第四步 关闭应用程序

在DX应用程序结束后必须把所有的DX对象设置成Nothing

所有代码如下:

Dim g_DX As New DirectX8
Dim g_D3D As Direct3D8 
Dim g_D3DDevice As Direct3DDevice8 
Private Sub Form_Load()
Me.Show
DoEvents
b = InitD3D(Picture1.hWnd)    '初始化设备
If Not b Then
MsgBox "Unable to CreateDevice (see InitD3D()source for comments)"
End
End If
Timer1.Enabled = True
End Sub
Private Sub Timer1_Timer()            
Render   '渲染
End Sub
Private Sub Form_Unload(Cancel As Integer)
Cleanup  '清除设备
End
End Sub
Function InitD3D(hWnd As Long) As Boolean'初始化
On Local Error Resume Next
Set g_D3D = g_DX.Direct3DCreate()
If g_D3D Is Nothing Then Exit Function
Dim mode As D3DDISPLAYMODE
g_D3D.GetAdapterDisplayMode D3DADAPTER_DEFAULT, mode
Dim d3dpp As D3DPRESENT_PARAMETERS
d3dpp.Windowed = 1
d3dpp.SwapEffect = D3DSWAPEFFECT_COPY_VSYNC
d3dpp.BackBufferFormat = mode.Format
Set g_D3DDevice =g_D3D.CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,D3DCREATE_SOFTWARE_VERTEXPROCESSING, d3dpp)
If g_D3DDevice Is Nothing Then Exit Function
InitD3D = True
End Function
Sub Cleanup() '清除设备
Set g_D3DDevice = Nothing
Set g_D3D = Nothing
End Sub
Sub Render()  '渲染
If g_D3DDevice Is Nothing Then Exit Sub
g_D3DDevice.Clear 0, ByVal 0, D3DCLEAR_TARGET, &HFF&, 1#, 0
g_D3DDevice.BeginScene
g_D3DDevice.EndScene
g_D3DDevice.Present ByVal 0, ByVal 0, 0, ByVal 0
End Sub

要使用D3D进行渲染就必须创建Direct3DDevice8对象
在DirectX8.Direct3DCreate方法先要创建一个Direct3d8对象
再用Direct3d8.CreateDevice方法创建Direct3DDevice8对象
其中还要Direct3D8.GetAdapterDisplayMode方法接受到当前的显示模式
并要设置D3DPRESENT_PARAMETERS成员来指定3D应用程序的表现
创建完后用Direct3DDevice8.Clear方法进行填充颜色
并开始场景用Direct3DDevice8.Present方法显示出来
最后还要把所有的DX对象设置成Nothing 来结束DX程序

顶点的渲染
 

使用顶点画几何图形,本例使用3个顶点,并使用了顶点缓冲区的概念

第一步:定义一个顶点类型
首先定义顶点格式,并指定在顶点缓冲区里描述画面顶点的FVF

第二步:设置顶点缓冲区
本例子用自定义的InitVB过程在创建了D3D所需的对象后来实现初始化顶点缓冲区, 接下来的代码初始了三个特定的顶点类型来填充顶点缓冲区

第三步 渲染显示表面
现在仍使用clear方法来清除表面并开始场景

所有代码如下:

