455 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			455 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
//
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// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
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//
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// This software is provided 'as-is', without any express or implied
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// warranty.  In no event will the authors be held liable for any damages
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// arising from the use of this software.
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// Permission is granted to anyone to use this software for any purpose,
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// including commercial applications, and to alter it and redistribute it
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// freely, subject to the following restrictions:
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// 1. The origin of this software must not be misrepresented; you must not
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//    claim that you wrote the original software. If you use this software
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//    in a product, an acknowledgment in the product documentation would be
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//    appreciated but is not required.
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// 2. Altered source versions must be plainly marked as such, and must not be
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//    misrepresented as being the original software.
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// 3. This notice may not be removed or altered from any source distribution.
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//
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#define _USE_MATH_DEFINES
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#include <math.h>
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#include <stdio.h>
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#include "Recast.h"
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#include "RecastAlloc.h"
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#include "RecastAssert.h"
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inline bool overlapBounds(const float* amin, const float* amax, const float* bmin, const float* bmax)
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{
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	bool overlap = true;
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	overlap = (amin[0] > bmax[0] || amax[0] < bmin[0]) ? false : overlap;
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	overlap = (amin[1] > bmax[1] || amax[1] < bmin[1]) ? false : overlap;
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	overlap = (amin[2] > bmax[2] || amax[2] < bmin[2]) ? false : overlap;
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	return overlap;
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}
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inline bool overlapInterval(unsigned short amin, unsigned short amax,
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							unsigned short bmin, unsigned short bmax)
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{
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	if (amax < bmin) return false;
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	if (amin > bmax) return false;
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	return true;
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}
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static rcSpan* allocSpan(rcHeightfield& hf)
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{
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	// If running out of memory, allocate new page and update the freelist.
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	if (!hf.freelist || !hf.freelist->next)
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	{
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		// Create new page.
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		// Allocate memory for the new pool.
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		rcSpanPool* pool = (rcSpanPool*)rcAlloc(sizeof(rcSpanPool), RC_ALLOC_PERM);
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		if (!pool) return 0;
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		// Add the pool into the list of pools.
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		pool->next = hf.pools;
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		hf.pools = pool;
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		// Add new items to the free list.
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		rcSpan* freelist = hf.freelist;
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		rcSpan* head = &pool->items[0];
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		rcSpan* it = &pool->items[RC_SPANS_PER_POOL];
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		do
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		{
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			--it;
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			it->next = freelist;
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			freelist = it;
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		}
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		while (it != head);
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		hf.freelist = it;
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	}
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	// Pop item from in front of the free list.
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	rcSpan* it = hf.freelist;
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	hf.freelist = hf.freelist->next;
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	return it;
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}
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static void freeSpan(rcHeightfield& hf, rcSpan* ptr)
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{
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	if (!ptr) return;
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	// Add the node in front of the free list.
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	ptr->next = hf.freelist;
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	hf.freelist = ptr;
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}
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static bool addSpan(rcHeightfield& hf, const int x, const int y,
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					const unsigned short smin, const unsigned short smax,
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					const unsigned char area, const int flagMergeThr)
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{
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	int idx = x + y*hf.width;
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	rcSpan* s = allocSpan(hf);
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	if (!s)
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		return false;
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	s->smin = smin;
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	s->smax = smax;
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	s->area = area;
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	s->next = 0;
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	// Empty cell, add the first span.
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	if (!hf.spans[idx])
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	{
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		hf.spans[idx] = s;
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		return true;
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	}
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	rcSpan* prev = 0;
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	rcSpan* cur = hf.spans[idx];
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	// Insert and merge spans.
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	while (cur)
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	{
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		if (cur->smin > s->smax)
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		{
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			// Current span is further than the new span, break.
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			break;
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		}
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		else if (cur->smax < s->smin)
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		{
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			// Current span is before the new span advance.
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			prev = cur;
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			cur = cur->next;
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		}
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		else
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		{
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			// Merge spans.
