Initial implementation of turntable orbit method (#525)

* Initial implementation of turntable orbit method

Author: jmwright

cq_editor/preferences.py

@@ -91,6 +91,14 @@ def add(self, name, component):
                 # Fill the light/dark theme in the general settings
                 elif child.name() == "Light/Dark Theme":
                     child.setLimits(["Light", "Dark"])
+                # Fill the orbit method
+                elif child.name() == "Orbit Method":
+                    child.setLimits(
+                        [
+                            "Turntable",
+                            "Trackball",
+                        ]
+                    )
 
     @pyqtSlot(QTreeWidgetItem, QTreeWidgetItem)
     def handleSelection(self, item, *args):

cq_editor/widgets/occt_widget.py

@@ -2,13 +2,14 @@
 
 
 from PyQt5.QtWidgets import QWidget, QApplication
-from PyQt5.QtCore import pyqtSlot, pyqtSignal, Qt, QEvent
+from PyQt5.QtCore import pyqtSlot, pyqtSignal, Qt, QPoint
 
 import OCP
 
 from OCP.Aspect import Aspect_DisplayConnection, Aspect_TypeOfTriedronPosition
 from OCP.OpenGl import OpenGl_GraphicDriver
 from OCP.V3d import V3d_Viewer
+from OCP.gp import gp_Trsf, gp_Ax1, gp_Dir
 from OCP.AIS import AIS_InteractiveContext, AIS_DisplayMode
 from OCP.Quantity import Quantity_Color
 
@@ -30,6 +31,15 @@ def __init__(self, parent=None):
 
         self._initialized = False
         self._needs_update = False
+        self._previous_pos = QPoint(
+            0, 0  # Keeps track of where the previous mouse position
+        )
+        self._rotate_step = (
+            0.008  # Controls the speed of rotation with the turntable orbit method
+        )
+
+        # Orbit method settings
+        self._orbit_method = "Turntable"
 
         # OCCT secific things
         self.display_connection = Aspect_DisplayConnection()
@@ -64,6 +74,20 @@ def prepare_display(self):
         ctx.SetDisplayMode(AIS_DisplayMode.AIS_Shaded, True)
         ctx.DefaultDrawer().SetFaceBoundaryDraw(True)
 
+    def set_orbit_method(self, method):
+        """
+        Set the orbit method for the OCCT view.
+        """
+
+        # Keep track of which orbit method is used
+        if method == "Turntable":
+            self._orbit_method = "Turntable"
+            self.view.SetUp(0, 0, 1)
+        elif method == "Trackball":
+            self._orbit_method = "Trackball"
+        else:
+            raise ValueError(f"Unknown orbit method: {method}")
+
     def wheelEvent(self, event):
 
         delta = event.angleDelta().y()
@@ -80,31 +104,51 @@ def mousePressEvent(self, event):
             self.pending_select = True
             self.left_press = pos
 
-            self.view.StartRotation(pos.x(), pos.y())
+            # We only start the rotation if the orbit method is set to Trackball
+            if self._orbit_method == "Trackball":
+                self.view.StartRotation(pos.x(), pos.y())
         elif event.button() == Qt.RightButton:
             self.view.StartZoomAtPoint(pos.x(), pos.y())
 
-        self.old_pos = pos
+        self._previous_pos = pos
 
     def mouseMoveEvent(self, event):
 
         pos = event.pos()
         x, y = pos.x(), pos.y()
 
+        # Check for mouse drag rotation
         if event.buttons() == Qt.LeftButton:
-            self.view.Rotation(x, y)
+            # Set the rotation differently based on the orbit method
+            if self._orbit_method == "Trackball":
+                self.view.Rotation(x, y)
+            elif self._orbit_method == "Turntable":
+                # Control the turntable rotation manually
+                delta_x, delta_y = (
+                    x - self._previous_pos.x(),
+                    y - self._previous_pos.y(),
+                )
+                cam = self.view.Camera()
+                z_rotation = gp_Trsf()
+                z_rotation.SetRotation(
+                    gp_Ax1(cam.Center(), gp_Dir(0, 0, 1)), -delta_x * self._rotate_step
+                )
+                cam.Transform(z_rotation)
+                self.view.Rotate(0, -delta_y * self._rotate_step, 0)
 
