main.py

main.py

import os

os.environ['KIVY_WINDOW'] = ''  # noqa

from kivy.base import EventLoop, runTouchApp
from kivy.core.window import WindowBase
from kivy.graphics import Callback, opengl as gl
from kivy.lang import Builder
from kivy.properties import ObjectProperty
from direct.showbase.ShowBase import ShowBase
from panda3d.core import CallbackNode, Camera, NodePath, OrthographicLens


def reset_gl_context():
    gl.glEnable(gl.GL_BLEND)
    gl.glDisable(gl.GL_DEPTH_TEST)
    gl.glEnable(gl.GL_STENCIL_TEST)
    gl.glBlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE_MINUS_SRC_ALPHA)
    gl.glBlendFuncSeparate(gl.GL_SRC_ALPHA, gl.GL_ONE_MINUS_SRC_ALPHA, gl.GL_ONE, gl.GL_ONE)
    gl.glActiveTexture(gl.GL_TEXTURE0)
    gl.glPixelStorei(gl.GL_UNPACK_ALIGNMENT, 1)


class PandaApp(ShowBase):
    def __init__(self):
        ShowBase.__init__(self)

        KivyWindow(
            panda_app=self,
            display_region=self.win.make_display_region(),
        )
        runTouchApp(
            Builder.load_string('''
BoxLayout:
    orientation: 'vertical'

    Label:
        text: 'Hello, world!'

    Button:
        text: 'Owi'
            '''),
            slave=True
        )

        scene = self.loader.loadModel('models/environment')
        scene.reparentTo(self.render)
        scene.setScale(0.25, 0.25, 0.25)


class KivyWindow(WindowBase):
    _clearcolor = ObjectProperty()

    def __init__(self, panda_app, display_region, **kwargs):
        self.panda_app = panda_app
        display_region.set_draw_callback(self.on_draw)

        super().__init__(**kwargs)

        with self.canvas.before:
            Callback(lambda _: reset_gl_context())
            Callback(lambda _: gl.glEnableVertexAttribArray(0))

        with self.canvas.after:
            Callback(lambda _: gl.glDisableVertexAttribArray(0))

    def on_draw(self, data=None):
        if data:
            self.size = self.panda_app.win.get_size()
            EventLoop.idle()
        else:
            super().on_draw()


PandaApp().run()