第二章：创建框架和窗口

没有翻译第一章是因为第一章只介绍了如何设置IDE，这方面网上文章很多，我就没有翻译，直接从第二章开始。

下面是原文链接，翻译有不对的地方请朋友们指正。

////////////////////////////////////////////////////////////////////////////////
// Filename: main.cpp
////////////////////////////////////////////////////////////////////////////////
#include "systemclass.h"


int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR pScmdline, int iCmdshow)
{
 SystemClass* System;
 bool result; 
 
 // Create the system object.
 // 创建system对象
 System = new SystemClass;
 if(!System)
 {
  return 0;
 }

 // Initialize and run the system object.
 // 初始化并运行system对象
 result = System->Initialize();
 if(result)
 {
  System->Run();
 }

 // Shutdown and release the system object.
 // 关闭并释放system对象
 System->Shutdown();
 delete System;
 System = 0;

 return 0;
}

////////////////////////////////////////////////////////////////////////////////
// Filename: systemclass.h
////////////////////////////////////////////////////////////////////////////////
#ifndef _SYSTEMCLASS_H_
#define _SYSTEMCLASS_H_

///////////////////////////////
// PRE-PROCESSING DIRECTIVES //
///////////////////////////////
#define WIN32_LEAN_AND_MEAN

///////////////////////
// MY CLASS INCLUDES //
///////////////////////
#include "openglclass.h"
#include "inputclass.h"
#include "graphicsclass.h"

////////////////////////////////////////////////////////////////////////////////
// Class name: SystemClass
////////////////////////////////////////////////////////////////////////////////
class SystemClass
{
public:
 SystemClass();
 SystemClass(const SystemClass&);
 ~SystemClass();

 bool Initialize();
 void Shutdown();
 void Run();

 LRESULT CALLBACK MessageHandler(HWND, UINT, WPARAM, LPARAM);

private:
 bool Frame();
 bool InitializeWindows(OpenGLClass*, int&, int&);
 void ShutdownWindows();

private:
 LPCWSTR m_applicationName;
 HINSTANCE m_hinstance;
 HWND m_hwnd;

 OpenGLClass* m_OpenGL;
 InputClass* m_Input;
 GraphicsClass* m_Graphics;
};

/////////////////////////
// FUNCTION PROTOTYPES //
/////////////////////////
static LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

/////////////
// GLOBALS //
/////////////
static SystemClass* ApplicationHandle = 0;

#endif

////////////////////////////////////////////////////////////////////////////////
// Filename: systemclass.cpp
////////////////////////////////////////////////////////////////////////////////
#include "systemclass.h"

SystemClass::SystemClass(const SystemClass& other)
{
}

SystemClass::~SystemClass()
{
}

bool SystemClass::Initialize()
{
 int screenWidth, screenHeight;
 bool result;

 // Initialize the width and height of the screen to zero.
 screenWidth = 0;
 screenHeight = 0;

 // Create the OpenGL object.
 m_OpenGL = new OpenGLClass;
 if(!m_OpenGL)
 {
  return false;
 }

 // Create the window the application will be using and also initialize OpenGL.
 // 创建程序用的窗口并初始化OpenGL
 result = InitializeWindows(m_OpenGL, screenWidth, screenHeight);
 if(!result)
 {
  MessageBox(m_hwnd, L"Could not initialize the window.", L"Error", MB_OK);
  return false;
 }
 
 // Create the input object.  This object will be used to handle reading the input from the user.
 m_Input = new InputClass;
 if(!m_Input)
 {
  return false;
 }

 // Initialize the input object.
 m_Input->Initialize();

 // Create the graphics object.  This object will handle rendering all the graphics for this application.
 m_Graphics = new GraphicsClass;
 if(!m_Graphics)
 {
  return false;
 }

 // Initialize the graphics object.
 result = m_Graphics->Initialize(m_OpenGL, m_hwnd);
 if(!result)
 {
  return false;
 }

 return true;
}

void SystemClass::Shutdown()
{
 // Release the graphics object.
 if(m_Graphics)
 {
  m_Graphics->Shutdown();
  delete m_Graphics;
  m_Graphics = 0;
 }

 // Release the input object.
 if(m_Input)
 {
  delete m_Input;
  m_Input = 0;
 }

 // Release the OpenGL object.
 if(m_OpenGL)
 {
  delete m_OpenGL;
  m_OpenGL = 0;
 }

 // Shutdown the window.
 ShutdownWindows();
 
 return;
}

void SystemClass::Run()
{
 MSG msg;
 bool done, result;

 // Initialize the message structure.
 ZeroMemory(&msg, sizeof(MSG));
 
 // Loop until there is a quit message from the window or the user.
 done = false;
 while(!done)
 {
  // Handle the windows messages.
  if(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
  {
   TranslateMessage(&msg);
   DispatchMessage(&msg);
  }

  // If windows signals to end the application then exit out.
  if(msg.message == WM_QUIT)
  {
   done = true;
  }
  else
  {
   // Otherwise do the frame processing.
   result = Frame();
   if(!result)
   {
    done = true;
   }
  }

