added orbital rotation mode and take scroll delta into account when zooming

Author: mbway

cq_editor/widgets/occt_widget.py

@@ -1,47 +1,55 @@
+import math
 from sys import platform
 
-
-from PyQt5.QtWidgets import QWidget, QApplication
-from PyQt5.QtCore import pyqtSlot, pyqtSignal, Qt, QEvent
-
-import OCP
-
+from OCP.AIS import AIS_InteractiveContext, AIS_DisplayMode
 from OCP.Aspect import Aspect_DisplayConnection, Aspect_TypeOfTriedronPosition
 from OCP.OpenGl import OpenGl_GraphicDriver
-from OCP.V3d import V3d_Viewer
-from OCP.AIS import AIS_InteractiveContext, AIS_DisplayMode
 from OCP.Quantity import Quantity_Color
+from OCP.V3d import V3d_Viewer
+from OCP.gp import gp_Trsf, gp_Ax1, gp_Dir
+from PyQt5.QtCore import pyqtSignal, Qt, QPoint
+from PyQt5.QtWidgets import QWidget
 
 
-ZOOM_STEP = 0.9
-
- 
 class OCCTWidget(QWidget):
 
  sigObjectSelected = pyqtSignal(list)
 
- def __init__(self,parent=None):
+ def __init__(self, parent=None, *,
+ orbital_rotation: bool = True,
+ rotate_step: float = 0.008,
+ zoom_step: float = 0.1):
 
- super(OCCTWidget,self).__init__(parent)
+ super(OCCTWidget, self).__init__(parent)
 
  self.setAttribute(Qt.WA_NativeWindow)
  self.setAttribute(Qt.WA_PaintOnScreen)
  self.setAttribute(Qt.WA_NoSystemBackground)
 
  self._initialized = False
  self._needs_update = False
+ self._old_pos = QPoint(0, 0)
+ self._rotate_step = rotate_step
+ self._zoom_step = zoom_step
+ self._orbital_rotation = orbital_rotation
 
- #OCCT secific things
+ # OCCT secific things
  self.display_connection = Aspect_DisplayConnection()
  self.graphics_driver = OpenGl_GraphicDriver(self.display_connection)
 
  self.viewer = V3d_Viewer(self.graphics_driver)
  self.view = self.viewer.CreateView()
  self.context = AIS_InteractiveContext(self.viewer)
 
- #Trihedorn, lights, etc
+ # Trihedorn, lights, etc
  self.prepare_display()
- 
+
+ def set_orbital_rotation(self, new_value: bool):
+ if self._orbital_rotation != new_value:
+ self._orbital_rotation = new_value
+ if self._orbital_rotation:
+ self.view.SetUp(0, 0, 1)
+
  def prepare_display(self):
 
  view = self.view
@@ -65,49 +73,58 @@ def prepare_display(self):
  ctx.DefaultDrawer().SetFaceBoundaryDraw(True)
 
  def wheelEvent(self, event):
- 
- delta = event.angleDelta().y()
- factor = ZOOM_STEP if delta<0 else 1/ZOOM_STEP
- 
+
+ # dividing by 120 gets number of notches on a typical scroll wheel.
+ # See QWheelEvent documentation
+ delta_notches = event.angleDelta().y() / 120
+ direction = math.copysign(1, delta_notches)
+ factor = (1 + self._zoom_step * direction) ** abs(delta_notches)
+
  self.view.SetZoom(factor)
 
- def mousePressEvent(self,event):
+ def mousePressEvent(self, event):
 
  pos = event.pos()
- 
+
  if event.button() == Qt.LeftButton:
- self.view.StartRotation(pos.x(), pos.y())
+ if not self._orbital_rotation:
+ self.view.StartRotation(pos.x(), pos.y())
  elif event.button() == Qt.RightButton:
  self.view.StartZoomAtPoint(pos.x(), pos.y())
 
- self.old_pos = pos
- 
- def mouseMoveEvent(self,event):
+ self._old_pos = pos
+
+ def mouseMoveEvent(self, event):
 
  pos = event.pos()
- x,y = pos.x(),pos.y()
- 
+ x, y = pos.x(), pos.y()
+
  if event.buttons() == Qt.LeftButton:
- self.view.Rotation(x,y)
- 
+ if self._orbital_rotation:
+ delta_x, delta_y = x - self._old_pos.x(), y - self._old_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)
+ else:
+ self.view.Rotation(x, y)
+
  elif event.buttons() == Qt.MiddleButton:
- self.view.Pan(x - self.old_pos.x(),
-  self.old_pos.y() - y, theToStart=True)
+ delta_x, delta_y = x - self._old_pos.x(), y - self._old_pos.y()
+ self.view.Pan(delta_x, -delta_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._old_pos.x(), y,
+ x, self._old_pos.y())
 
- self.old_pos = pos
+ self._old_pos = pos
 
- def mouseReleaseEvent(self,event):
+ def mouseReleaseEvent(self, event):
 
  if event.button() == Qt.LeftButton:
  pos = event.pos()
- x,y = pos.x(),pos.y()
- 
- self.context.MoveTo(x,y,self.view,True)
- 
+ self.context.MoveTo(pos.x(), pos.y(), self.view, True)
  self._handle_selection()
 
  def _handle_selection(self):

cq_editor/widgets/viewer.py

@@ -39,8 +39,9 @@ class OCCViewer(QWidget,ComponentMixin):
  {'name': 'Background color (aux)', 'type': 'color', 'value': (30,30,30)},
  {'name': 'Default object color', 'type': 'color', 'value': "FF0"},
  {'name': 'Deviation', 'type': 'float', 'value': 1e-5, 'dec': True, 'step': 1},
- {'name': 'Angular deviation', 'type': 'float', 'value': 0.1, 'dec': True, 'step': 1}])
- 
+ {'name': 'Angular deviation', 'type': 'float', 'value': 0.1, 'dec': True, 'step': 1},
+ {'name': 'Orbital rotation', 'type': 'bool', 'value': True}])
+
 
  IMAGE_EXTENSIONS = 'png'
 
@@ -71,6 +72,7 @@ def updatePreferences(self,*args):
  if not self.preferences['Use gradient']:
  color2 = color1
  self.canvas.view.SetBgGradientColors(color1,color2,theToUpdate=True)
+ self.canvas.set_orbital_rotation(self.preferences['Orbital rotation'])
 
  self.canvas.update()