我试图让着色器在具有OpenGL 4核心配置文件的MFC应用程序中工作.
我在Win32应用程序中这样做以确保它可以工作(确实如此,在窗口的下半部分绘制一个三角形):
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
HWND hWnd;
hInst = hInstance; // Store instance handle in our global variable
hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
if (!hWnd)
{
return FALSE;
}
m_hDC = ::GetDC(hWnd);
PIXELFORMATDESCRIPTOR pfd;
memset(&pfd, 0, sizeof(PIXELFORMATDESCRIPTOR));
pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DOUBLEBUFFER | PFD_SUPPORT_OPENGL | PFD_DRAW_TO_WINDOW;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 32;
pfd.cDepthBits = 32;
pfd.iLayerType = PFD_MAIN_PLANE;
int nPixelFormat = ChoosePixelFormat(m_hDC, &pfd);
if (nPixelFormat == 0) return false;
BOOL bResult = SetPixelFormat(m_hDC, nPixelFormat, &pfd);
if (!bResult) return false;
HGLRC tempContext = wglCreateContext(m_hDC);
wglMakeCurrent(m_hDC, tempContext);
GLenum err = glewInit();
if (GLEW_OK != err)
{
MessageBox(hWnd, (LPCWSTR)L"Glew not initialized", (LPCWSTR)L"Error", MB_ICONEXCLAMATION);
}
//Get a GL 4,2 context
int attribs[] =
{
WGL_CONTEXT_MAJOR_VERSION_ARB, 4,
WGL_CONTEXT_MINOR_VERSION_ARB, 2,
WGL_CONTEXT_FLAGS_ARB, 0,
0
};
if (wglewIsSupported("WGL_ARB_create_context") == 1)
{
m_hRC = wglCreateContextAttribsARB(m_hDC, 0, attribs);
wglMakeCurrent(NULL, NULL);
wglDeleteContext(tempContext);
wglMakeCurrent(m_hDC, m_hRC);
}
else
{ //It's not possible to make a GL 4.x context. Use the old style context (GL 2.1 and before)
m_hRC = tempContext;
}
if (!m_hRC) return false;
static const char * vs_source[] =
{
"#version 420 core \n"
" \n"
"void main(void) \n"
"{ \n"
" const vec4 vertices[] = vec4[](vec4( 2.25, -2.25, 0.5, 1.0), \n"
" vec4(-2.25, -2.25, 0.5, 1.0), \n"
" vec4( 2.25, 2.25, 0.5, 1.0)); \n"
" \n"
" gl_Position = vertices[gl_VertexID]; \n"
"} \n"
};
static const char * fs_source[] =
{
"#version 420 core \n"
" \n"
"out vec4 color; \n"
" \n"
"void main(void) \n"
"{ \n"
" color = vec4(1.0, 0.8, 1.0, 1.0); \n"
"} \n"
};
program = glCreateProgram();
GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fs, 1, fs_source, NULL);
glCompileShader(fs);
GLuint vs = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vs, 1, vs_source, NULL);
glCompileShader(vs);
glAttachShader(program, vs);
glAttachShader(program, fs);
glLinkProgram(program);
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
return TRUE;
}
const GLfloat green[] = { 0.0f, 0.25f, 0.0f, 1.0f };
//
// FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
switch (message)
{
case WM_COMMAND:
wmId = LOWORD(wParam);
wmEvent = HIWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
break;
case WM_PAINT:
//hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here...
glClearBufferfv(GL_COLOR, 0, green);
glUseProgram(program);
glDrawArrays(GL_TRIANGLES, 0, 3);
SwapBuffers(m_hDC);
//EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
然后我在MFC MDI程序中做了同样的事情,虽然背景被清除为与Win32应用程序相同的颜色,但着色器不会绘制任何东西.
为了完成,这里是我的MFC MDI视图类中的相关代码(它与Win32应用程序中的代码不同,因为我一直在试图弄清楚什么是错的,但它曾经和Win32应用程序代码一样,并且它没有'工作):
int CMFCApplication2View::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (CView::OnCreate(lpCreateStruct) == -1)
return -1;
// TODO: Add your specialized creation code here
m_hDC = ::GetDC(m_hWnd);
PIXELFORMATDESCRIPTOR pfd;
memset(&pfd, 0, sizeof(PIXELFORMATDESCRIPTOR));
pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DOUBLEBUFFER | PFD_SUPPORT_OPENGL | PFD_DRAW_TO_WINDOW;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 32;
pfd.cDepthBits = 24;
pfd.iLayerType = PFD_MAIN_PLANE;
int nPixelFormat = ChoosePixelFormat(m_hDC, &pfd);
if (nPixelFormat == 0) return false;
BOOL bResult = SetPixelFormat(m_hDC, nPixelFormat, &pfd);
if (!bResult) return false;
HGLRC tempContext = wglCreateContext(m_hDC);
wglMakeCurrent(m_hDC, tempContext);
glewExperimental = GL_TRUE;
GLenum err = glewInit();
if (GLEW_OK != err)
{
AfxMessageBox(_T("GLEW is not initialized!"));
}
//This is a modern pixel format attribute list.
