i=0; i<pairs.size(); i++) delete pairs[i];
-  for (i=0; i<excludes.size(); i++) delete excludes[i];
+  for (int i=0; i<excludes.size(); i++) delete excludes[i];
-  for (i=0; i<equalities.size(); i++) delete equalities[i];
+  for (int i=0; i<equalities.size(); i++) delete equalities[i];
-  for (i=0; i<tendons.size(); i++) delete tendons[i];  // also deletes wraps
+  for (int i=0; i<tendons.size(); i++) delete tendons[i];  // also deletes wraps
-  for (i=0; i<actuators.size(); i++) delete actuators[i];
+  for (int i=0; i<actuators.size(); i++) delete actuators[i];
-  for (i=0; i<sensors.size(); i++) delete sensors[i];
+  for (int i=0; i<sensors.size(); i++) delete sensors[i];
-  for (i=0; i<numerics.size(); i++) delete numerics[i];
+  for (int i=0; i<numerics.size(); i++) delete numerics[i];
-  for (i=0; i<texts.size(); i++) delete texts[i];
+  for (int i=0; i<texts.size(); i++) delete texts[i];
-  for (i=0; i<tuples.size(); i++) delete tuples[i];
+  for (int i=0; i<tuples.size(); i++) delete tuples[i];
-  for (i=0; i<keys.size(); i++) delete keys[i];
+  for (int i=0; i<keys.size(); i++) delete keys[i];
-  for (i=0; i<plugins.size(); i++) delete plugins[i];
+  for (int i=0; i<plugins.size(); i++) delete plugins[i];
-  for (i=0; i<defaults.size(); i++) delete defaults[i];
+  for (int i=0; i<defaults.size(); i++) delete defaults[i];
  // clear pointer lists created in model construction
  meshes.clear();
@@ -705,32 +703,28 @@ bool mjCModel::IsNullPose(const mjtNum* pos, const mjtNum* quat) {
 // make lists of objects in tree: bodies, geoms, joints, sites, cameras, lights
 void mjCModel::MakeLists(mjCBody* body) {
  unsigned int i;
  // add this body if not world
  if (body!=bodies[0]) {
    bodies.push_back(body);
  }
  // add body's geoms, joints, sites, cameras, lights
-  for (i=0; i<body->geoms.size(); i++) geoms.push_back(body->geoms[i]);
+  for (int i=0; i<body->geoms.size(); i++) geoms.push_back(body->geoms[i]);
-  for (i=0; i<body->joints.size(); i++) joints.push_back(body->joints[i]);
+  for (int i=0; i<body->joints.size(); i++) joints.push_back(body->joints[i]);
-  for (i=0; i<body->sites.size(); i++) sites.push_back(body->sites[i]);
+  for (int i=0; i<body->sites.size(); i++) sites.push_back(body->sites[i]);
-  for (i=0; i<body->cameras.size(); i++) cameras.push_back(body->cameras[i]);
+  for (int i=0; i<body->cameras.size(); i++) cameras.push_back(body->cameras[i]);
-  for (i=0; i<body->lights.size(); i++) lights.push_back(body->lights[i]);
+  for (int i=0; i<body->lights.size(); i++) lights.push_back(body->lights[i]);
  // recursive call to all child bodies
-  for (i=0; i<body->bodies.size(); i++) MakeLists(body->bodies[i]);
+  for (int i=0; i<body->bodies.size(); i++) MakeLists(body->bodies[i]);
 }
 // index assets
 void mjCModel::IndexAssets(void) {
  unsigned int i;
  // assets referenced in geoms
-  for (i=0; i<geoms.size(); i++) {
+  for (int i=0; i<geoms.size(); i++) {
    mjCGeom* pgeom = geoms[i];
    // find material by name
@@ -765,7 +759,7 @@ void mjCModel::IndexAssets(void) {
  }
  // assets referenced in skins
-  for (i=0; i<skins.size(); i++) {
+  for (int i=0; i<skins.size(); i++) {
    mjCSkin* pskin = skins[i];
    // find material by name
@@ -780,7 +774,7 @@ void mjCModel::IndexAssets(void) {
  }
  // materials referenced in sites
-  for (i=0; i<sites.size(); i++) {
+  for (int i=0; i<sites.size(); i++) {
    mjCSite* psite = sites[i];
    // find material by name
@@ -795,7 +789,7 @@ void mjCModel::IndexAssets(void) {
  }
  // materials referenced in tendons
-  for (i=0; i<tendons.size(); i++) {
+  for (int i=0; i<tendons.size(); i++) {
    mjCTendon* pten = tendons[i];
    // find material by name
@@ -810,7 +804,7 @@ void mjCModel::IndexAssets(void) {
  }
  // textures referenced in materials
-  for (i=0; i<materials.size(); i++) {
+  for (int i=0; i<materials.size(); i++) {
    mjCMaterial* pmat = materials[i];
    // find texture by name
@@ -830,10 +824,9 @@ void mjCModel::IndexAssets(void) {
 // if asset name is missing, set to filename
 void mjCModel::SetDefaultNames(void) {
  string stripped;
  unsigned int i;
  // meshes
-  for (i=0; i<meshes.size(); i++) {
+  for (int i=0; i<meshes.size(); i++) {
    if (meshes[i]->name.empty()) {
      stripped = mjuu_strippath(meshes[i]->file);
      meshes[i]->name = mjuu_stripext(stripped);
@@ -846,7 +839,7 @@ void mjCModel::SetDefaultNames(void) {
  }
  // skins
-  for (i=0; i<skins.size(); i++) {
+  for (int i=0; i<skins.size(); i++) {
    if (skins[i]->name.empty()) {
      stripped = mjuu_strippath(skins[i]->file);
      skins[i]->name = mjuu_stripext(stripped);
@@ -854,7 +847,7 @@ void mjCModel::SetDefaultNames(void) {
  }
  // hfields
-  for (i=0; i<hfields.size(); i++) {
+  for (int i=0; i<hfields.size(); i++) {
    if (hfields[i]->name.empty()) {
      stripped = mjuu_strippath(hfields[i]->file);
      hfields[i]->name = mjuu_stripext(stripped);
@@ -867,7 +860,7 @@ void mjCModel::SetDefaultNames(void) {
  }
  // textures
-  for (i=0; i<textures.size(); i++) {
+  for (int i=0; i<textures.size(); i++) {
    if (textures[i]->name.empty()) {
      stripped = mjuu_strippath(textures[i]->file);
      textures[i]->name = mjuu_stripext(stripped);
@@ -880,7 +873,7 @@ void mjCModel::SetDefaultNames(void) {
  }
  // materials: name check only
-  for (i=0; i<materials.size(); i++) {
+  for (int i=0; i<materials.size(); i++) {
    if (materials[i]->name.empty()) {
      throw mjCError(materials[i], "empty name in material");
    }
@@ -895,8 +888,6 @@ const int nVEL[4] = {6, 3, 1, 1};
 // set array sizes
 void mjCModel::SetSizes(void) {
  int i, j;
  // set from object list sizes
  nbody = (int)bodies.size();
  njnt = (int)joints.size();
@@ -921,13 +912,13 @@ void mjCModel::SetSizes(void) {
  nplugin = (int)plugins.size();
  // nq, nv
-  for (i=0; i<njnt; i++) {
+  for (int i=0; i<njnt; i++) {
    nq += nPOS[joints[i]->type];
    nv += nVEL[joints[i]->type];
  }
  // nu, na
-  for (i=0; i<(int)actuators.size(); i++) {
+  for (int i=0; i<(int)actuators.size(); i++) {
    if (actuators[i]->dyntype == mjDYN_NONE) {
      nu++;
    } else {
@@ -937,12 +928,12 @@ void mjCModel::SetSizes(void) {
  }
  // nbvh
-  for (i=0; i<nbody; i++) {
+  for (int i=0; i<nbody; i++) {
    nbvh += bodies[i]->nbvh;
  }
  // nmeshvert, nmeshface, nmeshtexcoord, nmeshgraph
-  for (i=0; i<nmesh; i++) {
+  for (int i=0; i<nmesh; i++) {
    nmeshvert += meshes[i]->nvert;
    nmeshnormal += meshes[i]->nnormal;
    nmeshface += meshes[i]->nface;
@@ -951,67 +942,67 @@ void mjCModel::SetSizes(void) {
  }
  // nskinvert, nskintexvert, nskinface, nskinbone, nskinbonevert
-  for (i=0; i<nskin; i++) {
+  for (int i=0; i<nskin; i++) {
    nskinvert += skins[i]->vert.size()/3;
    nskintexvert += skins[i]->texcoord.size()/2;
    nskinface += skins[i]->face.size()/3;
    nskinbone += skins[i]->bodyid.size();
-    for (j=0; j<skins[i]->bodyid.size(); j++) {
+    for (int j=0; j<skins[i]->bodyid.size(); j++) {
      nskinbonevert += skins[i]->vertid[j].size();
    }
  }
  // nhfielddata
-  for (i=0; i<nhfield; i++) nhfielddata += hfields[i]->nrow * hfields[i]->ncol;
+  for (int i=0; i<nhfield; i++) nhfielddata += hfields[i]->nrow * hfields[i]->ncol;
  // ntexdata
-  for (i=0; i<ntex; i++) ntexdata += 3 * textures[i]->width * textures[i]->height;
+  for (int i=0; i<ntex; i++) ntexdata += 3 * textures[i]->width * textures[i]->height;
  // nwrap
-  for (i=0; i<ntendon; i++) nwrap += (int)tendons[i]->path.size();
+  for (int i=0; i<ntendon; i++) nwrap += (int)tendons[i]->path.size();
  // nsensordata
-  for (i=0; i<nsensor; i++) nsensordata += sensors[i]->dim;
+  for (int i=0; i<nsensor; i++) nsensordata += sensors[i]->dim;
  // nnumericdata
-  for (i=0; i<nnumeric; i++) nnumericdata += numerics[i]->size;
+  for (int i=0; i<nnumeric; i++) nnumericdata += numerics[i]->size;
  // ntextdata
-  for (i=0; i<ntext; i++) ntextdata += (int)texts[i]->data.size() + 1;
+  for (int i=0; i<ntext; i++) ntextdata += (int)texts[i]->data.size() + 1;
  // ntupledata
-  for (i=0; i<ntuple; i++) ntupledata += (int)tuples[i]->objtype.size();
+  for (int i=0; i<ntuple; i++) ntupledata += (int)tuples[i]->objtype.size();
  // npluginattr
-  for (i=0; i<nplugin; i++) npluginattr += (int)plugins[i]->flattened_attributes.size();
+  for (int i=0; i<nplugin; i++) npluginattr += (int)plugins[i]->flattened_attributes.size();
