//-----------------------------------------------------------------
//?Background?object
//?C++?Source?-?Background.cpp
//-----------------------------------------------------------------

//-----------------------------------------------------------------
//?Include?Files
//-----------------------------------------------------------------
#include?“Background.h“

//-----------------------------------------------------------------
//?Background?Constructor（s）/Destructor
//-----------------------------------------------------------------
Background::Background（int?iWidth?int?iHeight?COLORREF?crColor）
{
??//?Initialize?the?member?variables
??m_iWidth?=?iWidth;
??m_iHeight?=?iHeight;
??m_crColor?=?crColor;
??m_pBitmap?=?NULL;
}

Background::Background（Bitmap*?pBitmap）
{
??//?Initialize?the?member?variables
??m_crColor?=?0;
??m_pBitmap?=?pBitmap;
??m_iWidth?=?pBitmap->GetWidth（）;
??m_iHeight?=?pBitmap->GetHeight（）;
}

Background::~Background（）
{
}

//-----------------------------------------------------------------
//?Background?General?Methods
//-----------------------------------------------------------------
void?Background::Update（）
{
??//?Do?nothing?since?the?basic?background?is?not?animated
}

void?Background::Draw（HDC?hDC）
{
??//?Draw?the?background
??if?（m_pBitmap?!=?NULL）
????m_pBitmap->Draw（hDC?0?0）;
??else
??{
????RECT????rect?=?{?0?0?m_iWidth?m_iHeight?};
????HBRUSH??hBrush?=?CreateSolidBrush（m_crColor）;
????FillRect（hDC?&rect?hBrush）;
????Deleteobject（hBrush）;
??}
}

//-----------------------------------------------------------------
//?StarryBackground?Constructor
//-----------------------------------------------------------------
StarryBackground::StarryBackground（int?iWidth?int?iHeight?int?iNumStars
??int?iTwinkleDelay）?:?Background（iWidth?iHeight?0）
{
??//?Initialize?the?member?variables
??m_iNumStars?=?min（iNumStars?100）;
??m_iTwinkleDelay?=?iTwinkleDelay;

??//?Create?the?stars
??for?（int?i?=?0;?i???{
????m_ptStars[i].x?=?rand（）?%?iWidth;
????m_ptStars[i].y?=?rand（）?%?iHeight;
????m_crStarColors[i]?=?RGB（128?128?128）;
??}
}

StarryBackground::~StarryBackground（）
{
}

//-----------------------------------------------------------------
//?StarryBackground?General?Methods
//-----------------------------------------------------------------
void?StarryBackground::Update（）
{
??//?Randomly?change?the?shade?of?the?stars?so?that?they?twinkle
??int?iRGB;
??for?（int?i?=?0;?i?????if?（（rand（）?%?m_iTwinkleDelay）?==?0）
????{
??????iRGB?=?rand（）?%?256;
??????m_crStarColors[i]?=?RGB（iRGB?iRGB?iRGB）;
????}
}

void?StarryBackground::Draw（HDC?hDC）
{
??//?Draw?the?solid?black?background
??RECT????rect?=?{?0?0?m_iWidth?m_iHeight?};
??HBRUSH??hBrush?=?CreateSolidBrush（RGB（0?0?0））;
??FillRect（hDC?&rect?hBrush）;
??Deleteobject（hBrush）;

??//?Draw?the?stars
??for?（int?i?=?0;?i?