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			if (cur->smin < s->smin)
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				s->smin = cur->smin;
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			if (cur->smax > s->smax)
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				s->smax = cur->smax;
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			// Merge flags.
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			if (rcAbs((int)s->smax - (int)cur->smax) <= flagMergeThr)
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				s->area = rcMax(s->area, cur->area);
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			// Remove current span.
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			rcSpan* next = cur->next;
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			freeSpan(hf, cur);
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			if (prev)
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				prev->next = next;
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			else
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				hf.spans[idx] = next;
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			cur = next;
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		}
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	}
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	// Insert new span.
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	if (prev)
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	{
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		s->next = prev->next;
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		prev->next = s;
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	}
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	else
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	{
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		s->next = hf.spans[idx];
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		hf.spans[idx] = s;
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	}
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	return true;
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}
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/// @par
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///
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/// The span addition can be set to favor flags. If the span is merged to
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/// another span and the new @p smax is within @p flagMergeThr units
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/// from the existing span, the span flags are merged.
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///
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/// @see rcHeightfield, rcSpan.
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bool rcAddSpan(rcContext* ctx, rcHeightfield& hf, const int x, const int y,
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			   const unsigned short smin, const unsigned short smax,
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			   const unsigned char area, const int flagMergeThr)
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{
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	rcAssert(ctx);
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	if (!addSpan(hf, x, y, smin, smax, area, flagMergeThr))
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	{
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		ctx->log(RC_LOG_ERROR, "rcAddSpan: Out of memory.");
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		return false;
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	}
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	return true;
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}
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// divides a convex polygons into two convex polygons on both sides of a line
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static void dividePoly(const float* in, int nin,
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					  float* out1, int* nout1,
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					  float* out2, int* nout2,
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					  float x, int axis)
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{
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	float d[12];
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	for (int i = 0; i < nin; ++i)
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		d[i] = x - in[i*3+axis];
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	int m = 0, n = 0;
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	for (int i = 0, j = nin-1; i < nin; j=i, ++i)
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	{
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		bool ina = d[j] >= 0;
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		bool inb = d[i] >= 0;
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		if (ina != inb)
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		{
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			float s = d[j] / (d[j] - d[i]);
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			out1[m*3+0] = in[j*3+0] + (in[i*3+0] - in[j*3+0])*s;
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			out1[m*3+1] = in[j*3+1] + (in[i*3+1] - in[j*3+1])*s;
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			out1[m*3+2] = in[j*3+2] + (in[i*3+2] - in[j*3+2])*s;
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			rcVcopy(out2 + n*3, out1 + m*3);
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			m++;
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			n++;
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			// add the i'th point to the right polygon. Do NOT add points that are on the dividing line
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			// since these were already added above
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			if (d[i] > 0)
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			{
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				rcVcopy(out1 + m*3, in + i*3);
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				m++;
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			}
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			else if (d[i] < 0)
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			{
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				rcVcopy(out2 + n*3, in + i*3);
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				n++;
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			}
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		}
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		else // same side
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		{
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			// add the i'th point to the right polygon. Addition is done even for points on the dividing line
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			if (d[i] >= 0)
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			{
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				rcVcopy(out1 + m*3, in + i*3);
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				m++;
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				if (d[i] != 0)
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					continue;
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			}
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			rcVcopy(out2 + n*3, in + i*3);
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			n++;
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		}
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	}
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	*nout1 = m;
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	*nout2 = n;
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}
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static bool rasterizeTri(const float* v0, const float* v1, const float* v2,
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						 const unsigned char area, rcHeightfield& hf,
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						 const float* bmin, const float* bmax,
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						 const float cs, const float ics, const float ich,
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						 const int flagMergeThr)
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{
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	const int w = hf.width;
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	const int h = hf.height;
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	float tmin[3], tmax[3];
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	const float by = bmax[1] - bmin[1];
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	// Calculate the bounding box of the triangle.
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	rcVcopy(tmin, v0);
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	rcVcopy(tmax, v0);
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	rcVmin(tmin, v1);
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	rcVmin(tmin, v2);
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	rcVmax(tmax, v1);
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	rcVmax(tmax, v2);
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	// If the triangle does not touch the bbox of the heightfield, skip the triagle.
