UNI-37183 fix not exporting last frame of animation

- issue was due to rounding errors when incrementing the key time causing the last frame to be missed

Author: vkovec

Assets/FbxExporters/Editor/FbxExporter.cs

@@ -1452,7 +1452,7 @@ public static HashSet<float> GetSampleTimes(AnimationCurve[] animCurves, double
                 var keyTimes = new HashSet<float>();
                 double fs = 1.0/sampleRate;
 
-                double currSample = double.MaxValue, firstTime = double.MaxValue, lastTime = double.MinValue;
+                double firstTime = double.MaxValue, lastTime = double.MinValue;
 
                 foreach (var ac in animCurves)
                 {
@@ -1462,9 +1462,10 @@ public static HashSet<float> GetSampleTimes(AnimationCurve[] animCurves, double
                     lastTime = System.Math.Max(lastTime, ac[ac.length-1].time);
                 }
 
-                for (currSample = firstTime; currSample < lastTime; currSample += fs) 
-                {
-                    keyTimes.Add((float)currSample);
+                int firstframe = (int)(firstTime * sampleRate);
+                int lastframe = (int)(lastTime * sampleRate);
+                for (int i = firstframe; i <= lastframe; i++) {
+                    keyTimes.Add ((float)(i * fs));
                 }
 
                 return keyTimes;