#include "stdafx.h"
#include "HTrackerTransform.h"

HTrackerTransform::HTrackerTransform()
	:m_handle(0)
	,m_bDrag(false)
	,m_bCanMoved(false)
	,m_nAllowMovePixel(5)
	,m_kind(HTRACKER_TRANSFORM_KIND_SCALE)
{
	m_StartPhi = 0.0f;
	m_Transform.Reset();
}

//参数:mousePt 开始拖拽时,鼠标的坐标.
void HTrackerTransform::Init(int handle, const CRect & boundRect, CPoint mousePt)
{
	m_bDrag = true;
	m_bCanMoved = false;
	m_StartPhi = 0.0f;
	m_StartPoint = mousePt;

	if (handle == 8) //平移
		m_kind = HTRACKER_TRANSFORM_KIND_MOVE;
	else
		m_kind = HTRACKER_TRANSFORM_KIND_SCALE;

	m_Transform.Reset();
	m_boundRect = boundRect;
	m_calculator.Calculate(m_boundRect);
	m_handle = handle;
	SetFixedPoints();
}

void HTrackerTransform::Draging(CPoint mousePt)
{
	if (m_bDrag == false)
		return;

	if (m_kind == HTRACKER_TRANSFORM_KIND_SCALE)
		Scale(mousePt);
	else if (m_kind == HTRACKER_TRANSFORM_KIND_MOVE)
		Move(mousePt);
	else if (m_kind == HTRACKER_TRANSFORM_KIND_ROTATION)
		Rotate(mousePt);
	else  //KIND_SHEAR
		Shear(mousePt);
}

void HTrackerTransform::EndDrag()
{
	m_bDrag = false;
	m_Transform.Reset();
	m_handle = 0;
	m_bCanMoved = false;
	m_StartPhi = 0.0f;
	m_kind = HTRACKER_TRANSFORM_KIND_SCALE;
}

Gdiplus::Matrix * HTrackerTransform::GetMatrix()
{
	return &m_Transform;
}

void HTrackerTransform::SetKind(HTRACKER_TRANSFORM_KIND kind)
{
	m_kind = kind;
	SetFixedPoints();
}

//函数功能:设置选中的handle对应的不动点。
//		HandleTopLeft	 HandleTop		HandleTopRight
//				0			1			2
//				*-----------*-----------*
//				|						|
//				|						|
//  HandleLeft	7 *			* 8			* 3  HandleRight
//				|		HandleCenter	|
//				|						|
//				*-----------*-----------*
//				6			5			4 
//拖拽Handle时的不动点
//拖拽0Handle时，对应的不动点为4。拖拽1Handle时，对应的不动点为5。依次为2-->6,3-->7,
//4-->0,5-->1,6-->2,7-->3.
//handle ^ 4， 会找到对应的不动点。
void HTrackerTransform::SetFixedPoints()
{
	//m_handle的范围:[0,8]
	if (m_handle < 0 || m_handle>8)
		return ;

	int hFixed =  m_handle ^ 4;

	//m_FixedSrc = GetHandlePoint(m_PointSrc, hFixed);
	//m_FixedDest = GetHandlePoint(m_PointDest, hFixed);
	m_FixedSrc  = m_calculator.GetHandlePoint(hFixed);
	m_FixedDest = m_FixedSrc;

	if (m_kind == HTRACKER_TRANSFORM_KIND_ROTATION)
	{
		CSize sz = CPoint(m_calculator.Test(m_handle / 2)) - m_FixedSrc;
		m_StartPhi = 180.0f * (Gdiplus::REAL) (atan2((double)sz.cy, sz.cx) / PI);
	}
}

//参数:point 鼠标点
void HTrackerTransform::Scale(CPoint & point)
{
	//m_FixedDest is the selected handle point of destination rectangle	
	CSize sz = point - m_FixedDest; 
	//m_FixedSrc  is the selected handle point of source rectangle	
	CSize szSrc = m_StartPoint - m_FixedSrc;
	Gdiplus::REAL scaleX = 1.0f;
	Gdiplus::REAL scaleY = 1.0f;
	if ((m_handle & 1) == 0)	//偶数点为角点，X,Y方向缩放。
	{
		if (szSrc.cx != 0)										
			scaleX = (Gdiplus::REAL) sz.cx / (Gdiplus::REAL) szSrc.cx;
		//if (!(m_Options & OptionAllowMirror) && scaleX < 0.0f) 
		//	scaleX = 0.0f;	//no allow mirror x
		if (szSrc.cy != 0)										
			scaleY = (Gdiplus::REAL) sz.cy / (Gdiplus::REAL) szSrc.cy;
		
		//if (!(m_Options & OptionAllowMirror) && scaleY < 0.0f) 
		//	scaleY = 0.0f;	//no allow mirror y

		//		if (!(nFlags & MK_SHIFT))	// maintain proportions, //当按下SHIFT键时等比例缩放
		//		{
		//			Gdiplus::REAL scaleXabs = fabsf(scaleX);
		//			Gdiplus::REAL scaleYabs = fabsf(scaleY);
		//			if (scaleXabs > scaleYabs)	scaleX = (scaleX < 0) ? -scaleYabs : scaleYabs;
		//			else						scaleY = (scaleY < 0) ? -scaleXabs : scaleXabs;
		//		}

