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/*
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* This file is a part of the C port of the Poly2Tri library
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* Porting to C done by (c) Barak Itkin <lightningismyname@gmail.com>
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* http://code.google.com/p/poly2tri-c/
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*
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* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
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* http://code.google.com/p/poly2tri/
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*
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* * Neither the name of Poly2Tri nor the names of its contributors may be
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* used to endorse or promote products derived from this software without specific
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* prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* Sweep-line, Constrained Delauney Triangulation (CDT) See: Domiter, V. and
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* Zalik, B.(2008)'Sweep-line algorithm for constrained Delaunay triangulation',
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* International Journal of Geographical Information Science
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*
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* "FlipScan" Constrained Edge Algorithm invented by Thomas �hl�n, thahlen@gmail.com
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*/
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#ifndef __P2TC_P2T_SWEEP_H__
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#define __P2TC_P2T_SWEEP_H__
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#include "../common/poly2tri-private.h"
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#include "../common/shapes.h"
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struct Sweep_
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{
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/* private: */
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P2tNodePtrArray nodes_;
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};
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void p2t_sweep_init (P2tSweep* THIS);
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P2tSweep* p2t_sweep_new ();
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/**
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* Destructor - clean up memory
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*/
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void p2t_sweep_destroy (P2tSweep* THIS);
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void p2t_sweep_free (P2tSweep* THIS);
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/**
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* Triangulate
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*
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* @param tcx
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*/
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void p2t_sweep_triangulate (P2tSweep *THIS, P2tSweepContext *tcx);
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/**
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* Start sweeping the Y-sorted point set from bottom to top
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*
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* @param tcx
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*/
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void p2t_sweep_sweep_points (P2tSweep *THIS, P2tSweepContext *tcx);
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/**
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* Find closes node to the left of the new point and
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* create a new triangle. If needed new holes and basins
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* will be filled to.
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*
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* @param tcx
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* @param point
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* @return
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*/
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P2tNode* p2t_sweep_point_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tPoint* point);
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/**
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*
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*
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* @param tcx
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* @param edge
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* @param node
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*/
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void p2t_sweep_edge_event_ed_n (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_edge_event_pt_pt_tr_pt (P2tSweep *THIS, P2tSweepContext *tcx, P2tPoint* ep, P2tPoint* eq, P2tTriangle* triangle, P2tPoint* point);
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/**
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* Creates a new front triangle and legalize it
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*
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* @param tcx
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* @param point
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* @param node
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* @return
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*/
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P2tNode* p2t_sweep_new_front_triangle (P2tSweep *THIS, P2tSweepContext *tcx, P2tPoint* point, P2tNode* node);
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/**
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* Adds a triangle to the advancing front to fill a hole.
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* @param tcx
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* @param node - middle node, that is the bottom of the hole
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*/
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void p2t_sweep_fill (P2tSweep *THIS, P2tSweepContext *tcx, P2tNode* node);
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/**
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* Returns true if triangle was legalized
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*/
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gboolean p2t_sweep_legalize (P2tSweep *THIS, P2tSweepContext *tcx, P2tTriangle *t);
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/**
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* <b>Requirement</b>:<br>
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* 1. a,b and c form a triangle.<br>
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* 2. a and d is know to be on opposite side of bc<br>
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* <pre>
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* a
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* +
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* / \
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* / \
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* b/ \c
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* +-------+
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* / d \
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* / \
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* </pre>
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* <b>Fact</b>: d has to be in area B to have a chance to be inside the circle formed by
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* a,b and c<br>
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* d is outside B if orient2d(a,b,d) or orient2d(c,a,d) is CW<br>
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* This preknowledge gives us a way to optimize the incircle test
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* @param a - triangle point, opposite d
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* @param b - triangle point
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* @param c - triangle point
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* @param d - point opposite a
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* @return true if d is inside circle, false if on circle edge
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*/
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gboolean p2t_sweep_incircle (P2tSweep *THIS, P2tPoint* pa, P2tPoint* pb, P2tPoint* pc, P2tPoint* pd);
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/**
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* Rotates a triangle pair one vertex CW
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*<pre>
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* n2 n2
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* P +-----+ P +-----+
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* | t /| |\ t |
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* | / | | \ |
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* n1| / |n3 n1| \ |n3
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* | / | after CW | \ |
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* |/ oT | | oT \|
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* +-----+ oP +-----+
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* n4 n4
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* </pre>
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*/
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void p2t_sweep_rotate_triangle_pair (P2tSweep *THIS, P2tTriangle *t, P2tPoint* p, P2tTriangle *ot, P2tPoint* op);
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/**
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* Fills holes in the Advancing Front
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*
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*
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* @param tcx
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* @param n
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*/
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void p2t_sweep_fill_advancingfront (P2tSweep *THIS, P2tSweepContext *tcx, P2tNode* n);
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/* Decision-making about when to Fill hole.
