import numpy as np
from vispy import app, scene
from vispy.scene.visuals import Mesh
from vispy.visuals.filters import ShadingFilter, WireframeFilter
from utils.files.input import ScannedObject


def render3D(obj:ScannedObject,show:bool=True):
    """
    Render a 3D model using vispy
    :param obj: A ScannedObject to be rendered
    """
    vertices = np.asarray(obj.get_vertices())
    faces = np.asarray(obj.get_faces())
    canvas = scene.SceneCanvas(keys='interactive', bgcolor='white')
    view = canvas.central_widget.add_view()
    view.camera = 'arcball'
    view.camera.depth_value = 1e3
    color = (0.3, 0.5, 0.8)
    mesh = Mesh(vertices, faces, color=color)
    view.add(mesh)
    wireframe_filter = WireframeFilter(width=0)
    shading_filter = ShadingFilter(shininess=0)
    mesh.attach(wireframe_filter)
    mesh.attach(shading_filter)

    def attach_headlight(view):
        light_dir = (0, 1, 0, 0)
        shading_filter.light_dir = light_dir[:3]
        initial_light_dir = view.camera.transform.imap(light_dir)
        @view.scene.transform.changed.connect
        def on_transform_change(event):
            transform = view.camera.transform
            shading_filter.light_dir = transform.map(initial_light_dir)[:3]
    attach_headlight(view)
    if show:
        canvas.show()
        app.run()
    else:
        return canvas