		// Set cursor; might be changed after flipping
		//int curs = (m_Handle & 2) / 2;				// 0 or 1
		//if (m_bMapFlip) curs ^= 1;
		//curs ^= scaleX < 0;
		//curs ^= scaleY < 0;
		//HCURSOR h = g_hCursor[curs];
		//if (h) 
		//	::SetCursor(h);
	}
	else if ((m_handle & 3) == 1)	 // horizontal edge, scale vertical
	{
		if (szSrc.cy != 0)										
			scaleY = (Gdiplus::REAL) sz.cy / (Gdiplus::REAL) szSrc.cy;
		//if (!(m_Options & OptionAllowMirror) && scaleY < 0.0f) 
		//	scaleY = 0.0f;
		//if (nFlags & MK_SHIFT)									
		//	scaleX = scaleY;	//当按下SHIFT键时等比例缩放
	}
	else if ((m_handle & 3) == 3)	 // vertical edge, scale horizontal
	{
		if (szSrc.cx != 0)										
			scaleX = (Gdiplus::REAL) sz.cx / (Gdiplus::REAL) szSrc.cx;
		//if (!(m_Options & OptionAllowMirror) && scaleX < 0.0f) 
		//	scaleX = 0.0f;
		//		if (nFlags & MK_SHIFT)									
		//			scaleY = scaleX;	//当按下SHIFT键时等比例缩放
	}

	m_Transform.Reset();
	// Translate the fixed point to the origin.
	m_Transform.Translate((Gdiplus::REAL) - m_FixedSrc.x, (Gdiplus::REAL) - m_FixedSrc.y, Gdiplus::MatrixOrderAppend);
	// Scale the object.
	m_Transform.Scale(scaleX, scaleY, Gdiplus::MatrixOrderAppend);
	// Translate back to fixed point (which may be different).
	m_Transform.Translate((Gdiplus::REAL)m_FixedDest.x, (Gdiplus::REAL)m_FixedDest.y, Gdiplus::MatrixOrderAppend);
}

void HTrackerTransform::Move(CPoint & point)
{
	CSize sz = point - m_StartPoint;

	//为了防止不小心移动元素，当超过该值时才起作用（允许移动像素个数）
	if (IsCanMove(point, m_StartPoint))
	{
		m_Transform.Reset();
		m_Transform.Translate((Gdiplus::REAL)sz.cx, (Gdiplus::REAL)sz.cy);
	}
}

bool HTrackerTransform::IsCanMove(const CPoint& nPrevPoint, const CPoint& nCurPoint)
{
	if (m_bCanMoved)
		return true;

	CSize sz = nCurPoint - nPrevPoint;
	//为了防止不小心移动元素，当超过该值时才起作用（允许移动像素个数）
	if (abs(sz.cx) >= m_nAllowMovePixel || abs(sz.cy) >= m_nAllowMovePixel)
	{
		m_bCanMoved = true;
		return true;
	}
	return false;
}

void HTrackerTransform::Rotate(CPoint & point)
{
	CSize sz = point - m_FixedDest;
	Gdiplus::REAL phi = 180.0f * (Gdiplus::REAL)(atan2((double)sz.cy, (double)sz.cx) / PI) - m_StartPhi;
	while (phi <= -180.0f) 
		phi += 360.0f;	// (-180, 180]

	m_Transform.Reset();
	m_Transform.Translate((Gdiplus::REAL) - m_FixedSrc.x, (Gdiplus::REAL) - m_FixedSrc.y);
	m_Transform.Rotate(phi, Gdiplus::MatrixOrderAppend);
	m_Transform.Translate((Gdiplus::REAL) m_FixedDest.x, (Gdiplus::REAL) m_FixedDest.y, Gdiplus::MatrixOrderAppend);
}

void HTrackerTransform::Shear(CPoint & point)
{
	CSize sz = point - m_FixedDest;
	CSize szSrc = m_StartPoint - m_FixedSrc;

	Gdiplus::REAL shearX = 0.0f;
	Gdiplus::REAL shearY = 0.0f;
	Gdiplus::REAL scaleX = 1.0f;
	Gdiplus::REAL scaleY = 1.0f;

	if (m_handle & 2)		// vertical edge
	{
		if (sz.cx != 0)										
			shearY = (Gdiplus::REAL) sz.cy / (Gdiplus::REAL) sz.cx;
		if (szSrc.cx != 0)									
			scaleX = (Gdiplus::REAL) sz.cx / (Gdiplus::REAL) szSrc.cx;
		//if (!(m_Options&OptionAllowMirror) && scaleX < 0.0f)	scaleX = 0.0f;
	}
	else		// horizontal edge
	{
		if (sz.cy != 0)										
			shearX = (Gdiplus::REAL) sz.cx / (Gdiplus::REAL) sz.cy;
		if (szSrc.cy != 0)									
			scaleY = (Gdiplus::REAL) sz.cy / (Gdiplus::REAL) szSrc.cy;
		//if (!(m_Options&OptionAllowMirror) && scaleY < 0.0f)	scaleY = 0.0f;
	}

	m_Transform.Reset();
	m_Transform.Translate((Gdiplus::REAL) - m_FixedSrc.x, (Gdiplus::REAL) - m_FixedSrc.y);

	// Don't scale the other direction if Shift is pressed
	//if ((nFlags & MK_SHIFT) == 0) m_Transform.Scale(scaleX, scaleY, Gdiplus::MatrixOrderAppend);

	m_Transform.Shear(shearX, shearY, Gdiplus::MatrixOrderAppend);
	m_Transform.Translate((Gdiplus::REAL) m_FixedDest.x, (Gdiplus::REAL) m_FixedDest.y, Gdiplus::MatrixOrderAppend);
}