//It has an extensible structure. Just add in more argument pairs
//befroe the null to request more features.
const int attribList[] =
{
WGL_DRAW_TO_WINDOW_ARB, GL_TRUE,
WGL_SUPPORT_OPENGL_ARB, GL_TRUE,
WGL_ACCELERATION_ARB, WGL_FULL_ACCELERATION_ARB,
WGL_DOUBLE_BUFFER_ARB, GL_TRUE,
WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_ARB,
WGL_COLOR_BITS_ARB, 32,
WGL_DEPTH_BITS_ARB, 24,
WGL_STENCIL_BITS_ARB, 8,
0, 0 //End
};
unsigned int numFormats;
int pixelFormat;
memset(&pfd, 0, sizeof(PIXELFORMATDESCRIPTOR));
//Select a pixel format number
wglChoosePixelFormatARB(m_hDC, attribList, NULL, 1, &pixelFormat, &numFormats);
//Optional: Get the pixel format's description. We must provide a
//description to SetPixelFormat(), but its contents mean little.
//According to MSDN:
// The system's metafile component uses this structure to record the logical
// pixel format specification. The structure has no other effect upon the
// behavior of the SetPixelFormat function.
//DescribePixelFormat(m_pDC->GetSafeHdc(), pixelFormat, sizeof(PIXELFORMATDESCRIPTOR), &pfd);
//Set it as the current
if (FALSE == SetPixelFormat(m_hDC, pixelFormat, &pfd))
{
}
//Get a GL 4,4 context
int attribs[] =
{
WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
WGL_CONTEXT_MINOR_VERSION_ARB, 2,
WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
//WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB,
0, 0 //End
};
if (wglewIsSupported("WGL_ARB_create_context") == 1)
{
m_hRC = wglCreateContextAttribsARB(m_hDC, 0, attribs);
wglMakeCurrent(NULL, NULL);
wglDeleteContext(tempContext);
wglMakeCurrent(m_hDC, m_hRC);
}
else
{ //It's not possible to make a GL 4.x context. Use the old style context (GL 2.1 and before)
m_hRC = tempContext;
}
if (!m_hRC) return false;
static const char * vs_source[] =
{
"#version 150 core \n"
" \n"
"void main(void) \n"
"{ \n"
" const vec4 vertices[] = vec4[](vec4( 2.25, -2.25, 0.5, 1.0), \n"
" vec4(-2.25, -2.25, 0.5, 1.0), \n"
" vec4( 2.25, 2.25, 0.5, 1.0)); \n"
" \n"
" gl_Position = vertices[gl_VertexID]; \n"
"} \n"
};
static const char * fs_source[] =
{
"#version 150 core \n"
" \n"
"out vec4 color; \n"
" \n"
"void main(void) \n"
"{ \n"
" color = vec4(1.0, 0.8, 1.0, 1.0); \n"
"} \n"
};
program = glCreateProgram();
GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fs, 1, fs_source, NULL);
glCompileShader(fs);
GLuint vs = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vs, 1, vs_source, NULL);
glCompileShader(vs);
glAttachShader(program, vs);
glAttachShader(program, fs);
glLinkProgram(program);
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
wglMakeCurrent(NULL, NULL);
return 0;
}
void CMFCApplication2View::OnDraw(CDC*/* pDC*/)
{
CMFCApplication2Doc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
if (!pDoc)
return;
// TODO: add draw code for native data here
// Make the rendering context current
wglMakeCurrent(m_hDC, m_hRC);
// TODO: add draw code for native data here
static const GLfloat green[] = { 1.0f, 0.0f, 0.0f, 1.0f };
glClearBufferfv(GL_COLOR, 0, green);
glUseProgram(program);
glDrawArrays(GL_TRIANGLES, 0, 3);
SwapBuffers(m_hDC);
// Allow other rendering contexts to coexist
wglMakeCurrent(NULL, NULL);
}
我通过AMD的GPU Perfstudio运行了两个可执行文件.Win32帧调试显示一切正常.MFC帧调试显示大小为0的帧缓冲区(win32 app的帧缓冲区大小是窗口的大小).这两个应用API跟踪都是相同的.
对可能发生的事情有任何想法？
显然,MFC中的OpenGL在使用核心配置文件时,需要通过glViewport设置视图端口.
处理WM_SIZE和glViewport(0, 0, (GLsizei)cx, (GLsizei)cy)解决问题.
作为一个注释,Andon说我不应该指定像素格式两次是正确的.它没有给出任何错误,这很奇怪,但当我删除它时,一切都继续工作.