//
// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty.  In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would be
//    appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
//    misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//

#include "Sample_TileMesh.h"

#include "SDL_opengl.h"

#include <cmath>
#include <cstdio>
#include <cstring>
#ifdef __APPLE__
#	include <OpenGL/glu.h>
#else
#	include <GL/glu.h>
#endif

#include "ConvexVolumeTool.h"
#include "CrowdTool.h"
#include "DetourDebugDraw.h"
#include "DetourNavMesh.h"
#include "DetourNavMeshBuilder.h"
#include "InputGeom.h"
#include "NavMeshPruneTool.h"
#include "NavMeshTesterTool.h"
#include "OffMeshConnectionTool.h"
#include "Recast.h"
#include "RecastDebugDraw.h"
#include "Sample.h"
#include "imgui.h"

#ifdef WIN32
#	define snprintf _snprintf
#endif

namespace
{
unsigned int nextPow2(unsigned int v)
{
	v--;
	v |= v >> 1;
	v |= v >> 2;
	v |= v >> 4;
	v |= v >> 8;
	v |= v >> 16;
	v++;
	return v;
}

unsigned int ilog2(unsigned int v)
{
	unsigned int r = (v > 0xffff) << 4;
	v >>= r;
	unsigned int shift = (v > 0xff) << 3;
	v >>= shift;
	r |= shift;
	shift = (v > 0xf) << 2;
	v >>= shift;
	r |= shift;
	shift = (v > 0x3) << 1;
	v >>= shift;
	r |= shift;
	r |= (v >> 1);
	return r;
}
}

class NavMeshTileTool : public SampleTool
{
	Sample_TileMesh* m_sample = nullptr;
	float m_hitPos[3] = {0, 0, 0};
	bool m_hitPosSet = false;

public:
	~NavMeshTileTool() override = default;

	SampleToolType type() override { return SampleToolType::TILE_EDIT; }
	void init(Sample* sample) override { m_sample = static_cast<Sample_TileMesh*>(sample); }
	void reset() override {}

	void handleMenu() override
	{
		imguiLabel("Create Tiles");
		if (imguiButton("Create All"))
		{
			if (m_sample)
			{
				m_sample->buildAllTiles();
			}
		}
		if (imguiButton("Remove All"))
		{
			if (m_sample)
			{
				m_sample->removeAllTiles();
			}
		}
	}

	void handleClick(const float* /*s*/, const float* p, bool shift) override
	{
		m_hitPosSet = true;
		rcVcopy(m_hitPos, p);
		if (m_sample)
		{
			if (shift)
			{
				m_sample->removeTile(m_hitPos);
			}
			else
			{
				m_sample->buildTile(m_hitPos);
			}
		}
	}

	void handleToggle() override {}

	void handleStep() override {}

	void handleUpdate(const float /*dt*/) override {}

	void handleRender() override
	{
		if (!m_hitPosSet)
		{
			return;
		}

		const float s = m_sample->getAgentRadius();
		glColor4ub(0, 0, 0, 128);
		glLineWidth(2.0f);
		glBegin(GL_LINES);
		glVertex3f(m_hitPos[0] - s, m_hitPos[1] + 0.1f, m_hitPos[2]);
		glVertex3f(m_hitPos[0] + s, m_hitPos[1] + 0.1f, m_hitPos[2]);
		glVertex3f(m_hitPos[0], m_hitPos[1] - s + 0.1f, m_hitPos[2]);
		glVertex3f(m_hitPos[0], m_hitPos[1] + s + 0.1f, m_hitPos[2]);
		glVertex3f(m_hitPos[0], m_hitPos[1] + 0.1f, m_hitPos[2] - s);
		glVertex3f(m_hitPos[0], m_hitPos[1] + 0.1f, m_hitPos[2] + s);
		glEnd();
		glLineWidth(1.0f);
	}

	void handleRenderOverlay(double* proj, double* model, int* view) override
	{
		GLdouble x, y, z;
		if (m_hitPosSet && gluProject(m_hitPos[0], m_hitPos[1], m_hitPos[2], model, proj, view, &x, &y, &z))
		{
			int tx = 0;
			int ty = 0;
			m_sample->getTilePos(m_hitPos, tx, ty);
			char text[32];
			snprintf(text, 32, "(%d,%d)", tx, ty);
			imguiDrawText(static_cast<int>(x), static_cast<int>(y) - 25, IMGUI_ALIGN_CENTER, text, imguiRGBA(0, 0, 0, 220));
		}

		// Tool help
		imguiDrawText(
			280,
			view[3] - 40,
			IMGUI_ALIGN_LEFT,
			"LMB: Rebuild hit tile.  Shift+LMB: Clear hit tile.",
			imguiRGBA(255, 255, 255, 192));
	}
};

Sample_TileMesh::Sample_TileMesh()
{
	resetCommonSettings();
	setTool(new NavMeshTileTool);
}

Sample_TileMesh::~Sample_TileMesh()
{
	cleanup();
	dtFreeNavMesh(navMesh);
	navMesh = 0;
}

void Sample_TileMesh::cleanup()
{
	delete[] triareas;
	triareas = nullptr;
	rcFreeHeightField(heightfield);
	heightfield = nullptr;
	rcFreeCompactHeightfield(compactHeightfield);
	compactHeightfield = nullptr;
	rcFreeContourSet(contourSet);
	contourSet = nullptr;
	rcFreePolyMesh(polyMesh);
	polyMesh = nullptr;
	rcFreePolyMeshDetail(detailPolyMesh);
	detailPolyMesh = nullptr;
}

void Sample_TileMesh::handleSettings()
{
	Sample::handleCommonSettings();

