axmol/3rdparty/poly2tri/sweep/advancing_front.cc

111 lines
3.1 KiB
C++

/*
* Poly2Tri Copyright (c) 2009-2018, Poly2Tri Contributors
* https://github.com/jhasse/poly2tri
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "advancing_front.h"
#include <cassert>
namespace p2t {
AdvancingFront::AdvancingFront(Node& head, Node& tail)
{
head_ = &head;
tail_ = &tail;
search_node_ = &head;
}
Node* AdvancingFront::LocateNode(double x)
{
Node* node = search_node_;
if (x < node->value) {
while ((node = node->prev) != nullptr) {
if (x >= node->value) {
search_node_ = node;
return node;
}
}
} else {
while ((node = node->next) != nullptr) {
if (x < node->value) {
search_node_ = node->prev;
return node->prev;
}
}
}
return nullptr;
}
Node* AdvancingFront::FindSearchNode(double x)
{
(void)x; // suppress compiler warnings "unused parameter 'x'"
// TODO: implement BST index
return search_node_;
}
Node* AdvancingFront::LocatePoint(const Point* point)
{
const double px = point->x;
Node* node = FindSearchNode(px);
const double nx = node->point->x;
if (px == nx) {
if (point != node->point) {
// We might have two nodes with same x value for a short time
if (point == node->prev->point) {
node = node->prev;
} else if (point == node->next->point) {
node = node->next;
} else {
assert(0);
}
}
} else if (px < nx) {
while ((node = node->prev) != nullptr) {
if (point == node->point) {
break;
}
}
} else {
while ((node = node->next) != nullptr) {
if (point == node->point)
break;
}
}
if(node) search_node_ = node;
return node;
}
AdvancingFront::~AdvancingFront()
{
}
} // namespace p2t