  // nnames
  nnames = (int)modelname.size() + 1;
-  for (i=0; i<nbody; i++)    nnames += (int)bodies[i]->name.length() + 1;
+  for (int i=0; i<nbody; i++)    nnames += (int)bodies[i]->name.length() + 1;
-  for (i=0; i<njnt; i++)     nnames += (int)joints[i]->name.length() + 1;
+  for (int i=0; i<njnt; i++)     nnames += (int)joints[i]->name.length() + 1;
-  for (i=0; i<ngeom; i++)    nnames += (int)geoms[i]->name.length() + 1;
+  for (int i=0; i<ngeom; i++)    nnames += (int)geoms[i]->name.length() + 1;
-  for (i=0; i<nsite; i++)    nnames += (int)sites[i]->name.length() + 1;
+  for (int i=0; i<nsite; i++)    nnames += (int)sites[i]->name.length() + 1;
-  for (i=0; i<ncam; i++)     nnames += (int)cameras[i]->name.length() + 1;
+  for (int i=0; i<ncam; i++)     nnames += (int)cameras[i]->name.length() + 1;
-  for (i=0; i<nlight; i++)   nnames += (int)lights[i]->name.length() + 1;
+  for (int i=0; i<nlight; i++)   nnames += (int)lights[i]->name.length() + 1;
-  for (i=0; i<nmesh; i++)    nnames += (int)meshes[i]->name.length() + 1;
+  for (int i=0; i<nmesh; i++)    nnames += (int)meshes[i]->name.length() + 1;
-  for (i=0; i<nskin; i++)    nnames += (int)skins[i]->name.length() + 1;
+  for (int i=0; i<nskin; i++)    nnames += (int)skins[i]->name.length() + 1;
-  for (i=0; i<nhfield; i++)  nnames += (int)hfields[i]->name.length() + 1;
+  for (int i=0; i<nhfield; i++)  nnames += (int)hfields[i]->name.length() + 1;
-  for (i=0; i<ntex; i++)     nnames += (int)textures[i]->name.length() + 1;
+  for (int i=0; i<ntex; i++)     nnames += (int)textures[i]->name.length() + 1;
-  for (i=0; i<nmat; i++)     nnames += (int)materials[i]->name.length() + 1;
+  for (int i=0; i<nmat; i++)     nnames += (int)materials[i]->name.length() + 1;
-  for (i=0; i<npair; i++)    nnames += (int)pairs[i]->name.length() + 1;
+  for (int i=0; i<npair; i++)    nnames += (int)pairs[i]->name.length() + 1;
-  for (i=0; i<nexclude; i++) nnames += (int)excludes[i]->name.length() + 1;
+  for (int i=0; i<nexclude; i++) nnames += (int)excludes[i]->name.length() + 1;
-  for (i=0; i<neq; i++)      nnames += (int)equalities[i]->name.length() + 1;
+  for (int i=0; i<neq; i++)      nnames += (int)equalities[i]->name.length() + 1;
-  for (i=0; i<ntendon; i++)  nnames += (int)tendons[i]->name.length() + 1;
+  for (int i=0; i<ntendon; i++)  nnames += (int)tendons[i]->name.length() + 1;
-  for (i=0; i<nu; i++)       nnames += (int)actuators[i]->name.length() + 1;
+  for (int i=0; i<nu; i++)       nnames += (int)actuators[i]->name.length() + 1;
-  for (i=0; i<nsensor; i++)  nnames += (int)sensors[i]->name.length() + 1;
+  for (int i=0; i<nsensor; i++)  nnames += (int)sensors[i]->name.length() + 1;
-  for (i=0; i<nnumeric; i++) nnames += (int)numerics[i]->name.length() + 1;
+  for (int i=0; i<nnumeric; i++) nnames += (int)numerics[i]->name.length() + 1;
-  for (i=0; i<ntext; i++)    nnames += (int)texts[i]->name.length() + 1;
+  for (int i=0; i<ntext; i++)    nnames += (int)texts[i]->name.length() + 1;
-  for (i=0; i<ntuple; i++)   nnames += (int)tuples[i]->name.length() + 1;
+  for (int i=0; i<ntuple; i++)   nnames += (int)tuples[i]->name.length() + 1;
-  for (i=0; i<nkey; i++)     nnames += (int)keys[i]->name.length() + 1;
+  for (int i=0; i<nkey; i++)     nnames += (int)keys[i]->name.length() + 1;
-  for (i=0; i<nplugin; i++)  nnames += (int)plugins[i]->name.length() + 1;
+  for (int i=0; i<nplugin; i++)  nnames += (int)plugins[i]->name.length() + 1;
  // nemax
-  for (i=0; i<neq; i++)
+  for (int i=0; i<neq; i++)
    if (equalities[i]->type==mjEQ_CONNECT) {
      nemax += 3;
    } else if (equalities[i]->type==mjEQ_WELD) {
@@ -1092,8 +1083,6 @@ void* LRfunc(void* arg) {
 // compute actuator lengthrange
 void mjCModel::LengthRange(mjModel* m, mjData* data) {
  int i;
  // save options and modify
  mjOption saveopt = m->opt;
  m->opt.disableflags = mjDSBL_FRICTIONLOSS | mjDSBL_CONTACT | mjDSBL_PASSIVE |
@@ -1107,7 +1096,7 @@ void mjCModel::LengthRange(mjModel* m, mjData* data) {
  // count actuators that need computation
  int cnt = 0;
-  for (i=0; i<m->nu; i++) {
+  for (int i=0; i<m->nu; i++) {
    // skip depending on mode and type
    int ismuscle = (m->actuator_gaintype[i]==mjGAIN_MUSCLE ||
                    m->actuator_biastype[i]==mjBIAS_MUSCLE);
@@ -1132,7 +1121,7 @@ void mjCModel::LengthRange(mjModel* m, mjData* data) {
  // single thread
  if (!usethread || cnt<2 || nthread<2) {
    char err[200];
-    for (i=0; i<m->nu; i++) {
+    for (int i=0; i<m->nu; i++) {
      if (!mj_setLengthRange(m, data, i, &LRopt, err, 200)) {
        throw mjCError(0, err);
      }
@@ -1144,7 +1133,7 @@ void mjCModel::LengthRange(mjModel* m, mjData* data) {
    // allocate mjData for each thread
    char err[16][200];
    mjData* pdata[16] = {data};
-    for (i=1; i<nthread; i++) {
+    for (int i=1; i<nthread; i++) {
      pdata[i] = mj_makeData(m);
    }
@@ -1156,7 +1145,7 @@ void mjCModel::LengthRange(mjModel* m, mjData* data) {
    // prepare thread function arguments, clear errors
    LRThreadArg arg[16];
-    for (i=0; i<nthread; i++) {
+    for (int i=0; i<nthread; i++) {
      LRThreadArg temp = {m, pdata[i], i*num, num, &LRopt, err[i], 200};
      arg[i] = temp;
      err[i][0] = 0;
@@ -1166,12 +1155,12 @@ void mjCModel::LengthRange(mjModel* m, mjData* data) {
 #if defined(_WIN32) || defined(__APPLE__)
    // launch threads
    thread th[16];
-    for (i=0; i<nthread; i++) {
+    for (int i=0; i<nthread; i++) {
      th[i] = thread(LRfunc, arg+i);
    }
    // wait for threads to finish
-    for (i=0; i<nthread; i++) {
+    for (int i=0; i<nthread; i++) {
      th[i].join();
    }
@@ -1179,23 +1168,23 @@ void mjCModel::LengthRange(mjModel* m, mjData* data) {
 #else
    // launch threads
    pthread_t th[16];
-    for (i=0; i<nthread; i++) {
+    for (int i=0; i<nthread; i++) {
      pthread_create(th+i, NULL, LRfunc, arg+i);
    }
    // wait for threads to finish
-    for (i=0; i<nthread; i++) {
+    for (int i=0; i<nthread; i++) {
      pthread_join(th[i], NULL);
    }
 #endif
    // free mjData allocated here
-    for (i=1; i<nthread; i++) {
+    for (int i=1; i<nthread; i++) {
      mj_deleteData(pdata[i]);
    }
    // report first error
-    for (i=0; i<nthread; i++) {
+    for (int i=0; i<nthread; i++) {
      if (err[i][0]) {
        throw mjCError(0, err[i]);
      }
@@ -1326,14 +1315,13 @@ void mjCModel::CopyNames(mjModel* m) {
 // copy objects inside kinematic tree
 void mjCModel::CopyTree(mjModel* m) {
  int i, j, j1;
  int jntadr = 0;         // addresses in global arrays
  int dofadr = 0;
  int qposadr = 0;
  int bvh_adr = 0;
  // main loop over bodies
-  for (i=0; i<nbody; i++) {
+  for (int i=0; i<nbody; i++) {
    // get body and parent pointers
    mjCBody* pb = bodies[i];
    mjCBody* par = bodies[pb->parentid];
@@ -1370,7 +1358,7 @@ void mjCModel::CopyTree(mjModel* m) {
    // count free joints
    int cntfree = 0;
-    for (j=0; j<(int)pb->joints.size(); j++) {
+    for (int j=0; j<(int)pb->joints.size(); j++) {
      cntfree += (pb->joints[j]->type == mjJNT_FREE);
    }
@@ -1396,7 +1384,7 @@ void mjCModel::CopyTree(mjModel* m) {
    m->body_sameframe[i] = IsNullPose(m->body_ipos+3*i, m->body_iquat+4*i);
    // init simple: sameframe, and (self-root, or parent is fixed child of world)
-    j = m->body_parentid[i];
+    int j = m->body_parentid[i];
    m->body_simple[i] = (m->body_sameframe[i] &&
                         (m->body_rootid[i]==i ||
                          (m->body_parentid[j]==0 &&
@@ -1409,7 +1397,7 @@ void mjCModel::CopyTree(mjModel* m) {
    // loop over joints for this body
    int rotfound = 0;
-    for (j=0; j<(int)pb->joints.size(); j++) {
+    for (int j=0; j<(int)pb->joints.size(); j++) {
      // get pointer and id
      mjCJoint* pj = pb->joints[j];
      int jid = pj->id;
@@ -1470,7 +1458,7 @@ void mjCModel::CopyTree(mjModel* m) {
      }
      // set dof fields for this joint
-      for (j1=0; j1<nVEL[pj->type]; j1++) {
+      for (int j1=0; j1<nVEL[pj->type]; j1++) {
        // set attributes
        m->dof_bodyid[dofadr] = pb->id;
        m->dof_jntid[dofadr] = jid;
@@ -1494,7 +1482,7 @@ void mjCModel::CopyTree(mjModel* m) {
    }
    // loop over geoms for this body
-    for (j=0; j<(int)pb->geoms.size(); j++) {
+    for (int j=0; j<(int)pb->geoms.size(); j++) {
      // get pointer and id
