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      "source": [
        "%gui qt"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "\n# Show a rotating textured cube\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
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      "source": [
        "import numpy as np\n\nfrom vispy import gloo, app\nfrom vispy.gloo import Program, VertexBuffer, IndexBuffer\nfrom vispy.util.transforms import perspective, translate, rotate\nfrom vispy.geometry import create_cube\n\n\nvertex = \"\"\"\nuniform mat4 model;\nuniform mat4 view;\nuniform mat4 projection;\nuniform sampler2D texture;\n\nattribute vec3 position;\nattribute vec2 texcoord;\nattribute vec3 normal;\nattribute vec4 color;\n\nvarying vec2 v_texcoord;\nvoid main()\n{\n    gl_Position = projection * view * model * vec4(position,1.0);\n    v_texcoord = texcoord;\n}\n\"\"\"\n\nfragment = \"\"\"\nuniform sampler2D texture;\nvarying vec2 v_texcoord;\nvoid main()\n{\n    gl_FragColor = texture2D(texture, v_texcoord);\n}\n\"\"\"\n\n\ndef checkerboard(grid_num=8, grid_size=32):\n    row_even = grid_num // 2 * [0, 1]\n    row_odd = grid_num // 2 * [1, 0]\n    Z = np.row_stack(grid_num // 2 * (row_even, row_odd)).astype(np.uint8)\n    return 255 * Z.repeat(grid_size, axis=0).repeat(grid_size, axis=1)\n\n\nclass Canvas(app.Canvas):\n    def __init__(self):\n        app.Canvas.__init__(self, size=(512, 512), title='Textured cube',\n                            keys='interactive')\n        self.timer = app.Timer('auto', self.on_timer)\n\n        # Build cube data\n        V, I, _ = create_cube()\n        vertices = VertexBuffer(V)\n        self.indices = IndexBuffer(I)\n\n        # Build program\n        self.program = Program(vertex, fragment)\n        self.program.bind(vertices)\n\n        # Build view, model, projection & normal\n        view = translate((0, 0, -5))\n        model = np.eye(4, dtype=np.float32)\n        self.program['model'] = model\n        self.program['view'] = view\n        self.program['texture'] = checkerboard()\n\n        self.activate_zoom()\n\n        self.phi, self.theta = 0, 0\n\n        # OpenGL initalization\n        gloo.set_state(clear_color=(0.30, 0.30, 0.35, 1.00), depth_test=True)\n        self.timer.start()\n\n        self.show()\n\n    def on_draw(self, event):\n        gloo.clear(color=True, depth=True)\n        self.program.draw('triangles', self.indices)\n\n    def on_resize(self, event):\n        self.activate_zoom()\n\n    def activate_zoom(self):\n        gloo.set_viewport(0, 0, *self.physical_size)\n        projection = perspective(45.0, self.size[0] / float(self.size[1]),\n                                 2.0, 10.0)\n        self.program['projection'] = projection\n\n    def on_timer(self, event):\n        self.theta += .5\n        self.phi += .5\n        self.program['model'] = np.dot(rotate(self.theta, (0, 0, 1)),\n                                       rotate(self.phi, (0, 1, 0)))\n        self.update()\n\nif __name__ == '__main__':\n    c = Canvas()\n    app.run()"
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