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Posted on 2008-10-25 10:56 千张 阅读(1159) 评论(0) 编辑 收藏 引用 所属分类: 图形学
下面，我将NEHE的LESSON1中的代码改成C++版的。 代码如下： 第一部分是Opengl.h
#pragma once
#include "OpenGLModel.h"
class COpengl
{
public:
COpengl(void);
~COpengl(void);
int InitGL(GLvoid);
int DrawGLScene(GLvoid);
GLvoid ReSizeGLScene(GLsizei,GLsizei);
GLvoid KillGLWindow(GLvoid);
BOOL CreateGLWindow(char*,int,int,int,bool);
private:
HDC hDC; //设备描述表(Device Context)
HGLRC hRC; //着色描述表(Rendering Context)
HWND hWnd; //保存窗口句柄
HINSTANCE hInstance; //保存程序的实例
public:
bool keys[256]; //用于监控键盘动作的数组
bool active; //窗口是否处于最小化状态
bool fullscreen; //是否全屏显示
};
第二部分是Opengl.cpp
 #include"Opengl.h"
extern LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
COpengl::COpengl()
   {
 hDC=NULL;
hRC=NULL;
hWnd=NULL;
active=TRUE;
fullscreen=TRUE;
 }
COpengl::~COpengl(void)
{
}
//初始化OpenGL
int COpengl::InitGL(GLvoid)
{
glClearColor(0.0f,0.0f,1.0f,0.0f); //把颜色设置为蓝色
return TRUE; // 初始化成功
}
//视口设置、投影变换
GLvoid COpengl::ReSizeGLScene(GLsizei width, GLsizei height)
{
//防止被0所除
if(height==0)
  {
height=1;
 }
//把视口设置为窗口的大小
glViewport(0,0,width,height);
//透视投影(重置坐标系统)
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);
//模型视图变换设置(重置坐标系统)
glMatrixMode(GL_MODELVIEW); // 选择模型观察矩阵
glLoadIdentity(); // 重置模型观察矩阵
}
int COpengl::DrawGLScene(GLvoid)
{
glClear(GL_COLOR_BUFFER_BIT); //用当前的清除色清除窗口(蓝色)
SwapBuffers(hDC);
return TRUE;
}
GLvoid COpengl::KillGLWindow(GLvoid)
{
if(fullscreen)
{
ChangeDisplaySettings(NULL,0);
ShowCursor(TRUE);
}
if(hRC)
{
if(!wglMakeCurrent(NULL,NULL))
{
MessageBox(NULL,"Release of 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)) // Are We Able To Unregister Class
{
MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
hInstance=NULL; // Set hInstance To NULL
}
}
BOOL COpengl::CreateGLWindow(char *title, int width, int height, int bits, bool fullscreenflag)
{
GLuint PixelFormat; // 保存查找匹配的结果
DWORD dwExStyle; // Window Extended Style
DWORD dwStyle; // Window Style
RECT WindowRect; // Grabs Rectangle Upper Left / Lower Right Values
WindowRect.left=(long)0; // Set Left Value To 0
WindowRect.right=(long)width; // Set Right Value To Requested Width
WindowRect.top=(long)0; // Set Top Value To 0
WindowRect.bottom=(long)height; // Set Bottom Value To Requested Height
fullscreen=fullscreenflag; // Set The Global Fullscreen Flag
//定义窗口类
WNDCLASS wc; // Windows Class Structure
hInstance = GetModuleHandle(NULL); // Grab An Instance For Our Window
wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // Redraw On Size, And Own DC For Window.
wc.lpfnWndProc = (WNDPROC) WndProc; // WndProc Handles Messages
wc.cbClsExtra = 0; // No Extra Window Data
wc.cbWndExtra = 0; // No Extra Window Data
wc.hInstance = hInstance; // Set The Instance
wc.hIcon = LoadIcon(NULL, IDI_WINLOGO); // Load The Default Icon
wc.hCursor = LoadCursor(NULL, IDC_ARROW); // Load The Arrow Pointer
wc.hbrBackground = NULL; // No Background Required For GL
wc.lpszMenuName = NULL; // We Don't Want A Menu
wc.lpszClassName = "OpenGL"; // Set The Class Name
if (!RegisterClass(&wc)) // Attempt To Register The Window Class
{
MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
if (fullscreen) // Attempt Fullscreen Mode?