	if (imguiCheck("Build All Tiles", buildAll))
	{
		buildAll = !buildAll;
	}

	imguiLabel("Tiling");
	imguiSlider("TileSize", &tileSize, 16.0f, 1024.0f, 16.0f);

	if (inputGeometry)
	{
		const float* navMeshBoundsMin = inputGeometry->getNavMeshBoundsMin();
		const float* navMeshBoundsMax = inputGeometry->getNavMeshBoundsMax();
		int gridWidth = 0;
		int gridHeight = 0;
		rcCalcGridSize(navMeshBoundsMin, navMeshBoundsMax, cellSize, &gridWidth, &gridHeight);
		const int tileSize = static_cast<int>(tileSize);
		const int tileWidth = (gridWidth + tileSize - 1) / tileSize;
		const int tileHeight = (gridHeight + tileSize - 1) / tileSize;

		char text[64];
		snprintf(text, 64, "Tiles  %d x %d", tileWidth, tileHeight);
		imguiValue(text);

		// Max tiles and max polys affect how the tile IDs are calculated.
		// There are 22 bits available for identifying a tile and a polygon.
		int tileBits = rcMin((int)ilog2(nextPow2(tileWidth * tileHeight)), 14);
		tileBits = rcMin(tileBits, 14);
		int polyBits = 22 - tileBits;
		maxTiles = 1 << tileBits;
		maxPolysPerTile = 1 << polyBits;
		snprintf(text, 64, "Max Tiles  %d", maxTiles);
		imguiValue(text);
		snprintf(text, 64, "Max Polys  %d", maxPolysPerTile);
		imguiValue(text);
	}
	else
	{
		maxTiles = 0;
		maxPolysPerTile = 0;
	}

	imguiSeparator();

	imguiIndent();
	imguiIndent();

	if (imguiButton("Save"))
	{
		Sample::saveAll("all_tiles_navmesh.bin", navMesh);
	}

	if (imguiButton("Load"))
	{
		dtFreeNavMesh(navMesh);
		navMesh = Sample::loadAll("all_tiles_navmesh.bin");
		navQuery->init(navMesh, 2048);
	}

	imguiUnindent();
	imguiUnindent();

	char msg[64];
	snprintf(msg, 64, "Build Time: %.1fms", totalBuildTimeMs);
	imguiLabel(msg);

	imguiSeparator();
	imguiSeparator();
}

void Sample_TileMesh::handleTools()
{
	const SampleToolType type = !tool ? SampleToolType::NONE : tool->type();

	if (imguiCheck("Test Navmesh", type == SampleToolType::NAVMESH_TESTER))
	{
		setTool(new NavMeshTesterTool);
	}
	if (imguiCheck("Prune Navmesh", type == SampleToolType::NAVMESH_PRUNE))
	{
		setTool(new NavMeshPruneTool);
	}
	if (imguiCheck("Create Tiles", type == SampleToolType::TILE_EDIT))
	{
		setTool(new NavMeshTileTool);
	}
	if (imguiCheck("Create Off-Mesh Links", type == SampleToolType::OFFMESH_CONNECTION))
	{
		setTool(new OffMeshConnectionTool);
	}
	if (imguiCheck("Create Convex Volumes", type == SampleToolType::CONVEX_VOLUME))
	{
		setTool(new ConvexVolumeTool);
	}
	if (imguiCheck("Create Crowds", type == SampleToolType::CROWD))
	{
		setTool(new CrowdTool);
	}

	imguiSeparatorLine();

	imguiIndent();

	if (tool)
	{
		tool->handleMenu();
	}

	imguiUnindent();
}

void Sample_TileMesh::UI_DrawModeOption(const char* name, DrawMode drawMode, bool enabled)
{
	if (imguiCheck(name, this->drawMode == drawMode, enabled))
	{
		this->drawMode = drawMode;
	}
}

void Sample_TileMesh::handleDebugMode()
{
	imguiLabel("Draw");
	UI_DrawModeOption("Input Mesh", DrawMode::MESH, true);
	UI_DrawModeOption("Navmesh", DrawMode::NAVMESH, navMesh != nullptr);
	UI_DrawModeOption("Navmesh Invis", DrawMode::NAVMESH_INVIS, navMesh != nullptr);
	UI_DrawModeOption("Navmesh Trans", DrawMode::NAVMESH_TRANS, navMesh != nullptr);
	UI_DrawModeOption("Navmesh BVTree", DrawMode::NAVMESH_BVTREE, navMesh != nullptr);
	UI_DrawModeOption("Navmesh Nodes", DrawMode::NAVMESH_NODES, navQuery != nullptr);
	UI_DrawModeOption("Navmesh Portals", DrawMode::NAVMESH_PORTALS, navMesh != nullptr);
	UI_DrawModeOption("Voxels", DrawMode::VOXELS, heightfield != nullptr);
	UI_DrawModeOption("Walkable Voxels", DrawMode::VOXELS_WALKABLE, heightfield != nullptr);
	UI_DrawModeOption("Compact", DrawMode::COMPACT, compactHeightfield != nullptr);
	UI_DrawModeOption("Compact Distance", DrawMode::COMPACT_DISTANCE, compactHeightfield != nullptr);
	UI_DrawModeOption("Compact Regions", DrawMode::COMPACT_REGIONS, compactHeightfield != nullptr);
	UI_DrawModeOption("Region Connections", DrawMode::REGION_CONNECTIONS, contourSet != nullptr);
	UI_DrawModeOption("Raw Contours", DrawMode::RAW_CONTOURS, contourSet != nullptr);
	UI_DrawModeOption("Both Contours", DrawMode::BOTH_CONTOURS, contourSet != nullptr);
	UI_DrawModeOption("Contours", DrawMode::CONTOURS, contourSet != nullptr);
	UI_DrawModeOption("Poly Mesh", DrawMode::POLYMESH, polyMesh != nullptr);
	UI_DrawModeOption("Poly Mesh Detail", DrawMode::POLYMESH_DETAIL, detailPolyMesh != nullptr);
}

void Sample_TileMesh::handleRender()
{
	if (!inputGeometry || !inputGeometry->getMesh())
	{
		return;
	}

	const float texScale = 1.0f / (cellSize * 10.0f);

