aliensprite.cpp

来自「《24小时教会你游戏编程》上的源码」· C++ 代码 · 共 80 行

//-----------------------------------------------------------------
// Alien Sprite Object
// C++ Source - AlienSprite.cpp
//-----------------------------------------------------------------

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

//-----------------------------------------------------------------
// External Global Variables
//-----------------------------------------------------------------
extern Bitmap* _pBlobboBitmap;
extern Bitmap* _pBMissileBitmap;
extern Bitmap* _pJellyBitmap;
extern Bitmap* _pJMissileBitmap;
extern Bitmap* _pTimmyBitmap;
extern Bitmap* _pTMissileBitmap;
extern int     _iDifficulty;

//-----------------------------------------------------------------
// AlienSprite Constructor(s)/Destructor
//-----------------------------------------------------------------
AlienSprite::AlienSprite(Bitmap* pBitmap, RECT& rcBounds,
  BOUNDSACTION baBoundsAction) : Sprite(pBitmap, rcBounds,
  baBoundsAction)
{
}

AlienSprite::~AlienSprite()
{
}

//-----------------------------------------------------------------
// AlienSprite General Methods
//-----------------------------------------------------------------
SPRITEACTION AlienSprite::Update()
{
  // Call the base sprite Update() method
  SPRITEACTION saSpriteAction;
  saSpriteAction = Sprite::Update();

  // See if the alien should fire a missile
  if ((rand() % (_iDifficulty / 2)) == 0)
    saSpriteAction |= SA_ADDSPRITE;

  return saSpriteAction;
}

Sprite* AlienSprite::AddSprite()
{
  // Create a new missile sprite
  RECT    rcBounds = { 0, 0, 640, 410 };
  RECT    rcPos = GetPosition();
  Sprite* pSprite = NULL;
  if (GetBitmap() == _pBlobboBitmap)
  {
    // Blobbo missile
    pSprite = new Sprite(_pBMissileBitmap, rcBounds, BA_DIE);
    pSprite->SetVelocity(0, 7);
  }
  else if (GetBitmap() == _pJellyBitmap)
  {
    // Jelly missile
    pSprite = new Sprite(_pJMissileBitmap, rcBounds, BA_DIE);
    pSprite->SetVelocity(0, 5);
  }
  else
  {
    // Timmy missile
    pSprite = new Sprite(_pTMissileBitmap, rcBounds, BA_DIE);
    pSprite->SetVelocity(0, 3);
  }

  // Set the missile sprite's position and return it
  pSprite->SetPosition(rcPos.left + (GetWidth() / 2), rcPos.bottom);
  return pSprite;
}