本文是介绍对寻路库recastnavigation 改造，使得使用更加友好。
Git仓库:
https://github.com/jiangguilong2000/recastnavigation

首先，我们要做一些前置操作
SDL: 开放源代码的跨平台多媒体开发库
Premake：量跨平台构建系统

环境:
VS 2019以及完整的C++编译环境

Rider For Unreal Engine 2022.2.1（下面简称Rider）

Unity 2019.4.8 lts

.Net Core 2.2

1.首先把git库拉到本地，先将下载的SDL库放到ecastnavigation\RecastDemo\Contrib,需要改名为SDL，应该得到如下目录recastnavigation-master\RecastDemo\Contrib\SDL\lib\x64
2/然后将下载premake5.exe放入
recastnavigation\RecastDemo
3.然后通过命令行控制premake编译recastnavigation为sln工程

PS E:\recastnavigation\RecastDemo> .\premake5.exe vs2019
Building configurations...
Running action 'vs2019'...
Generated Build/vs2019/recastnavigation.sln...
Generated Build/vs2019/DebugUtils.vcxproj...
Generated Build/vs2019/DebugUtils.vcxproj.filters...
Generated Build/vs2019/Detour.vcxproj...
Generated Build/vs2019/Detour.vcxproj.filters...
Generated Build/vs2019/DetourCrowd.vcxproj...
Generated Build/vs2019/DetourCrowd.vcxproj.filters...
Generated Build/vs2019/DetourTileCache.vcxproj...
Generated Build/vs2019/DetourTileCache.vcxproj.filters...
Generated Build/vs2019/Recast.vcxproj...
Generated Build/vs2019/Recast.vcxproj.filters...
Generated Build/vs2019/RecastDemo.vcxproj...
Generated Build/vs2019/RecastDemo.vcxproj.user...
Generated Build/vs2019/RecastDemo.vcxproj.filters...
Generated Build/vs2019/Tests.vcxproj...
Generated Build/vs2019/Tests.vcxproj.user...
Generated Build/vs2019/Tests.vcxproj.filters...
Done (160ms).

然后目录中会生成一个Build文件夹，里面是我们编译出来的sln工程

recastnavigation\RecastDemo\Build\vs2019\recastnavigation.sln

用rider打开，直接运行，我们就能看到编辑器画面了

接下去我们要对源码进行一些改造：
原始的recast是没有开始点和结束点的坐标的，那如何能显示出来呢？

void NavMeshTesterTool::handleRenderOverlay(double* proj, double* model, int* view)
{
	GLdouble x, y, z;
	char buf[64];

	// Draw start and end point labels
	if (m_sposSet && gluProject((GLdouble)m_spos[0], (GLdouble)m_spos[1], (GLdouble)m_spos[2],
		model, proj, view, &x, &y, &z))
	{
		if (m_showCoord)
		{
			snprintf(buf, sizeof(buf), "Start (%.1f, %.1f, %.1f)", m_spos[0], m_spos[1], m_spos[2]);
			imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, buf, imguiRGBA(0, 0, 0, 220));
		}
		else
			imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, "Start", imguiRGBA(0, 0, 0, 220));
	}


	if (m_toolMode == TOOLMODE_RAYCAST && m_hitResult && m_showCoord &&
		gluProject((GLdouble)m_hitPos[0], (GLdouble)m_hitPos[1], (GLdouble)m_hitPos[2],
			model, proj, view, &x, &y, &z))
	{
		snprintf(buf, sizeof(buf), "HitPos (%.1f, %.1f, %.1f)", m_hitPos[0], m_hitPos[1], m_hitPos[2]);
		imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, buf, imguiRGBA(0, 0, 0, 220));
	}
	if (m_eposSet && gluProject((GLdouble)m_epos[0], (GLdouble)m_epos[1], (GLdouble)m_epos[2],
		model, proj, view, &x, &y, &z))
	{
		if (m_showCoord)
		{
			float totalCost = 0.0f;
			for (int i = 0; i + 1 < m_nstraightPath; i++)
				totalCost += dtVdist(&m_straightPath[i * 3], &m_straightPath[(i + 1) * 3]);
			snprintf(buf, sizeof(buf), "End (%.1f, %.1f, %.1f), Cost %.1f", m_epos[0], m_epos[1], m_epos[2], totalCost);
			imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, buf, imguiRGBA(0, 0, 0, 220));
		}
		else
			imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, "End", imguiRGBA(0, 0, 0, 220));
	}
}

那么，如何能显示出关键点point list?，首先，路径搜索的模式要改成TOOLMODE_PATHFIND_STRAIGHT模式，代码需要增加如下的打印，
在NavMeshTesterTool.cpp中增加，

void NavMeshTesterTool::recalc(){
....
....
	if (m_toolMode == TOOLMODE_PATHFIND_STRAIGHT&& m_nstraightPath>0) 
    	{
    		stringstream os;
    		os << "total point size=" << m_nstraightPath<< ",";
    		//m_sample->getContext()->log(RC_LOG_PROGRESS, "total point size=%d", m_nstraightPath);
    		for (int i = 0; i < m_nstraightPath; ++i)
    		{
    			if (i > 0&&i%10==0) {
    				m_sample->getContext()->log(RC_LOG_PROGRESS, "%s", os.str().c_str());
    				os.str("");
    			}
    			os << "[" << m_straightPath[i * 3] << "," << m_straightPath[i * 3 + 1] << "," << m_straightPath[i * 3 + 2] << "] ";
    		}
    		m_sample->getContext()->log(RC_LOG_PROGRESS, "%s", os.str().c_str());
    	}
}

在Sample.h中增加

public:
	Sample();
	virtual ~Sample();
	
	void setContext(BuildContext* ctx) { m_ctx = ctx; }
	BuildContext* getContext() {
		return m_ctx;
	}

最后一个问题，如何把显示日志的地方的文本能鼠标选中？目前还没搞定