{
DEVMODE dmScreenSettings; // Device Mode
memset(&dmScreenSettings,0,sizeof(dmScreenSettings)); // Makes Sure Memory's Cleared
dmScreenSettings.dmSize=sizeof(dmScreenSettings); // Size Of The Devmode Structure
dmScreenSettings.dmPelsWidth = width; // Selected Screen Width
dmScreenSettings.dmPelsHeight = height; // Selected Screen Height
dmScreenSettings.dmBitsPerPel = bits; // Selected Bits Per Pixel
dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;
// Try To Set Selected Mode And Get Results. NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar.
if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL)
{
// If The Mode Fails, Offer Two Options. Quit Or Use Windowed Mode.
if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES)
{
fullscreen=FALSE; // Windowed Mode Selected. Fullscreen = FALSE
}
else
{
// Pop Up A Message Box Letting User Know The Program Is Closing.
MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);
return FALSE; // Return FALSE
}
}
}
if (fullscreen) // Are We Still In Fullscreen Mode?
{
dwExStyle=WS_EX_APPWINDOW; // Window Extended Style
dwStyle=WS_POPUP; // Windows Style
ShowCursor(FALSE); // Hide Mouse Pointer
}
else
{
dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; // Window Extended Style
dwStyle=WS_OVERLAPPEDWINDOW; // Windows Style
}
AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle); // Adjust Window To True Requested Size
// Create The Window
if (!(hWnd=CreateWindowEx( dwExStyle, // Extended Style For The Window
"OpenGL", // Class Name
title, // Window Title
dwStyle | // Defined Window Style
WS_CLIPSIBLINGS | // Required Window Style
WS_CLIPCHILDREN, // Required Window Style
0, 0, // Window Position
WindowRect.right-WindowRect.left, // Calculate Window Width
WindowRect.bottom-WindowRect.top, // Calculate Window Height
NULL, // No Parent Window
NULL, // No Menu
hInstance, // Instance
NULL))) // Dont Pass Anything To WM_CREATE
{
KillGLWindow(); // Reset The Display
MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
static PIXELFORMATDESCRIPTOR pfd= // pfd Tells Windows How We Want Things To Be
{
sizeof(PIXELFORMATDESCRIPTOR), // Size Of This Pixel Format Descriptor
1, // Version Number
PFD_DRAW_TO_WINDOW | // Format Must Support Window
PFD_SUPPORT_OPENGL | // Format Must Support OpenGL
PFD_DOUBLEBUFFER, // Must Support Double Buffering
PFD_TYPE_RGBA, // Request An RGBA Format
bits, // Select Our Color Depth
0, 0, 0, 0, 0, 0, // Color Bits Ignored
0, // No Alpha Buffer
0, // Shift Bit Ignored
0, // No Accumulation Buffer
0, 0, 0, 0, // Accumulation Bits Ignored
16, // 16Bit Z-Buffer (Depth Buffer)
0, // No Stencil Buffer
0, // No Auxiliary Buffer
PFD_MAIN_PLANE, // Main Drawing Layer
0, // Reserved
0, 0, 0 // Layer Masks Ignored
};
if (!(hDC=GetDC(hWnd))) // Did We Get A Device Context?
{
KillGLWindow(); // Reset The Display
MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd))) // Did Windows Find A Matching Pixel Format?
{
KillGLWindow(); // Reset The Display
MessageBox(NULL,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
if(!SetPixelFormat(hDC,PixelFormat,&pfd)) // Are We Able To Set The Pixel Format?
{
KillGLWindow(); // Reset The Display
MessageBox(NULL,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
if (!(hRC=wglCreateContext(hDC))) // Are We Able To Get A Rendering Context?
{
KillGLWindow(); // Reset The Display
MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
if(!wglMakeCurrent(hDC,hRC)) // Try To Activate The Rendering Context
{
KillGLWindow(); // Reset The Display
MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
ShowWindow(hWnd,SW_SHOW); // Show The Window
SetForegroundWindow(hWnd); // Slightly Higher Priority
SetFocus(hWnd); // Sets Keyboard Focus To The Window
ReSizeGLScene(width, height); // Set Up Our Perspective GL Screen
if (!InitGL()) // Initialize Our Newly Created GL Window
{
KillGLWindow(); // Reset The Display
MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE; // Return FALSE
}
return TRUE;
}
第三部分是OpenGLModel.h
#ifndef OPENGLMODEL_H
#define OPENGLMODEL_H
#include <windows.h>
#include <gl/gl.h>
#include <gl/glu.h>
#endif OPENGLMODEL_H
第四部分是OpenGLModel.cpp
#include"OpenGLModel.h"
#include "Opengl.h"
COpengl theOpengl;
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain( HINSTANCE hInstance, // Instance
HINSTANCE hPrevInstance, // Previous Instance
LPSTR lpCmdLine, // Command Line Parameters
int nCmdShow) // Window Show State
{
MSG msg; // Windows Message Structure
BOOL done=FALSE; // Bool Variable To Exit Loop
// Ask The User Which Screen Mode They Prefer
if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO)
{
theOpengl.fullscreen=FALSE; // Windowed Mode
}
// Create Our OpenGL Window
if (!theOpengl.CreateGLWindow("NeHe's OpenGL Framework",640,480,16,theOpengl.fullscreen))
{
return 0; // Quit If Window Was Not Created
}
while(!done) // Loop That Runs While done=FALSE
{
if (PeekMessage(&msg,NULL,0,0,PM_REMOVE)) // Is There A Message Waiting?