	// Draw mesh
	if (drawMode != DrawMode::NAVMESH_TRANS)
	{
		// Draw mesh
		duDebugDrawTriMeshSlope(
			&debugDraw,
			inputGeometry->getMesh()->getVerts(),
			inputGeometry->getMesh()->getVertCount(),
			inputGeometry->getMesh()->getTris(),
			inputGeometry->getMesh()->getNormals(),
			inputGeometry->getMesh()->getTriCount(),
			agentMaxSlope,
			texScale);
		inputGeometry->drawOffMeshConnections(&debugDraw);
	}

	glDepthMask(GL_FALSE);

	// Draw bounds
	const float* navMeshBoundsMin = inputGeometry->getNavMeshBoundsMin();
	const float* navMeshBoundsMax = inputGeometry->getNavMeshBoundsMax();
	duDebugDrawBoxWire(
		&debugDraw,
		navMeshBoundsMin[0],
		navMeshBoundsMin[1],
		navMeshBoundsMin[2],
		navMeshBoundsMax[0],
		navMeshBoundsMax[1],
		navMeshBoundsMax[2],
		duRGBA(255, 255, 255, 128),
		1.0f);

	// Tiling grid.
	int gridWith = 0;
	int gridHeight = 0;
	rcCalcGridSize(navMeshBoundsMin, navMeshBoundsMax, cellSize, &gridWith, &gridHeight);
	const int tileWidth = (gridWith + static_cast<int>(tileSize) - 1) / static_cast<int>(tileSize);
	const int tileHeight = (gridHeight + static_cast<int>(tileSize) - 1) / static_cast<int>(tileSize);
	const float size = tileSize * cellSize;
	duDebugDrawGridXZ(
		&debugDraw,
		navMeshBoundsMin[0],
		navMeshBoundsMin[1],
		navMeshBoundsMin[2],
		tileWidth,
		tileHeight,
		size,
		duRGBA(0, 0, 0, 64),
		1.0f);

	// Draw active tile
	duDebugDrawBoxWire(
		&debugDraw,
		lastBuiltTileBoundsMin[0],
		lastBuiltTileBoundsMin[1],
		lastBuiltTileBoundsMin[2],
		lastBuiltTileBoundsMax[0],
		lastBuiltTileBoundsMax[1],
		lastBuiltTileBoundsMax[2],
		tileColor,
		1.0f);

	if (navMesh && navQuery &&
	    (drawMode == DrawMode::NAVMESH || drawMode == DrawMode::NAVMESH_TRANS || drawMode == DrawMode::NAVMESH_BVTREE ||
	     drawMode == DrawMode::NAVMESH_NODES || drawMode == DrawMode::NAVMESH_PORTALS || drawMode == DrawMode::NAVMESH_INVIS))
	{
		if (drawMode != DrawMode::NAVMESH_INVIS)
		{
			duDebugDrawNavMeshWithClosedList(&debugDraw, *navMesh, *navQuery, navMeshDrawFlags);
		}
		if (drawMode == DrawMode::NAVMESH_BVTREE)
		{
			duDebugDrawNavMeshBVTree(&debugDraw, *navMesh);
		}
		if (drawMode == DrawMode::NAVMESH_PORTALS)
		{
			duDebugDrawNavMeshPortals(&debugDraw, *navMesh);
		}
		if (drawMode == DrawMode::NAVMESH_NODES)
		{
			duDebugDrawNavMeshNodes(&debugDraw, *navQuery);
		}
		duDebugDrawNavMeshPolysWithFlags(&debugDraw, *navMesh, SAMPLE_POLYFLAGS_DISABLED, duRGBA(0, 0, 0, 128));
	}

	glDepthMask(GL_TRUE);

	if (compactHeightfield && drawMode == DrawMode::COMPACT)
	{
		duDebugDrawCompactHeightfieldSolid(&debugDraw, *compactHeightfield);
	}

	if (compactHeightfield && drawMode == DrawMode::COMPACT_DISTANCE)
	{
		duDebugDrawCompactHeightfieldDistance(&debugDraw, *compactHeightfield);
	}
	if (compactHeightfield && drawMode == DrawMode::COMPACT_REGIONS)
	{
		duDebugDrawCompactHeightfieldRegions(&debugDraw, *compactHeightfield);
	}
	if (heightfield && drawMode == DrawMode::VOXELS)
	{
		glEnable(GL_FOG);
		duDebugDrawHeightfieldSolid(&debugDraw, *heightfield);
		glDisable(GL_FOG);
	}
	if (heightfield && drawMode == DrawMode::VOXELS_WALKABLE)
	{
		glEnable(GL_FOG);
		duDebugDrawHeightfieldWalkable(&debugDraw, *heightfield);
		glDisable(GL_FOG);
	}

	if (contourSet && drawMode == DrawMode::RAW_CONTOURS)
	{
		glDepthMask(GL_FALSE);
		duDebugDrawRawContours(&debugDraw, *contourSet);
		glDepthMask(GL_TRUE);
	}