             # If the user moves the mouse at all, the selection will not happen
             if abs(x - self.left_press.x()) > 2 or abs(y - self.left_press.y()) > 2:
                 self.pending_select = False
 
         elif event.buttons() == Qt.MiddleButton:
-            self.view.Pan(x - self.old_pos.x(), self.old_pos.y() - y, theToStart=True)
+            self.view.Pan(
+                x - self._previous_pos.x(), self._previous_pos.y() - y, theToStart=True
+            )
 
         elif event.buttons() == Qt.RightButton:
-            self.view.ZoomAtPoint(self.old_pos.x(), y, x, self.old_pos.y())
+            self.view.ZoomAtPoint(self._previous_pos.x(), y, x, self._previous_pos.y())
 
-        self.old_pos = pos
+        self._previous_pos = pos
 
     def mouseReleaseEvent(self, event):
 

cq_editor/widgets/viewer.py

@@ -85,6 +85,15 @@ class OCCViewer(QWidget, ComponentMixin):
                     "OverUnder",
                 ],
             },
+            {
+                "name": "Orbit Method",
+                "type": "list",
+                "value": "Turntable",
+                "values": [
+                    "Turntable",
+                    "Trackball",
+                ],
+            },
         ],
     )
     IMAGE_EXTENSIONS = "png"
@@ -136,6 +145,12 @@ def updatePreferences(self, *args):
             color2 = color1
         self.canvas.view.SetBgGradientColors(color1, color2, theToUpdate=True)
 
+        # Set the orbit method
+        orbit_method = self.preferences["Orbit Method"]
+        if not orbit_method:
+            orbit_method = "Trackball"
+        self.canvas.set_orbit_method(orbit_method)
+
         self.canvas.update()
 
         ctx = self.canvas.context

tests/test_app.py

@@ -10,8 +10,9 @@
 import pytestqt
 import cadquery as cq
 
-from PyQt5.QtCore import Qt, QSettings
+from PyQt5.QtCore import Qt, QSettings, QPoint, QEvent
 from PyQt5.QtWidgets import QFileDialog, QMessageBox
+from PyQt5.QtGui import QMouseEvent
 
 from cq_editor.__main__ import MainWindow
 from cq_editor.widgets.editor import Editor
@@ -1846,3 +1847,65 @@ def test_autocomplete_keystrokes(main):
     qtbot.wait(250)
     # Check that the completion list is still visible
     assert editor.completion_list.isVisible()
+
+
+def test_viewer_orbit_methods(main):
+    """
+    Tests that mouse movements in the viewer work as expected.
+    """
+
+    qtbot, win = main
+
+    viewer = win.components["viewer"]
+
+    # Make sure the editor is focused
+    viewer.setFocus()
+    qtbot.waitExposed(viewer)
+
+    # Simulate a drag to rotate
+    qtbot.mousePress(viewer, Qt.LeftButton)
+    qtbot.mouseMove(viewer, QPoint(100, 100))
+    qtbot.mouseMove(viewer, QPoint(300, 300))
+    qtbot.mouseRelease(viewer, Qt.LeftButton)
+
+    # Simulate a drag to pan
+    qtbot.mousePress(viewer, Qt.MiddleButton)
+    event = QMouseEvent(
+        QEvent.MouseMove,
+        QPoint(100, 100),
+        Qt.RightButton,
+        Qt.RightButton,
+        Qt.NoModifier,
+    )
+    viewer.mouseMoveEvent(event)
+    event = QMouseEvent(
+        QEvent.MouseMove,
+        QPoint(300, 300),
+        Qt.RightButton,
+        Qt.RightButton,
+        Qt.NoModifier,
+    )
+    viewer.mouseMoveEvent(event)
+    qtbot.mouseRelease(viewer, Qt.MiddleButton)
+
+    # Simulate drag to zoom
+    qtbot.mousePress(viewer, Qt.RightButton)
+    event = QMouseEvent(
+        QEvent.MouseMove,
+        QPoint(100, 100),
+        Qt.RightButton,
+        Qt.RightButton,
+        Qt.NoModifier,
+    )
+    viewer.mouseMoveEvent(event)
+    event = QMouseEvent(
+        QEvent.MouseMove,
+        QPoint(300, 300),
+        Qt.RightButton,
+        Qt.RightButton,
+        Qt.NoModifier,
+    )
+    viewer.mouseMoveEvent(event)
+    qtbot.mouseRelease(viewer, Qt.RightButton)
+
+    assert True