 }

 return;
}

bool SystemClass::Frame()
{
 bool result;

 // Check if the user pressed escape and wants to exit the application.
 if(m_Input->IsKeyDown(VK_ESCAPE))
 {
  return false;
 }

 // Do the frame processing for the graphics object.
 result = m_Graphics->Frame();
 if(!result)
 {
  return false;
 }

 return true;
}

LRESULT CALLBACK SystemClass::MessageHandler(HWND hwnd, UINT umsg, WPARAM wparam, LPARAM lparam)
{
 switch(umsg)
 {
  // Check if a key has been pressed on the keyboard.
  case WM_KEYDOWN:
  {
   // If a key is pressed send it to the input object so it can record that state.
   m_Input->KeyDown((unsigned int)wparam);
   return 0;
  }

  // Check if a key has been released on the keyboard.
  case WM_KEYUP:
  {
   // If a key is released then send it to the input object so it can unset the state for that key.
   m_Input->KeyUp((unsigned int)wparam);
   return 0;
  }

  // Any other messages send to the default message handler as our application won't make use of them.
  default:
  {
   return DefWindowProc(hwnd, umsg, wparam, lparam);
  }
 }
}

bool SystemClass::InitializeWindows(OpenGLClass* OpenGL, int& screenWidth, int& screenHeight)
{
 WNDCLASSEX wc;
 DEVMODE dmScreenSettings;
 int posX, posY;

 // Get an external pointer to this object.
 ApplicationHandle = this;

 // Get the instance of this application.
 m_hinstance = GetModuleHandle(NULL);

 // Give the application a name.
 m_applicationName = L"Engine";

 // Setup the windows class with default settings.
 wc.style         = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
 wc.lpfnWndProc   = WndProc;
 wc.cbClsExtra    = 0;
 wc.cbWndExtra    = 0;
 wc.hInstance     = m_hinstance;
 wc.hIcon         = LoadIcon(NULL, IDI_WINLOGO);
 wc.hIconSm       = wc.hIcon;
 wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
 wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
 wc.lpszMenuName  = NULL;
 wc.lpszClassName = m_applicationName;
 wc.cbSize        = sizeof(WNDCLASSEX);
 
 // Register the window class.
 RegisterClassEx(&wc);

 // Create a temporary window for the OpenGL extension setup.
 m_hwnd = CreateWindowEx(WS_EX_APPWINDOW, m_applicationName, m_applicationName, WS_POPUP,
    0, 0, 640, 480, NULL, NULL, m_hinstance, NULL);
 if(m_hwnd == NULL)
 {
  return false;
 }

 // Don't show the window.
 ShowWindow(m_hwnd, SW_HIDE);

 // Release the temporary window now that the extensions have been initialized.
 DestroyWindow(m_hwnd);
 m_hwnd = NULL;

// Determine the resolution of the clients desktop screen.
 screenWidth  = GetSystemMetrics(SM_CXSCREEN);
 screenHeight = GetSystemMetrics(SM_CYSCREEN);

 // Setup the screen settings depending on whether it is running in full screen or in windowed mode.
 if(FULL_SCREEN)
 {
  // If full screen set the screen to maximum size of the users desktop and 32bit.
  memset(&dmScreenSettings, 0, sizeof(dmScreenSettings));
  dmScreenSettings.dmSize       = sizeof(dmScreenSettings);
  dmScreenSettings.dmPelsWidth  = (unsigned long)screenWidth;
  dmScreenSettings.dmPelsHeight = (unsigned long)screenHeight;
  dmScreenSettings.dmBitsPerPel = 32;
  dmScreenSettings.dmFields     = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;

  // Change the display settings to full screen.
  ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN);

  // Set the position of the window to the top left corner.
  posX = posY = 0;
 }
 else
 {
  // If windowed then set it to 800x600 resolution.
  screenWidth  = 800;
  screenHeight = 600;

  // Place the window in the middle of the screen.
  posX = (GetSystemMetrics(SM_CXSCREEN) - screenWidth)  / 2;
  posY = (GetSystemMetrics(SM_CYSCREEN) - screenHeight) / 2;
 }

 // Create the window with the screen settings and get the handle to it.
 m_hwnd = CreateWindowEx(WS_EX_APPWINDOW, m_applicationName, m_applicationName, WS_POPUP,
    posX, posY, screenWidth, screenHeight, NULL, NULL, m_hinstance, NULL);
 if(m_hwnd == NULL)
 {
  return false;
 }

 // Bring the window up on the screen and set it as main focus.
 ShowWindow(m_hwnd, SW_SHOW);
 SetForegroundWindow(m_hwnd);
 SetFocus(m_hwnd);

 // Hide the mouse cursor.
 ShowCursor(false);

 return true;
}

void SystemClass::ShutdownWindows()
{
 // Show the mouse cursor.
 ShowCursor(true);

 // Fix the display settings if leaving full screen mode.
 if(FULL_SCREEN)
 {
  ChangeDisplaySettings(NULL, 0);
 }

