From ac3ac0d28fcc0a822e9b3de9dbdd239e71d5c6b3 Mon Sep 17 00:00:00 2001
From: Yuval Tassa <tassa@google.com>
Date: Wed, 16 Aug 2023 04:02:59 -0700
Subject: [PATCH] Fix timing plots issue in simulate.

Before this change timing plots would report zeros if the render thread was faster than the physics thread, making them unreadable when slowdown was used.

PiperOrigin-RevId: 557432042
Change-Id: Ie9a18fb84cab788d11dfbede4e3052f24441b4c4
---
 simulate/simulate.cc | 44 +++++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/simulate/simulate.cc b/simulate/simulate.cc
index 776729d9..1f6b9a60 100644
--- a/simulate/simulate.cc
+++ b/simulate/simulate.cc
@@ -326,28 +326,30 @@ void UpdateProfiler(mj::Simulate* sim, const mjModel* m, const mjData* d) {
     total = d->timer[mjTIMER_FORWARD].duration;
     number = d->timer[mjTIMER_FORWARD].number;
   }
-  number = mjMAX(1, number);
-  float tdata[5] = {
-    static_cast<float>(total/number),
-    static_cast<float>(d->timer[mjTIMER_POS_COLLISION].duration/number),
-    static_cast<float>(d->timer[mjTIMER_POS_MAKE].duration/number) +
-    static_cast<float>(d->timer[mjTIMER_POS_PROJECT].duration/number),
-    static_cast<float>(d->timer[mjTIMER_CONSTRAINT].duration/number),
-    0
-  };
-  tdata[4] = tdata[0] - tdata[1] - tdata[2] - tdata[3];
 
-  // update figtimer
-  int pnt = mjMIN(201, sim->figtimer.linepnt[0]+1);
-  for (int n=0; n<5; n++) {
-    // shift data
-    for (int i=pnt-1; i>0; i--) {
-      sim->figtimer.linedata[n][2*i+1] = sim->figtimer.linedata[n][2*i-1];
+  if (number) {  // skip update if no measurements
+    float tdata[5] = {
+      static_cast<float>(total/number),
+      static_cast<float>(d->timer[mjTIMER_POS_COLLISION].duration/number),
+      static_cast<float>(d->timer[mjTIMER_POS_MAKE].duration/number) +
+      static_cast<float>(d->timer[mjTIMER_POS_PROJECT].duration/number),
+      static_cast<float>(d->timer[mjTIMER_CONSTRAINT].duration/number),
+      0
+    };
+    tdata[4] = tdata[0] - tdata[1] - tdata[2] - tdata[3];
+
+    // update figtimer
+    int pnt = mjMIN(201, sim->figtimer.linepnt[0]+1);
+    for (int n=0; n<5; n++) {
+      // shift data
+      for (int i=pnt-1; i>0; i--) {
+        sim->figtimer.linedata[n][2*i+1] = sim->figtimer.linedata[n][2*i-1];
+      }
+
+      // assign new
+      sim->figtimer.linepnt[n] = pnt;
+      sim->figtimer.linedata[n][1] = tdata[n];
     }
-
-    // assign new
-    sim->figtimer.linepnt[n] = pnt;
-    sim->figtimer.linedata[n][1] = tdata[n];
   }
 
   // get sizes: nv, nbody, nefc, sqrt(nnz), ncont, iter
@@ -361,7 +363,7 @@ void UpdateProfiler(mj::Simulate* sim, const mjModel* m, const mjData* d) {
   };
 
   // update figsize
-  pnt = mjMIN(201, sim->figsize.linepnt[0]+1);
+  int pnt = mjMIN(201, sim->figsize.linepnt[0]+1);
   for (int n=0; n<6; n++) {
     // shift data
     for (int i=pnt-1; i>0; i--) {