id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	blockedby	blocking	notify_on_close	platform	project
2552	Enhancement: mousemode to Z-shift CofR	Tristan Croll	Tom Goddard	"I've just added this to Clipper, but it might make sense as part of ChimeraX in general to go with the ""cofr centerOfView"" mode? Will attach a quick movie to demonstrate.

{{{
class Z_Shift_CofR(MouseMode):
    def __init__(self, session):
        self._step_multiplier = 1
        super().__init__(session)
        from chimerax.core.graphics import Drawing
        d = self._drawing = Drawing('Depth Indicator')
        d.set_geometry(*self._drawing_geometry())
        d.display = False
        self.view.drawing.add_drawing(d)

    def cleanup(self):
        self.view.drawing.remove_drawing(self._drawing)

    def mouse_down(self, event):
        MouseMode.mouse_down(self, event)
        self._set_drawing_position()
        self._set_drawing_color()
        self._drawing.display=True

    def mouse_drag(self, event):
        dx, dy = self.mouse_motion(event)
        self.move_camera_and_cofr(-3*self.pixel_size()*dy)
        self._set_drawing_position()

    def mouse_up(self, event):
        self._drawing.display=False
        MouseMode.mouse_up(self, event)

    def wheel(self, event):
        d = event.wheel_value()
        psize = self.pixel_size()
        self.move_camera_and_cofr(-100*d*psize)

    def move_camera_and_cofr(self, dz):
        cofr = self.view.center_of_rotation
        cofr_method = self.view.center_of_rotation_method
        camera = self.view.camera
        cpos = self.camera_position.origin()
        vd = camera.view_direction()
        import numpy
        cc = cofr-cpos
        shift_vec = numpy.dot(cc/numpy.linalg.norm(cc), vd) *vd * dz
        from chimerax.core.geometry import translation
        t = translation(shift_vec)
        self.view.center_of_rotation += shift_vec
        self.view.center_of_rotation_method = cofr_method
        camera.set_position(t*camera.position)

    def _drawing_geometry(self):
        from chimerax.surface.shapes import box_geometry
        return box_geometry((-1,-1,-0.01), (1,1,0.01))

    def _set_drawing_position(self):
        from chimerax.core.geometry import Place, scale
        scale = 300*self.pixel_size()
        p = Place(axes=self.view.camera.position.axes()*scale, origin=self.view.center_of_rotation)
        self._drawing.position = p

    def _set_drawing_color(self):
        from chimerax.core.colors import contrast_with, Color
        import numpy
        color = numpy.array([0,0,0,0.5], numpy.float32)
        color[:3] = contrast_with(self.view.background_color)
        self._drawing.color = Color(color).uint8x4()

}}}"	enhancement	assigned	moderate		Graphics								all	ChimeraX