Gui: Added classic trackball orbit style (#20535)

* Gui: add classic trackball orbit

* Gui: add rounded arcball orbit

src/Gui/Navigation/NavigationStyle.cpp

@@ -64,7 +64,9 @@ public:
     enum OrbitStyle {
         Turntable,
         Trackball,
-        FreeTurntable
+        FreeTurntable,
+        TrackballClassic,
+        RoundedArcball
     };
 
     static constexpr float defaultSphereRadius = 0.8F;
@@ -87,9 +89,114 @@ public:
 
     SbVec3f project(const SbVec2f &point) override
     {
+        if (orbit != RoundedArcball) {
             return inherited::project(point);
         }
 
+        // Rounded Arcball implementation
+        // based on SbSphereSheetProjector in Open Inventor
+        SbVec3f result;
+        SbLine workingLine = getWorkingLine(point);
+
+        if (needSetup) {
+            setupPlane();
+        }
+
+        SbVec3f planeIntersection;
+
+        SbVec3f sphereIntersection, dontCare;
+        SbBool hitSphere;
+        if (intersectFront == TRUE) {
+            hitSphere = sphere.intersect(workingLine, sphereIntersection, dontCare);
+        }
+        else {
+            hitSphere = sphere.intersect(workingLine, dontCare, sphereIntersection);
+        }
+
+        if (hitSphere) {
+            // drop the sphere intersection onto the tolerance plane
+
+            SbLine projectLine(sphereIntersection, sphereIntersection + planeDir);
+            if (!tolPlane.intersect(projectLine, planeIntersection))
+#ifdef DEBUG
+                SoDebugError::post("SbSphereSheetProjector::project",
+                                   "Couldn't intersect working line with plane");
+#else
+                /* Do nothing */;
+#endif
+        }
+        else if (!tolPlane.intersect(workingLine, planeIntersection))
+#ifdef DEBUG
+            SoDebugError::post("SbSphereSheetProjector::project", "Couldn't intersect with plane");
+#else
+            /* Do nothing */;
+#endif
+
+        // Three possibilities:
+        // (1) Intersection is on the sphere inside where the fillet
+        //	    hits it
+        // (2) Intersection is on the fillet
+        // (3) Intersection is on the plane
+        float distance = (planeIntersection - planePoint).length();
+
+        // Amount of filleting
+        // 0 = no fillet (just sphere and plane)
+        // infinity = only fillet
+        float border = 0.5;
+
+        // Radius where the fillet meets the plane in "squished space"
+        float r_a = 1.0F + border;
+        // Radius where the sphere meets the fillet in "squished space"
+        float r_i = 2.0 / (r_a + 1.0 / r_a);
+
+        // Distance squared in "squished space"
+        float d_2 = (distance * distance) * r_a * r_a;
+        // Distance in "squished space"
+        float d = std::sqrt(d_2);
+
+        // Compute how far off the plane we are
+        float offsetDist = 0.0;
+
+        if (d > r_a) {
+            // On the plane
+            offsetDist = 0.0;
+        }
+        else if (d < r_i) {
+            // On the sphere inside the fillet
+            offsetDist = std::sqrt(1.0 - d_2);
+        }
+        else {
+            // On the fillet
+            float d_r = r_a - d;
+            float a = border * (1.0 + border / 2.0);
+            offsetDist = a - std::sqrt((a + d_r) * (a - d_r));
+        }
+
+        SbVec3f offset;
+        if (orientToEye) {
+            if (viewVol.getProjectionType() == SbViewVolume::PERSPECTIVE) {
+                offset = workingProjPoint - planeIntersection;
+            }
+            else {
+                worldToWorking.multDirMatrix(viewVol.zVector(), offset);
+            }
+
+            offset.normalize();
+        }
+        else {
+            offset.setValue(0, 0, 1);
+        }
+        if (intersectFront == FALSE) {
+            offset *= -1.0;
+        }
+
+        offset *= offsetDist;
+        result = planeIntersection + offset;
+
+        lastPoint = result;
+        return result;
+    }
+
     SbRotation getRotation(const SbVec3f &point1, const SbVec3f &point2) override
     {
         SbRotation rot = inherited::getRotation(point1, point2);
@@ -99,6 +206,9 @@ public:
         if (orbit == FreeTurntable) {
             return getFreeTurntable(point1, point2);
         }
+        if (orbit == TrackballClassic) {
+            return getTrackballClassic(point1, point2);
+        }
 
         return rot;
     }
@@ -164,6 +274,22 @@ private:
         return zrot * xrot;
     }
 
+    SbRotation getTrackballClassic(const SbVec3f &point1, const SbVec3f &point2) const
+    {
+        // Classic trackball
+        SbRotation zrot;
+        SbRotation yrot;
+        SbVec3f dif = point1 - point2;
+
+        SbVec3f zaxis(1,0,0);
+        zrot.setValue(zaxis, dif[1]);
+
+        SbVec3f yaxis(0,1,0);
+        yrot.setValue(yaxis, -dif[0]);
+
+        return zrot * yrot;
+    }
+
 private:
     SbMatrix worldToScreen;
     OrbitStyle orbit{Trackball};
@@ -888,7 +1014,9 @@ void NavigationStyle::spin(const SbVec2f & pointerpos)
     float sensitivity = getSensitivity();
 
