基于MFC的Direct3D程序设计
原文链接：
MFC D3D Application: Direct3D Tutorial Part I
作者这个 MFC 程序中第一个有趣的地方是让用于 Direct3D 绘制的窗口类从 CWnd 类和 CXD3D 类继承下来：
//
-----------------------------------------------------------------------------
//
CXD3D class: the class a view class will derive from to provide a window
//
handle to render into, and that will override the 3D scene rendering.
//
-----------------------------------------------------------------------------
class
CXD3D
{
protected:
// internal state variables
bool m_bActive; // toggled on Pause, can be queried upon
// initializing to issue a Create [false]
bool m_bStartFullscreen; // queried on ChooseInitialSettings [false]
bool m_bShowCursor; // in fullscreen mode [true]
bool m_bClipCursor; // in fullscreen mode [true]
bool m_bWindowed; // queried on BuildPresentParamsFromSettings
// [true]
bool m_bIgnoreSizeChange; // queried on HandlePossibleSizeChange [false]
bool m_bDeviceLost; // true when the device's Present fails
bool m_bDeviceObjectsInited; // true if InitDeviceObjects succeeds
bool m_bDeviceObjectsRestored; // true if RestoreDeviceObjects succeeds
// internal timing variables
FLOAT m_fTime; // absolute time handled by DXUtil_Timer
FLOAT m_fElapsedTime; // elapsed time handled by DXUtil_Timer
FLOAT m_fFPS; // the frame rate, or frames per second
// statistics
TCHAR m_strDeviceStats[256]; // device description
TCHAR m_strFrameStats[16]; // frame statistics
// main objects used for creating and rendering the 3D scene
HWND m_hWndRender; // device window
HWND m_hWndFocus; // focus window
LPDIRECT3D9 m_pd3d; // main D3D object
LPDIRECT3DDEVICE9 m_pd3dDevice; // D3D rendering device
D3DPRESENT_PARAMETERS m_d3dpp; // presentation parameters
DWORD m_dwCreateFlags; // sw/hw VP + pure device
DWORD m_dwWindowStyle; // saved for mode switches
RECT m_rcWindow; // window and client rects,
RECT m_rcClient; // saved for mode switches
// setup objects
CXD3DEnum Enumeration; // hierarchy of adapters, modes, devices, etc.
CXD3DSettings Settings; // current display settings
protected:
// internal error handling function
HRESULT DisplayErrorMsg(HRESULT hr, DWORD dwType);
// internal management functions
void BuildPresentParamsFromSettings();
bool FindBestWindowedMode(bool bHAL, bool bREF);
bool FindBestFullscreenMode(bool bHAL, bool bREF);
HRESULT ChooseInitialSettings();
HRESULT InitializeEnvironment();
HRESULT ResetEnvironment();
void CleanupEnvironment();
public:
HRESULT RenderEnvironment();
HRESULT HandlePossibleSizeChange();
protected:
void UpdateStats();
// Overridable functions for the 3D scene created by the app
virtual HRESULT OneTimeSceneInit() { return S_OK; }
virtual HRESULT InitDeviceObjects() { return S_OK; }
virtual HRESULT RestoreDeviceObjects() { return S_OK; }
virtual HRESULT FrameMove() { return S_OK; }
virtual HRESULT InvalidateDeviceObjects() { return S_OK; }
virtual HRESULT DeleteDeviceObjects() { return S_OK; }
virtual HRESULT FinalCleanup() { return S_OK; }
public:
virtual HRESULT Render() { return S_OK; }
// construct/destruct, create and pause/play
CXD3D();
virtual ~CXD3D() { }
virtual HRESULT CreateD3D();
virtual void Pause(bool bPause);
// active state wrapper
bool IsActive() { return m_bActive; };
// device and frame statistics wrappers
LPCTSTR GetDeviceStats() { return m_strDeviceStats; }
LPCTSTR GetFrameStats() { return m_strFrameStats; }
}
;
CXD3D实现文件
Enumeration
|
+
-- AdapterInfos[
0
]
| |
|
+
-- DisplayModes[
0
]
|
+
-- DisplayModes[
1
]
|
| |
|
+
-- DeviceInfos[
0
]
| | |
| |
+
-- DeviceCombos[
0
]
| | | |
| | |
+
-- VPTypes
| | |
+
-- DSFormats
| | |
+
-- MSTypes
| | |
+
-- MSQualityLevels
| | |
+
-- DSMSConflicts
| | |
+
-- PresentIntervals
| |
+
-- DeviceCombos[
1
]
| |
|
+
-- DeviceInfos[
1
]
|
+
-- AdapterInfos[
1
]
作者这个 MFC 程序中第一个有趣的地方是让用于 Direct3D 绘制的窗口类从 CWnd 类和 CXD3D 类继承下来：
class CD3DWnd : public CXD3D, public CWnd
CD3DWnd类是用于窗口中控件（比如一个PictureBox）的基类，这个控件将提供普通Cwnd类的功能，但同时也拥有CXD3D的3D绘制的能力。
先来看CXD3D类：
//
-----------------------------------------------------------------------------
//
CXD3D class: the class a view class will derive from to provide a window
//
handle to render into, and that will override the 3D scene rendering.
