motorcyclesprite.cpp

游戏编程源码

//-----------------------------------------------------------------
// Motorcycle Sprite Object
// C++ Source - MotorcycleSprite.cpp
//-----------------------------------------------------------------

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

//-----------------------------------------------------------------
// External Global Variables
//-----------------------------------------------------------------
extern HINSTANCE  g_hInstance;
extern int        g_bGameOver;

//-----------------------------------------------------------------
// MotorcycleSprite Constructor(s)/Destructor
//-----------------------------------------------------------------
MotorcycleSprite::MotorcycleSprite(Bitmap* pBitmap, RECT& rcBounds,
  BOUNDSACTION baBoundsAction) : Sprite(pBitmap, rcBounds,
  baBoundsAction), m_iMINSPEED(1), m_iMAXSPEED(10), m_iHANGTIME(6)
{
  // Initialize the motorcycle sprite variables
  m_iCurFrame = 6;  // the frame where the motorcycle is level
  m_bJumping = FALSE;
  m_iJumpCounter = 0;
  m_bLandedSafely = TRUE;
}

MotorcycleSprite::~MotorcycleSprite()
{
}

//-----------------------------------------------------------------
// MotorcycleSprite Virtual Methods
//-----------------------------------------------------------------
void MotorcycleSprite::UpdateFrame()
{
  if (m_bJumping)
  {
    // Start jumping
    if (m_iJumpCounter-- >= 0)
    {
      // See if the motorcycle is on the way up
      if (m_iJumpCounter > (m_ptVelocity.x * m_iHANGTIME / 2))
      {
        // Change the frame to show the motorcycle tilt upward
        m_iCurFrame = min(m_iCurFrame + 1, 12);

        // Change the vertical velocity to cause the motorcycle to ascend
        if (m_iJumpCounter % (m_iHANGTIME / 2) == 0)
          m_ptVelocity.y++;
      }
      // See if the motorcycle is on the way down
      else if (m_iJumpCounter <= (m_ptVelocity.x * m_iHANGTIME / 2))
      {
        // Change the frame to show the motorcycle tilt downward
        m_iCurFrame = max(m_iCurFrame - 1, 0);

        // Change the vertical velocity to cause the motorcycle to descend
        if (m_iJumpCounter % (m_iHANGTIME / 2) == 0)
          m_ptVelocity.y++;
      }
    }
    else
    {
      // Stop the jump and level the motorcycle
      m_bJumping = FALSE;
      m_iCurFrame = 6;
      m_ptVelocity.y = 0;

      // See if the motorcycle overshot the landing ramp
      if (!m_bLandedSafely)
      {
        // Play the crash sound
        PlaySound((LPCSTR)IDW_CRASH, g_hInstance, SND_ASYNC |
          SND_RESOURCE);

        // End the game
        m_ptVelocity.x = 0;
        g_bGameOver = TRUE;
      }
    }
  }
}

//-----------------------------------------------------------------
// MotorcycleSprite General Methods
//-----------------------------------------------------------------
void MotorcycleSprite::IncreaseSpeed()
{
  if (!m_bJumping)
    // Increase the horizontal speed of the motorcycle
    m_ptVelocity.x = min((int)(m_ptVelocity.x + 1), m_iMAXSPEED);
}

void MotorcycleSprite::DecreaseSpeed()
{
  if (!m_bJumping)
    // Decrease the horizontal speed of the motorcycle
    m_ptVelocity.x = max((int)(m_ptVelocity.x - 1), m_iMINSPEED);
}

void MotorcycleSprite::StartJumping()
{
  if (!m_bJumping)
  {
    // Start the motorcycle jumping
    m_iJumpCounter = m_ptVelocity.x * m_iHANGTIME;
    m_ptVelocity.y = -m_ptVelocity.x;
    m_bJumping = TRUE;
    m_bLandedSafely = FALSE;
  }
}

void MotorcycleSprite::LandedSafely()
{
  // Flag the motorcycle as having landed safely (hit the landing ramp)
  m_bLandedSafely = TRUE;
}