我试图将OpenGL控件添加到MFC对话框中。该对话框是从一个也运行OpenGL的窗口启动的...这使得它变得复杂。由于一次只有一个OpenGL上下文可以进入一个线程，所以我要么必须拥有整个对话框，要么只需控制它自己的线程。我选择尝试后者，因为它会使我们项目中的其他对话框的实现更容易使用。
我对MFC的了解很多，因为我一直在学习，所以如果我错过了一些巨大的东西，我会道歉。我真的可以使用一些MFC帮助来传达消息的最佳方式，或者从对话框中为控件设置属性。凭借纯粹的运气，我似乎有所作为。
我使用OnSize作为一个例子。我在控件包装器类中创建了这个函数，试图将消息从对话框推送到控件。
void AddOpenGLControl::PostMessageToControl(UINT Msg, WPARAM wParam, LPARAM lParam)
{
if (dialogHandle != NULL)
PostMessage(dialogHandle, Msg, wParam, lParam);
}
但是这让我试图在对话框中模拟可能已经存在的虚假Windows消息以发送到控件。
WPARAM wp = nType;
LPARAM lp = MAKELPARAM(ctrlRect.Width(), ctrlRect.Height());
openGlControlOnThread.PostMessageToControl(WM_SIZE, wp, lp);
我知道我想要访问触发更多的消息，就像我正常的控制一样，而且这种方法会很快变得麻烦。
有没有办法简单地传递消息？很难问我不知道什么，但我在思考继承，或在包装类中的消息映射，或预翻译消息，或从隐藏的正常控件中窃取消息以发送或者......好吧，我会采取任何可以跨线程工作的东西。
这是所有代码，以填补空白。我将代码配对到我可以做的，但我确实必须使用我们的消息循环（抱歉！）。这是我从窗口开始的标准发布：
//Main thread (with existing openGL window)
class TCADTLSandbox2
{
public:
virtual bool DoCmd(); // Main Entry Point
};
bool TCADTLSandbox2::DoCmd()
{
TCADTLSandbox2Dialog dialog;
dialog.Create(TCADTLSandbox2Dialog::IDD);
dialog.ShowWindow(SW_SHOW);
// We have to use the main window's accessors to get any messages from the window
WPARAM dialogMessage;
while (!GetUITools()->WaitForCommandMessage("", dialogMessage) || (dialogMessage != TIMsgIDCancel))
{
if (dialogMessage == TIMsgIDOK)
{
break;
}
}
dialog.ShowWindow(SW_HIDE);
dialog.DestroyWindow();
return true;
}
这是对话类。类成员 openGlControlOnThread 和 OnSize（）是您感兴趣的两件事。
//Dialog
class TCADTLSandbox2Dialog : public CDialog
{
DECLARE_DYNAMIC(TCADTLSandbox2Dialog)
public:
TCADTLSandbox2Dialog(CWnd* pParent = NULL);
virtual ~TCADTLSandbox2Dialog();
enum { IDD = IDD_SANDBOX2 };
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
DECLARE_MESSAGE_MAP()
private:
AddOpenGLControl openGlControlOnThread;
virtual BOOL OnInitDialog();
afx_msg void OnBnClickedOk();
afx_msg void OnBnClickedCancel();
afx_msg void OnSize(UINT nType, int cx, int cy);
};
IMPLEMENT_DYNAMIC(TCADTLSandbox2Dialog, CDialog)
TCADTLSandbox2Dialog::TCADTLSandbox2Dialog(CWnd* pParent /*=NULL*/): CDialog(TCADTLSandbox2Dialog::IDD, pParent){}
TCADTLSandbox2Dialog::~TCADTLSandbox2Dialog(){}
void TCADTLSandbox2Dialog::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
}
BEGIN_MESSAGE_MAP(TCADTLSandbox2Dialog, CDialog)
ON_BN_CLICKED(IDOK, &TCADTLSandbox2Dialog::OnBnClickedOk)
ON_BN_CLICKED(IDCANCEL, &TCADTLSandbox2Dialog::OnBnClickedCancel)
ON_WM_SIZE()
END_MESSAGE_MAP()
BOOL TCADTLSandbox2Dialog::OnInitDialog()
{
CDialog::OnInitDialog();
CRect rect;
GetDlgItem(IDC_CADTL_SANDBOX_OPENGLTEST)->GetWindowRect(rect);
ScreenToClient(rect);
openGlControlOnThread.Create(rect, this);
initialized = true;
return TRUE;
}
void TCADTLSandbox2Dialog::OnSize(UINT nType, int cx, int cy)
{
CDialog::OnSize(nType, cx, cy);
if (initialized)
{
CRect ctrlRect(0, 0, 0, 0);
GetDlgItem(IDC_CADTL_SANDBOX_OPENGLTEST)->GetWindowRect(ctrlRect);
ScreenToClient(ctrlRect);
//int buttonWidth = ctrlRect.Width();
ctrlRect.left = 20;
ctrlRect.right = cx - 20;
ctrlRect.bottom = cy - 50;
WPARAM wp = nType;
LPARAM lp = MAKELPARAM(ctrlRect.Width(), ctrlRect.Height());
openGlControlOnThread.PostMessageToControl(WM_SIZE, wp, lp);
}
}
void TCADTLSandbox2Dialog::OnBnClickedOk()
{
PostQuitMessage(0);
}
void TCADTLSandbox2Dialog::OnBnClickedCancel()
{
PostQuitMessage(0);
CDialog::OnCancel();
}
在这里，它变得有趣。这就是我将OpenGL控件包装到新线程上的方法。 PostMessageToControl 是我希望用更简单的东西取而代之的。
// Class to kickoff the control thread
class AddOpenGLControl
{
public:
AddOpenGLControl();
~AddOpenGLControl();
void Create(CRect rect, CWnd *parent);
// You can send something along the lines of (WM_DESTROY, NULL, NULL)
void PostMessageToControl(UINT Msg, WPARAM wParam, LPARAM lParam);
private:
void StartThread(CRect rect, CWnd *parent);
std::thread controlThread;
};
// *** The thread class ***
AddOpenGLControl::AddOpenGLControl(){}
AddOpenGLControl::~AddOpenGLControl()
{
WaitForSingleObject(controlThread.native_handle(), INFINITE); // Okay?