     // Adjust the spin projector sphere to the screen position of the rotation center when the mouse intersects an object
-    if (getOrbitStyle() == Trackball && rotationCenterMode & RotationCenterMode::ScenePointAtCursor && rotationCenterFound && rotationCenterIsScenePointAtCursor) {
+    if ((getOrbitStyle() == Trackball || getOrbitStyle() == TrackballClassic || getOrbitStyle() == RoundedArcball)
+        && rotationCenterMode & RotationCenterMode::ScenePointAtCursor && rotationCenterFound
+        && rotationCenterIsScenePointAtCursor) {
         const auto pointOnScreen = viewer->getPointOnViewport(rotationCenter);
         const auto sphereCenter = 2 * normalizePixelPos(pointOnScreen) - SbVec2f {1, 1};
 

src/Gui/Navigation/NavigationStyle.h

@@ -103,7 +103,9 @@ public:
     enum OrbitStyle {
         Turntable,
         Trackball,
-        FreeTurntable
+        FreeTurntable,
+        TrackballClassic,
+        RoundedArcball,
     };
 
     enum class RotationCenterMode {

src/Gui/PreferencePages/DlgSettingsNavigation.ui

@@ -475,7 +475,9 @@ Select a set and then press the button to view said configurations.</string>
          <string>Rotation orbit style.
 Trackball: moving the mouse horizontally will rotate the part around the y-axis
 Turntable: the part will be rotated around the z-axis (with constrained axes).
-Free Turntable: the part will be rotated around the z-axis.</string>
+Free Turntable: the part will be rotated around the z-axis.
+Trackball Classic: moving the mouse will rotate the part allowing precession
+Rounded Arcball: moving the mouse in the corners of the screen will only roll the part.</string>
         </property>
         <property name="currentIndex">
          <number>1</number>
@@ -495,6 +497,16 @@ Free Turntable: the part will be rotated around the z-axis.</string>
           <string>Free Turntable</string>
          </property>
         </item>
+        <item>
+         <property name="text">
+          <string>Trackball Classic</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Rounded Arcball</string>
+         </property>
+        </item>
        </widget>
       </item>
       <item row="2" column="0">

src/Mod/Tux/NavigationIndicatorGui.py

@@ -612,6 +612,8 @@ def retranslateUi():
     aTurntable.setText(translate("NavigationIndicator", "Turntable"))
     aFreeTurntable.setText(translate("NavigationIndicator", "Free Turntable"))
     aTrackball.setText(translate("NavigationIndicator", "Trackball"))
+    aTrackballClassic.setText(translate("NavigationIndicator", "Trackball Classic"))
+    aRoundedArcball.setText(translate("NavigationIndicator", "Rounded Arcball"))
     a0.setText(translate("NavigationIndicator", "Undefined"))
 
 
@@ -648,10 +650,18 @@ aTrackball.setCheckable(True)
 aFreeTurntable = QtGui.QAction(gOrbit)
 aFreeTurntable.setObjectName("NavigationIndicator_FreeTurntable")
 aFreeTurntable.setCheckable(True)
+aTrackballClassic = QtGui.QAction(gOrbit)
+aTrackballClassic.setObjectName("NavigationIndicator_TrackballClassic")
+aTrackballClassic.setCheckable(True)
+aRoundedArcball = QtGui.QAction(gOrbit)
+aRoundedArcball.setObjectName("NavigationIndicator_RoundedArcball")
+aRoundedArcball.setCheckable(True)
 
 menuOrbit.addAction(aTurntable)
 menuOrbit.addAction(aTrackball)
 menuOrbit.addAction(aFreeTurntable)
+menuOrbit.addAction(aTrackballClassic)
+menuOrbit.addAction(aRoundedArcball)
 
 menuSettings.addMenu(menuOrbit)
 menuSettings.addSeparator()
@@ -795,6 +805,10 @@ def onOrbit():
         pView.SetInt("OrbitStyle", 1)
     elif aFreeTurntable.isChecked():
         pView.SetInt("OrbitStyle", 2)
+    elif aTrackballClassic.isChecked():
+        pView.SetInt("OrbitStyle", 3)
+    elif aRoundedArcball.isChecked():
+        pView.SetInt("OrbitStyle", 4)
 
 
 def onOrbitShow():
@@ -808,6 +822,10 @@ def onOrbitShow():
         aTrackball.setChecked(True)
     elif OrbitStyle == 2:
         aFreeTurntable.setChecked(True)
+    elif OrbitStyle == 3:
+        aTrackballClassic.setChecked(True)
+    elif OrbitStyle == 4:
+        aRoundedArcball.setChecked(True)
     gOrbit.blockSignals(False)