wg_rect.cpp

一个小巧的嵌入式图形系统wGUI, 可以用VC编译

// wg_rect.cpp
//
// CRect class implementation
//
//
// Copyright (c) 2002 Rob Wiskow
// [e-mail]
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//


#include "wgui_include_config.h"
#include "wg_rect.h"
#include "wg_error.h"
#include <algorithm>
#ifdef WIN32
#include <limits>
#endif // WIN32


namespace wGui
{


SDL_Rect CRect::SDLRect(void) const
{
#ifdef WIN32
#ifndef MSVC6  // There are problems with VC6 and these std lib template classes
	if (m_Left < std::numeric_limits<short int>::min() ||m_Left > std::numeric_limits<short int>::max()
		|| m_Top < std::numeric_limits<short int>::min() ||m_Top > std::numeric_limits<short int>::max()
		|| m_Right < std::numeric_limits<short int>::min() ||m_Right > std::numeric_limits<short int>::max()
		|| m_Bottom < std::numeric_limits<short int>::min() ||m_Bottom > std::numeric_limits<short int>::max())
	{
		throw(Wg_Ex_Range("CRect::SDLRect : Out of range - converting int to short int!"));
	}
#endif // MSVC6
#endif // WIN32
	SDL_Rect sdlRect;
	//Normalize the rect...
	sdlRect.x = static_cast<short int>(std::min(m_Left, m_Right));
	sdlRect.y = static_cast<short int>(std::min(m_Top, m_Bottom));
	sdlRect.w = static_cast<short int>(Width());
	sdlRect.h = static_cast<short int>(Height());

	return sdlRect;
}


// assignment operator
CRect& CRect::operator=(const CRect& r)
{
	m_Top = r.Top();
	m_Left = r.Left();
	m_Right = r.Right();
	m_Bottom = r.Bottom();

	return *this;
}


CRect CRect::operator+(const CPoint& p) const
{
	CRect result(m_Left + p.XPos(), m_Top + p.YPos(), m_Right + p.XPos(), m_Bottom + p.YPos());

	return result;
}


CRect CRect::operator-(const CPoint& p) const
{
	CRect result(m_Left - p.XPos(), m_Top - p.YPos(), m_Right - p.XPos(), m_Bottom - p.YPos());

	return result;
}


CRect& CRect::Grow(int iGrowAmount)
{
	m_Top -= iGrowAmount;
	m_Left -= iGrowAmount;
	m_Right += iGrowAmount;
	m_Bottom += iGrowAmount;

	return *this;
}


CRect& CRect::Move(int iOffsetX, int iOffsetY)
{
	m_Top += iOffsetX;
	m_Left += iOffsetY;
	m_Right += iOffsetX;
	m_Bottom += iOffsetY;

	return *this;
}


bool CRect::Overlaps(const CRect& r)
{
	bool bOverlap = false;

	if (HitTest(r.TopLeft()) == RELPOS_INSIDE || HitTest(r.TopRight()) == RELPOS_INSIDE || HitTest(r.BottomRight()) == RELPOS_INSIDE
		|| HitTest(r.BottomLeft()) == RELPOS_INSIDE || r.HitTest(TopLeft()) == RELPOS_INSIDE || r.HitTest(TopRight()) == RELPOS_INSIDE
		|| r.HitTest(BottomRight()) == RELPOS_INSIDE || r.HitTest(BottomLeft()) == RELPOS_INSIDE)
	{
		bOverlap = true;
	}

// TODO: Still need to check for one more case where no corner lies in another rect

	return bOverlap;
}


void CRect::ClipTo(const CRect& r)
{
	if (m_Left < r.Left())
	{
		m_Left = r.Left();
	}
	if (m_Right < r.Left())
	{
		m_Right = r.Left();
	}
	if (m_Top < r.Top())
	{
		m_Top = r.Top();
	}
	if (m_Bottom < r.Top())
	{
		m_Bottom = r.Top();
	}
	if (m_Right > r.Right())
	{
		m_Right = r.Right();
	}
	if (m_Left > r.Right())
	{
		m_Left = r.Right();
	}
	if (m_Bottom > r.Bottom())
	{
		m_Bottom = r.Bottom();
	}
	if (m_Top > r.Bottom())
	{
		m_Top = r.Bottom();
	}
}


// test to see if the point lies within the rect
unsigned int CRect::HitTest(const CPoint& p) const
{
	unsigned int eRelPos = 0;

	eRelPos |= (p.XPos() < m_Left) ? RELPOS_LEFT : 0;
	eRelPos |= (p.YPos() < m_Top) ? RELPOS_ABOVE: 0;
	eRelPos |= (p.XPos() > m_Right) ? RELPOS_RIGHT : 0;
	eRelPos |= (p.YPos() > m_Bottom) ? RELPOS_BELOW: 0;
	eRelPos |= (p.XPos() >= m_Left && p.XPos() <= m_Right &&
		p.YPos() >= m_Top && p.YPos() <= m_Bottom) ? RELPOS_INSIDE : 0;

	return eRelPos;
}

}