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* Contributed by ToolmakerSteve2 */
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gboolean p2t_sweep_large_hole_dont_fill (P2tSweep* THIS, P2tNode* node);
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gboolean p2t_sweep_angle_exceeds_90_degrees (P2tSweep* THIS, P2tPoint* origin, P2tPoint* pa, P2tPoint* pb);
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gboolean p2t_sweep_angle_exceeds_plus_90_degrees_or_is_negative (P2tSweep* THIS, P2tPoint* origin, P2tPoint* pa, P2tPoint* pb);
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gdouble p2t_sweep_angle (P2tSweep* THIS, P2tPoint* origin, P2tPoint* pa, P2tPoint* pb);
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/**
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*
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* @param node - middle node
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* @return the angle between 3 front nodes
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*/
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double p2t_sweep_hole_angle (P2tSweep *THIS, P2tNode* node);
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/**
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* The basin angle is decided against the horizontal line [1,0]
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*/
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double p2t_sweep_basin_angle (P2tSweep *THIS, P2tNode* node);
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/**
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* Fills a basin that has formed on the Advancing Front to the right
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* of given node.<br>
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* First we decide a left,bottom and right node that forms the
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* boundaries of the basin. Then we do a reqursive fill.
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*
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* @param tcx
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* @param node - starting node, this or next node will be left node
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*/
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void p2t_sweep_fill_basin (P2tSweep *THIS, P2tSweepContext *tcx, P2tNode* node);
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/**
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* Recursive algorithm to fill a Basin with triangles
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*
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* @param tcx
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* @param node - bottom_node
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* @param cnt - counter used to alternate on even and odd numbers
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*/
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void p2t_sweep_fill_basin_req (P2tSweep *THIS, P2tSweepContext *tcx, P2tNode* node);
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gboolean p2t_sweep_is_shallow (P2tSweep *THIS, P2tSweepContext *tcx, P2tNode* node);
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gboolean p2t_sweep_is_edge_side_of_triangle (P2tSweep *THIS, P2tTriangle *triangle, P2tPoint* ep, P2tPoint* eq);
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void p2t_sweep_fill_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_fill_right_above_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_fill_right_below_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_fill_right_concave_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_fill_right_convex_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_fill_left_above_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_fill_left_below_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_fill_left_concave_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_fill_left_convex_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tEdge* edge, P2tNode* node);
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void p2t_sweep_flip_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tPoint* ep, P2tPoint* eq, P2tTriangle* t, P2tPoint* p);
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/**
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* After a flip we have two triangles and know that only one will still be
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* intersecting the edge. So decide which to contiune with and legalize the other
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*
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* @param tcx
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* @param o - should be the result of an orient2d( eq, op, ep )
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* @param t - triangle 1
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* @param ot - triangle 2
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* @param p - a point shared by both triangles
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* @param op - another point shared by both triangles
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* @return returns the triangle still intersecting the edge
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*/
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P2tTriangle* p2t_sweep_next_flip_triangle (P2tSweep *THIS, P2tSweepContext *tcx, int o, P2tTriangle *t, P2tTriangle *ot, P2tPoint* p, P2tPoint* op);
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/**
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* When we need to traverse from one triangle to the next we need
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* the point in current triangle that is the opposite point to the next
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* triangle.
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*
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* @param ep
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* @param eq
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* @param ot
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* @param op
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* @return
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*/
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P2tPoint* p2t_sweep_next_flip_point (P2tSweep *THIS, P2tPoint* ep, P2tPoint* eq, P2tTriangle *ot, P2tPoint* op);
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/**
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* Scan part of the FlipScan algorithm<br>
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* When a triangle pair isn't flippable we will scan for the next
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* point that is inside the flip triangle scan area. When found
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* we generate a new flipEdgeEvent
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*
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* @param tcx
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* @param ep - last point on the edge we are traversing
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* @param eq - first point on the edge we are traversing
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* @param flipTriangle - the current triangle sharing the point eq with edge
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* @param t
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* @param p
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*/
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void p2t_sweep_flip_scan_edge_event (P2tSweep *THIS, P2tSweepContext *tcx, P2tPoint* ep, P2tPoint* eq, P2tTriangle *flip_triangle, P2tTriangle *t, P2tPoint* p);
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void p2t_sweep_finalization_polygon (P2tSweep *THIS, P2tSweepContext *tcx);
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#endif
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