//
// Copyright (c) 2009 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 <float.h>
#define _USE_MATH_DEFINES
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "Recast.h"
#include "RecastLog.h"
#include "RecastTimer.h"


bool rcErodeArea(unsigned char areaId, int radius, rcCompactHeightfield& chf)
{
	const int w = chf.width;
	const int h = chf.height;
	
	rcTimeVal startTime = rcGetPerformanceTimer();
	
	unsigned char* dist = new unsigned char[chf.spanCount];
	if (!dist)
		return false;
	
	// Init distance.
	memset(dist, 0xff, sizeof(unsigned char)*chf.spanCount);
	
	// Mark boundary cells.
	for (int y = 0; y < h; ++y)
	{
		for (int x = 0; x < w; ++x)
		{
			const rcCompactCell& c = chf.cells[x+y*w];
			for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
			{
				if (chf.areas[i] != RC_NULL_AREA)
				{
					const rcCompactSpan& s = chf.spans[i];
					int nc = 0;
					for (int dir = 0; dir < 4; ++dir)
					{
						if (rcGetCon(s, dir) != RC_NOT_CONNECTED)
						{
							const int ax = x + rcGetDirOffsetX(dir);
							const int ay = y + rcGetDirOffsetY(dir);
							const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, dir);
							if (chf.areas[ai] == areaId)
								nc++;
						}
					}
					// At least one missing neighbour.
					if (nc != 4)
						dist[i] = 0;
				}
			}
		}
	}
	
	unsigned char nd;
	
	// Pass 1
	for (int y = 0; y < h; ++y)
	{
		for (int x = 0; x < w; ++x)
		{
			const rcCompactCell& c = chf.cells[x+y*w];
			for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
			{
				const rcCompactSpan& s = chf.spans[i];
				
				if (rcGetCon(s, 0) != RC_NOT_CONNECTED)
				{
					// (-1,0)
					const int ax = x + rcGetDirOffsetX(0);
					const int ay = y + rcGetDirOffsetY(0);
					const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 0);
					const rcCompactSpan& as = chf.spans[ai];
					nd = (unsigned char)rcMin((int)dist[ai]+2, 255);
					if (nd < dist[i])
						dist[i] = nd;
					
					// (-1,-1)
					if (rcGetCon(as, 3) != RC_NOT_CONNECTED)
					{
						const int aax = ax + rcGetDirOffsetX(3);
						const int aay = ay + rcGetDirOffsetY(3);
						const int aai = (int)chf.cells[aax+aay*w].index + rcGetCon(as, 3);
						nd = (unsigned char)rcMin((int)dist[aai]+3, 255);
						if (nd < dist[i])
							dist[i] = nd;
					}
				}
				if (rcGetCon(s, 3) != RC_NOT_CONNECTED)
				{
					// (0,-1)
					const int ax = x + rcGetDirOffsetX(3);
					const int ay = y + rcGetDirOffsetY(3);
					const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 3);
					const rcCompactSpan& as = chf.spans[ai];
					nd = (unsigned char)rcMin((int)dist[ai]+2, 255);
					if (nd < dist[i])
						dist[i] = nd;
					
					// (1,-1)
					if (rcGetCon(as, 2) != RC_NOT_CONNECTED)
					{
						const int aax = ax + rcGetDirOffsetX(2);
						const int aay = ay + rcGetDirOffsetY(2);
						const int aai = (int)chf.cells[aax+aay*w].index + rcGetCon(as, 2);
						nd = (unsigned char)rcMin((int)dist[aai]+3, 255);
						if (nd < dist[i])
							dist[i] = nd;
					}
				}
			}
		}
	}
	
	// Pass 2
	for (int y = h-1; y >= 0; --y)
	{
		for (int x = w-1; x >= 0; --x)
		{
			const rcCompactCell& c = chf.cells[x+y*w];
			for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
			{
				const rcCompactSpan& s = chf.spans[i];
				
				if (rcGetCon(s, 2) != RC_NOT_CONNECTED)
				{
					// (1,0)
					const int ax = x + rcGetDirOffsetX(2);
					const int ay = y + rcGetDirOffsetY(2);
					const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 2);
					const rcCompactSpan& as = chf.spans[ai];
					nd = (unsigned char)rcMin((int)dist[ai]+2, 255);
					if (nd < dist[i])
						dist[i] = nd;
					
					// (1,1)
					if (rcGetCon(as, 1) != RC_NOT_CONNECTED)
					{
						const int aax = ax + rcGetDirOffsetX(1);
						const int aay = ay + rcGetDirOffsetY(1);
						const int aai = (int)chf.cells[aax+aay*w].index + rcGetCon(as, 1);
						nd = (unsigned char)rcMin((int)dist[aai]+3, 255);
						if (nd < dist[i])
							dist[i] = nd;
					}
				}
				if (rcGetCon(s, 1) != RC_NOT_CONNECTED)
				{
					// (0,1)
					const int ax = x + rcGetDirOffsetX(1);
					const int ay = y + rcGetDirOffsetY(1);
					const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 1);
					const rcCompactSpan& as = chf.spans[ai];
					nd = (unsigned char)rcMin((int)dist[ai]+2, 255);
					if (nd < dist[i])
						dist[i] = nd;
					
