import sys
from direct.showbase.ShowBase import ShowBase
from direct.task import Task
from panda3d.core import *

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

        # Move camera for a better view
        self.disableMouse() # if you leave mouse mode enabled camera position will be governed by Panda mouse control
        self.camera.setY(- 10)

        # Enable fast exit
        self.accept("escape", sys.exit)

        # Create cube
        gNode = self.createCube()
        self.cubeNodePath = self.render.attachNewNode(gNode)

        # Add a simple point light
        plight = PointLight('plight')
        plight.setColor(VBase4(0.5, 0.5, 0.5, 1))
        #plight.setAttenuation(Point3(0, 0, 0.5))
        plnp = self.render.attachNewNode(plight)
        plnp.setPos(4, -4, 4)
        self.render.setLight(plnp)
        # Add an ambient light
        alight = AmbientLight('alight')
        alight.setColor(VBase4(0.2, 0.2, 0.2, 1))
        alnp = self.render.attachNewNode(alight)
        self.render.setLight(alnp)

        # Add the spinCubeTask procedure to the task manager.
        self.taskMgr.add(self.spinCubeTask, "spinCubeTask")

    def spinCubeTask(self, task):
        angleDegrees = task.time * 6.0
        self.cubeNodePath.setHpr(angleDegrees, angleDegrees, angleDegrees)
        return Task.cont

    def createCube(self):
        format = GeomVertexFormat.getV3n3t2()
        vertexData = GeomVertexData('cube', format, Geom.UHStatic)

        vertexData.setNumRows(24)

        vertices = GeomVertexWriter(vertexData, 'vertex')
        normals = GeomVertexWriter(vertexData, 'normal')
        texcoord = GeomVertexWriter(vertexData, 'texcoord')

        n_forward = (0, 0, 1)
        n_back = (0, 0, -1)
        n_down = (0, -1, 0)
        n_left = (-1, 0, 0)
        n_right = (1, 0, 0)
        n_up = (0, 1, 0)

        p0 = (-0.5, -0.5, 0.5)
        p1 = (0.5, -0.5,  0.5)
        p2 = (0.5, -0.5, -0.5)
        p3 = (-0.5, -0.5, -0.5)
        p4 = (-0.5, 0.5, 0.5)
        p5 = (0.5, 0.5, 0.5)
        p6 = (0.5, 0.5, -0.5)
        p7 = (-0.5, 0.5, -0.5)

        uv00 = (0, 0)
        uv10 = (1, 0)
        uv01 = (0, 1)
        uv11 = (1, 1)

        vertices.addData3f(p4)
        vertices.addData3f(p5)
        vertices.addData3f(p1)
        vertices.addData3f(p0)

        texcoord.addData2f(uv11)
        texcoord.addData2f(uv01)
        texcoord.addData2f(uv00)
        texcoord.addData2f(uv10)

        normals.addData3f(n_forward)
        normals.addData3f(n_forward)
        normals.addData3f(n_forward)
        normals.addData3f(n_forward)

        primitive = GeomTriangles(Geom.UHStatic)
        primitive.addVertices(3, 1, 0)
        primitive.addVertices(3, 2, 1)

        geom = Geom(vertexData)
        geom.addPrimitive(primitive)

        node = GeomNode('cube gnode')
        node.addGeom(geom)
        return node

app = MyApp()
app.run()