      mjCGeom* pg = pb->geoms[j];
      int gid = pg->id;
@@ -1549,7 +1537,7 @@ void mjCModel::CopyTree(mjModel* m) {
    }
    // loop over sites for this body
-    for (j=0; j<(int)pb->sites.size(); j++) {
+    for (int j=0; j<(int)pb->sites.size(); j++) {
      // get pointer and id
      mjCSite* ps = pb->sites[j];
      int sid = ps->id;
@@ -1582,7 +1570,7 @@ void mjCModel::CopyTree(mjModel* m) {
    }
    // loop over cameras for this body
-    for (j=0; j<(int)pb->cameras.size(); j++) {
+    for (int j=0; j<(int)pb->cameras.size(); j++) {
      // get pointer and id
      mjCCamera* pc = pb->cameras[j];
      int cid = pc->id;
@@ -1599,7 +1587,7 @@ void mjCModel::CopyTree(mjModel* m) {
    }
    // loop over lights for this body
-    for (j=0; j<(int)pb->lights.size(); j++) {
+    for (int j=0; j<(int)pb->lights.size(); j++) {
      // get pointer and id
      mjCLight* pl = pb->lights[j];
      int lid = pl->id;
@@ -1629,12 +1617,12 @@ void mjCModel::CopyTree(mjModel* m) {
  // compute nM and dof_Madr
  nM = 0;
-  for (i=0; i<nv; i++) {
+  for (int i=0; i<nv; i++) {
    // set address of this dof
    m->dof_Madr[i] = nM;
    // count ancestor dofs including self
-    j = i;
+    int j = i;
    while (j>=0) {
      nM++;
      j = m->dof_parentid[j];
@@ -1647,7 +1635,7 @@ void mjCModel::CopyTree(mjModel* m) {
  m->nD = nD;
  // compute subtreedofs in backward pass over bodies
-  for (i = nbody - 1; i > 0; i--) {
+  for (int i = nbody - 1; i > 0; i--) {
    // add body dofs to self count
    bodies[i]->subtreedofs += bodies[i]->dofnum;
@@ -1662,12 +1650,12 @@ void mjCModel::CopyTree(mjModel* m) {
  // compute nB
  nB = 0;
-  for (i = 0; i < nbody; i++) {
+  for (int i = 0; i < nbody; i++) {
    // add subtree dofs (including self)
    nB += bodies[i]->subtreedofs;
    // add dofs in ancestor bodies
-    j = bodies[i]->parentid;
+    int j = bodies[i]->parentid;
    while (j > 0) {
      nB += bodies[j]->dofnum;
      j = bodies[j]->parentid;
@@ -1677,7 +1665,7 @@ void mjCModel::CopyTree(mjModel* m) {
  // set dof_simplenum
  int scnt = 0;
-  for (i=nv-1; i>=0; i--) {
+  for (int i=nv-1; i>=0; i--) {
    // dof in simple body
    if (m->body_simple[m->dof_bodyid[i]]) {
      scnt++;
@@ -1696,7 +1684,7 @@ void mjCModel::CopyTree(mjModel* m) {
 // copy objects outside kinematic tree
 void mjCModel::CopyObjects(mjModel* m) {
-  int i, j, adr, bone_adr, vert_adr, normal_adr, face_adr, texcoord_adr;
+  int adr, bone_adr, vert_adr, normal_adr, face_adr, texcoord_adr;
  int bonevert_adr, graph_adr, data_adr;
  // sizes outside call to mj_makeModel
@@ -1712,7 +1700,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  texcoord_adr = 0;
  face_adr = 0;
  graph_adr = 0;
-  for (i=0; i<nmesh; i++) {
+  for (int i=0; i<nmesh; i++) {
    // get pointer
    mjCMesh* pme = meshes[i];
@@ -1756,7 +1744,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  texcoord_adr = 0;
  bone_adr = 0;
  bonevert_adr = 0;
-  for (i=0; i<nskin; i++) {
+  for (int i=0; i<nskin; i++) {
    // get pointer
    mjCSkin* psk = skins[i];
@@ -1789,7 +1777,7 @@ void mjCModel::CopyObjects(mjModel* m) {
           psk->bodyid.size()*sizeof(int));
    // copy per-bone vertex data, advance vertex counter
-    for (j=0; j<m->skin_bonenum[i]; j++) {
+    for (int j=0; j<m->skin_bonenum[i]; j++) {
      // set fields
      m->skin_bonevertadr[bone_adr+j] = bonevert_adr;
      m->skin_bonevertnum[bone_adr+j] = (int)psk->vertid[j].size();
@@ -1813,7 +1801,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  // hfields
  data_adr = 0;
-  for (i=0; i<nhfield; i++) {
+  for (int i=0; i<nhfield; i++) {
    // get pointer
    mjCHField* phf = hfields[i];
@@ -1832,7 +1820,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  // textures
  data_adr = 0;
-  for (i=0; i<ntex; i++) {
+  for (int i=0; i<ntex; i++) {
    // get pointer
    mjCTexture* ptex = textures[i];
@@ -1850,7 +1838,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  }
  // materials
-  for (i=0; i<nmat; i++) {
+  for (int i=0; i<nmat; i++) {
    // get pointer
    mjCMaterial* pmat = materials[i];
@@ -1866,7 +1854,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  }
  // geom pairs to include
-  for (i=0; i<npair; i++) {
+  for (int i=0; i<npair; i++) {
    m->pair_dim[i] = pairs[i]->condim;
    m->pair_geom1[i] = pairs[i]->geom1;
    m->pair_geom2[i] = pairs[i]->geom2;
@@ -1879,12 +1867,12 @@ void mjCModel::CopyObjects(mjModel* m) {
  }
  // body pairs to exclude
-  for (i=0; i<nexclude; i++) {
+  for (int i=0; i<nexclude; i++) {
    m->exclude_signature[i] = excludes[i]->signature;
  }
  // equality constraints
-  for (i=0; i<neq; i++) {
+  for (int i=0; i<neq; i++) {
    // get pointer
    mjCEquality* peq = equalities[i];
@@ -1900,7 +1888,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  // tendons and wraps
  adr = 0;
-  for (i=0; i<ntendon; i++) {
+  for (int i=0; i<ntendon; i++) {
    // get pointer
    mjCTendon* pte = tendons[i];
@@ -1927,7 +1915,7 @@ void mjCModel::CopyObjects(mjModel* m) {
    copyvec(m->tendon_rgba+4*i, pte->rgba, 4);
    // set wraps
-    for (j=0; j<(int)pte->path.size(); j++) {
+    for (int j=0; j<(int)pte->path.size(); j++) {
      m->wrap_type[adr+j] = pte->path[j]->type;
      m->wrap_objid[adr+j] = pte->path[j]->objid;
      m->wrap_prm[adr+j] = (mjtNum)pte->path[j]->prm;
@@ -1942,7 +1930,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  // actuators
  adr = 0;
-  for (i=0; i<nu; i++) {
+  for (int i=0; i<nu; i++) {
    // get pointer
    mjCActuator* pac = actuators[i];
@@ -1974,7 +1962,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  // sensors
  adr = 0;
-  for (i=0; i<nsensor; i++) {
+  for (int i=0; i<nsensor; i++) {
    // get pointer
    mjCSensor* psen = sensors[i];
@@ -1998,17 +1986,17 @@ void mjCModel::CopyObjects(mjModel* m) {
  // numeric fields
  adr = 0;
-  for (i=0; i<nnumeric; i++) {
+  for (int i=0; i<nnumeric; i++) {
    // get pointer
    mjCNumeric* pcu = numerics[i];
    // set fields
    m->numeric_adr[i] = adr;
    m->numeric_size[i] = pcu->size;
-    for (j=0; j<(int)pcu->data.size(); j++) {
+    for (int j=0; j<(int)pcu->data.size(); j++) {
      m->numeric_data[adr+j] = (mjtNum)pcu->data[j];
    }
-    for (j=(int)pcu->data.size(); j<(int)pcu->size; j++) {
+    for (int j=(int)pcu->data.size(); j<(int)pcu->size; j++) {
      m->numeric_data[adr+j] = 0;
    }
@@ -2018,7 +2006,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  // text fields
  adr = 0;
-  for (i=0; i<ntext; i++) {
+  for (int i=0; i<ntext; i++) {
    // get pointer
    mjCText* pte = texts[i];
@@ -2033,14 +2021,14 @@ void mjCModel::CopyObjects(mjModel* m) {
  // tuple fields
  adr = 0;
-  for (i=0; i<ntuple; i++) {
+  for (int i=0; i<ntuple; i++) {
    // get pointer
    mjCTuple* ptu = tuples[i];
    // set fields
    m->tuple_adr[i] = adr;
    m->tuple_size[i] = (int)ptu->objtype.size();
-    for (j=0; j<m->tuple_size[i]; j++) {
+    for (int j=0; j<m->tuple_size[i]; j++) {
      m->tuple_objtype[adr+j] = (int)ptu->objtype[j];
      m->tuple_objid[adr+j] = ptu->objid[j];
      m->tuple_objprm[adr+j] = (mjtNum)ptu->objprm[j];
@@ -2051,7 +2039,7 @@ void mjCModel::CopyObjects(mjModel* m) {
  }
  // copy keyframe data
-  for (i=0; i<nkey; i++) {
+  for (int i=0; i<nkey; i++) {
    // copy data
    m->key_time[i] = (mjtNum)keys[i]->time;
    copyvec(m->key_qpos+i*nq, keys[i]->qpos.data(), nq);
@@ -2065,14 +2053,14 @@ void mjCModel::CopyObjects(mjModel* m) {
    }
    // normalize quaternions in m->key_qpos
-    for (j=0; j<m->njnt; j++) {
+    for (int j=0; j<m->njnt; j++) {
      if (m->jnt_type[j]==mjJNT_BALL || m->jnt_type[j]==mjJNT_FREE) {
        mju_normalize4(m->key_qpos+i*nq+m->jnt_qposadr[j]+3*(m->jnt_type[j]==mjJNT_FREE));
      }
    }
    // normalize quaternions in m->key_mquat
-    for (j=0; j<nmocap; j++) {
+    for (int j=0; j<nmocap; j++) {
      mju_normalize4(m->key_mquat+i*4*nmocap+4*j);
    }
@@ -2103,35 +2091,33 @@ static void changeframe(double childpos[3], double childquat[4],
 // reindex elements during fuse
 void mjCModel::FuseReindex(mjCBody* body) {
  size_t i;
  // set parentid and weldid of children
-  for (i=0; i<body->bodies.size(); i++) {
+  for (int i=0; i<body->bodies.size(); i++) {
    body->bodies[i]->parentid = body->id;
    body->bodies[i]->weldid = (!body->bodies[i]->joints.empty() ?