					// (-1,1)
					if (rcGetCon(as, 0) != RC_NOT_CONNECTED)
					{
						const int aax = ax + rcGetDirOffsetX(0);
						const int aay = ay + rcGetDirOffsetY(0);
						const int aai = (int)chf.cells[aax+aay*w].index + rcGetCon(as, 0);
						nd = (unsigned char)rcMin((int)dist[aai]+3, 255);
						if (nd < dist[i])
							dist[i] = nd;
					}
				}
			}
		}
	}
	
	const unsigned char thr = (unsigned char)(radius*2);
	for (int i = 0; i < chf.spanCount; ++i)
		if (dist[i] < thr)
			chf.areas[i] = 0;
	
	delete [] dist;
	
	rcTimeVal endTime = rcGetPerformanceTimer();
	
	if (rcGetBuildTimes())
	{
		rcGetBuildTimes()->erodeArea += rcGetDeltaTimeUsec(startTime, endTime);
	}
	
	return true;
}

void rcMarkBoxArea(const float* bmin, const float* bmax, unsigned char areaId,
				   rcCompactHeightfield& chf)
{
	int minx = (int)((bmin[0]-chf.bmin[0])/chf.cs);
	int miny = (int)((bmin[1]-chf.bmin[1])/chf.ch);
	int minz = (int)((bmin[2]-chf.bmin[2])/chf.cs);
	int maxx = (int)((bmax[0]-chf.bmin[0])/chf.cs);
	int maxy = (int)((bmax[1]-chf.bmin[1])/chf.ch);
	int maxz = (int)((bmax[2]-chf.bmin[2])/chf.cs);
	
	if (maxx < 0) return;
	if (minx >= chf.width) return;
	if (maxz < 0) return;
	if (minz >= chf.height) return;

	if (minx < 0) minx = 0;
	if (maxx >= chf.width) maxx = chf.width-1;
	if (minz < 0) minz = 0;
	if (maxz >= chf.height) maxz = chf.height-1;	
	
	for (int z = minz; z <= maxz; ++z)
	{
		for (int x = minx; x <= maxx; ++x)
		{
			const rcCompactCell& c = chf.cells[x+z*chf.width];
			for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
			{
				rcCompactSpan& s = chf.spans[i];
				if ((int)s.y >= miny && (int)s.y <= maxy)
				{
					if (areaId < chf.areas[i])
						chf.areas[i] = areaId;
				}
			}
		}
	}
}


static int pointInPoly(int nvert, const float* verts, const float* p)
{
	int i, j, c = 0;
	for (i = 0, j = nvert-1; i < nvert; j = i++)
	{
		const float* vi = &verts[i*3];
		const float* vj = &verts[j*3];
		if (((vi[2] > p[2]) != (vj[2] > p[2])) &&
			(p[0] < (vj[0]-vi[0]) * (p[2]-vi[2]) / (vj[2]-vi[2]) + vi[0]) )
			c = !c;
	}
	return c;
}

void rcMarkConvexPolyArea(const float* verts, const int nverts,
						  const float hmin, const float hmax, unsigned char areaId,
						  rcCompactHeightfield& chf)
{
	float bmin[3], bmax[3];
	vcopy(bmin, verts);
	vcopy(bmax, verts);
	for (int i = 1; i < nverts; ++i)
	{
		vmin(bmin, &verts[i*3]);
		vmax(bmax, &verts[i*3]);
	}
	bmin[1] = hmin;
	bmax[1] = hmax;

	int minx = (int)((bmin[0]-chf.bmin[0])/chf.cs);
	int miny = (int)((bmin[1]-chf.bmin[1])/chf.ch);
	int minz = (int)((bmin[2]-chf.bmin[2])/chf.cs);
	int maxx = (int)((bmax[0]-chf.bmin[0])/chf.cs);
	int maxy = (int)((bmax[1]-chf.bmin[1])/chf.ch);
	int maxz = (int)((bmax[2]-chf.bmin[2])/chf.cs);
	
	if (maxx < 0) return;
	if (minx >= chf.width) return;
	if (maxz < 0) return;
	if (minz >= chf.height) return;
	
	if (minx < 0) minx = 0;
	if (maxx >= chf.width) maxx = chf.width-1;
	if (minz < 0) minz = 0;
	if (maxz >= chf.height) maxz = chf.height-1;	
	
	
	// TODO: Optimize.
	for (int z = minz; z <= maxz; ++z)
	{
		for (int x = minx; x <= maxx; ++x)
		{
			const rcCompactCell& c = chf.cells[x+z*chf.width];
			for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
			{
				rcCompactSpan& s = chf.spans[i];
				if ((int)s.y >= miny && (int)s.y <= maxy)
				{
					if (areaId < chf.areas[i])
					{
						float p[3];
						p[0] = chf.bmin[0] + (x+0.5f)*chf.cs; 
						p[1] = 0;
						p[2] = chf.bmin[2] + (z+0.5f)*chf.cs; 

						if (pointInPoly(nverts, verts, p))
						{
							chf.areas[i] = areaId;
						}
					}
				}
			}
		}
	}
	

}