今晚根据OpenGL Tutorial 教程Lesson 0，把书中代码实现了一下，结果程序运行无法全屏，
正确代码代码如下
#include <windows.h>
#include <gl/glu.h>
#include <gl/glut.h>
#include <gl/glaux.h>
HGLRC hRC = NULL;
HDC hDC = NULL;
HWND hWnd = NULL;
HINSTANCE hInstance;
bool keys[256];
bool active = true;
bool fullscreen = true;
LRESULT CALLBACK WndProc(HWND hWnd, UINT, WPARAM, LPARAM);
GLvoid ReSizeGLScene(GLsizei width, GLsizei height)
{
if (height == 0)
{
height = 1;
}
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0f, (GLfloat)width / (GLfloat)height, 0.1f, 100.0f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
int InitGL(GLvoid)
{
glShadeModel(GL_SMOOTH);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
return true;
}
int DrawGLScene(GLvoid)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
return true;
}
GLvoid KillGLWindow(GLvoid)
{
if (fullscreen)
{
ChangeDisplaySettings(NULL, 0);
ShowCursor(true);
}
if (hRC)
{
if (!wglMakeCurrent(NULL, NULL))
{
MessageBox(NULL, "Release DC and RC failed", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
}
if (!wglDeleteContext(hRC))
{
MessageBox(NULL, "Release Rendering Context Failed", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
}
hRC = NULL;
}
if (hDC && !ReleaseDC(hWnd, hDC))
{
MessageBox(NULL, "Release Device Context Failed", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
hDC = NULL;
}
if (hWnd && !DestroyWindow(hWnd))
{
MessageBox(NULL, "Could Not Release hWnd", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
hWnd = NULL;
}
if (!UnregisterClass("OpenGL", hInstance))
{
MessageBox(NULL, "Could Not Unregister Class", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
hInstance = NULL;
}
}
BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag)
{
GLuint PixelFormat;
WNDCLASS wc;
DWORD dwExStyle;
DWORD dwStyle;
RECT WindowRect;
WindowRect.left = (long)0;
WindowRect.right = (long)width;
WindowRect.top = (long)0;
WindowRect.bottom = (long)height;
fullscreen = fullscreenflag;
hInstance = GetModuleHandle(NULL);
wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
wc.lpfnWndProc = (WNDPROC)WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = NULL;
wc.lpszMenuName = NULL;
wc.lpszClassName = "OpenGL";
if (!RegisterClass(&wc))
{
MessageBox(NULL, "Failed To Register The Window Class", "ERROR", MB_OK | MB_ICONINFORMATION);
return false;
}
if (fullscreen)
{
DEVMODE dmScreenSettings;
memset(&dmScreenSettings, 0, sizeof(dmScreenSettings));
dmScreenSettings.dmSize = sizeof(dmScreenSettings); // mistake dmScreenSettings.dmSize to dmScreenSettings.dmScal
dmScreenSettings.dmPelsWidth = width;
dmScreenSettings.dmPelsHeight = height;
dmScreenSettings.dmBitsPerPel = bits;
dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;
if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN) != DISP_CHANGE_SUCCESSFUL)
{
if (MessageBox(NULL, "The Request Fullscreen Mode Is Not Supported By/nYour Video Card. Use Windowed mode Instead?", "NeHe GL", MB_YESNO | MB_ICONINFORMATION) == IDYES)
{
fullscreen = false;
}
else
{
MessageBox(NULL, "Program Will Now Close.", "ERROR", MB_OK | MB_ICONSTOP);
return false;
}
}
}
if (fullscreen)
{
dwExStyle = WS_EX_APPWINDOW;
dwStyle = WS_POPUP;
ShowCursor(false);
}
else
{
dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;
dwStyle = WS_OVERLAPPEDWINDOW;
}
AdjustWindowRectEx(&WindowRect, dwStyle, false, dwExStyle);
if (!(hWnd = CreateWindowEx(dwExStyle,
"OpenGL",
