fasthittest.cpp

最小二乘法(least squares analysis)是一种 数学 优化 技术

// FastHitTest.cpp: implementation of the FastHitTest class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "FastHitTest.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

FastHitTest::FastHitTest(const Region* pRegion, Graphics* pGraphics)
{
	initColor();

	pRegion->GetBounds(&m_Bounds,pGraphics);
	
	m_RegionBuffer = new Bitmap(m_Bounds.Width,m_Bounds.Height,PixelFormat32bppRGB);
	
	Graphics g(m_RegionBuffer);
	
	
	SolidBrush backgroundBrush(m_BackgroundColor);
	g.FillRectangle(&backgroundBrush,0,0,m_Bounds.Width,m_Bounds.Height);
	
	SolidBrush foregroundBrush(m_ForegroundColor);
	
	Region *r = pRegion->Clone();
	r->Translate(-1 * m_Bounds.GetLeft(), -1 * m_Bounds.GetTop());
	g.FillRegion(&foregroundBrush,r);
	delete r;

	Lock();
	
}

FastHitTest::FastHitTest(const GraphicsPath* pPath,BOOL includeEdge)
{
	initColor();

	init(pPath,includeEdge);

	Lock();
}

FastHitTest::FastHitTest(const Point *pPoint, int num,BOOL includeEdge)
{
	// debug required

	initColor();

	Point *p = NULL;
	int n = num;

	if( n == 1 || (n == 2 && pPoint[0].X == pPoint[1].X && pPoint[0].Y == pPoint[1].Y) )
	{
		m_Bounds.X = pPoint->X ;
		m_Bounds.Y = pPoint->Y ;
		m_Bounds.Width = 1 ;
		m_Bounds.Height = 1 ;
		m_RegionBuffer = new Bitmap(m_Bounds.Width,m_Bounds.Height,PixelFormat32bppRGB);
		m_RegionBuffer->SetPixel(0,0,m_ForegroundColor);

	}
	else if( n >= 2 )
	{
		 if(n == 2) 
		{
			p = new Point[3];

			p[0] = pPoint[0];
			p[1] = pPoint[1];
			p[2] = pPoint[0];
			n = 3;
		}

		GraphicsPath pPath(FillModeWinding);
		pPath.AddPolygon(p,n);

		init(&pPath,includeEdge);
	}

	Lock();

}

void FastHitTest::initColor()
{
	m_ForegroundColor = Color(255,255,0,255);
	m_BackgroundColor = Color(255,0,0,255);
}

void FastHitTest::init(const GraphicsPath* pPath,BOOL includeEdge)
{
	pPath->GetBounds(&m_Bounds);

	m_RegionBuffer = new Bitmap(m_Bounds.Width,m_Bounds.Height,PixelFormat32bppRGB);

	Graphics g(m_RegionBuffer);

	SolidBrush backgroundBrush(m_BackgroundColor);
	g.FillRectangle(&backgroundBrush,0,0,m_Bounds.Width,m_Bounds.Height);

	SolidBrush foregroundBrush(m_ForegroundColor);
	Pen foregroundPen(&foregroundBrush);

	GraphicsPath *path = pPath->Clone();
	Matrix mat;

	mat.Translate((float)(-1.0 * m_Bounds.GetLeft()), (float)(-1 * m_Bounds.GetTop()));
	path->Transform(&mat);

	g.FillPath(&foregroundBrush,path);

	//confirm required
	if (includeEdge) {
		g.DrawPath(&foregroundPen,path);
	}

	delete path;
}

void FastHitTest::Lock()
{
	Rect rect(0,0,m_Bounds.Width,m_Bounds.Height);
	
	if( m_RegionBuffer )
	{
		m_RegionBuffer->LockBits(&rect, 
			ImageLockModeRead,
			m_RegionBuffer->GetPixelFormat(),
			&m_Data);
	}

}

FastHitTest::~FastHitTest()
{
	m_RegionBuffer->UnlockBits(&m_Data);

	if (m_RegionBuffer!=NULL) {
		delete m_RegionBuffer;
	}

}

BOOL FastHitTest::IsVisible(int x, int y)
{
	if( !m_RegionBuffer )
	{
		return FALSE;
	}

	if ( x < m_Bounds.GetLeft() || x >= m_Bounds.GetRight() 
		|| y < m_Bounds.GetTop() || y >= m_Bounds.GetBottom() )
	{
		return FALSE;
	}

	UINT *p = (UINT*)m_Data.Scan0 + m_Data.Stride * (y-m_Bounds.GetTop() ) / 4 + (x - m_Bounds.GetLeft());

	if ( *p == m_ForegroundColor.GetValue() ) {
		return TRUE;
	}

	return FALSE;
}