//
-----------------------------------------------------------------------------
class
CXD3D
{protected: // internal state variables bool m_bActive; // toggled on Pause, can be queried upon // initializing to issue a Create [false] bool m_bStartFullscreen; // queried on ChooseInitialSettings [false] bool m_bShowCursor; // in fullscreen mode [true] bool m_bClipCursor; // in fullscreen mode [true] bool m_bWindowed; // queried on BuildPresentParamsFromSettings // [true] bool m_bIgnoreSizeChange; // queried on HandlePossibleSizeChange [false] bool m_bDeviceLost; // true when the device's Present fails bool m_bDeviceObjectsInited; // true if InitDeviceObjects succeeds bool m_bDeviceObjectsRestored; // true if RestoreDeviceObjects succeeds // internal timing variables FLOAT m_fTime; // absolute time handled by DXUtil_Timer FLOAT m_fElapsedTime; // elapsed time handled by DXUtil_Timer FLOAT m_fFPS; // the frame rate, or frames per second // statistics TCHAR m_strDeviceStats[256]; // device description TCHAR m_strFrameStats[16]; // frame statistics // main objects used for creating and rendering the 3D scene HWND m_hWndRender; // device window HWND m_hWndFocus; // focus window LPDIRECT3D9 m_pd3d; // main D3D object LPDIRECT3DDEVICE9 m_pd3dDevice; // D3D rendering device D3DPRESENT_PARAMETERS m_d3dpp; // presentation parameters DWORD m_dwCreateFlags; // sw/hw VP + pure device DWORD m_dwWindowStyle; // saved for mode switches RECT m_rcWindow; // window and client rects, RECT m_rcClient; // saved for mode switches // setup objects CXD3DEnum Enumeration; // hierarchy of adapters, modes, devices, etc. CXD3DSettings Settings; // current display settingsprotected: // internal error handling function HRESULT DisplayErrorMsg(HRESULT hr, DWORD dwType); // internal management functions void BuildPresentParamsFromSettings(); bool FindBestWindowedMode(bool bHAL, bool bREF); bool FindBestFullscreenMode(bool bHAL, bool bREF); HRESULT ChooseInitialSettings(); HRESULT InitializeEnvironment(); HRESULT ResetEnvironment(); void CleanupEnvironment();public: HRESULT RenderEnvironment(); HRESULT HandlePossibleSizeChange();protected: void UpdateStats(); // Overridable functions for the 3D scene created by the app virtual HRESULT OneTimeSceneInit() { return S_OK; }
virtual HRESULT InitDeviceObjects() { return S_OK; } virtual HRESULT RestoreDeviceObjects() { return S_OK; } virtual HRESULT FrameMove() { return S_OK; } virtual HRESULT InvalidateDeviceObjects() { return S_OK; } virtual HRESULT DeleteDeviceObjects() { return S_OK; } virtual HRESULT FinalCleanup() { return S_OK; } public: virtual HRESULT Render() { return S_OK; } // construct/destruct, create and pause/play CXD3D(); virtual ~CXD3D() { } virtual HRESULT CreateD3D(); virtual void Pause(bool bPause); // active state wrapper bool IsActive() { return m_bActive; }; // device and frame statistics wrappers LPCTSTR GetDeviceStats() { return m_strDeviceStats; } LPCTSTR GetFrameStats() { return m_strFrameStats; }}
;
CXD3D实现文件
}在CXD3D::CreateD3D函数中，首先初始化了一个D3D对象，然后构建了一个列表，这个列表包含了机器上的所有显卡，显卡模式和设备。我们需要知道机器上有多少显卡（一般只有一个），而且每个显卡也可以支持多个设备。对于每个设备会有一种支持的格式，设置和能力，这对于应用程序来说不一定是合适的，因此我们需要一个列表来跟踪这些信息，以便挑选出合适的。
再来看枚举类CXD3DEnum，它用来为应用程序中使用的分辨率，颜色，A通道，显示格式，后备缓冲格式，深度/模板缓冲格式，多重采样类型，提交显示时间间隔等参数建立约束。
文中枚举类的代码很多，但我们只需要记住一点就可以了，要使Direct3D建立起来，我们首先得不断地枚举，枚举，再枚举，不断检查它的各种属性，各种能力是否满足，基本上检查的顺序可以用下图来表示：
Enumeration|
+
-- AdapterInfos[
0
]| ||
+
-- DisplayModes[
0
]|
+
-- DisplayModes[
1
]|
| ||
+
-- DeviceInfos[
0
]| | || |
+
-- DeviceCombos[
0
]| | | || | |
+
-- VPTypes| | |
+
-- DSFormats| | |
+
-- MSTypes| | |
+
-- MSQualityLevels| | |
+
-- DSMSConflicts| | |
+
-- PresentIntervals| |
+
-- DeviceCombos[
1
]| |
|
+
-- DeviceInfos[
1
]|
+
-- AdapterInfos[
1
]