diff --git a/app/src/main/java/net/voussoir/trkpt/TrackFragment.kt b/app/src/main/java/net/voussoir/trkpt/TrackFragment.kt
index 0e42f91..e031fb6 100644
--- a/app/src/main/java/net/voussoir/trkpt/TrackFragment.kt
+++ b/app/src/main/java/net/voussoir/trkpt/TrackFragment.kt
@@ -62,6 +62,7 @@ import org.osmdroid.views.overlay.TilesOverlay
 import org.osmdroid.views.overlay.simplefastpoint.SimpleFastPointOverlay
 import org.osmdroid.views.overlay.simplefastpoint.SimpleFastPointOverlayOptions
 import org.osmdroid.views.overlay.simplefastpoint.SimplePointTheme
+import java.lang.Math.*
 import java.util.*
 
 class TrackFragment : Fragment(), MapListener, YesNoDialog.YesNoDialogListener
@@ -87,7 +88,9 @@ class TrackFragment : Fragment(), MapListener, YesNoDialog.YesNoDialogListener
     lateinit var isolate_trkseg_button: ImageButton
     lateinit var when_was_i_here_button: ImageButton
     lateinit var interpolate_points_button: ImageButton
+    lateinit var straighten_points_button: ImageButton
     var ready_to_interpolate: Boolean = false
+    var ready_to_straighten: Boolean = false
     var track_query_start_time_previous: Int = 0
     var track_query_end_time_previous: Int = 0
     private lateinit var mapView: MapView
@@ -347,6 +350,11 @@ class TrackFragment : Fragment(), MapListener, YesNoDialog.YesNoDialogListener
         interpolate_points_button = rootView.findViewById(R.id.interpolate_points_button)
         interpolate_points_button.setOnClickListener {
             Log.i("VOUSSOIR", "interpolate_points_button.")
+            if (ready_to_straighten)
+            {
+                ready_to_straighten = false
+                straighten_points_button.setColorFilter(null)
+            }
             if (ready_to_interpolate)
             {
                 interpolate_points_button.setColorFilter(null)
@@ -358,6 +366,25 @@ class TrackFragment : Fragment(), MapListener, YesNoDialog.YesNoDialogListener
             ready_to_interpolate = !ready_to_interpolate
         }
 
+        straighten_points_button = rootView.findViewById(R.id.straighten_points_button)
+        straighten_points_button.setOnClickListener {
+            Log.i("VOUSSOIR", "straighten_points_button.")
+            if (ready_to_interpolate)
+            {
+                ready_to_interpolate = false
+                interpolate_points_button.setColorFilter(null)
+            }
+            if (ready_to_straighten)
+            {
+                straighten_points_button.setColorFilter(null)
+            }
+            else
+            {
+                straighten_points_button.setColorFilter(resources.getColor(R.color.fuchsia))
+            }
+            ready_to_straighten = !ready_to_straighten
+        }
+
         save_track_button.setOnClickListener {
             val dialog = Dialog(activity as Context)
             dialog.setContentView(R.layout.dialog_rename_track)
@@ -450,9 +477,12 @@ class TrackFragment : Fragment(), MapListener, YesNoDialog.YesNoDialogListener
             mapView.invalidate()
         }
         ready_to_interpolate = false
+        ready_to_straighten = false
         interpolate_points_button.setColorFilter(null)
+        straighten_points_button.setColorFilter(null)
         delete_selected_trkpt_button.visibility = View.GONE
         interpolate_points_button.visibility = View.GONE
+        straighten_points_button.visibility = View.GONE
         use_trkpt_as_start_button.visibility = View.GONE
         use_trkpt_as_end_button.visibility = View.GONE
         isolate_trkseg_button.visibility = View.GONE
@@ -560,6 +590,13 @@ class TrackFragment : Fragment(), MapListener, YesNoDialog.YesNoDialogListener
                     handler.post(requery_and_render)
                     return
                 }
+                else if (ready_to_straighten && selected_trkpt != null)
+                {
+                    straighten_points(selected_trkpt!!, trkpt)
+                    deselect_trkpt()
+                    handler.post(requery_and_render)
+                    return
+                }
                 selected_trkpt = trkpt
                 selected_trkpt_info.text = "${trkpt.time}\n${iso8601_local(trkpt.time)}\n${trkpt.latitude}\n${trkpt.longitude}\n${trkpt.accuracy}"
                 selected_trkpt_marker.position = trkpt
@@ -568,6 +605,7 @@ class TrackFragment : Fragment(), MapListener, YesNoDialog.YesNoDialogListener
                     mapView.overlays.add(selected_trkpt_marker)
                 }
                 interpolate_points_button.visibility = View.VISIBLE
+                straighten_points_button.visibility = View.VISIBLE
                 delete_selected_trkpt_button.visibility = View.VISIBLE
                 use_trkpt_as_start_button.visibility = View.VISIBLE
                 use_trkpt_as_end_button.visibility = View.VISIBLE
@@ -593,6 +631,28 @@ class TrackFragment : Fragment(), MapListener, YesNoDialog.YesNoDialogListener
         return pl
     }
 
