Animated Object with Lights

From IronPython Cookbook

Adapted from this blog entry.

A moving object, with a light source.

import clr
clr.AddReference("System.Drawing")
clr.AddReference("System.Windows.Forms")

# .NET Framework 1.1 DirectX
clr.AddReference("Microsoft.DirectX, Version=1.0.2902.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35")
clr.AddReference("Microsoft.DirectX.Direct3D")

from System import Array, Environment, Math
from System.Drawing import *
from System.Windows.Forms import *

from Microsoft.DirectX import *
from Microsoft.DirectX.Direct3D import *


class Lights(Form):
    def __init__(self):
        self.ClientSize = Size(400, 300)
        self.Text = "D3D Tutorial 04: Lights"

        self.pause = False
        self.device = None
        self.vertexBuffer = None
        
        self.Paint += lambda *_: self.render()
        self.initializeGraphics()


    def initializeGraphics(self):
        presentParams = PresentParameters()
        presentParams.Windowed = True
        presentParams.SwapEffect = SwapEffect.Discard
        presentParams.EnableAutoDepthStencil = True
        presentParams.AutoDepthStencilFormat = DepthFormat.D16

        self.device = Device(0, DeviceType.Hardware, self, 
                             CreateFlags.SoftwareVertexProcessing, 
                             presentParams)
                             
        self.device.DeviceReset += self.onResetDevice

        self.onCreateDevice(self.device, None)
        self.onResetDevice(self.device, None)


    def onCreateDevice(self, dev, event):
        self.vertexBuffer = VertexBuffer(
            CustomVertex.PositionNormal, 100,
            dev,
            Usage.WriteOnly, # ?? ???? ??
            CustomVertex.PositionNormal.Format,
            Pool.Default)

        self.vertexBuffer.Created += self.onCreateVertexBuffer

        self.onCreateVertexBuffer(self.vertexBuffer, None)


    def onResetDevice(self, dev, event):
        dev.RenderState.CullMode = Cull.None
        dev.RenderState.Lighting = True
        dev.RenderState.ZBufferEnable = True


    def onCreateVertexBuffer(self, vb, event):
        verts = vb.Lock(0, LockFlags.None) 
        
        for i in xrange(50):
            theta = (2 * Math.PI * i) / 49
            sin_theta = Math.Sin(theta)
            cos_theta = Math.Cos(theta)
            verts[2 * i] = CustomVertex.PositionNormal(
                Vector3(sin_theta, -1, cos_theta),  # Position
                Vector3(sin_theta,  0, cos_theta)   # Normal
            )
            verts[2 * i + 1] = CustomVertex.PositionNormal(
                Vector3(sin_theta, 1, cos_theta),   # Position
                Vector3(sin_theta, 0, cos_theta)    # Normal
            )

        vb.Unlock()


    def setupLights(self):
            col = Color.White
            
            mtrl = Material()
            mtrl.Diffuse = col
            mtrl.Ambient = col
            self.device.Material = mtrl

            tick_step = Environment.TickCount / 250.0
            self.device.Lights[0].Type       = LightType.Directional
            self.device.Lights[0].Diffuse    = Color.DarkTurquoise
            self.device.Lights[0].Direction  = Vector3(
                Math.Cos(tick_step), 1.0, Math.Sin(tick_step))

            self.device.Lights[0].Enabled = True

            self.device.RenderState.Ambient = Color.FromArgb(0x202020)


    def render(self):
        if not self.device:
            print "error"
            return

        if self.pause:
            return

        self.device.Clear(ClearFlags.Target|ClearFlags.ZBuffer, Color.Blue, 1.0, 0)

        self.device.BeginScene()

        self.setupLights()
        self.setupMatrices()

        self.device.SetStreamSource(0, self.vertexBuffer, 0)
        self.device.VertexFormat = CustomVertex.PositionNormal.Format
        self.device.DrawPrimitives(PrimitiveType.TriangleStrip, 0, (4*25)-2)
        self.device.EndScene()
        self.device.Present()


    def setupMatrices(self):
        tick_step   = Environment.TickCount / 250.0
        roll_step   = Environment.TickCount / 3000.0
        axis        = Vector3(Math.Cos(tick_step), 1, Math.Sin(tick_step))
        self.device.Transform.World = Matrix.RotationAxis(axis, roll_step)

        self.device.Transform.View = Matrix.LookAtLH(
            Vector3(0.0, 3.0, -5.0),
            Vector3(0.0, 0.0, 0.0),
            Vector3(0.0, 1.0, 0.0)
        )

        self.device.Transform.Projection = Matrix.PerspectiveFovLH(
            Math.PI / 4, 1.0, 1.0, 100.0)


lights = Lights()
lights.Show()

# A loop to ensure continuous repainting
while (lights.Created):
    lights.render()
    Application.DoEvents()

Back to Contents.