	if (contourSet && drawMode == DrawMode::BOTH_CONTOURS)
	{
		glDepthMask(GL_FALSE);
		duDebugDrawRawContours(&debugDraw, *contourSet, 0.5f);
		duDebugDrawContours(&debugDraw, *contourSet);
		glDepthMask(GL_TRUE);
	}
	if (contourSet && drawMode == DrawMode::CONTOURS)
	{
		glDepthMask(GL_FALSE);
		duDebugDrawContours(&debugDraw, *contourSet);
		glDepthMask(GL_TRUE);
	}
	if (compactHeightfield && contourSet && drawMode == DrawMode::REGION_CONNECTIONS)
	{
		duDebugDrawCompactHeightfieldRegions(&debugDraw, *compactHeightfield);

		glDepthMask(GL_FALSE);
		duDebugDrawRegionConnections(&debugDraw, *contourSet);
		glDepthMask(GL_TRUE);
	}
	if (polyMesh && drawMode == DrawMode::POLYMESH)
	{
		glDepthMask(GL_FALSE);
		duDebugDrawPolyMesh(&debugDraw, *polyMesh);
		glDepthMask(GL_TRUE);
	}
	if (detailPolyMesh && drawMode == DrawMode::POLYMESH_DETAIL)
	{
		glDepthMask(GL_FALSE);
		duDebugDrawPolyMeshDetail(&debugDraw, *detailPolyMesh);
		glDepthMask(GL_TRUE);
	}

	inputGeometry->drawConvexVolumes(&debugDraw);

	if (tool)
	{
		tool->handleRender();
	}
	renderToolStates();

	glDepthMask(GL_TRUE);
}

void Sample_TileMesh::handleRenderOverlay(double* proj, double* model, int* view)
{
	GLdouble x, y, z;

	// Draw start and end point labels
	const int projectResult = gluProject(
		static_cast<GLdouble>(lastBuiltTileBoundsMin[0] + lastBuiltTileBoundsMax[0]) / 2,
		static_cast<GLdouble>(lastBuiltTileBoundsMin[1] + lastBuiltTileBoundsMax[1]) / 2,
		static_cast<GLdouble>(lastBuiltTileBoundsMin[2] + lastBuiltTileBoundsMax[2]) / 2,
		model,
		proj,
		view,
		&x,
		&y,
		&z);
	if (tileBuildTime > 0.0f && projectResult == GL_TRUE)
	{
		char text[32];
		snprintf(text, 32, "%.3fms / %dTris / %.1fkB", tileBuildTime, tileTriCount, tileMemUsage);
		imguiDrawText(static_cast<int>(x), static_cast<int>(y) - 25, IMGUI_ALIGN_CENTER, text, imguiRGBA(0, 0, 0, 220));
	}

	if (tool)
	{
		tool->handleRenderOverlay(proj, model, view);
	}
	renderOverlayToolStates(proj, model, view);
}

void Sample_TileMesh::handleMeshChanged(InputGeom* geom)
{
	Sample::handleMeshChanged(geom);

	const BuildSettings* buildSettings = geom->getBuildSettings();
	if (buildSettings && buildSettings->tileSize > 0)
	{
		tileSize = buildSettings->tileSize;
	}

	cleanup();

	dtFreeNavMesh(navMesh);
	navMesh = nullptr;

	if (tool)
	{
		tool->reset();
		tool->init(this);
	}
	resetToolStates();
	initToolStates(this);
}

bool Sample_TileMesh::handleBuild()
{
	if (!inputGeometry || !inputGeometry->getMesh())
	{
		buildContext->log(RC_LOG_ERROR, "buildTiledNavigation: No vertices and triangles.");
		return false;
	}

	dtFreeNavMesh(navMesh);

	navMesh = dtAllocNavMesh();
	if (!navMesh)
	{
		buildContext->log(RC_LOG_ERROR, "buildTiledNavigation: Could not allocate navmesh.");
		return false;
	}

	dtNavMeshParams params;
	rcVcopy(params.orig, inputGeometry->getNavMeshBoundsMin());
	params.tileWidth = tileSize * cellSize;
	params.tileHeight = tileSize * cellSize;
	params.maxTiles = maxTiles;
	params.maxPolys = maxPolysPerTile;

	dtStatus status = navMesh->init(&params);
	if (dtStatusFailed(status))
	{
		buildContext->log(RC_LOG_ERROR, "buildTiledNavigation: Could not init navmesh.");
		return false;
	}

	status = navQuery->init(navMesh, 2048);
	if (dtStatusFailed(status))
	{
		buildContext->log(RC_LOG_ERROR, "buildTiledNavigation: Could not init Detour navmesh query");
		return false;
	}

	if (buildAll)
	{
		buildAllTiles();
	}

	if (tool)
	{
		tool->init(this);
	}
	initToolStates(this);

	return true;
}

void Sample_TileMesh::collectSettings(BuildSettings& settings)
{
	Sample::collectSettings(settings);

	settings.tileSize = tileSize;
}

void Sample_TileMesh::buildTile(const float* pos)
{
	if (!inputGeometry)
	{
		return;
	}
	if (!navMesh)
	{
		return;
	}

	const float* navMeshBoundsMin = inputGeometry->getNavMeshBoundsMin();
	const float* navMeshBoundsMax = inputGeometry->getNavMeshBoundsMax();

	const float tileSize = tileSize * cellSize;
	const int tileX = static_cast<int>((pos[0] - navMeshBoundsMin[0]) / tileSize);
	const int tileY = static_cast<int>((pos[2] - navMeshBoundsMin[2]) / tileSize);

	lastBuiltTileBoundsMin[0] = navMeshBoundsMin[0] + static_cast<float>(tileX) * tileSize;
	lastBuiltTileBoundsMin[1] = navMeshBoundsMin[1];
	lastBuiltTileBoundsMin[2] = navMeshBoundsMin[2] + static_cast<float>(tileY) * tileSize;

	lastBuiltTileBoundsMax[0] = navMeshBoundsMin[0] + static_cast<float>(tileX + 1) * tileSize;
	lastBuiltTileBoundsMax[1] = navMeshBoundsMax[1];
	lastBuiltTileBoundsMax[2] = navMeshBoundsMin[2] + static_cast<float>(tileY + 1) * tileSize;

	tileColor = duRGBA(255, 255, 255, 64);

	buildContext->resetLog();

	int tileMeshDataSize = 0;
	unsigned char* tileMeshData = buildTileMesh(tileX, tileY, lastBuiltTileBoundsMin, lastBuiltTileBoundsMax, tileMeshDataSize);