                               body->bodies[i]->id : body->weldid);
  }
  // joints
-  for (i=0; i<body->joints.size(); i++) {
+  for (int i=0; i<body->joints.size(); i++) {
    body->joints[i]->id = (int)joints.size();
    joints.push_back(body->joints[i]);
  }
  // geoms
-  for (i=0; i<body->geoms.size(); i++) {
+  for (int i=0; i<body->geoms.size(); i++) {
    body->geoms[i]->id = (int)geoms.size();
    geoms.push_back(body->geoms[i]);
  }
  // sites
-  for (i=0; i<body->sites.size(); i++) {
+  for (int i=0; i<body->sites.size(); i++) {
    body->sites[i]->id = (int)sites.size();
    sites.push_back(body->sites[i]);
  }
  // process children recursively
-  for (i=0; i<body->bodies.size(); i++) {
+  for (int i=0; i<body->bodies.size(); i++) {
    FuseReindex(body->bodies[i]);
  }
 }
@@ -2140,8 +2126,6 @@ void mjCModel::FuseReindex(mjCBody* body) {
 // fuse static bodies with their parent
 void mjCModel::FuseStatic(void) {
  int i, j, k;
  // skip if model has potential to reference elements with changed ids
  if (!skins.empty()        ||
      !pairs.empty()        ||
@@ -2157,7 +2141,7 @@ void mjCModel::FuseStatic(void) {
  }
  // process fusable bodies
-  for (i=1; i<bodies.size(); i++) {
+  for (int i=1; i<bodies.size(); i++) {
    // get body and parent
    mjCBody* body = bodies[i];
    mjCBody* par = bodies[body->parentid];
@@ -2195,7 +2179,7 @@ void mjCModel::FuseStatic(void) {
      // compute total mass
      par->mass = 0;
      mjuu_setvec(par->locipos, 0, 0, 0);
-      for (j=0; j<2; j++) {
+      for (int j=0; j<2; j++) {
        par->mass += mass[j];
        par->locipos[0] += mass[j]*ipos[j][0];
        par->locipos[1] += mass[j]*ipos[j][1];
@@ -2219,7 +2203,7 @@ void mjCModel::FuseStatic(void) {
        // add inertias
        double toti[6] = {0, 0, 0, 0, 0, 0};
-        for (j=0; j<2; j++) {
+        for (int j=0; j<2; j++) {
          double inertA[6], inertB[6];
          double dpos[3] = {
            ipos[j][0] - par->locipos[0],
@@ -2229,7 +2213,7 @@ void mjCModel::FuseStatic(void) {
          mjuu_globalinertia(inertA, inertia[j], iquat[j]);
          mjuu_offcenter(inertB, mass[j], dpos);
-          for (k=0; k<6; k++) {
+          for (int k=0; k<6; k++) {
            toti[k] += inertA[k] + inertB[k];
          }
        }
@@ -2247,7 +2231,7 @@ void mjCModel::FuseStatic(void) {
    //------------- replace body with its children in parent body list
    // change frames of child bodies
-    for (j=0; j<body->bodies.size(); j++)
+    for (int j=0; j<body->bodies.size(); j++)
      changeframe(body->bodies[j]->locpos, body->bodies[j]->locquat,
                  body->locpos, body->locquat);
@@ -2280,7 +2264,7 @@ void mjCModel::FuseStatic(void) {
    //------------- assign geoms and sites to parent, change frames
    // geoms
-    for (j=0; j<body->geoms.size(); j++) {
+    for (int j=0; j<body->geoms.size(); j++) {
      // assign
      body->geoms[j]->body = par;
      par->geoms.push_back(body->geoms[j]);
@@ -2290,7 +2274,7 @@ void mjCModel::FuseStatic(void) {
    }
    // sites
-    for (j=0; j<body->sites.size(); j++) {
+    for (int j=0; j<body->sites.size(); j++) {
      // assign
      body->sites[j]->body = par;
      par->sites.push_back(body->sites[j]);
@@ -2321,7 +2305,7 @@ void mjCModel::FuseStatic(void) {
    //------------- re-index bodies, joints, geoms, sites
    // body ids
-    for (j=0; j<bodies.size(); j++) {
+    for (int j=0; j<bodies.size(); j++) {
      bodies[j]->id = j;
    }
@@ -2872,8 +2856,6 @@ void mjCModel::TryCompile(mjModel*& m, mjData*& d, const mjVFS* vfs) {
 // get numeric data back from mjModel
 bool mjCModel::CopyBack(const mjModel* m) {
  int i, j;
  // check for null pointer
  if (!m) {
    errInfo = mjCError(0, "mjModel pointer is null in CopyBack");
@@ -2905,7 +2887,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  visual = m->vis;
  // qpos0, qpos_spring
-  for (i=0; i<njnt; i++) {
+  for (int i=0; i<njnt; i++) {
    switch (joints[i]->type) {
    case mjJNT_FREE:
      copyvec(bodies[m->jnt_bodyid[i]]->pos, m->qpos0+m->jnt_qposadr[i], 3);
@@ -2927,7 +2909,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  // body
  mjCBody* pb;
-  for (i=0; i<nbody; i++) {
+  for (int i=0; i<nbody; i++) {
    pb = bodies[i];
    copyvec(pb->locpos, m->body_pos+3*i, 3);
@@ -2944,7 +2926,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  // joint and dof
  mjCJoint* pj;
-  for (i=0; i<njnt; i++) {
+  for (int i=0; i<njnt; i++) {
    pj = joints[i];
    // joint data
@@ -2961,7 +2943,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
    }
    // dof data
-    j = m->jnt_dofadr[i];
+    int j = m->jnt_dofadr[i];
    copyvec(pj->solref_friction, m->dof_solref+mjNREF*j, mjNREF);
    copyvec(pj->solimp_friction, m->dof_solimp+mjNIMP*j, mjNIMP);
    pj->armature = (double)m->dof_armature[j];
@@ -2971,7 +2953,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  // geom
  mjCGeom* pg;
-  for (i=0; i<ngeom; i++) {
+  for (int i=0; i<ngeom; i++) {
    pg = geoms[i];
    copyvec(pg->size, m->geom_size+3*i, 3);
@@ -2991,7 +2973,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  }
  // sites
-  for (i=0; i<nsite; i++) {
+  for (int i=0; i<nsite; i++) {
    copyvec(sites[i]->size, m->site_size + 3 * i, 3);
    copyvec(sites[i]->locpos, m->site_pos+3*i, 3);
    copyvec(sites[i]->locquat, m->site_quat+4*i, 4);
@@ -3003,7 +2985,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  }
  // cameras
-  for (i=0; i<ncam; i++) {
+  for (int i=0; i<ncam; i++) {
    copyvec(cameras[i]->pos, m->cam_pos+3*i, 3);
    copyvec(cameras[i]->quat, m->cam_quat+4*i, 4);
    cameras[i]->fovy = (double)m->cam_fovy[i];
@@ -3015,7 +2997,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  }
  // lights
-  for (i=0; i<nlight; i++) {
+  for (int i=0; i<nlight; i++) {
    copyvec(lights[i]->pos, m->light_pos+3*i, 3);
    copyvec(lights[i]->dir, m->light_dir+3*i, 3);
    copyvec(lights[i]->attenuation, m->light_attenuation+3*i, 3);
@@ -3027,7 +3009,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  }
  // materials
-  for (i=0; i<nmat; i++) {
+  for (int i=0; i<nmat; i++) {
    copyvec(materials[i]->texrepeat, m->mat_texrepeat+2*i, 2);
    materials[i]->emission = m->mat_emission[i];
    materials[i]->specular = m->mat_specular[i];
@@ -3037,7 +3019,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  }
  // pairs
-  for (i=0; i<npair; i++) {
+  for (int i=0; i<npair; i++) {
    copyvec(pairs[i]->solref, m->pair_solref+mjNREF*i, mjNREF);
    copyvec(pairs[i]->solimp, m->pair_solimp+mjNIMP*i, mjNIMP);
    pairs[i]->margin = (double)m->pair_margin[i];
@@ -3046,14 +3028,14 @@ bool mjCModel::CopyBack(const mjModel* m) {
  }
  // equality constraints
-  for (i=0; i<neq; i++) {
+  for (int i=0; i<neq; i++) {
    copyvec(equalities[i]->data, m->eq_data+mjNEQDATA*i, mjNEQDATA);
    copyvec(equalities[i]->solref, m->eq_solref+mjNREF*i, mjNREF);
    copyvec(equalities[i]->solimp, m->eq_solimp+mjNIMP*i, mjNIMP);
  }
  // tendons
-  for (i=0; i<ntendon; i++) {
+  for (int i=0; i<ntendon; i++) {
    copyvec(tendons[i]->range, m->tendon_range+2*i, 2);
    copyvec(tendons[i]->solref_limit, m->tendon_solref_lim+mjNREF*i, mjNREF);
    copyvec(tendons[i]->solimp_limit, m->tendon_solimp_lim+mjNIMP*i, mjNIMP);
@@ -3073,7 +3055,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  // actuators
  mjCActuator* pa;
-  for (i=0; i<nu; i++) {
+  for (int i=0; i<nu; i++) {
    pa = actuators[i];
    copyvec(pa->dynprm, m->actuator_dynprm+i*mjNDYN, mjNDYN);
@@ -3092,7 +3074,7 @@ bool mjCModel::CopyBack(const mjModel* m) {
  }
  // sensors
-  for (i=0; i<nsensor; i++) {
