GLViewWidget.py 文件源码

def pixelSize(self, pos):
        """
        Return the approximate size of a screen pixel at the location pos
        Pos may be a Vector or an (N,3) array of locations
        """
        cam = self.cameraPosition()
        if isinstance(pos, np.ndarray):
            cam = np.array(cam).reshape((1,)*(pos.ndim-1)+(3,))
            dist = ((pos-cam)**2).sum(axis=-1)**0.5
        else:
            dist = (pos-cam).length()
        xDist = dist * 2. * np.tan(0.5 * self.opts['fov'] * np.pi / 180.)
        return xDist / self.width()