	// Remove any previous data (navmesh owns and deletes the data).
	navMesh->removeTile(navMesh->getTileRefAt(tileX, tileY, 0), 0, 0);

	// Add tile, or leave the location empty.
	if (tileMeshData)
	{
		// Let the navmesh own the data.
		const dtStatus status = navMesh->addTile(tileMeshData, tileMeshDataSize, DT_TILE_FREE_DATA, 0, 0);
		if (dtStatusFailed(status))
		{
			dtFree(tileMeshData);
		}
	}

	buildContext->dumpLog("Build Tile (%d,%d):", tileX, tileY);
}

void Sample_TileMesh::getTilePos(const float* pos, int& outTileX, int& outTileY) const
{
	if (!inputGeometry)
	{
		return;
	}

	const float* navMeshBoundsMin = inputGeometry->getNavMeshBoundsMin();

	const float tileSize = tileSize * cellSize;
	outTileX = static_cast<int>((pos[0] - navMeshBoundsMin[0]) / tileSize);
	outTileY = static_cast<int>((pos[2] - navMeshBoundsMin[2]) / tileSize);
}

void Sample_TileMesh::removeTile(const float* pos)
{
	if (!inputGeometry)
	{
		return;
	}
	if (!navMesh)
	{
		return;
	}

	const float* navMeshBoundsMin = inputGeometry->getNavMeshBoundsMin();
	const float* navmeshBoundsMax = inputGeometry->getNavMeshBoundsMax();

	const float tileSize = tileSize * cellSize;
	const int tileX = static_cast<int>((pos[0] - navMeshBoundsMin[0]) / tileSize);
	const int tileY = static_cast<int>((pos[2] - navMeshBoundsMin[2]) / tileSize);

	lastBuiltTileBoundsMin[0] = navMeshBoundsMin[0] + static_cast<float>(tileX) * tileSize;
	lastBuiltTileBoundsMin[1] = navMeshBoundsMin[1];
	lastBuiltTileBoundsMin[2] = navMeshBoundsMin[2] + static_cast<float>(tileY) * tileSize;

	lastBuiltTileBoundsMax[0] = navMeshBoundsMin[0] + static_cast<float>(tileX + 1) * tileSize;
	lastBuiltTileBoundsMax[1] = navmeshBoundsMax[1];
	lastBuiltTileBoundsMax[2] = navMeshBoundsMin[2] + static_cast<float>(tileY + 1) * tileSize;

	tileColor = duRGBA(128, 32, 16, 64);

	navMesh->removeTile(navMesh->getTileRefAt(tileX, tileY, 0), 0, 0);
}

void Sample_TileMesh::buildAllTiles()
{
	if (!inputGeometry)
	{
		return;
	}
	if (!navMesh)
	{
		return;
	}

	const float* navMeshBoundsMin = inputGeometry->getNavMeshBoundsMin();
	const float* navMeshBoundsMax = inputGeometry->getNavMeshBoundsMax();
	int gridWidth = 0;
	int gridHeight = 0;
	rcCalcGridSize(navMeshBoundsMin, navMeshBoundsMax, cellSize, &gridWidth, &gridHeight);
	const int tileSize = static_cast<int>(tileSize);
	const int tileWidth = (gridWidth + tileSize - 1) / tileSize;
	const int tileHeight = (gridHeight + tileSize - 1) / tileSize;
	const float tileCellSize = tileSize * cellSize;

	// Start the build process.
	buildContext->startTimer(RC_TIMER_TEMP);

	for (int y = 0; y < tileHeight; ++y)
	{
		for (int x = 0; x < tileWidth; ++x)
		{
			lastBuiltTileBoundsMin[0] = navMeshBoundsMin[0] + static_cast<float>(x) * tileCellSize;
			lastBuiltTileBoundsMin[1] = navMeshBoundsMin[1];
			lastBuiltTileBoundsMin[2] = navMeshBoundsMin[2] + static_cast<float>(y) * tileCellSize;

			lastBuiltTileBoundsMax[0] = navMeshBoundsMin[0] + static_cast<float>(x + 1) * tileCellSize;
			lastBuiltTileBoundsMax[1] = navMeshBoundsMax[1];
			lastBuiltTileBoundsMax[2] = navMeshBoundsMin[2] + static_cast<float>(y + 1) * tileCellSize;

			int tileMeshDataSize = 0;
			unsigned char* tileMeshData = buildTileMesh(x, y, lastBuiltTileBoundsMin, lastBuiltTileBoundsMax, tileMeshDataSize);
			if (!tileMeshData)
			{
				continue;
			}

			// Remove any previous data (navmesh owns and deletes the data).
			navMesh->removeTile(navMesh->getTileRefAt(x, y, 0), 0, 0);
			// Let the navmesh own the data.
			const dtStatus status = navMesh->addTile(tileMeshData, tileMeshDataSize, DT_TILE_FREE_DATA, 0, 0);
			if (dtStatusFailed(status))
			{
				dtFree(tileMeshData);
			}
		}
	}