controlThread.join(); // Also okay?
}
void AddOpenGLControl::PostMessageToControl(UINT Msg, WPARAM wParam, LPARAM lParam)
{
if (dialogHandle != NULL)
PostMessage(dialogHandle, Msg, wParam, lParam);
}
void AddOpenGLControl::Create(CRect rect, CWnd *parent)
{
std::thread initThread(&AddOpenGLControl::StartThread, this, rect, std::ref(parent));
controlThread = std::move(initThread);
}
void AddOpenGLControl::StartThread(CRect rect, CWnd *parent)
{
COpenGLControl *openGLControl = new COpenGLControl;
openGLControl->Create(rect, parent);
openGLControl->m_unpTimer = openGLControl->SetTimer(1, 1000, 0);
HWND threadHandle = (HWND)openGLControl->GetSafeHwnd();
// This is where I start getting lost. Taken from MSDN
MSG msg;
BOOL bRet;
while ((bRet = GetMessage(&msg, threadHandle, 0, 0)) != 0)
{
if (bRet == -1)
{
// handle the error and possibly exit
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
}
以下是控件本身：
// OpenGL Dialog Control thread (now it can have it's own openGL context)
class COpenGLControl : public CWnd
{
public:
UINT_PTR m_unpTimer;
COpenGLControl();
virtual ~COpenGLControl();
void Create(CRect rect, CWnd *parent);
void UpdateOpenGLDispay();
afx_msg void OnSize(UINT nType, int cx, int cy);
void ParentDialogResize(UINT nType, int cx, int cy);
private:
CWnd *hWnd;
HDC hDC;
HGLRC openGLRC;
CString className;
void Initialize();
void DrawCRD(double centerX, double centerY, double centerZ, double crdScale);
afx_msg void OnPaint();
afx_msg void OnDraw(CDC *pDC);
afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
afx_msg void OnTimer(UINT_PTR nIDEvent);
DECLARE_MESSAGE_MAP()
};
// *** The actual control ***
COpenGLControl::COpenGLControl()
{
initialized = false;
display = new Display2d;
}
COpenGLControl::~COpenGLControl()
{
CleanUp();
}
BEGIN_MESSAGE_MAP(COpenGLControl, CWnd)
ON_WM_PAINT()
ON_WM_CREATE()
ON_WM_TIMER()
ON_WM_SIZE()
ON_WM_DESTROY()
END_MESSAGE_MAP()
int COpenGLControl::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (CWnd::OnCreate(lpCreateStruct) == -1)
return -1;
Initialize();
return 0;
}
void COpenGLControl::Initialize()
{
// Initial Setup:
//
//Set up the pixal descriptor for using openGL on the graphics card
PIXELFORMATDESCRIPTOR pfd = {
sizeof(PIXELFORMATDESCRIPTOR), // Size of this structure
1, // Version of this structure
PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
PFD_TYPE_RGBA,
24, // Want 24bit color
0, 0, 0, 0, 0, 0, // Not used to select mode
0, 0, // Not used to select mode
0, 0, 0, 0, 0, // Not used to select mode
32, // Size of depth buffer
0, // Not used to select mode
0, // Not used to select mode
PFD_MAIN_PLANE, // Draw in main plane
0, // Not used to select mode
0, 0, 0 }; // Not used to select mode
// Store the device context
if (!(hDC = GetDC()->m_hDC)) // From the dialog?
{
AfxMessageBox("Can't Create A GL Device Context.");
//May not be able to unregister class?? May not need to?
return;
}
// Choose a pixel format that best matches that described in pfd
int nPixelFormat; // Pixel format index
nPixelFormat = ChoosePixelFormat(hDC, &pfd);
// Set the pixel format for the device context
if (!SetPixelFormat(hDC, nPixelFormat, &pfd))
AfxMessageBox("Setting pixel format failed");
// Create the rendering context and make it current
if (!(openGLRC = wglCreateContext(hDC)))
{
AfxMessageBox("Can't Create A GL Rendering Context.");
//May not be able to unregister class?? May not need to?
return;
}
if (!wglMakeCurrent(hDC, openGLRC))
AfxMessageBox("WGLFailed");
// Set color to use when clearing the background.