+  for (int i=0; i<nsensor; i++) {
    sensors[i]->cutoff = (double)m->sensor_cutoff[i];
    sensors[i]->noise = (double)m->sensor_noise[i];
@@ -3102,21 +3084,21 @@ bool mjCModel::CopyBack(const mjModel* m) {
  }
  // numeric data
-  for (i=0; i<nnumeric; i++) {
+  for (int i=0; i<nnumeric; i++) {
-    for (j=0; j<m->numeric_size[i]; j++) {
+    for (int j=0; j<m->numeric_size[i]; j++) {
      numerics[i]->data[j] = (double)m->numeric_data[m->numeric_adr[i]+j];
    }
  }
  // tuple data
-  for (i=0; i<ntuple; i++) {
+  for (int i=0; i<ntuple; i++) {
-    for (j=0; j<m->tuple_size[i]; j++) {
+    for (int j=0; j<m->tuple_size[i]; j++) {
      tuples[i]->objprm[j] = (double)m->tuple_objprm[m->tuple_adr[i]+j];
    }
  }
  // keyframes
-  for (i=0; i<m->nkey; i++) {
+  for (int i=0; i<m->nkey; i++) {
    mjCKey* pk = keys[i];
    pk->time = (double)m->key_time[i];
@@ -356,15 +356,13 @@ mjCBody::mjCBody(mjCModel* _model) {
 // destructor
 mjCBody::~mjCBody() {
  unsigned int i;
  // delete objects allocated here
-  for (i=0; i<bodies.size(); i++) delete bodies[i];
+  for (int i=0; i<bodies.size(); i++) delete bodies[i];
-  for (i=0; i<geoms.size(); i++) delete geoms[i];
+  for (int i=0; i<geoms.size(); i++) delete geoms[i];
-  for (i=0; i<joints.size(); i++) delete joints[i];
+  for (int i=0; i<joints.size(); i++) delete joints[i];
-  for (i=0; i<sites.size(); i++) delete sites[i];
+  for (int i=0; i<sites.size(); i++) delete sites[i];
-  for (i=0; i<cameras.size(); i++) delete cameras[i];
+  for (int i=0; i<cameras.size(); i++) delete cameras[i];
-  for (i=0; i<lights.size(); i++) delete lights[i];
+  for (int i=0; i<lights.size(); i++) delete lights[i];
  bodies.clear();
  geoms.clear();
@@ -576,14 +574,14 @@ mjCBase* mjCBody::FindObject(mjtObj type, string _name, bool recursive) {
 // compute geom inertial frame: ipos, iquat, mass, inertia
 void mjCBody::GeomFrame(void) {
-  int i, sz;
+  int sz;
  double com[3] = {0, 0, 0};
  double toti[6] = {0, 0, 0, 0, 0, 0};
  vector<mjCGeom*> sel;
  // select geoms based on group
  sel.clear();
-  for (i=0; i<geoms.size(); i++) {
+  for (int i=0; i<geoms.size(); i++) {
    if (geoms[i]->group>=model->inertiagrouprange[0] &&
        geoms[i]->group<=model->inertiagrouprange[1]) {
      sel.push_back(geoms[i]);
@@ -603,7 +601,7 @@ void mjCBody::GeomFrame(void) {
  else if (sz>1) {
    // compute total mass and center of mass
    mass = 0;
-    for (i=0; i<sz; i++) {
+    for (int i=0; i<sz; i++) {
      mass += sel[i]->mass;
      com[0] += sel[i]->mass * sel[i]->pos[0];
      com[1] += sel[i]->mass * sel[i]->pos[1];
@@ -621,7 +619,7 @@ void mjCBody::GeomFrame(void) {
    ipos[2] = com[2]/mass;
    // add geom inertias
-    for (i=0; i<sz; i++) {
+    for (int i=0; i<sz; i++) {
      double inert0[6], inert1[6];
      double dpos[3] = {
        sel[i]->pos[0] - ipos[0],
@@ -820,8 +818,6 @@ int mjCBody::MakeBVH(std::vector<mjCGeom *>& elements, int lev) {
 // compiler
 void mjCBody::Compile(void) {
  unsigned int i;
  // resize userdata
  if (userdata.size() > model->nuser_body) {
    throw mjCError(this, "user has more values than nuser_body in body '%s' (id = %d)",
@@ -839,7 +835,7 @@ void mjCBody::Compile(void) {
  mjuu_normvec(iquat, 4);
  // set parentid and weldid of children
-  for (i=0; i<bodies.size(); i++) {
+  for (int i=0; i<bodies.size(); i++) {
    bodies[i]->parentid = id;
    bodies[i]->weldid = (!bodies[i]->joints.empty() ? bodies[i]->id : weldid);
  }
@@ -857,7 +853,7 @@ void mjCBody::Compile(void) {
  }
  // compile all geoms, phase 1
-  for (i=0; i<geoms.size(); i++) {
+  for (int i=0; i<geoms.size(); i++) {
    geoms[i]->inferinertia = id>0 &&
      (!explicitinertial || model->inertiafromgeom == mjINERTIAFROMGEOM_TRUE) &&
      geoms[i]->group >= model->inertiagrouprange[0] &&
@@ -924,7 +920,7 @@ void mjCBody::Compile(void) {
  }
  // make local frames of geoms
-  for (i=0; i<geoms.size(); i++) {
+  for (int i=0; i<geoms.size(); i++) {
    MakeLocal(geoms[i]->locpos, geoms[i]->locquat, geoms[i]->pos, geoms[i]->quat);
  }
@@ -935,7 +931,7 @@ void mjCBody::Compile(void) {
  // compile all joints, count dofs
  dofnum = 0;
-  for (i=0; i<joints.size(); i++) {
+  for (int i=0; i<joints.size(); i++) {
    dofnum += joints[i]->Compile();
  }
@@ -946,7 +942,7 @@ void mjCBody::Compile(void) {
  // check for rotation dof after ball joint
  bool hasball = false;
-  for (i=0; i<joints.size(); i++) {
+  for (int i=0; i<joints.size(); i++) {
    if ((joints[i]->type==mjJNT_BALL || joints[i]->type==mjJNT_HINGE) && hasball) {
      throw mjCError(this, "ball followed by rotation in body '%s'", name.c_str());
    }
@@ -962,13 +958,13 @@ void mjCBody::Compile(void) {
    }
  // compile all sites
-  for (i=0; i<sites.size(); i++) sites[i]->Compile();
+  for (int i=0; i<sites.size(); i++) sites[i]->Compile();
  // compile all cameras
-  for (i=0; i<cameras.size(); i++) cameras[i]->Compile();
+  for (int i=0; i<cameras.size(); i++) cameras[i]->Compile();
  // compile all lights
-  for (i=0; i<lights.size(); i++) lights[i]->Compile();
+  for (int i=0; i<lights.size(); i++) lights[i]->Compile();
  // plugin
  if (is_plugin) {
@@ -2217,11 +2213,10 @@ mjCTexture::~mjCTexture() {
 // insert random dots
 static void randomdot(unsigned char* rgb, const double* markrgb,
                      int width, int height, double probability) {
-  int r, c, j;
+  for (int r=0; r<height; r++) {
-  for (r=0; r<height; r++) {
+    for (int c=0; c<width; c++) {
    for (c=0; c<width; c++) {
      if (rand()<probability*RAND_MAX) {
-        for (j=0; j<3; j++) {
+        for (int j=0; j<3; j++) {
          rgb[3*(r*width+c)+j] = (mjtByte)(255*markrgb[j]);
        }
      }
@@ -2251,25 +2246,23 @@ static void interp(unsigned char* rgb, const double* rgb1, const double* rgb2, d
 // make checker pattern for one side
 static void checker(unsigned char* rgb, const unsigned char* RGB1, const unsigned char* RGB2,
                    int width, int height) {
-  int r, c;
+  for (int r=0; r<height/2; r++) {
-
+    for (int c=0; c<width/2; c++) {
  for (r=0; r<height/2; r++) {
    for (c=0; c<width/2; c++) {
      memcpy(rgb+3*(r*width+c), RGB1, 3);
    }
  }
-  for (r=height/2; r<height; r++) {
+  for (int r=height/2; r<height; r++) {
-    for (c=width/2; c<width; c++) {
+    for (int c=width/2; c<width; c++) {
      memcpy(rgb+3*(r*width+c), RGB1, 3);
    }
  }
-  for (r=0; r<height/2; r++) {
+  for (int r=0; r<height/2; r++) {
-    for (c=width/2; c<width; c++) {
+    for (int c=width/2; c<width; c++) {
      memcpy(rgb+3*(r*width+c), RGB2, 3);
    }
  }
-  for (r=height/2; r<height; r++) {
+  for (int r=height/2; r<height; r++) {
-    for (c=0; c<width/2; c++) {
+    for (int c=0; c<width/2; c++) {
      memcpy(rgb+3*(r*width+c), RGB2, 3);
    }
  }
@@ -2280,10 +2273,8 @@ static void checker(unsigned char* rgb, const unsigned char* RGB1, const unsigne
 // make builtin: 2D
 void mjCTexture::Builtin2D(void) {
  unsigned char RGB1[3], RGB2[3], RGBm[3];
  int r, c, j;
  // convert fixed colors
-  for (j=0; j<3; j++) {
+  for (int j=0; j<3; j++) {
    RGB1[j] = (mjtByte)(255*rgb1[j]);
    RGB2[j] = (mjtByte)(255*rgb2[j]);
    RGBm[j] = (mjtByte)(255*markrgb[j]);
@@ -2293,8 +2284,8 @@ void mjCTexture::Builtin2D(void) {
  // gradient
  if (builtin==mjBUILTIN_GRADIENT) {
-    for (r=0; r<height; r++) {
+    for (int r=0; r<height; r++) {
-      for (c=0; c<width; c++) {
+      for (int c=0; c<width; c++) {
        // compute normalized coordinates and radius
        double x = 2*c/((double)(width-1)) - 1;
        double y = 1 - 2*r/((double)(height-1));