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	if (!overlapBounds(bmin, bmax, tmin, tmax))
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		return true;
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	// Calculate the footprint of the triangle on the grid's y-axis
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	int y0 = (int)((tmin[2] - bmin[2])*ics);
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	int y1 = (int)((tmax[2] - bmin[2])*ics);
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	y0 = rcClamp(y0, 0, h-1);
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	y1 = rcClamp(y1, 0, h-1);
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	// Clip the triangle into all grid cells it touches.
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	float buf[7*3*4];
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	float *in = buf, *inrow = buf+7*3, *p1 = inrow+7*3, *p2 = p1+7*3;
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	rcVcopy(&in[0], v0);
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	rcVcopy(&in[1*3], v1);
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	rcVcopy(&in[2*3], v2);
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	int nvrow, nvIn = 3;
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	for (int y = y0; y <= y1; ++y)
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	{
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		// Clip polygon to row. Store the remaining polygon as well
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		const float cz = bmin[2] + y*cs;
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		dividePoly(in, nvIn, inrow, &nvrow, p1, &nvIn, cz+cs, 2);
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		rcSwap(in, p1);
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		if (nvrow < 3) continue;
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		// find the horizontal bounds in the row
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		float minX = inrow[0], maxX = inrow[0];
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		for (int i=1; i<nvrow; ++i)
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		{
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			if (minX > inrow[i*3])	minX = inrow[i*3];
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			if (maxX < inrow[i*3])	maxX = inrow[i*3];
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		}
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		int x0 = (int)((minX - bmin[0])*ics);
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		int x1 = (int)((maxX - bmin[0])*ics);
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		x0 = rcClamp(x0, 0, w-1);
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		x1 = rcClamp(x1, 0, w-1);
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		int nv, nv2 = nvrow;
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		for (int x = x0; x <= x1; ++x)
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		{
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			// Clip polygon to column. store the remaining polygon as well
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			const float cx = bmin[0] + x*cs;
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			dividePoly(inrow, nv2, p1, &nv, p2, &nv2, cx+cs, 0);
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			rcSwap(inrow, p2);
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			if (nv < 3) continue;
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			// Calculate min and max of the span.
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			float smin = p1[1], smax = p1[1];
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			for (int i = 1; i < nv; ++i)
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			{
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				smin = rcMin(smin, p1[i*3+1]);
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				smax = rcMax(smax, p1[i*3+1]);
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			}
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			smin -= bmin[1];
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			smax -= bmin[1];
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			// Skip the span if it is outside the heightfield bbox
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			if (smax < 0.0f) continue;
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			if (smin > by) continue;
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			// Clamp the span to the heightfield bbox.
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			if (smin < 0.0f) smin = 0;
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			if (smax > by) smax = by;
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			// Snap the span to the heightfield height grid.
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			unsigned short ismin = (unsigned short)rcClamp((int)floorf(smin * ich), 0, RC_SPAN_MAX_HEIGHT);
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			unsigned short ismax = (unsigned short)rcClamp((int)ceilf(smax * ich), (int)ismin+1, RC_SPAN_MAX_HEIGHT);
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			if (!addSpan(hf, x, y, ismin, ismax, area, flagMergeThr))
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				return false;
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		}
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	}
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	return true;
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}
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/// @par
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///
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/// No spans will be added if the triangle does not overlap the heightfield grid.
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///
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/// @see rcHeightfield
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bool rcRasterizeTriangle(rcContext* ctx, const float* v0, const float* v1, const float* v2,
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						 const unsigned char area, rcHeightfield& solid,
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						 const int flagMergeThr)
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{
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	rcAssert(ctx);
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	rcScopedTimer timer(ctx, RC_TIMER_RASTERIZE_TRIANGLES);
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	const float ics = 1.0f/solid.cs;
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	const float ich = 1.0f/solid.ch;
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	if (!rasterizeTri(v0, v1, v2, area, solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr))
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	{
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		ctx->log(RC_LOG_ERROR, "rcRasterizeTriangle: Out of memory.");
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		return false;
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	}
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	return true;
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}
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/// @par
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///
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/// Spans will only be added for triangles that overlap the heightfield grid.
