www.gusucode.com > VC++ 碰撞检测 - 如何判断两个运动中的物体已碰触源码程序 > VC++ 碰撞检测 - 如何判断两个运动中的物体已碰触源码程序/code/Sprite.cpp

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

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

//-----------------------------------------------------------------
// Sprite Constructor(s)/Destructor
//-----------------------------------------------------------------
Sprite::Sprite(Bitmap* pBitmap)
{
  // Initialize the member variables
  m_pBitmap = pBitmap;
  SetRect(&m_rcPosition, 0, 0, pBitmap->GetWidth(), pBitmap->GetHeight());
  CalcCollisionRect();
  m_ptVelocity.x = m_ptVelocity.y = 0;
  m_iZOrder = 0;
  SetRect(&m_rcBounds, 0, 0, 640, 480);
  m_baBoundsAction = BA_STOP;
  m_bHidden = FALSE;
}

Sprite::Sprite(Bitmap* pBitmap, RECT& rcBounds, BOUNDSACTION baBoundsAction)
{
  // Calculate a random position
  int iXPos = rand() % (rcBounds.right - rcBounds.left);
  int iYPos = rand() % (rcBounds.bottom - rcBounds.top);

  // Initialize the member variables
  m_pBitmap = pBitmap;
  SetRect(&m_rcPosition, iXPos, iYPos, iXPos + pBitmap->GetWidth(),
    iYPos + pBitmap->GetHeight());
  CalcCollisionRect();
  m_ptVelocity.x = m_ptVelocity.y = 0;
  m_iZOrder = 0;
  CopyRect(&m_rcBounds, &rcBounds);
  m_baBoundsAction = baBoundsAction;
  m_bHidden = FALSE;
}

Sprite::Sprite(Bitmap* pBitmap, POINT ptPosition, POINT ptVelocity, int iZOrder,
    RECT& rcBounds, BOUNDSACTION baBoundsAction)
{
  // Initialize the member variables
  m_pBitmap = pBitmap;
  SetRect(&m_rcPosition, ptPosition.x, ptPosition.y,
    ptPosition.x + pBitmap->GetWidth(), ptPosition.y + pBitmap->GetHeight());
  CalcCollisionRect();
  m_ptVelocity = ptVelocity;
  m_iZOrder = iZOrder;
  CopyRect(&m_rcBounds, &rcBounds);
  m_baBoundsAction = baBoundsAction;
  m_bHidden = FALSE;
}

Sprite::~Sprite()
{
}

//-----------------------------------------------------------------
// Sprite General Methods
//-----------------------------------------------------------------
SPRITEACTION Sprite::Update()
{
  // Update the position
  POINT ptNewPosition, ptSpriteSize, ptBoundsSize;
  ptNewPosition.x = m_rcPosition.left + m_ptVelocity.x;
  ptNewPosition.y = m_rcPosition.top + m_ptVelocity.y;
  ptSpriteSize.x = m_rcPosition.right - m_rcPosition.left;
  ptSpriteSize.y = m_rcPosition.bottom - m_rcPosition.top;
  ptBoundsSize.x = m_rcBounds.right - m_rcBounds.left;
  ptBoundsSize.y = m_rcBounds.bottom - m_rcBounds.top;

  // Check the bounds
  // Wrap?
  if (m_baBoundsAction == BA_WRAP)
  {
    if ((ptNewPosition.x + ptSpriteSize.x) < m_rcBounds.left)
      ptNewPosition.x = m_rcBounds.right;
    else if (ptNewPosition.x > m_rcBounds.right)
      ptNewPosition.x = m_rcBounds.left - ptSpriteSize.x;
    if ((ptNewPosition.y + ptSpriteSize.y) < m_rcBounds.top)
      ptNewPosition.y = m_rcBounds.bottom;
    else if (ptNewPosition.y > m_rcBounds.bottom)
      ptNewPosition.y = m_rcBounds.top - ptSpriteSize.y;
  }
  // Bounce?
  else if (m_baBoundsAction == BA_BOUNCE)
  {
    BOOL bBounce = FALSE;
    POINT ptNewVelocity = m_ptVelocity;
    if (ptNewPosition.x < m_rcBounds.left)
    {
      bBounce = TRUE;
      ptNewPosition.x = m_rcBounds.left;
      ptNewVelocity.x = -ptNewVelocity.x;
    }
    else if ((ptNewPosition.x + ptSpriteSize.x) > m_rcBounds.right)
    {
      bBounce = TRUE;
      ptNewPosition.x = m_rcBounds.right - ptSpriteSize.x;
      ptNewVelocity.x = -ptNewVelocity.x;
    }
    if (ptNewPosition.y < m_rcBounds.top)
    {
      bBounce = TRUE;
      ptNewPosition.y = m_rcBounds.top;
      ptNewVelocity.y = -ptNewVelocity.y;
    }
    else if ((ptNewPosition.y + ptSpriteSize.y) > m_rcBounds.bottom)
    {
      bBounce = TRUE;
      ptNewPosition.y = m_rcBounds.bottom - ptSpriteSize.y;
      ptNewVelocity.y = -ptNewVelocity.y;
    }
    if (bBounce)
      SetVelocity(ptNewVelocity);
  }
  // Die?
  else if (m_baBoundsAction == BA_DIE)
  {
    if ((ptNewPosition.x + ptSpriteSize.x) < m_rcBounds.left ||
      ptNewPosition.x > m_rcBounds.right ||
      (ptNewPosition.y + ptSpriteSize.y) < m_rcBounds.top ||
      ptNewPosition.y > m_rcBounds.bottom)
      return SA_KILL;
  }
  // Stop (default)
  else
  {
    if (ptNewPosition.x  < m_rcBounds.left ||
      ptNewPosition.x > (m_rcBounds.right - ptSpriteSize.x))
    {
      ptNewPosition.x = max(m_rcBounds.left, min(ptNewPosition.x,
        m_rcBounds.right - ptSpriteSize.x));
      SetVelocity(0, 0);
    }
    if (ptNewPosition.y  < m_rcBounds.top ||
      ptNewPosition.y > (m_rcBounds.bottom - ptSpriteSize.y))
    {
      ptNewPosition.y = max(m_rcBounds.top, min(ptNewPosition.y,
        m_rcBounds.bottom - ptSpriteSize.y));
      SetVelocity(0, 0);
    }
  }
  SetPosition(ptNewPosition);

  return SA_NONE;
}

void Sprite::Draw(HDC hDC)
{
  // Draw the sprite if it isn't hidden
  if (m_pBitmap != NULL && !m_bHidden)
    m_pBitmap->Draw(hDC, m_rcPosition.left, m_rcPosition.top, TRUE);
}