@@ -2313,8 +2304,8 @@ void mjCTexture::Builtin2D(void) {
  // flat
  else if (builtin==mjBUILTIN_FLAT) {
-    for (r=0; r<height; r++) {
+    for (int r=0; r<height; r++) {
-      for (c=0; c<width; c++) {
+      for (int c=0; c<width; c++) {
        memcpy(rgb+3*(r*width+c), RGB1, 3);
      }
    }
@@ -2324,11 +2315,11 @@ void mjCTexture::Builtin2D(void) {
  // edge
  if (mark==mjMARK_EDGE) {
-    for (r=0; r<height; r++) {
+    for (int r=0; r<height; r++) {
      memcpy(rgb+3*(r*width+0), RGBm, 3);
      memcpy(rgb+3*(r*width+width-1), RGBm, 3);
    }
-    for (c=0; c<width; c++) {
+    for (int c=0; c<width; c++) {
      memcpy(rgb+3*(0*width+c), RGBm, 3);
      memcpy(rgb+3*((height-1)*width+c), RGBm, 3);
    }
@@ -2336,10 +2327,10 @@ void mjCTexture::Builtin2D(void) {
  // cross
  else if (mark==mjMARK_CROSS) {
-    for (r=0; r<height; r++) {
+    for (int r=0; r<height; r++) {
      memcpy(rgb+3*(r*width+width/2), RGBm, 3);
    }
-    for (c=0; c<width; c++) {
+    for (int c=0; c<width; c++) {
      memcpy(rgb+3*(height/2*width+c), RGBm, 3);
    }
  }
@@ -2355,10 +2346,9 @@ void mjCTexture::Builtin2D(void) {
 // make builtin: Cube
 void mjCTexture::BuiltinCube(void) {
  unsigned char RGB1[3], RGB2[3], RGBm[3], RGBi[3];
  int r, c, j;
  // convert fixed colors
-  for (j=0; j<3; j++) {
+  for (int j=0; j<3; j++) {
    RGB1[j] = (mjtByte)(255*rgb1[j]);
    RGB2[j] = (mjtByte)(255*rgb2[j]);
    RGBm[j] = (mjtByte)(255*markrgb[j]);
@@ -2368,8 +2358,8 @@ void mjCTexture::BuiltinCube(void) {
  // gradient
  if (builtin==mjBUILTIN_GRADIENT) {
-    for (r=0; r<width; r++) {
+    for (int r=0; r<width; r++) {
-      for (c=0; c<width; c++) {
+      for (int c=0; c<width; c++) {
        // compute normalized pixel coordinates
        double x = 2*c/((double)(width-1)) - 1;
        double y = 1 - 2*r/((double)(width-1));
@@ -2404,8 +2394,8 @@ void mjCTexture::BuiltinCube(void) {
  // flat
  else if (builtin==mjBUILTIN_FLAT) {
-    for (r=0; r<width; r++) {
+    for (int r=0; r<width; r++) {
-      for (c=0; c<width; c++) {
+      for (int c=0; c<width; c++) {
        // set sides and up
        memcpy(rgb+0*3*width*width+3*(r*width+c), RGB1, 3);
        memcpy(rgb+1*3*width*width+3*(r*width+c), RGB1, 3);
@@ -2423,12 +2413,12 @@ void mjCTexture::BuiltinCube(void) {
  // edge
  if (mark==mjMARK_EDGE) {
-    for (j=0; j<6; j++) {
+    for (int j=0; j<6; j++) {
-      for (r=0; r<width; r++) {
+      for (int r=0; r<width; r++) {
        memcpy(rgb+j*3*width*width+3*(r*width+0), RGBm, 3);
        memcpy(rgb+j*3*width*width+3*(r*width+width-1), RGBm, 3);
      }
-      for (c=0; c<width; c++) {
+      for (int c=0; c<width; c++) {
        memcpy(rgb+j*3*width*width+3*(0*width+c), RGBm, 3);
        memcpy(rgb+j*3*width*width+3*((width-1)*width+c), RGBm, 3);
      }
@@ -2437,11 +2427,11 @@ void mjCTexture::BuiltinCube(void) {
  // cross
  else if (mark==mjMARK_CROSS) {
-    for (j=0; j<6; j++) {
+    for (int j=0; j<6; j++) {
-      for (r=0; r<width; r++) {
+      for (int r=0; r<width; r++) {
        memcpy(rgb+j*3*width*width+3*(r*width+width/2), RGBm, 3);
      }
-      for (c=0; c<width; c++) {
+      for (int c=0; c<width; c++) {
        memcpy(rgb+j*3*width*width+3*(width/2*width+c), RGBm, 3);
      }
    }
@@ -2637,8 +2627,6 @@ void mjCTexture::Load2D(string filename, const mjVFS* vfs) {
 // load cube or skybox from single file (repeated or grid)
 void mjCTexture::LoadCubeSingle(string filename, const mjVFS* vfs) {
  int i, j, k, s;
  // check gridsize
  if (gridsize[0]<1 || gridsize[1]<1 || gridsize[0]*gridsize[1]>12) {
    throw mjCError(this,
@@ -2685,9 +2673,9 @@ void mjCTexture::LoadCubeSingle(string filename, const mjVFS* vfs) {
    int loaded[6] = {0, 0, 0, 0, 0, 0};
    // process grid
-    for (k=0; k<gridsize[0]*gridsize[1]; k++) {
+    for (int k=0; k<gridsize[0]*gridsize[1]; k++) {
      // decode face symbol
-      i = -1;
+      int i = -1;
      if (gridlayout[k]=='R') {
        i = 0;
      } else if (gridlayout[k]=='L') {
@@ -2709,7 +2697,7 @@ void mjCTexture::LoadCubeSingle(string filename, const mjVFS* vfs) {
        // extract sub-image
        int rstart = width*(k/gridsize[1]);
        int cstart = width*(k%gridsize[1]);
-        for (j=0; j<width; j++) {
+        for (int j=0; j<width; j++) {
          memcpy(rgb+i*3*width*width+j*3*width, image.data()+(j+rstart)*3*w+3*cstart, 3*width);
        }
@@ -2719,11 +2707,11 @@ void mjCTexture::LoadCubeSingle(string filename, const mjVFS* vfs) {
    }
    // set undefined faces to rgb1
-    for (i=0; i<6; i++) {
+    for (int i=0; i<6; i++) {
      if (!loaded[i]) {
-        for (k=0; k<width; k++) {
+        for (int k=0; k<width; k++) {
-          for (s=0; s<width; s++) {
+          for (int s=0; s<width; s++) {
-            for (j=0; j<3; j++) {
+            for (int j=0; j<3; j++) {
              rgb[i*3*width*width + 3*(k*width+s) + j] = (mjtByte)(255*rgb1[j]);
            }
          }
@@ -2739,13 +2727,11 @@ void mjCTexture::LoadCubeSingle(string filename, const mjVFS* vfs) {
 // load cube or skybox from separate file
 void mjCTexture::LoadCubeSeparate(const mjVFS* vfs) {
  int i, j, k, s;
  // keep track of which faces were defined
  int loaded[6] = {0, 0, 0, 0, 0, 0};
  // process nonempty files
-  for (i=0; i<6; i++) {
+  for (int i=0; i<6; i++) {
    if (!cubefiles[i].empty()) {
      // remove path from file if necessary
      if (model->strippath) {
@@ -2796,11 +2782,11 @@ void mjCTexture::LoadCubeSeparate(const mjVFS* vfs) {
  }
  // set undefined faces to rgb1
-  for (i=0; i<6; i++) {
+  for (int i=0; i<6; i++) {
    if (!loaded[i]) {
-      for (k=0; k<width; k++) {
+      for (int k=0; k<width; k++) {
-        for (s=0; s<width; s++) {
+        for (int s=0; s<width; s++) {
-          for (j=0; j<3; j++) {
+          for (int j=0; j<3; j++) {
            rgb[i*3*width*width + 3*(k*width+s) + j] = (mjtByte)(255*rgb1[j]);
          }
        }
@@ -4419,12 +4405,11 @@ mjCKey::~mjCKey() {
 // compiler
 void mjCKey::Compile(const mjModel* m) {
  int i;
  // qpos: allocate or check size
  if (qpos.empty()) {
    qpos.resize(m->nq);
-    for (i=0; i<m->nq; i++) {
+    for (int i=0; i<m->nq; i++) {
      qpos[i] = (double)m->qpos0[i];
    }
  } else if (qpos.size()!=m->nq) {
@@ -4434,7 +4419,7 @@ void mjCKey::Compile(const mjModel* m) {
  // qvel: allocate or check size
  if (qvel.empty()) {
    qvel.resize(m->nv);
-    for (i=0; i<m->nv; i++) {
+    for (int i=0; i<m->nv; i++) {
      qvel[i] = 0;
    }
  } else if (qvel.size()!=m->nv) {
@@ -4444,7 +4429,7 @@ void mjCKey::Compile(const mjModel* m) {
  // act: allocate or check size
  if (act.empty()) {
    act.resize(m->na);
-    for (i=0; i<m->na; i++) {
+    for (int i=0; i<m->na; i++) {
      act[i] = 0;
    }
  } else if (act.size()!=m->na) {
@@ -4455,7 +4440,7 @@ void mjCKey::Compile(const mjModel* m) {
  if (mpos.empty()) {
    mpos.resize(3*m->nmocap);
    if (m->nmocap) {
-      for (i=0; i<m->nbody; i++) {
+      for (int i=0; i<m->nbody; i++) {
        if (m->body_mocapid[i]>=0) {
          int mocapid = m->body_mocapid[i];
          mpos[3*mocapid]   = m->body_pos[3*i];
@@ -4472,7 +4457,7 @@ void mjCKey::Compile(const mjModel* m) {
  if (mquat.empty()) {
    mquat.resize(4*m->nmocap);
    if (m->nmocap) {
-      for (i=0; i<m->nbody; i++) {
+      for (int i=0; i<m->nbody; i++) {
        if (m->body_mocapid[i]>=0) {
          int mocapid = m->body_mocapid[i];
          mquat[4*mocapid]   = m->body_quat[4*i];
@@ -4489,7 +4474,7 @@ void mjCKey::Compile(const mjModel* m) {
  // ctrl: allocate or check size
  if (ctrl.empty()) {
    ctrl.resize(m->nu);
