#include "pch.h"
#include "IntersectionUtil.h"
#include <ppl.h>
#include <array>
using namespace concurrency;

CIntersectionUtil::CIntersectionUtil(void)
{
	//m_Segments;
}
CIntersectionUtil::~CIntersectionUtil(void)
{
}
void CIntersectionUtil::SetSourceLines(const Paths64 * subjects)
{
	this->m_pSourceLines = subjects;
	this->PrepareData();
}

bool CIntersectionUtil::Intersects(LineSegment& clip)
{
	size_t nSegCount = m_Segments.size();
	if (nSegCount == 0) {
		return false;
	}
	//Point64 ptStart = clip.ptStart;
	//Point64 ptEnd = clip.ptEnd;
	Envelope clipRange = clip.Range;
	LineSegment lineClip();	

	int nLeft = 0;
	int nRight = nSegCount - 1;

	// 最小X符合要求的线段
	//int nFindIndex = 0;
	//if (m_Segments.at(0).Range.MinX > clip.Range.MaxX)
	//{
	//	return false;
	//}

	int nMid = 0;
	while (nLeft <= nRight) {
		//nMid = (nLeft + nRight) / 2;
		nMid = 0.618*nRight + 0.382*nLeft;
		if (nMid == nSegCount -1) {
			//nFindIndex = nMid;
			break;
		}
		if (m_Segments[nMid].Range.MinX <= clipRange.MaxX &&
			m_Segments[nMid + 1].Range.MinX >= clipRange.MaxX) {
			//nFindIndex = nMid;
			break;
		}
		else if (m_Segments[nMid].Range.MinX > clipRange.MaxX) {
			nRight = nMid - 1;
		}
		else {
			nLeft = nMid + 1;
		}
	}
	// 按右端点再次查找
	vector <LineSegment> segmentsR(m_Segments.begin(), m_Segments.begin()+ nMid+1);
	std::sort(segmentsR.begin(), segmentsR.end(), SegmentSortR);

	nSegCount = segmentsR.size();

	nLeft = 0;
	nRight = nSegCount - 1;
	//nFindIndex = 0;
	nMid = 0;
	while (nLeft <= nRight) {
		//nMid = (nLeft + nRight) / 2;
		nMid = 0.618*nRight + 0.382*nLeft;
		if (nMid == 0) {
			//nFindIndex = nMid;
			break;
		}
		if (segmentsR[nMid].Range.MaxX >= clipRange.MinX&&
			segmentsR[nMid - 1].Range.MaxX <= clipRange.MinX) {
			//nFindIndex = nMid;
			break;
		}
		else if (segmentsR[nMid].Range.MaxX < clipRange.MinX) {
			nLeft = nMid + 1;
		}
		else {
			nRight = nMid - 1;
		}
	}

	for (int i = nMid; i < nSegCount; i++) {
		if (clipRange.Intersects(segmentsR[i].Range)) {
			if (SegmentsIntersect(segmentsR[i].ptStart, segmentsR[i].ptEnd, clip.ptStart, clip.ptEnd, true)) {
				return true;
			}
		}
	}
	return false;
}

void CIntersectionUtil::PrepareData()
{
	m_Segments.clear();
	// 生成线段列表
	for (const auto& path : *m_pSourceLines) { // 使用范围循环和引用避免拷贝
		const size_t pointCount = path.size();

		for (size_t j = 1; j < pointCount; ++j) { // 使用size_t防止负数索引
			const Point64 rawStart = path[j - 1];
			const Point64 rawEnd = path[j];

			// 确定有序的起点和终点
			bool needSwap = (rawStart.x > rawEnd.x) ||
				((rawStart.x == rawEnd.x) && (rawStart.y > rawEnd.y));

			const Point64 sortedStart = needSwap ? rawEnd : rawStart;
			const Point64 sortedEnd = needSwap ? rawStart : rawEnd;
			Point64 startCopy = sortedStart;
			Point64 endCopy = sortedEnd;
			m_Segments.emplace_back(startCopy, endCopy); // 直接使用有序点
			//m_Segments.emplace_back(
			//	const_cast<Point64&>(sortedStart),
			//	const_cast<Point64&>(sortedEnd)
			//);
		}
	}
	//for (int i = 0; i < this->m_pSourceLines->size(); i++) {
	//	Path64 line = this->m_pSourceLines->at(i);
	//	int nLineCount = line.size();
	//	for (int j = 1; j < nLineCount;j++) {
	//		Point64 ptStart = line[j - 1];
	//		Point64 ptEnd = line[j];
	//		if (ptStart.x > ptEnd.x)
	//		{
	//			ptStart = line[j];
	//			ptEnd = line[j - 1];
	//		}
	//		else {
	//			if (ptStart.y > ptEnd.y) {
	//				ptStart = line[j];
	//				ptEnd = line[j - 1];
	//			}
	//		}
	//		m_Segments.push_back(LineSegment(line[j-1], line[j]));
	//	}
	//}
	// 按起始坐标排序parallel_sort
	std::sort(m_Segments.begin(), m_Segments.end(), CIntersectionUtil::SegmentSort);

	//m_SegmentsR.clear();
	//m_SegmentsR.
	//for (int i = 0; i < m_Segments.size(); i++)
	//{
	//	int nMin = m_Segments.at(i).Range.MinX;
	//	TRACE("%d\r\n" , nMin);
	//}
}
bool CIntersectionUtil::SegmentSort(LineSegment& seg1, LineSegment& seg2)
{
	return seg1.ptStart.x < seg2.ptStart.x;
		//|| (seg1.ptStart.x == seg2.ptStart.x
		//	&&( seg1.ptStart.y < seg2.ptStart.y && seg1.ptEnd.x < seg2.ptEnd.x && seg1.ptEnd.y < seg2.ptEnd.y));

}
bool CIntersectionUtil::SegmentSortR(LineSegment& seg1, LineSegment& seg2)
{
	return seg1.ptEnd.x < seg2.ptEnd.x;
		//|| (seg1.ptStart.x == seg2.ptStart.x
		//	&& (seg1.ptStart.y < seg2.ptStart.y && seg1.ptEnd.x < seg2.ptEnd.x && seg1.ptEnd.y < seg2.ptEnd.y));
		//|| (seg1.ptEnd.x == seg2.ptEnd.x && seg1.ptStart.y < seg2.ptStart.y);
	//if (seg1.ptEnd.x == seg2.ptEnd.x)
	//	return true;
	//else
	//	return seg1.ptEnd.x < seg2.ptEnd.x;
}

Envelope::Envelope()
{
}

Envelope::Envelope(int64_t x1, int64_t x2, int64_t y1, int64_t y2)
{
	Init(x1, x2, y1, y2);
}

Envelope::Envelope(Point64& p1, Point64& p2)
{
}
void Envelope::Init(Point64& p1, Point64& p2)
{
	Init(p1.x, p2.x, p1.y, p2.y);
}
void Envelope::Init(int64_t x1, int64_t x2, int64_t y1, int64_t y2)
{
	if (x1 < x2)
	{
		MinX = x1;
		MaxX = x2;
	}
	else
	{
		MinX = x2;
		MaxX = x1;
	}

	if (y1 < y2)
	{
		MinY = y1;
		MaxY = y2;
	}
	else
	{
		MinY = y2;
		MaxY = y1;
	}
}
bool Envelope::Intersects(Envelope& other)
{
	return !(other.MinX > MaxX || other.MaxX < MinX || other.MinY > MaxY || other.MaxY < MinY);
}
//public bool IsNull
//{
//	get
//	{
//		return _maxX < _minX;
//	}
//}