	// Record the total build time.
	buildContext->stopTimer(RC_TIMER_TEMP);
	totalBuildTimeMs = static_cast<float>(buildContext->getAccumulatedTime(RC_TIMER_TEMP)) / 1000.0f;
}

void Sample_TileMesh::removeAllTiles() const
{
	if (inputGeometry == nullptr)
	{
		return;
	}
	if (navMesh == nullptr)
	{
		return;
	}

	const float* navMeshBoundsMin = inputGeometry->getNavMeshBoundsMin();
	const float* navMeshBoundsMax = inputGeometry->getNavMeshBoundsMax();
	int gridWidth = 0;
	int gridHeight = 0;
	rcCalcGridSize(navMeshBoundsMin, navMeshBoundsMax, cellSize, &gridWidth, &gridHeight);
	const int tileSize = static_cast<int>(tileSize);
	const int tileWidth = (gridWidth + tileSize - 1) / tileSize;
	const int tileHeight = (gridHeight + tileSize - 1) / tileSize;

	for (int tileY = 0; tileY < tileHeight; ++tileY)
	{
		for (int tileX = 0; tileX < tileWidth; ++tileX)
		{
			navMesh->removeTile(navMesh->getTileRefAt(tileX, tileY, 0), 0, 0);
		}
	}
}

unsigned char* Sample_TileMesh::buildTileMesh(
	const int tileX,
	const int tileY,
	const float* boundsMin,
	const float* boundsMax,
	int& outDataSize)
{
	if (!inputGeometry || !inputGeometry->getMesh() || !inputGeometry->getChunkyMesh())
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Input mesh is not specified.");
		return 0;
	}

	tileMemUsage = 0;
	tileBuildTime = 0;

	cleanup();

	const float* verts = inputGeometry->getMesh()->getVerts();
	const int numVerts = inputGeometry->getMesh()->getVertCount();
	const int numTris = inputGeometry->getMesh()->getTriCount();
	const rcChunkyTriMesh* chunkyMesh = inputGeometry->getChunkyMesh();

	// Init build configuration from GUI
	memset(&config, 0, sizeof(config));
	config.cs = cellSize;
	config.ch = cellHeight;
	config.walkableSlopeAngle = agentMaxSlope;
	config.walkableHeight = static_cast<int>(ceilf(agentHeight / config.ch));
	config.walkableClimb = static_cast<int>(floorf(agentMaxClimb / config.ch));
	config.walkableRadius = static_cast<int>(ceilf(agentRadius / config.cs));
	config.maxEdgeLen = static_cast<int>(edgeMaxLen / cellSize);
	config.maxSimplificationError = edgeMaxError;
	config.minRegionArea = static_cast<int>(rcSqr(regionMinSize));      // Note: area = size*size
	config.mergeRegionArea = static_cast<int>(rcSqr(regionMergeSize));  // Note: area = size*size
	config.maxVertsPerPoly = static_cast<int>(vertsPerPoly);
	config.tileSize = static_cast<int>(tileSize);
	config.borderSize = config.walkableRadius + 3;  // Reserve enough padding.
	config.width = config.tileSize + config.borderSize * 2;
	config.height = config.tileSize + config.borderSize * 2;
	config.detailSampleDist = detailSampleDist < 0.9f ? 0 : cellSize * detailSampleDist;
	config.detailSampleMaxError = cellHeight * detailSampleMaxError;

	// Expand the heightfield bounding box by border size to find the extents of geometry we need to build this tile.
	//
	// This is done in order to make sure that the navmesh tiles connect correctly at the borders,
	// and the obstacles close to the border work correctly with the dilation process.
	// No polygons (or contours) will be created on the border area.
	//
	// IMPORTANT!
	//
	//   :''''''''':
	//   : +-----+ :
	//   : |     | :
	//   : |     |<--- tile to build
	//   : |     | :
	//   : +-----+ :<-- geometry needed
	//   :.........:
	//
	// You should use this bounding box to query your input geometry.
	//
	// For example if you build a navmesh for terrain, and want the navmesh tiles to match the terrain tile size
	// you will need to pass in data from neighbour terrain tiles too! In a simple case, just pass in all the 8 neighbours,
	// or use the bounding box below to only pass in a sliver of each of the 8 neighbours.
	rcVcopy(config.bmin, boundsMin);
	rcVcopy(config.bmax, boundsMax);
	config.bmin[0] -= static_cast<float>(config.borderSize) * config.cs;
	config.bmin[2] -= static_cast<float>(config.borderSize) * config.cs;
	config.bmax[0] += static_cast<float>(config.borderSize) * config.cs;
	config.bmax[2] += static_cast<float>(config.borderSize) * config.cs;

	// Reset build times gathering.
	buildContext->resetTimers();

	// Start the build process.
	buildContext->startTimer(RC_TIMER_TOTAL);

	buildContext->log(RC_LOG_PROGRESS, "Building navigation:");
	buildContext->log(RC_LOG_PROGRESS, " - %d x %d cells", config.width, config.height);
	buildContext->log(
		RC_LOG_PROGRESS,
		" - %.1fK verts, %.1fK tris",
		static_cast<float>(numVerts) / 1000.0f,
		static_cast<float>(numTris) / 1000.0f);

	// Allocate voxel heightfield where we rasterize our input data to.
	heightfield = rcAllocHeightfield();
	if (!heightfield)
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Out of memory 'solid'.");
		return 0;
	}
	if (!rcCreateHeightfield(
			buildContext,
			*heightfield,
			config.width,
			config.height,
			config.bmin,
			config.bmax,
			config.cs,
			config.ch))
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not create solid heightfield.");
		return 0;
	}