title,
dwStyle |
WS_CLIPSIBLINGS |
WS_CLIPCHILDREN,
0, 0,
WindowRect.right- WindowRect.left,
WindowRect.bottom - WindowRect.top,
NULL,
NULL,
hInstance,
NULL)))
{
KillGLWindow();
MessageBox(NULL, "Window Creation Error", "ERROR", MB_OK | MB_ICONEXCLAMATION);
return false;
}
static PIXELFORMATDESCRIPTOR pfd =
{
sizeof(PIXELFORMATDESCRIPTOR),
1,
PFD_DRAW_TO_WINDOW |
PFD_SUPPORT_OPENGL |
PFD_DOUBLEBUFFER,
PFD_TYPE_RGBA,
bits,
0, 0, 0, 0, 0, 0,
0,
0,
0,
0, 0, 0, 0,
16,
0,
0,
PFD_MAIN_PLANE,
0,
0, 0, 0
};
if (!(hDC = GetDC(hWnd)))
{
KillGLWindow();
MessageBox(NULL, "Can't Create A GL Device Context", "ERROR", MB_OK | MB_ICONEXCLAMATION);
return false;
}
if (!(PixelFormat = ChoosePixelFormat(hDC, &pfd)))
{
KillGLWindow();
MessageBox(NULL, "Can't Find A Suitalbe PixelFormat.","ERROR",
MB_OK | MB_ICONEXCLAMATION);
return false;
}
if (!SetPixelFormat(hDC, PixelFormat, &pfd))
{
KillGLWindow();
MessageBox(NULL, "Can't Set The PixelFormat.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
return false;
}
if (!(hRC = wglCreateContext(hDC)))
{
KillGLWindow();
MessageBox(NULL, "Can't Create A GL Rendering Context.", "ERROR",
MB_OK | MB_ICONEXCLAMATION);
return false;
}
if (!wglMakeCurrent(hDC, hRC))
{
KillGLWindow();
MessageBox(NULL, "Can't Active The GL Rendering Context.", "ERROR",
MB_OK | MB_ICONEXCLAMATION);
return false;
}
ShowWindow(hWnd, SW_SHOW);
SetForegroundWindow(hWnd);
SetFocus(hWnd);
ReSizeGLScene(width, height);
if (!InitGL())
{
KillGLWindow();
MessageBox(NULL, "Initialization Failed.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
return false;
}
return true;
}
LRESULT CALLBACK WndProc(HWND hWnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam)
{
switch (uMsg)
{
case WM_ACTIVATE:
if (!HIWORD(wParam))
{
active = true;
}
else
{
active = false;
}
return 0;
case WM_SYSCOMMAND:
{
switch (wParam)
{
case SC_SCREENSAVE:
case SC_MONITORPOWER:
return 0;
}
break;
}
case WM_CLOSE:
{
PostQuitMessage(0);
return 0;
}
case WM_KEYDOWN:
{
keys[wParam] = true;
return 0;
}
case WM_KEYUP:
{
keys[wParam] = false;
return 0;
}
case WM_SIZE:
{
ReSizeGLScene(LOWORD(lParam), HIWORD(lParam));
return 0;
}
}
return DefWindowProc(hWnd, uMsg, wParam, lParam);
}
int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd )
{
MSG msg;
BOOL done = false;
if (MessageBox(NULL, "Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",
MB_YESNO | MB_ICONQUESTION) == IDNO)
{
fullscreen = false;
}
if (!CreateGLWindow("NeHe's OpenGL Framework", 640, 480, 16, fullscreen))
{
return 0;
}
while (!done)
{
if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
{
if (msg.message == WM_QUIT)
{
done = true;
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
else
{
if (active)
{
if (keys[VK_ESCAPE])
{
done = true;
}
else
{
DrawGLScene();
SwapBuffers(hDC);
}
if (keys[VK_F1])
{
keys[VK_F1] = false;
KillGLWindow();
fullscreen = !fullscreen;
if (!CreateGLWindow("NeHe's OpenGL Framwork", 640, 480, 16, fullscreen))
{
return 0;
}
}
}
}
}
KillGLWindow();
return msg.wParam;
最后发现原因是在113行把dmScreenSettings.dmSize写成dmScreenSettings.dmScal
郁闷~~~~
查阅MSDN，DEVMODE <script src="langref.js"></script> The DEVMODE data structure contains information about the device initialization and environment of a printer.
DEVMODE包含了设备初始化信息，在执行函数ChangeDisplaySettings，需要对dmScreenSetting进行初始化，由于没有dmScreenSetting.dmSize赋值导致dmScreenSetting的初始化无效，所以无法全屏，程序运行窗口如下所示：（具体原因任然不甚明了，明日继续研究~~~~睡觉去~~~~）