Dim g_DX As New DirectX8
Dim g_D3D As Direct3D8
Dim g_D3DDevice As Direct3DDevice8
Dim g_VB As Direct3DVertexBuffer8
Private Type CUSTOMVERTEX
x As Single
y As Single
z As Single
rhw As Single
color As Long
End Type
Const D3DFVF_CUSTOMVERTEX = (D3DFVF_XYZRHW Or D3DFVF_DIFFUSE)
Private Sub Form_Load()
Dim b As Boolean
Me.Show
DoEvents
b = InitD3D(Picture1.hWnd)
If Not b Then
MsgBox "Unable to CreateDevice (see InitD3D() source for comments)"
End
End If
b = InitVB()
If Not b Then
MsgBox "Unable to Create VertexBuffer"
End
End If
Timer1.Enabled = True
End Sub
Private Sub Timer1_Timer()
Render
End Sub
Private Sub Form_Unload(Cancel As Integer)
Cleanup
End
End Sub
Function InitD3D(hWnd As Long) As Boolean
Set g_D3D = g_DX.Direct3DCreate()
If g_D3D Is Nothing Then Exit Function
Dim mode As D3DDISPLAYMODE
g_D3D.GetAdapterDisplayMode D3DADAPTER_DEFAULT, mode
Dim d3dpp As D3DPRESENT_PARAMETERS
d3dpp.Windowed = 1
d3dpp.SwapEffect = D3DSWAPEFFECT_COPY_VSYNC
d3dpp.BackBufferFormat = mode.Format
Set g_D3DDevice = g_D3D.CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, d3dpp)
If g_D3DDevice Is Nothing Then Exit Function
InitD3D = True
End Function
Function InitVB() As Boolean
Dim Vertices(3) As CUSTOMVERTEX
Dim VertexSizeInBytes As Long
VertexSizeInBytes = Len(Vertices(0))
With Vertices(0): .x = 150: .y = 50: .z = 0.5: .rhw = 1: .color = &HFFFF0000: End With
With Vertices(1): .x = 250: .y = 250: .z = 0.5: .rhw = 1: .color = &HFF00FF00: End With
With Vertices(2): .x = 50: .y = 250: .z = 0.5: .rhw = 1: .color = &HFF00FFFF: End With
Set g_VB = g_D3DDevice.CreateVertexBuffer(VertexSizeInBytes * 3, 0, D3DFVF_CUSTOMVERTEX, D3DPOOL_DEFAULT)
If g_VB Is Nothing Then Exit Function
D3DVertexBuffer8SetData g_VB, 0, VertexSizeInBytes * 3, 0, Vertices(0)
InitVB = True
End Function
Sub Cleanup()
Set g_VB = Nothing
Set g_D3DDevice = Nothing
Set g_D3D = Nothing
End Sub
Sub Render()
Dim v As CUSTOMVERTEX
Dim sizeOfVertex As Long
If g_D3DDevice Is Nothing Then Exit Sub
g_D3DDevice.Clear 0, ByVal 0, D3DCLEAR_TARGET, &HFF&, 1#, 0
g_D3DDevice.BeginScene
sizeOfVertex = Len(v)
g_D3DDevice.SetStreamSource 0, g_VB, sizeOfVertex
g_D3DDevice.SetVertexShader D3DFVF_CUSTOMVERTEX
g_D3DDevice.DrawPrimitive D3DPT_TRIANGLELIST, 0, 1
g_D3DDevice.EndScene
g_D3DDevice.Present ByVal 0, ByVal 0, 0, ByVal 0
End Sub

总结:

首先你要定义CUSTOMVERTEX结构和FVF
象大多数D3D程序一样要初始化3D设备(教程1内容)
再设定3个CUSTOMVERTEX类型的顶点
建立顶点缓冲区是必须的,并为其填充要包含的数据
清除场景,把顶点缓冲区绑定在流上,是渲染的开始
接着创建顶点遮盖,把顶点在顶点缓冲区里进行渲染
后面就是交换前后缓冲,把渲染结果呈现出来
结束所有D3D设备

使用矩阵
 

本教程介绍了如何使用矩阵,我们在顶点的例子里,渲染了一个2D的三角形,而本例子将把它转化为3D

第一步:定义世界变化矩阵
介绍在3-D空间里矩阵的世界矩阵如何转化,度量,和旋转几何图形
首先使用D3DXMatrixRotationY方法把三角形围绕Y轴旋转

第二步:定义视图变化矩阵
视图矩阵定义了视图的位置和转动,相当于一个场景摄象机.
首先使用D3DXMatrixLookAtLH方法

第三步:定义投影变化矩阵
投影矩阵定义了几何图形被从2D转化为3D首先使用D3DXMatrixPerspectiveFovLH方法,在观察视野创建一个左手透视投影矩阵(相当于人的视野）