Show a rotating textured cube

/home/runner/work/vispy/vispy/examples/gloo/textured_cube.py:53: DeprecationWarning: `row_stack` alias is deprecated. Use `np.vstack` directly.
  Z = np.row_stack(grid_num // 2 * (row_even, row_odd)).astype(np.uint8)

import numpy as np

from vispy import gloo, app
from vispy.gloo import Program, VertexBuffer, IndexBuffer
from vispy.util.transforms import perspective, translate, rotate
from vispy.geometry import create_cube


vertex = """
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
uniform sampler2D texture;

attribute vec3 position;
attribute vec2 texcoord;
attribute vec3 normal;
attribute vec4 color;

varying vec2 v_texcoord;
void main()
{
    gl_Position = projection * view * model * vec4(position,1.0);
    v_texcoord = texcoord;
}
"""

fragment = """
uniform sampler2D texture;
varying vec2 v_texcoord;
void main()
{
    gl_FragColor = texture2D(texture, v_texcoord);
}
"""


def checkerboard(grid_num=8, grid_size=32):
    row_even = grid_num // 2 * [0, 1]
    row_odd = grid_num // 2 * [1, 0]
    Z = np.row_stack(grid_num // 2 * (row_even, row_odd)).astype(np.uint8)
    return 255 * Z.repeat(grid_size, axis=0).repeat(grid_size, axis=1)


class Canvas(app.Canvas):
    def __init__(self):
        app.Canvas.__init__(self, size=(512, 512), title='Textured cube',
                            keys='interactive')
        self.timer = app.Timer('auto', self.on_timer)

        # Build cube data
        V, I, _ = create_cube()
        vertices = VertexBuffer(V)
        self.indices = IndexBuffer(I)

        # Build program
        self.program = Program(vertex, fragment)
        self.program.bind(vertices)

        # Build view, model, projection & normal
        view = translate((0, 0, -5))
        model = np.eye(4, dtype=np.float32)
        self.program['model'] = model
        self.program['view'] = view
        self.program['texture'] = checkerboard()

        self.activate_zoom()

        self.phi, self.theta = 0, 0

        # OpenGL initalization
        gloo.set_state(clear_color=(0.30, 0.30, 0.35, 1.00), depth_test=True)
        self.timer.start()

        self.show()

    def on_draw(self, event):
        gloo.clear(color=True, depth=True)
        self.program.draw('triangles', self.indices)

    def on_resize(self, event):
        self.activate_zoom()

    def activate_zoom(self):
        gloo.set_viewport(0, 0, *self.physical_size)
        projection = perspective(45.0, self.size[0] / float(self.size[1]),
                                 2.0, 10.0)
        self.program['projection'] = projection

    def on_timer(self, event):
        self.theta += .5
        self.phi += .5
        self.program['model'] = np.dot(rotate(self.theta, (0, 0, 1)),
                                       rotate(self.phi, (0, 1, 0)))
        self.update()

if __name__ == '__main__':
    c = Canvas()
    app.run()