+    fun straighten_points(a: Trkpt, b: Trkpt)
+    {
+        val subtrack = Track(track.database, track.device_id)
+        subtrack.load_trkpts(trackbook.database.select_trkpt_start_end(
+            track.device_id,
+            start_time=min(a.time, b.time),
+            end_time=max(a.time, b.time),
+        ))
+        val lat_step = (b.latitude - a.latitude) / (b.time - a.time)
+        val lon_step = (b.longitude - a.longitude) / (b.time - a.time)
+        val ele_step = (b.altitude - a.altitude) / (b.time - a.time)
+        for (trkpt in subtrack.trkpts)
+        {
+            val index = trkpt.time - a.time
+            trkpt.latitude = a.latitude + (index  * lat_step)
+            trkpt.longitude = a.longitude + (index * lon_step)
+            trkpt.altitude = a.altitude + (index * ele_step)
+            trackbook.database.update_trkpt(trkpt, commit=false)
+        }
+        trackbook.database.commit()
+    }
+
     fun set_datetime(datepicker: DatePicker, timepicker: TimePicker, setdate: Date, _ending: Boolean)
     {
         datetime_change_listener_enabled = false
diff --git a/app/src/main/res/drawable/ic_straighten_24dp.xml b/app/src/main/res/drawable/ic_straighten_24dp.xml
new file mode 100644
index 0000000..0e0d4c1
--- /dev/null
+++ b/app/src/main/res/drawable/ic_straighten_24dp.xml
@@ -0,0 +1,13 @@
+<vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:name="vector"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:name="path"
+        android:pathData="M 3.014 9.656 C 1.725 9.656 0.67 10.711 0.67 12 C 0.67 13.289 1.725 14.344 3.014 14.344 C 3.944 14.344 4.747 13.791 5.125 13 L 6.895 13 C 7.272 13.791 8.073 14.344 9.004 14.344 C 9.934 14.344 10.737 13.791 11.115 13 L 12.885 13 C 13.263 13.791 14.066 14.344 14.996 14.344 C 15.927 14.344 16.728 13.791 17.105 13 L 18.875 13 C 19.253 13.791 20.056 14.344 20.986 14.344 C 22.275 14.344 23.33 13.289 23.33 12 C 23.33 10.711 22.275 9.656 20.986 9.656 C 20.056 9.656 19.253 10.209 18.875 11 L 17.105 11 C 16.728 10.209 15.927 9.656 14.996 9.656 C 14.066 9.656 13.263 10.209 12.885 11 L 11.115 11 C 10.737 10.209 9.934 9.656 9.004 9.656 C 8.073 9.656 7.272 10.209 6.895 11 L 5.125 11 C 4.747 10.209 3.944 9.656 3.014 9.656 Z"
+        android:fillColor="@color/icon_default"
+        />
+</vector>
diff --git a/app/src/main/res/layout/fragment_track.xml b/app/src/main/res/layout/fragment_track.xml
index baec6c5..837e022 100755
--- a/app/src/main/res/layout/fragment_track.xml
+++ b/app/src/main/res/layout/fragment_track.xml
@@ -133,6 +133,19 @@
                 app:layout_constraintEnd_toStartOf="@+id/isolate_trkseg_button"
                 app:srcCompat="@drawable/ic_bug_report_24dp" />
 
+            <ImageButton
+                android:id="@+id/straighten_points_button"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:contentDescription="Straighten points"
+                android:tooltipText="Straighten points"
+                android:src="@drawable/ic_straighten_24dp"
+                android:visibility="gone"
+                app:backgroundTint="@color/default_transparent"
+                app:layout_constraintTop_toTopOf="@+id/interpolate_points_button"
+                app:layout_constraintEnd_toStartOf="@+id/interpolate_points_button"
+                app:srcCompat="@drawable/ic_straighten_24dp" />
+
             <ImageButton
                 android:id="@+id/delete_selected_trkpt_button"
                 android:layout_width="wrap_content"