	// Allocate array that can hold triangle flags.
	// If you have multiple meshes you need to process, allocate
	// and array which can hold the max number of triangles you need to process.
	triareas = new unsigned char[chunkyMesh->maxTrisPerChunk];
	if (!triareas)
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Out of memory 'triareas' (%d).", chunkyMesh->maxTrisPerChunk);
		return 0;
	}

	float tileBoundsMin[2];
	float tileBoundsMax[2];
	tileBoundsMin[0] = config.bmin[0];
	tileBoundsMin[1] = config.bmin[2];
	tileBoundsMax[0] = config.bmax[0];
	tileBoundsMax[1] = config.bmax[2];
	int overlappingChunkIndexes[512];  // TODO: Make grow when returning too many items.
	const int numOverlappingChunks =
		chunkyMesh->GetChunksOverlappingRect(tileBoundsMin, tileBoundsMax, overlappingChunkIndexes, 512);
	if (!numOverlappingChunks)
	{
		return 0;
	}

	tileTriCount = 0;

	for (int i = 0; i < numOverlappingChunks; ++i)
	{
		const rcChunkyTriMeshNode& node = chunkyMesh->nodes[overlappingChunkIndexes[i]];
		const int* nodeTris = &chunkyMesh->tris[node.i * 3];
		const int numNodeTris = node.n;

		tileTriCount += numNodeTris;

		memset(triareas, 0, numNodeTris * sizeof(unsigned char));
		rcMarkWalkableTriangles(buildContext, config.walkableSlopeAngle, verts, numVerts, nodeTris, numNodeTris, triareas);

		if (!rcRasterizeTriangles(
				buildContext,
				verts,
				numVerts,
				nodeTris,
				triareas,
				numNodeTris,
				*heightfield,
				config.walkableClimb))
		{
			return 0;
		}
	}

	// Once all geometry is rasterized, we do initial pass of filtering to
	// remove unwanted overhangs caused by the conservative rasterization
	// as well as filter spans where the character cannot possibly stand.
	if (filterLowHangingObstacles)
	{
		rcFilterLowHangingWalkableObstacles(buildContext, config.walkableClimb, *heightfield);
	}
	if (filterLedgeSpans)
	{
		rcFilterLedgeSpans(buildContext, config.walkableHeight, config.walkableClimb, *heightfield);
	}
	if (filterWalkableLowHeightSpans)
	{
		rcFilterWalkableLowHeightSpans(buildContext, config.walkableHeight, *heightfield);
	}

	// Compact the heightfield so that it is faster to handle from now on.
	// This will result more cache coherent data as well as the neighbours
	// between walkable cells will be calculated.
	compactHeightfield = rcAllocCompactHeightfield();
	if (!compactHeightfield)
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Out of memory 'chf'.");
		return 0;
	}
	if (!rcBuildCompactHeightfield(
			buildContext,
			config.walkableHeight,
			config.walkableClimb,
			*heightfield,
			*compactHeightfield))
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not build compact data.");
		return 0;
	}

	// Erode the walkable area by agent radius.
	if (!rcErodeWalkableArea(buildContext, config.walkableRadius, *compactHeightfield))
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not erode.");
		return 0;
	}

	// (Optional) Mark areas.
	const ConvexVolume* convexVolumes = inputGeometry->getConvexVolumes();
	for (int i = 0; i < inputGeometry->getConvexVolumeCount(); ++i)
	{
		rcMarkConvexPolyArea(
			buildContext,
			convexVolumes[i].verts,
			convexVolumes[i].nverts,
			convexVolumes[i].hmin,
			convexVolumes[i].hmax,
			static_cast<unsigned char>(convexVolumes[i].area),
			*compactHeightfield);
	}

	// Partition the heightfield so that we can use simple algorithm later to triangulate the walkable areas.
	// There are 3 martitioning methods, each with some pros and cons:
	// 1) Watershed partitioning
	//   - the classic Recast partitioning
	//   - creates the nicest tessellation
	//   - usually slowest
	//   - partitions the heightfield into nice regions without holes or overlaps
	//   - the are some corner cases where this method creates produces holes and overlaps
	//      - holes may appear when a small obstacles is close to large open area (triangulation can handle this)
	//      - overlaps may occur if you have narrow spiral corridors (i.e stairs), this make triangulation to fail
	//   * generally the best choice if you precompute the nacmesh, use this if you have large open areas
	// 2) Monotone partioning
	//   - fastest
	//   - partitions the heightfield into regions without holes and overlaps (guaranteed)
	//   - creates long thin polygons, which sometimes causes paths with detours
	//   * use this if you want fast navmesh generation
	// 3) Layer partitoining
	//   - quite fast
	//   - partitions the heighfield into non-overlapping regions
	//   - relies on the triangulation code to cope with holes (thus slower than monotone partitioning)
	//   - produces better triangles than monotone partitioning
	//   - does not have the corner cases of watershed partitioning
	//   - can be slow and create a bit ugly tessellation (still better than monotone)
	//     if you have large open areas with small obstacles (not a problem if you use tiles)
	//   * good choice to use for tiled navmesh with medium and small sized tiles

	if (partitionType == SAMPLE_PARTITION_WATERSHED)
	{
		// Prepare for region partitioning, by calculating distance field along the walkable surface.
		if (!rcBuildDistanceField(buildContext, *compactHeightfield))
		{
			buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not build distance field.");
			return 0;
		}

		// Partition the walkable surface into simple regions without holes.
		if (!rcBuildRegions(
				buildContext,
				*compactHeightfield,
				config.borderSize,
				config.minRegionArea,
				config.mergeRegionArea))
		{
			buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not build watershed regions.");
			return 0;
		}
	}
	else if (partitionType == SAMPLE_PARTITION_MONOTONE)
	{
		// Partition the walkable surface into simple regions without holes.
		// Monotone partitioning does not need distancefield.
		if (!rcBuildRegionsMonotone(
				buildContext,
				*compactHeightfield,
				config.borderSize,
				config.minRegionArea,
				config.mergeRegionArea))
		{
			buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not build monotone regions.");
			return 0;
		}
	}
	else  // SAMPLE_PARTITION_LAYERS
	{
		// Partition the walkable surface into simple regions without holes.
		if (!rcBuildLayerRegions(buildContext, *compactHeightfield, config.borderSize, config.minRegionArea))
		{
			buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not build layer regions.");
			return 0;
		}
	}