{
if (msg.message==WM_QUIT) // Have We Received A Quit Message?
{
done=TRUE; // If So done=TRUE
}
else // If Not, Deal With Window Messages
{
TranslateMessage(&msg); // Translate The Message
DispatchMessage(&msg); // Dispatch The Message
}
}
else // If There Are No Messages
{
// Draw The Scene. Watch For ESC Key And Quit Messages From DrawGLScene()
if ((theOpengl.active && !theOpengl.DrawGLScene()) || theOpengl.keys[VK_ESCAPE]) // Active? Was There A Quit Received?
{
done=TRUE; // ESC or DrawGLScene Signalled A Quit
}
if (theOpengl.keys[VK_F1]) // Is F1 Being Pressed?
{
theOpengl.keys[VK_F1]=FALSE; // If So Make Key FALSE
theOpengl.KillGLWindow(); // Kill Our Current Window
theOpengl.fullscreen=!theOpengl.fullscreen; // Toggle Fullscreen / Windowed Mode
// Recreate Our OpenGL Window
if (!theOpengl.CreateGLWindow("NeHe's OpenGL Framework",640,480,32,theOpengl.fullscreen))
{
return 0; // Quit If Window Was Not Created
}
}
}
}
// Shutdown
theOpengl.KillGLWindow(); // Kill The Window
return (msg.wParam); // Exit The Program
}
LRESULT CALLBACK WndProc( HWND hWnd, // Handle For This Window
UINT uMsg, // Message For This Window
WPARAM wParam, // Additional Message Information
LPARAM lParam) // Additional Message Information
{
switch (uMsg) // Check For Windows Messages
{
case WM_ACTIVATE: // Watch For Window Activate Message
{
if (!HIWORD(wParam)) // Check Minimization State
{
theOpengl.active=TRUE; // Program Is Active
}
else
{
theOpengl.active=FALSE; // Program Is No Longer Active
}
return 0; // Return To The Message Loop
}
case WM_SYSCOMMAND: // Intercept System Commands
{
switch (wParam) // Check System Calls
{
case SC_SCREENSAVE: // Screensaver Trying To Start?
case SC_MONITORPOWER: // Monitor Trying To Enter Powersave?
return 0; // Prevent From Happening
}
break; // Exit
}
case WM_CLOSE: // Did We Receive A Close Message?
{
PostQuitMessage(0); // Send A Quit Message
return 0; // Jump Back
}
case WM_KEYDOWN: // Is A Key Being Held Down?
{
theOpengl.keys[wParam] = TRUE; // If So, Mark It As TRUE
return 0; // Jump Back
}
case WM_KEYUP: // Has A Key Been Released?
{
theOpengl.keys[wParam] = FALSE; // If So, Mark It As FALSE
return 0; // Jump Back
}
case WM_SIZE: // Resize The OpenGL Window
{
theOpengl.ReSizeGLScene(LOWORD(lParam),HIWORD(lParam)); // LoWord=Width, HiWord=Height
return 0; // Jump Back
}
}
// Pass All Unhandled Messages To DefWindowProc
return DefWindowProc(hWnd,uMsg,wParam,lParam);
}
函数调用流程： WinMain函数为入口函数，该函数调用CreateGLWindow函数。 CreateGLWindow函数中，定义窗口类，并注册窗口，然后调用CreateWindowEx函数创建窗口。之后设置像素格式，获得DC，并激活RC，然后显示窗口，再调用ReSizeGLScene函数设置OpenGL透视窗口，之后调用InitGL函数，对OpenGL窗口进行初始化。 OpenGL窗口创建成功并初始化后，进入消息循环。用PeekMessage函数检查是否有新的消息，若 没有消息，则调用DrawGLScene函数绘制我们的OpenGL场景。
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