 // Remove the window.
 DestroyWindow(m_hwnd);
 m_hwnd = NULL;

 // Remove the application instance.
 UnregisterClass(m_applicationName, m_hinstance);
 m_hinstance = NULL;

 // Release the pointer to this class.
 ApplicationHandle = NULL;

 return;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT umessage, WPARAM wparam, LPARAM lparam)
{
 switch(umessage)
 {
  // Check if the window is being closed.
  case WM_CLOSE:
  {
   PostQuitMessage(0);
   return 0;
  }

  // All other messages pass to the message handler in the system class.
  default:
  {
   return ApplicationHandle->MessageHandler(hwnd, umessage, wparam, lparam);
  }
 }
}

////////////////////////////////////////////////////////////////////////////////
// Filename: inputclass.h
////////////////////////////////////////////////////////////////////////////////
#ifndef _INPUTCLASS_H_
#define _INPUTCLASS_H_

////////////////////////////////////////////////////////////////////////////////
// Class name: InputClass
////////////////////////////////////////////////////////////////////////////////
class InputClass
{
public:
 InputClass();
 InputClass(const InputClass&);
 ~InputClass();

 void Initialize();

 void KeyDown(unsigned int);
 void KeyUp(unsigned int);

 bool IsKeyDown(unsigned int);

private:
 bool m_keys[256];
};

#endif

////////////////////////////////////////////////////////////////////////////////
// Filename: inputclass.cpp
////////////////////////////////////////////////////////////////////////////////
#include "inputclass.h"

InputClass::InputClass()
{
}

InputClass::InputClass(const InputClass& other)
{
}

InputClass::~InputClass()
{
}

void InputClass::Initialize()
{
 int i; 

 // Initialize all the keys to being released and not pressed.
 for(i=0; i<256; i++)
 {
  m_keys[i] = false;
 }

 return;
}

void InputClass::KeyDown(unsigned int input)
{
 // If a key is pressed then save that state in the key array.
 m_keys[input] = true;
 return;
}

void InputClass::KeyUp(unsigned int input)
{
 // If a key is released then clear that state in the key array.
 m_keys[input] = false;
 return;
}

bool InputClass::IsKeyDown(unsigned int key)
{
 // Return what state the key is in (pressed/not pressed).
 return m_keys[key];
}

////////////////////////////////////////////////////////////////////////////////
// Filename: graphicsclass.h
////////////////////////////////////////////////////////////////////////////////
#ifndef _GRAPHICSCLASS_H_
#define _GRAPHICSCLASS_H_

///////////////////////
// MY CLASS INCLUDES //
///////////////////////
#include "openglclass.h"

/////////////
// GLOBALS //
/////////////
const bool FULL_SCREEN = false;
const bool VSYNC_ENABLED = true;
const float SCREEN_DEPTH = 1000.0f;
const float SCREEN_NEAR = 0.1f;

////////////////////////////////////////////////////////////////////////////////
// Class name: GraphicsClass
////////////////////////////////////////////////////////////////////////////////
class GraphicsClass
{
public:
 GraphicsClass();
 GraphicsClass(const GraphicsClass&);
 ~GraphicsClass();

 bool Initialize(OpenGLClass*, HWND);
 void Shutdown();
 bool Frame();

private:
 bool Render();

private:

};

#endif

////////////////////////////////////////////////////////////////////////////////
// Filename: graphicsclass.cpp
////////////////////////////////////////////////////////////////////////////////
#include "graphicsclass.h"

GraphicsClass::GraphicsClass()
{
}

GraphicsClass::GraphicsClass(const GraphicsClass& other)
{
}

GraphicsClass::~GraphicsClass()
{
}

bool GraphicsClass::Initialize(OpenGLClass* OpenGL, HWND hwnd)
{
 return true;
}

void GraphicsClass::Shutdown()
{
 return;
}

bool GraphicsClass::Frame()
{
 return true;
}

bool GraphicsClass::Render()
{
 return true;
}

////////////////////////////////////////////////////////////////////////////////
// Filename: openglclass.h
////////////////////////////////////////////////////////////////////////////////
#ifndef _OPENGLCLASS_H_
#define _OPENGLCLASS_H_

//////////////
// INCLUDES //
//////////////
#include <windows.h>

////////////////////////////////////////////////////////////////////////////////
// Class name: OpenGLClass
////////////////////////////////////////////////////////////////////////////////
class OpenGLClass
{
public:
 OpenGLClass();
 OpenGLClass(const OpenGLClass&);
 ~OpenGLClass();

private:

};

#endif

////////////////////////////////////////////////////////////////////////////////
// Filename: openglclass.cpp
////////////////////////////////////////////////////////////////////////////////
#include "openglclass.h"

OpenGLClass::OpenGLClass()
{
}

OpenGLClass::OpenGLClass(const OpenGLClass& other)
{
}

OpenGLClass::~OpenGLClass()
{
}

第二章：创建框架和窗口

原文：http://blog.csdn.net/weyson/article/details/46755043