Merge pull request #8 from ch-sa/mac-retina-fix

Fix coordinate problem for retina displays

labelCloud/utils/oglhelper.py

@@ -12,6 +12,8 @@
 Color4f = Tuple[float, float, float, float]  # type alias for type hinting
 PointList = List[List[float]]
 
+DEVICE_PIXEL_RATIO = None  # is set once and for every window resize (retina display fix)
+
 
 def draw_points(points: PointList, color: Color4f = (0, 1, 1, 1), point_size: int = 10) -> None:
     GL.glColor4d(*color)
@@ -96,6 +98,9 @@ def get_pick_ray(x: float, y: float, modelview, projection) -> Tuple[List[float]
     :param projection: projection matrix
     :return: two points of the pick ray from the closest and furthest frustum
     """
+    x *= DEVICE_PIXEL_RATIO
+    y *= DEVICE_PIXEL_RATIO
+
     viewport = GL.glGetIntegerv(GL.GL_VIEWPORT)
     real_y = viewport[3] - y  # adjust for down-facing y positions
 

labelCloud/view/viewer.py

@@ -15,13 +15,16 @@
 
 # Main widget for presenting the point cloud
 class GLWidget(QtOpenGL.QGLWidget):
+
     def __init__(self, parent=None):
         self.parent = parent
         QtOpenGL.QGLWidget.__init__(self, parent)
         self.setMouseTracking(True)  # mouseMoveEvent is called also without button pressed
 
         self.modelview = None
         self.projection = None
+        self.DEVICE_PIXEL_RATIO = self.devicePixelRatioF()  # 1 = normal; 2 = retina display
+        oglhelper.DEVICE_PIXEL_RATIO = self.DEVICE_PIXEL_RATIO  # set for helper functions
 
         self.pcd_controller = None
         self.bbox_controller = None
@@ -111,6 +114,9 @@ def paintGL(self):
 
     # Translates the 2D cursor position from screen plane into 3D world space coordinates
     def get_world_coords(self, x: int, y: int, z: float = None, correction: bool = False):
+        x *= self.DEVICE_PIXEL_RATIO  # For fixing mac retina bug
+        y *= self.DEVICE_PIXEL_RATIO
+
         viewport = GL.glGetIntegerv(GL.GL_VIEWPORT)  # Stored projection matrices are taken from loop
         real_y = viewport[3] - y  # adjust for down-facing y positions