	// Create contours.
	contourSet = rcAllocContourSet();
	if (!contourSet)
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Out of memory 'cset'.");
		return 0;
	}
	if (!rcBuildContours(buildContext, *compactHeightfield, config.maxSimplificationError, config.maxEdgeLen, *contourSet))
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not create contours.");
		return 0;
	}

	if (contourSet->nconts == 0)
	{
		return 0;
	}

	// Build polygon navmesh from the contours.
	polyMesh = rcAllocPolyMesh();
	if (!polyMesh)
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Out of memory 'pmesh'.");
		return 0;
	}
	if (!rcBuildPolyMesh(buildContext, *contourSet, config.maxVertsPerPoly, *polyMesh))
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Could not triangulate contours.");
		return 0;
	}

	// Build detail mesh.
	detailPolyMesh = rcAllocPolyMeshDetail();
	if (!detailPolyMesh)
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Out of memory 'dmesh'.");
		return 0;
	}

	if (!rcBuildPolyMeshDetail(
			buildContext,
			*polyMesh,
			*compactHeightfield,
			config.detailSampleDist,
			config.detailSampleMaxError,
			*detailPolyMesh))
	{
		buildContext->log(RC_LOG_ERROR, "buildNavigation: Could build polymesh detail.");
		return 0;
	}

	unsigned char* navData = 0;
	int navDataSize = 0;
	if (config.maxVertsPerPoly <= DT_VERTS_PER_POLYGON)
	{
		if (polyMesh->nverts >= 0xffff)
		{
			// The vertex indices are ushorts, and cannot point to more than 0xffff vertices.
			buildContext->log(RC_LOG_ERROR, "Too many vertices per tile %d (max: %d).", polyMesh->nverts, 0xffff);
			return 0;
		}

		// Update poly flags from areas.
		for (int i = 0; i < polyMesh->npolys; ++i)
		{
			if (polyMesh->areas[i] == RC_WALKABLE_AREA)
			{
				polyMesh->areas[i] = SAMPLE_POLYAREA_GROUND;
			}

			if (polyMesh->areas[i] == SAMPLE_POLYAREA_GROUND || polyMesh->areas[i] == SAMPLE_POLYAREA_GRASS ||
			    polyMesh->areas[i] == SAMPLE_POLYAREA_ROAD)
			{
				polyMesh->flags[i] = SAMPLE_POLYFLAGS_WALK;
			}
			else if (polyMesh->areas[i] == SAMPLE_POLYAREA_WATER)
			{
				polyMesh->flags[i] = SAMPLE_POLYFLAGS_SWIM;
			}
			else if (polyMesh->areas[i] == SAMPLE_POLYAREA_DOOR)
			{
				polyMesh->flags[i] = SAMPLE_POLYFLAGS_WALK | SAMPLE_POLYFLAGS_DOOR;
			}
		}

		dtNavMeshCreateParams params;
		memset(&params, 0, sizeof(params));
		params.verts = polyMesh->verts;
		params.vertCount = polyMesh->nverts;
		params.polys = polyMesh->polys;
		params.polyAreas = polyMesh->areas;
		params.polyFlags = polyMesh->flags;
		params.polyCount = polyMesh->npolys;
		params.nvp = polyMesh->nvp;
		params.detailMeshes = detailPolyMesh->meshes;
		params.detailVerts = detailPolyMesh->verts;
		params.detailVertsCount = detailPolyMesh->nverts;
		params.detailTris = detailPolyMesh->tris;
		params.detailTriCount = detailPolyMesh->ntris;
		params.offMeshConVerts = inputGeometry->getOffMeshConnectionVerts();
		params.offMeshConRad = inputGeometry->getOffMeshConnectionRads();
		params.offMeshConDir = inputGeometry->getOffMeshConnectionDirs();
		params.offMeshConAreas = inputGeometry->getOffMeshConnectionAreas();
		params.offMeshConFlags = inputGeometry->getOffMeshConnectionFlags();
		params.offMeshConUserID = inputGeometry->getOffMeshConnectionId();
		params.offMeshConCount = inputGeometry->getOffMeshConnectionCount();
		params.walkableHeight = agentHeight;
		params.walkableRadius = agentRadius;
		params.walkableClimb = agentMaxClimb;
		params.tileX = tileX;
		params.tileY = tileY;
		params.tileLayer = 0;
		rcVcopy(params.bmin, polyMesh->bmin);
		rcVcopy(params.bmax, polyMesh->bmax);
		params.cs = config.cs;
		params.ch = config.ch;
		params.buildBvTree = true;

		if (!dtCreateNavMeshData(&params, &navData, &navDataSize))
		{
			buildContext->log(RC_LOG_ERROR, "Could not build Detour navmesh.");
			return 0;
		}
	}
	tileMemUsage = static_cast<float>(navDataSize) / 1024.0f;

	buildContext->stopTimer(RC_TIMER_TOTAL);

	// Show performance stats.
	duLogBuildTimes(*buildContext, buildContext->getAccumulatedTime(RC_TIMER_TOTAL));
	buildContext->log(RC_LOG_PROGRESS, ">> Polymesh: %d vertices  %d polygons", polyMesh->nverts, polyMesh->npolys);

	tileBuildTime = static_cast<float>(buildContext->getAccumulatedTime(RC_TIMER_TOTAL)) / 1000.0f;

	outDataSize = navDataSize;
	return navData;
}