ufo.cpp

来自「《24小时教会你游戏编程》上的源码」· C++ 代码 · 共 154 行

//-----------------------------------------------------------------
// UFO 2 Application
// C++ Source - UFO.cpp
//-----------------------------------------------------------------

//-----------------------------------------------------------------
// Include Files
//-----------------------------------------------------------------
#include "UFO.h"

//-----------------------------------------------------------------
// Game Engine Functions
//-----------------------------------------------------------------
BOOL GameInitialize(HINSTANCE hInstance)
{
  // Create the game engine
  _pGame = new GameEngine(hInstance, TEXT("UFO 2"),
    TEXT("UFO 2"), IDI_UFO, IDI_UFO_SM, 500, 400);
  if (_pGame == NULL)
    return FALSE;
  
  // Set the frame rate
  _pGame->SetFrameRate(30);

  // Initialize the joystick
  _pGame->InitJoystick();

  // Store the instance handle
  _hInstance = hInstance;

  return TRUE;
}

void GameStart(HWND hWindow)
{
  // Seed the random number generator
  srand(GetTickCount());

  // Create and load the background and saucer bitmaps
  HDC hDC = GetDC(hWindow);
  _pBackground = new Bitmap(hDC, IDB_BACKGROUND, _hInstance);
  _pSaucer[0] = new Bitmap(hDC, IDB_SAUCER, _hInstance);
  _pSaucer[1] = new Bitmap(hDC, IDB_SAUCERFLAME, _hInstance);

  // Set the initial saucer position and speed
  _iSaucerX = 250 - (_pSaucer[0]->GetWidth() / 2);
  _iSaucerY = 200 - (_pSaucer[0]->GetHeight() / 2);
  _iSpeedX = 0;
  _iSpeedY = 0;
}

void GameEnd()
{
  // Cleanup the background and saucer bitmaps
  delete _pBackground;
  delete _pSaucer[0];
  delete _pSaucer[1];

  // Cleanup the game engine
  delete _pGame;
}

void GameActivate(HWND hWindow)
{
  // Capture the joystick
  _pGame->CaptureJoystick();
}

void GameDeactivate(HWND hWindow)
{
  // Release the joystick
  _pGame->ReleaseJoystick();
}

void GamePaint(HDC hDC)
{
  // Draw the background and saucer bitmaps
  _pBackground->Draw(hDC, 0, 0);
  _pSaucer[_bSaucerFlame ? 1:0]->Draw(hDC, _iSaucerX, _iSaucerY, TRUE);
}

void GameCycle()
{
  // Update the saucer position
  _iSaucerX = min(500 - _pSaucer[0]->GetWidth(), max(0, _iSaucerX + _iSpeedX));
  _iSaucerY = min(320, max(0, _iSaucerY + _iSpeedY));

  // Force a repaint to redraw the saucer
  InvalidateRect(_pGame->GetWindow(), NULL, FALSE);
}

void HandleKeys()
{
  // Change the speed of the saucer in response to arrow key presses
  if (GetAsyncKeyState(VK_LEFT) < 0)
    _iSpeedX = max(-_iMAXSPEED, --_iSpeedX);
  else if (GetAsyncKeyState(VK_RIGHT) < 0)
    _iSpeedX = min(_iMAXSPEED, ++_iSpeedX);
  if (GetAsyncKeyState(VK_UP) < 0)
    _iSpeedY = max(-_iMAXSPEED, --_iSpeedY);
  else if (GetAsyncKeyState(VK_DOWN) < 0)
    _iSpeedY = min(_iMAXSPEED, ++_iSpeedY);
}

void MouseButtonDown(int x, int y, BOOL bLeft)
{
  if (bLeft)
  {
    // Set the saucer position to the mouse position
    _iSaucerX = x - (_pSaucer[0]->GetWidth() / 2);
    _iSaucerY = y - (_pSaucer[0]->GetHeight() / 2);
  }
  else
  {
    // Stop the saucer
    _iSpeedX = 0;
    _iSpeedY = 0;
  }
}

void MouseButtonUp(int x, int y, BOOL bLeft)
{
}

void MouseMove(int x, int y)
{
}

void HandleJoystick(JOYSTATE jsJoystickState)
{
  // Check horizontal movement
  if (jsJoystickState & JOY_LEFT)
    _iSpeedX = max(-_iMAXSPEED, _iSpeedX - 2);
  else if (jsJoystickState & JOY_RIGHT)
    _iSpeedX = min(_iMAXSPEED, _iSpeedX + 2);

  // Check vertical movement
  if (jsJoystickState & JOY_UP)
    _iSpeedY = max(-_iMAXSPEED, _iSpeedY - 2);
  else if (jsJoystickState & JOY_DOWN)
    _iSpeedY = min(_iMAXSPEED, _iSpeedY + 2);

  // Check primary joystick button
  _bSaucerFlame = (jsJoystickState & JOY_FIRE1);

  // Check secondary joystick button
  if (jsJoystickState & JOY_FIRE2)
  {
    // Force the flying saucer into hyperspace
    _iSaucerX = rand() % (500 - _pSaucer[0]->GetWidth());
    _iSaucerY = rand() % 320;
  }
}