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glClearDepth(1.0f);
// Turn on backface culling
glFrontFace(GL_CCW);
glCullFace(GL_BACK);
// Turn on depth testing
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
// Enable alpha blending
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
UpdateOpenGLDispay();
initialized = true;
}
void COpenGLControl::Create(CRect rect, CWnd *parent)
{
className = AfxRegisterWndClass(CS_HREDRAW | CS_VREDRAW | CS_OWNDC, NULL, (HBRUSH)GetStockObject(BLACK_BRUSH), NULL);
CreateEx(0, className, "OpenGL", WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_CLIPCHILDREN, rect, parent, 0);
hWnd = parent;
}
void COpenGLControl::OnPaint()
{
// Attempt to help with flickering
UpdateOpenGLDispay();
CPaintDC dc(this);
ValidateRect(NULL);
}
void COpenGLControl::OnDraw(CDC *pDC)
{
UpdateOpenGLDispay();
}
void COpenGLControl::UpdateOpenGLDispay()
{
DrawCRD(); // ... just draw something
SwapBuffers(hDC);
}
void COpenGLControl::DrawCRD(double centerX, double centerY, double centerZ, double crdScale)
{
// X CRD
glColor4f(1.0f, 0.0f, 0.0f, 1);//R
glBegin(GL_LINES);
glVertex3f(centerX, centerY, centerZ);
glVertex3f(centerX + 1 * crdScale, centerY, centerZ);
glEnd();
// Y CRD
glColor4f(0.0f, 0.0f, 1.0f, 1);//B
glBegin(GL_LINES);
glVertex3f(centerX, centerY, centerZ);
glVertex3f(centerX, centerY + 1 * crdScale, centerZ);
glEnd();
// Z CRD
glColor4f(0.0f, 1.0f, 0.0f, 1);//G
glBegin(GL_LINES);
glVertex3f(centerX, centerY, centerZ);
glVertex3f(centerX, centerY, centerZ + 1 * crdScale);
glEnd();
}
void COpenGLControl::OnTimer(UINT_PTR nIDEvent)
{
switch (nIDEvent)
{
case 1:
UpdateOpenGLDispay();
break;
}
CWnd::OnTimer(nIDEvent);
}
void COpenGLControl::OnSize(UINT nType, int cx, int cy)
{
CWnd::OnSize(nType, cx, cy);
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
if (nType == SIZE_RESTORED)
ParentDialogResize(nType, cx, cy);
}
void COpenGLControl::ParentDialogResize(UINT nType, int cx, int cy)
{
if (initialized)
{
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
this->SetWindowPos(NULL, 20, 20, cx, cy, SWP_SHOWWINDOW); // fixed for this example
}
}
void COpenGLControl::OnDestroy()
{
CWnd::OnDestroy();
PostQuitMessage(0);
}
void COpenGLControl::CleanUp()
{
if (!wglDeleteContext(openGLRC))
AfxMessageBox("Deleting OpenGL Rendering Context failed");
if (!wglMakeCurrent(hDC, NULL))
AfxMessageBox("Removing current DC Failed");
//ReleaseDC(hDC); // The internets say the device context should automatically be deleted since it's CS_OWNDC
}
// Sorry for the heap of code. Or is it stack?
谢谢！
答案 0 :(得分：0)
似乎我错过了MFC的一些重要方面。如果有人遵循类似的路径，最好在尝试创建opengl控件之前完成子类化常规控件的过程。
有几种方法可以做到这一点。如果我使用OnWndMsg或类似WindowProc，我可以在仍然处于wParam / lParam状态的情况下查看该消息，并将其传递给它。
BOOL TCADTLSandbox2Dialog::OnWndMsg(UINT message, WPARAM wParam, LPARAM lParam, LRESULT* pResult)
{
//This is one way to just pass the message along. For some cases, we may need to check the mouse position as well.
if (message == WM_MOUSEWHEEL)
{
openGlControlOnThread.PostMessageToControl(message, wParam, lParam);
return true;
}
if (wParam == WM_LBUTTONDOWN)
{
openGlControlOnThread.PostMessageToControl(message, wParam, lParam);
return true;
}
return CDialog::OnWndMsg(message, wParam, lParam, pResult);
}
另外，事实证明PreTranslateMessage是我可以使用的选项，但我当时并没有看到它。
BOOL TCADTLSandbox2Dialog::PreTranslateMessage(MSG* pMsg)
{
// Send the message to the control (the dialog gets it by default)
if (pMsg->message == WM_MOUSEWHEEL)
{
openGlControlOnThread.PostMessageToControl(pMsg->message, pMsg->wParam, pMsg->lParam);
return true;
}
return MCDialog::PreTranslateMessage(pMsg);
}
希望这可以帮助其他人！