-    for (i=0; i<m->nu; i++) {
+    for (int i=0; i<m->nu; i++) {
      ctrl[i] = 0;
    }
  } else if (ctrl.size()!=m->nu) {
@@ -141,9 +141,8 @@ double mjuu_L1(const double* a, const double* b, int n) {
 // normalize vector to unit length, return previous length
 double mjuu_normvec(double* vec, const int n) {
  double nrm = 0;
  int i;
-  for (i=0; i<n; i++) {
+  for (int i=0; i<n; i++) {
    nrm += vec[i]*vec[i];
  }
  if (nrm < mjEPS) {
@@ -151,7 +150,7 @@ double mjuu_normvec(double* vec, const int n) {
  }
  nrm = sqrt(nrm);
-  for (i=0; i<n; i++) {
+  for (int i=0; i<n; i++) {
    vec[i] /= nrm;
  }
@@ -730,8 +730,6 @@ void mjXReader::PrintSchema(std::stringstream& str, bool html, bool pad) {
 // main entry point for XML parser
 //  mjCModel is allocated here; caller is responsible for deallocation
 void mjXReader::Parse(XMLElement* root) {
  XMLElement *section;
  // check schema
  if (!schema.GetError().empty()) {
    throw mjXError(0, "XML Schema Construction Error: %s\n",
@@ -757,86 +755,86 @@ void mjXReader::Parse(XMLElement* root) {
  //------------------- parse MuJoCo sections embedded in all XML formats
-  for (section = root->FirstChildElement("compiler"); section;
+  for (XMLElement* section = root->FirstChildElement("compiler"); section;
       section = section->NextSiblingElement("compiler")) {
    Compiler(section, model);
  }
-  for (section = root->FirstChildElement("option"); section;
+  for (XMLElement* section = root->FirstChildElement("option"); section;
       section = section->NextSiblingElement("option")) {
    Option(section, &model->option);
  }
-  for (section = root->FirstChildElement("size"); section;
+  for (XMLElement* section = root->FirstChildElement("size"); section;
       section = section->NextSiblingElement("size")) {
    Size(section, model);
  }
  //------------------ parse MJCF-specific sections
-  for (section = root->FirstChildElement("visual"); section;
+  for (XMLElement* section = root->FirstChildElement("visual"); section;
       section = section->NextSiblingElement("visual")) {
    Visual(section);
  }
-  for (section = root->FirstChildElement("statistic"); section;
+  for (XMLElement* section = root->FirstChildElement("statistic"); section;
       section = section->NextSiblingElement("statistic")) {
    Statistic(section);
  }
  readingdefaults = true;
-  for (section = root->FirstChildElement("default"); section;
+  for (XMLElement* section = root->FirstChildElement("default"); section;
       section = section->NextSiblingElement("default")) {
    Default(section, -1);
  }
  readingdefaults = false;
-  for (section = root->FirstChildElement("extension"); section;
+  for (XMLElement* section = root->FirstChildElement("extension"); section;
       section = section->NextSiblingElement("extension")) {
    Extension(section);
  }
-  for (section = root->FirstChildElement("custom"); section;
+  for (XMLElement* section = root->FirstChildElement("custom"); section;
       section = section->NextSiblingElement("custom")) {
    Custom(section);
  }
-  for (section = root->FirstChildElement("asset"); section;
+  for (XMLElement* section = root->FirstChildElement("asset"); section;
       section = section->NextSiblingElement("asset")) {
    Asset(section);
  }
-  for (section = root->FirstChildElement("worldbody"); section;
+  for (XMLElement* section = root->FirstChildElement("worldbody"); section;
       section = section->NextSiblingElement("worldbody")) {
    Body(section, model->GetWorld());
  }
-  for (section = root->FirstChildElement("contact"); section;
+  for (XMLElement* section = root->FirstChildElement("contact"); section;
       section = section->NextSiblingElement("contact")) {
    Contact(section);
  }
-  for (section = root->FirstChildElement("equality"); section;
+  for (XMLElement* section = root->FirstChildElement("equality"); section;
       section = section->NextSiblingElement("equality")) {
    Equality(section);
  }
-  for (section = root->FirstChildElement("tendon"); section;
+  for (XMLElement* section = root->FirstChildElement("tendon"); section;
       section = section->NextSiblingElement("tendon")) {
    Tendon(section);
  }
-  for (section = root->FirstChildElement("actuator"); section;
+  for (XMLElement* section = root->FirstChildElement("actuator"); section;
       section = section->NextSiblingElement("actuator")) {
    Actuator(section);
  }
-  for (section = root->FirstChildElement("sensor"); section;
+  for (XMLElement* section = root->FirstChildElement("sensor"); section;
       section = section->NextSiblingElement("sensor")) {
    Sensor(section);
  }
-  for (section = root->FirstChildElement("keyframe"); section;
+  for (XMLElement* section = root->FirstChildElement("keyframe"); section;
       section = section->NextSiblingElement("keyframe")) {
    Keyframe(section);
  }
@@ -1605,7 +1603,6 @@ void mjXReader::OneTendon(XMLElement* elem, mjCTendon* pten) {
 // actuator element parser
 void mjXReader::OneActuator(XMLElement* elem, mjCActuator* pact) {
  int n;
  string text, type;
  double diameter;
@@ -1672,6 +1669,7 @@ void mjXReader::OneActuator(XMLElement* elem, mjCActuator* pact) {
  // explicit attributes
  if (type=="general") {
    // explicit attributes
    int n;
    if (MapValue(elem, "dyntype", &n, dyn_map, dyn_sz)) {
      pact->dyntype = (mjtDyn)n;
    }
@@ -1811,7 +1809,7 @@ void mjXReader::OneActuator(XMLElement* elem, mjCActuator* pact) {
    ReadAttr(elem, "fvmax", 1, pact->gainprm+8, text);
    // biasprm = gainprm
-    for (n=0; n<9; n++) {
+    for (int n=0; n<9; n++) {
      pact->biasprm[n] = pact->gainprm[n];
    }
@@ -1135,7 +1135,6 @@ void mjXWriter::Extension(XMLElement* root) {
 // custom section
 void mjXWriter::Custom(XMLElement* root) {
  XMLElement* elem;
  int i, j;
  // get sizes, skip section if empty
  int nnum = model->NumObjects(mjOBJ_NUMERIC);
@@ -1151,7 +1150,7 @@ void mjXWriter::Custom(XMLElement* root) {
  XMLElement* section = InsertEnd(root, "custom");
  // write all numerics
-  for (i=0; i<nnum; i++) {
+  for (int i=0; i<nnum; i++) {
    mjCNumeric* ptr = (mjCNumeric*)model->GetObject(mjOBJ_NUMERIC, i);
    elem = InsertEnd(section, "numeric");
    WriteAttrTxt(elem, "name", ptr->name);
@@ -1160,7 +1159,7 @@ void mjXWriter::Custom(XMLElement* root) {
  }
  // write all texts
-  for (i=0; i<ntxt; i++) {
+  for (int i=0; i<ntxt; i++) {
    mjCText* ptr = (mjCText*)model->GetObject(mjOBJ_TEXT, i);
    elem = InsertEnd(section, "text");
    WriteAttrTxt(elem, "name", ptr->name);
@@ -1168,13 +1167,13 @@ void mjXWriter::Custom(XMLElement* root) {
  }
  // write all tuples
-  for (i=0; i<ntup; i++) {
+  for (int i=0; i<ntup; i++) {
    mjCTuple* ptr = (mjCTuple*)model->GetObject(mjOBJ_TUPLE, i);
    elem = InsertEnd(section, "tuple");
    WriteAttrTxt(elem, "name", ptr->name);
    // write objects in tuple
-    for (j=0; j<(int)ptr->objtype.size(); j++) {
+    for (int j=0; j<(int)ptr->objtype.size(); j++) {
      XMLElement* obj = InsertEnd(elem, "element");
      WriteAttrTxt(obj, "objtype", mju_type2Str((int)ptr->objtype[j]));
      WriteAttrTxt(obj, "objname", ptr->objname[j].c_str());
@@ -1191,7 +1190,6 @@ void mjXWriter::Custom(XMLElement* root) {
 // asset section
 void mjXWriter::Asset(XMLElement* root) {
  XMLElement* elem;
  int i;
  // get sizes
  int ntex = model->NumObjects(mjOBJ_TEXTURE);
@@ -1210,7 +1208,7 @@ void mjXWriter::Asset(XMLElement* root) {
  // write textures
  mjCTexture deftex(0);
-  for (i=0; i<ntex; i++) {
+  for (int i=0; i<ntex; i++) {
    // create element
    mjCTexture* ptex = (mjCTexture*)model->GetObject(mjOBJ_TEXTURE, i);
