ufo.cpp

游戏编程源码

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

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

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

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

  // Store the instance handle
  g_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);
  g_pBackground = new Bitmap(hDC, IDB_BACKGROUND, g_hInstance);
  g_pSaucer[0] = new Bitmap(hDC, IDB_SAUCER, g_hInstance);
  g_pSaucer[1] = new Bitmap(hDC, IDB_SAUCERFLAME, g_hInstance);

  // Set the initial saucer position and speed
  g_iSaucerX = 250 - (g_pSaucer[0]->GetWidth() / 2);
  g_iSaucerY = 200 - (g_pSaucer[0]->GetHeight() / 2);
  g_iSpeedX = 0;
  g_iSpeedY = 0;
}

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

  // Cleanup the game engine
  delete g_pGame;
}

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

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

void GamePaint(HDC hDC)
{
  // Draw the background and saucer bitmaps
  g_pBackground->Draw(hDC, 0, 0);
  g_pSaucer[g_bSaucerFlame ? 1:0]->Draw(hDC, g_iSaucerX, g_iSaucerY, TRUE);
}

void GameCycle()
{
  // Update the saucer position
  g_iSaucerX = min(500 - g_pSaucer[0]->GetWidth(), max(0, g_iSaucerX + g_iSpeedX));
  g_iSaucerY = min(320, max(0, g_iSaucerY + g_iSpeedY));

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

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

void MouseButtonDown(int x, int y, BOOL bLeft)
{
  if (bLeft)
  {
    // Set the saucer position to the mouse position
    g_iSaucerX = x - (g_pSaucer[0]->GetWidth() / 2);
    g_iSaucerY = y - (g_pSaucer[0]->GetHeight() / 2);
  }
  else
  {
    // Stop the saucer
    g_iSpeedX = 0;
    g_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)
    g_iSpeedX = max(-g_iMAXSPEED, g_iSpeedX - 2);
  else if (jsJoystickState & JOY_RIGHT)
    g_iSpeedX = min(g_iMAXSPEED, g_iSpeedX + 2);

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

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

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