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///
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/// @see rcHeightfield
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bool rcRasterizeTriangles(rcContext* ctx, const float* verts, const int /*nv*/,
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						  const int* tris, const unsigned char* areas, const int nt,
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						  rcHeightfield& solid, const int flagMergeThr)
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{
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	rcAssert(ctx);
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	rcScopedTimer timer(ctx, RC_TIMER_RASTERIZE_TRIANGLES);
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	const float ics = 1.0f/solid.cs;
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	const float ich = 1.0f/solid.ch;
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	// Rasterize triangles.
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	for (int i = 0; i < nt; ++i)
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	{
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		const float* v0 = &verts[tris[i*3+0]*3];
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		const float* v1 = &verts[tris[i*3+1]*3];
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		const float* v2 = &verts[tris[i*3+2]*3];
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		// Rasterize.
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		if (!rasterizeTri(v0, v1, v2, areas[i], solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr))
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		{
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			ctx->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
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			return false;
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		}
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	}
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	return true;
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}
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/// @par
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///
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/// Spans will only be added for triangles that overlap the heightfield grid.
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///
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/// @see rcHeightfield
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bool rcRasterizeTriangles(rcContext* ctx, const float* verts, const int /*nv*/,
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						  const unsigned short* tris, const unsigned char* areas, const int nt,
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						  rcHeightfield& solid, const int flagMergeThr)
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{
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	rcAssert(ctx);
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	rcScopedTimer timer(ctx, RC_TIMER_RASTERIZE_TRIANGLES);
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	const float ics = 1.0f/solid.cs;
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	const float ich = 1.0f/solid.ch;
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	// Rasterize triangles.
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	for (int i = 0; i < nt; ++i)
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	{
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		const float* v0 = &verts[tris[i*3+0]*3];
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		const float* v1 = &verts[tris[i*3+1]*3];
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		const float* v2 = &verts[tris[i*3+2]*3];
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		// Rasterize.
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						|
		if (!rasterizeTri(v0, v1, v2, areas[i], solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr))
 | 
						|
		{
 | 
						|
			ctx->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
 | 
						|
			return false;
 | 
						|
		}
 | 
						|
	}
 | 
						|
 | 
						|
	return true;
 | 
						|
}
 | 
						|
 | 
						|
/// @par
 | 
						|
///
 | 
						|
/// Spans will only be added for triangles that overlap the heightfield grid.
 | 
						|
///
 | 
						|
/// @see rcHeightfield
 | 
						|
bool rcRasterizeTriangles(rcContext* ctx, const float* verts, const unsigned char* areas, const int nt,
 | 
						|
						  rcHeightfield& solid, const int flagMergeThr)
 | 
						|
{
 | 
						|
	rcAssert(ctx);
 | 
						|
	
 | 
						|
	rcScopedTimer timer(ctx, RC_TIMER_RASTERIZE_TRIANGLES);
 | 
						|
	
 | 
						|
	const float ics = 1.0f/solid.cs;
 | 
						|
	const float ich = 1.0f/solid.ch;
 | 
						|
	// Rasterize triangles.
 | 
						|
	for (int i = 0; i < nt; ++i)
 | 
						|
	{
 | 
						|
		const float* v0 = &verts[(i*3+0)*3];
 | 
						|
		const float* v1 = &verts[(i*3+1)*3];
 | 
						|
		const float* v2 = &verts[(i*3+2)*3];
 | 
						|
		// Rasterize.
 | 
						|
		if (!rasterizeTri(v0, v1, v2, areas[i], solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr))
 | 
						|
		{
 | 
						|
			ctx->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
 | 
						|
			return false;
 | 
						|
		}
 | 
						|
	}
 | 
						|
 | 
						|
	return true;
 | 
						|
}
 |