    elem = InsertEnd(section, "texture");
@@ -1260,7 +1258,7 @@ void mjXWriter::Asset(XMLElement* root) {
  }
  // write materials
-  for (i=0; i<nmat; i++) {
+  for (int i=0; i<nmat; i++) {
    // create element and write
    mjCMaterial* pmat = (mjCMaterial*)model->GetObject(mjOBJ_MATERIAL, i);
    elem = InsertEnd(section, "material");
@@ -1268,7 +1266,7 @@ void mjXWriter::Asset(XMLElement* root) {
  }
  // write meshes
-  for (i=0; i<nmesh; i++) {
+  for (int i=0; i<nmesh; i++) {
    // create element and write
    mjCMesh* pmesh = (mjCMesh*)model->GetObject(mjOBJ_MESH, i);
    elem = InsertEnd(section, "mesh");
@@ -1276,7 +1274,7 @@ void mjXWriter::Asset(XMLElement* root) {
  }
  // write skins
-  for (i=0; i<nskin; i++) {
+  for (int i=0; i<nskin; i++) {
    // create element and write
    mjCSkin* pskin = (mjCSkin*)model->GetObject(mjOBJ_SKIN, i);
    elem = InsertEnd(section, "skin");
@@ -1284,7 +1282,7 @@ void mjXWriter::Asset(XMLElement* root) {
  }
  // write hfields
-  for (i=0; i<nhfield; i++) {
+  for (int i=0; i<nhfield; i++) {
    // create element
    mjCHField* phf = (mjCHField*)model->GetObject(mjOBJ_HFIELD, i);
    elem = InsertEnd(section, "hfield");
@@ -1306,7 +1304,6 @@ void mjXWriter::Asset(XMLElement* root) {
 // recursive body writer
 void mjXWriter::Body(XMLElement* elem, mjCBody* body) {
  double unitq[4] = {1, 0, 0, 0};
  unsigned int i;
  if (!body) {
    throw mjXError(0, "missing body in XML write");  // SHOULD NOT OCCUR
@@ -1340,27 +1337,27 @@ void mjXWriter::Body(XMLElement* elem, mjCBody* body) {
  }
  // write joints
-  for (i=0; i<body->joints.size(); i++) {
+  for (int i=0; i<body->joints.size(); i++) {
    OneJoint(InsertEnd(elem, "joint"), body->joints[i], body->joints[i]->def);
  }
  // write geoms
-  for (i=0; i<body->geoms.size(); i++) {
+  for (int i=0; i<body->geoms.size(); i++) {
    OneGeom(InsertEnd(elem, "geom"), body->geoms[i], body->geoms[i]->def);
  }
  // write sites
-  for (i=0; i<body->sites.size(); i++) {
+  for (int i=0; i<body->sites.size(); i++) {
    OneSite(InsertEnd(elem, "site"), body->sites[i], body->sites[i]->def);
  }
  // write cameras
-  for (i=0; i<body->cameras.size(); i++) {
+  for (int i=0; i<body->cameras.size(); i++) {
    OneCamera(InsertEnd(elem, "camera"), body->cameras[i], body->cameras[i]->def);
  }
  // write lights
-  for (i=0; i<body->lights.size(); i++) {
+  for (int i=0; i<body->lights.size(); i++) {
    OneLight(InsertEnd(elem, "light"), body->lights[i], body->lights[i]->def);
  }
@@ -1387,7 +1384,7 @@ void mjXWriter::Body(XMLElement* elem, mjCBody* body) {
  }
  // write child bodies recursively
-  for (i=0; i<body->bodies.size(); i++) {
+  for (int i=0; i<body->bodies.size(); i++) {
    Body(InsertEnd(elem, "body"), body->bodies[i]);
  }
 }
@@ -1397,7 +1394,6 @@ void mjXWriter::Body(XMLElement* elem, mjCBody* body) {
 // collision section
 void mjXWriter::Contact(XMLElement* root) {
  XMLElement* elem;
  int i;
  // get number of pairs of each type
  int npair = model->NumObjects(mjOBJ_PAIR);
@@ -1412,7 +1408,7 @@ void mjXWriter::Contact(XMLElement* root) {
  XMLElement* section = InsertEnd(root, "contact");
  // write all geom pairs
-  for (i=0; i<npair; i++) {
+  for (int i=0; i<npair; i++) {
    // create element and write
    mjCPair* ppair = (mjCPair*)model->GetObject(mjOBJ_PAIR, i);
    elem = InsertEnd(section, "pair");
@@ -1420,7 +1416,7 @@ void mjXWriter::Contact(XMLElement* root) {
  }
  // write all exclude pairs
-  for (i=0; i<nexclude; i++) {
+  for (int i=0; i<nexclude; i++) {
    // create element
    mjCBodyPair* pexclude = (mjCBodyPair*)model->GetObject(mjOBJ_EXCLUDE, i);
    elem = InsertEnd(section, "exclude");
@@ -74,7 +74,7 @@ void mjXURDF::Clear(void) {
 void mjXURDF::Parse(XMLElement* root) {
  std::string name, text;
  XMLElement *elem, *temp;
-  int id_parent, id_child, i;
+  int id_parent, id_child;
  // set compiler defaults suitable for URDF
  model->strippath = true;
@@ -158,7 +158,7 @@ void mjXURDF::Parse(XMLElement* root) {
  }
  // find all top-level bodies, call recursive tree constructor
-  for (i=0; i<(int)urName.size(); i++) {
+  for (int i=0; i<(int)urName.size(); i++) {
    if (urParent[i] < 0) {
      AddToTree(i);
    }
@@ -282,8 +282,6 @@ static int _max(int a, int b) {
 // print schema as text
 void mjXSchema::Print(std::stringstream& str, int level) {
  int i;
  // replace body with (world)body
  string name1 = (name=="body" ? "(world)body" : name);
@@ -297,7 +295,7 @@ void mjXSchema::Print(std::stringstream& str, int level) {
  // attributes
  int cnt = _max(baselen, 30);
-  for (i=0; i<(int)attr.size(); i++) {
+  for (int i=0; i<(int)attr.size(); i++) {
    if (cnt>60) {
      str << "\n";
      printspace(str, (cnt = _max(30, baselen)), " ");
@@ -310,7 +308,7 @@ void mjXSchema::Print(std::stringstream& str, int level) {
  str << "\n";
  // children
-  for (i=0; i<(int)child.size(); i++) {
+  for (int i=0; i<(int)child.size(); i++) {
    child[i]->Print(str, level+1);
  }
 }
@@ -319,8 +317,6 @@ void mjXSchema::Print(std::stringstream& str, int level) {
 // print schema as HTML table
 void mjXSchema::PrintHTML(std::stringstream& str, int level, bool pad) {
  int i;
  // replace body with (world)body
  string name1 = (name=="body" ? "(world)body" : name);
@@ -350,7 +346,7 @@ void mjXSchema::PrintHTML(std::stringstream& str, int level, bool pad) {
  // attributes
  str << "\t<td class=\"at\">";
  if (!attr.empty()) {
-    for (i=0; i<(int)attr.size(); i++) {
+    for (int i=0; i<(int)attr.size(); i++) {
      str << attr[i] << " ";
    }
  } else {
@@ -359,7 +355,7 @@ void mjXSchema::PrintHTML(std::stringstream& str, int level, bool pad) {
  str << "</td>\n</tr>\n";
  // children
-  for (i=0; i<(int)child.size(); i++) {
+  for (int i=0; i<(int)child.size(); i++) {
    child[i]->PrintHTML(str, level+1, pad);
  }
@@ -394,7 +390,6 @@ bool mjXSchema::NameMatch(XMLElement* elem, int level) {
 // validator
 XMLElement* mjXSchema::Check(XMLElement* elem, int level) {
  int i;
  bool missing;
  char msg[100];
  XMLElement *bad, *sub;
@@ -414,7 +409,7 @@ XMLElement* mjXSchema::Check(XMLElement* elem, int level) {
  const XMLAttribute* attribute = elem->FirstAttribute();
  while (attribute) {
    missing = true;
-    for (i=0; i<(int)attr.size(); i++) {
+    for (int i=0; i<(int)attr.size(); i++) {
      if (attr[i]==attribute->Name()) {
        missing = false;
        break;
@@ -445,7 +440,7 @@ XMLElement* mjXSchema::Check(XMLElement* elem, int level) {
  }
  // clear reference counts
-  for (i=0; i<(int)child.size(); i++) {
+  for (int i=0; i<(int)child.size(); i++) {
    child[i]->refcnt = 0;
  }
@@ -454,7 +449,7 @@ XMLElement* mjXSchema::Check(XMLElement* elem, int level) {
  while (sub) {
    // find in child array, update refcnt
    missing = true;
-    for (i=0; i<(int)child.size(); i++) {
+    for (int i=0; i<(int)child.size(); i++) {
      if (child[i]->NameMatch(sub, level+1)) {
        // check sub-tree
        if ((bad = child[i]->Check(sub, level+1))) {
@@ -481,7 +476,7 @@ XMLElement* mjXSchema::Check(XMLElement* elem, int level) {
  // enforce sub-element types
  msg[0] = 0;
-  for (i=0; i<(int)child.size(); i++) {
+  for (int i=0; i<(int)child.size(); i++) {
    switch (child[i]->type) {
    case '!':
      if (child[i]->refcnt != 1)
@@ -92,8 +92,7 @@ bool isQPminimum(const mjtNum* res, const mjtNum* H, const mjtNum* g, int n,
  // compare to nudged solution
  mju_copy(res_nudge, res, n);
-  int i;
+  for (int i=0; i < n; i++) {
  for (i=0; i < n; i++) {
    // nudge down
    res_nudge[i] = res[i] - eps;
    if (lower) {