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Triangle::NeighborAcross to return a pointer 

Same as Triangle::NeighborCW and Triangle::NeighborCCW
This commit is contained in:
Pierre Dejoue 2020-10-25 17:32:28 +01:00
parent 35b2fa916a
commit 1054475eeb
4 changed files with 50 additions and 47 deletions
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28
poly2tri/common/shapes.cc
View File

@ -243,6 +243,17 @@ Point* Triangle::PointCCW(const Point& point)
return nullptr;
}
// The neighbor across to given point
Triangle* Triangle::NeighborAcross(const Point& point)
{
if (&point == points_[0]) {
return neighbors_[0];
} else if (&point == points_[1]) {
return neighbors_[1];
}
return neighbors_[2];
}
// The neighbor clockwise to given point
Triangle* Triangle::NeighborCW(const Point& point)
{
@ -349,23 +360,6 @@ void Triangle::SetDelunayEdgeCW(const Point& p, bool e)
}
}
// The neighbor across to given point
Triangle& Triangle::NeighborAcross(const Point& opoint)
{
Triangle* neighbor = nullptr;
if (&opoint == points_[0]) {
neighbor = neighbors_[0];
} else if (&opoint == points_[1]) {
neighbor = neighbors_[1];
} else {
neighbor = neighbors_[2];
}
if (neighbor == nullptr) {
throw std::runtime_error("NeighborAcross - null neighbor");
}
return *neighbor;
}
void Triangle::DebugPrint()
{
std::cout << *points_[0] << " " << *points_[1] << " " << *points_[2] << std::endl;

3
poly2tri/common/shapes.h
View File

@ -176,6 +176,7 @@ void MarkConstrainedEdge(Point* p, Point* q);
int Index(const Point* p);
int EdgeIndex(const Point* p1, const Point* p2);
Triangle* NeighborAcross(const Point& point);
Triangle* NeighborCW(const Point& point);
Triangle* NeighborCCW(const Point& point);
bool GetConstrainedEdgeCCW(const Point& p);
@ -203,8 +204,6 @@ void ClearDelunayEdges();
inline bool IsInterior();
inline void IsInterior(bool b);
Triangle& NeighborAcross(const Point& opoint);
void DebugPrint();
bool CircumcicleContains(const Point&) const;

58
poly2tri/sweep/sweep.cc
View File

@ -108,6 +108,9 @@ void Sweep::EdgeEvent(SweepContext& tcx, Edge* edge, Node* node)
void Sweep::EdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* triangle, Point& point)
{
if (triangle == nullptr) {
throw std::runtime_error("EdgeEvent - null triangle");
}
if (IsEdgeSideOfTriangle(*triangle, ep, eq)) {
return;
}
@ -115,13 +118,13 @@ void Sweep::EdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* triangl
Point* p1 = triangle->PointCCW(point);
Orientation o1 = Orient2d(eq, *p1, ep);
if (o1 == COLLINEAR) {
if( triangle->Contains(&eq, p1)) {
triangle->MarkConstrainedEdge(&eq, p1 );
if (triangle->Contains(&eq, p1)) {
triangle->MarkConstrainedEdge(&eq, p1);
// We are modifying the constraint maybe it would be better to
// not change the given constraint and just keep a variable for the new constraint
tcx.edge_event.constrained_edge->q = p1;
triangle = &triangle->NeighborAcross(point);
EdgeEvent( tcx, ep, *p1, triangle, *p1 );
triangle = triangle->NeighborAcross(point);
EdgeEvent(tcx, ep, *p1, triangle, *p1);
} else {
throw std::runtime_error("EdgeEvent - collinear points not supported");
}
@ -131,13 +134,13 @@ void Sweep::EdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* triangl
Point* p2 = triangle->PointCW(point);
Orientation o2 = Orient2d(eq, *p2, ep);
if (o2 == COLLINEAR) {
if( triangle->Contains(&eq, p2)) {
triangle->MarkConstrainedEdge(&eq, p2 );
if (triangle->Contains(&eq, p2)) {
triangle->MarkConstrainedEdge(&eq, p2);
// We are modifying the constraint maybe it would be better to
// not change the given constraint and just keep a variable for the new constraint
tcx.edge_event.constrained_edge->q = p2;
triangle = &triangle->NeighborAcross(point);
EdgeEvent( tcx, ep, *p2, triangle, *p2 );
triangle = triangle->NeighborAcross(point);
EdgeEvent(tcx, ep, *p2, triangle, *p2);
} else {
throw std::runtime_error("EdgeEvent - collinear points not supported");
}
@ -149,12 +152,13 @@ void Sweep::EdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* triangl
// that will cross edge
if (o1 == CW) {
triangle = triangle->NeighborCCW(point);
} else{
} else {
triangle = triangle->NeighborCW(point);
}
EdgeEvent(tcx, ep, eq, triangle, point);
} else {
// This triangle crosses constraint so lets flippin start!
assert(triangle);
FlipEdgeEvent(tcx, ep, eq, triangle, point);
}
}
@ -215,7 +219,6 @@ void Sweep::Fill(SweepContext& tcx, Node& node)
if (!Legalize(tcx, *triangle)) {
tcx.MapTriangleToNodes(*triangle);
}
}
void Sweep::FillAdvancingFront(SweepContext& tcx, Node& n)
@ -293,7 +296,7 @@ double Sweep::Angle(const Point* origin, const Point* pa, const Point* pb) const
*/
const double px = origin->x;
const double py = origin->y;
const double ax = pa->x- px;
const double ax = pa->x - px;
const double ay = pa->y - py;
const double bx = pb->x - px;
const double by = pb->y - py;
@ -586,7 +589,7 @@ void Sweep::FillRightBelowEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
if (Orient2d(*node.point, *node.next->point, *node.next->next->point) == CCW) {
// Concave
FillRightConcaveEdgeEvent(tcx, edge, node);
} else{
} else {
// Convex
FillRightConvexEdgeEvent(tcx, edge, node);
// Retry this one
@ -610,7 +613,6 @@ void Sweep::FillRightConcaveEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
}
}
}
}
void Sweep::FillRightConvexEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
@ -619,13 +621,13 @@ void Sweep::FillRightConvexEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
if (Orient2d(*node.next->point, *node.next->next->point, *node.next->next->next->point) == CCW) {
// Concave
FillRightConcaveEdgeEvent(tcx, edge, *node.next);
} else{
} else {
// Convex
// Next above or below edge?
if (Orient2d(*edge->q, *node.next->next->point, *edge->p) == CCW) {
// Below
FillRightConvexEdgeEvent(tcx, edge, *node.next);
} else{
} else {
// Above
}
}
@ -664,13 +666,13 @@ void Sweep::FillLeftConvexEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
if (Orient2d(*node.prev->point, *node.prev->prev->point, *node.prev->prev->prev->point) == CW) {
// Concave
FillLeftConcaveEdgeEvent(tcx, edge, *node.prev);
} else{
} else {
// Convex
// Next above or below edge?
if (Orient2d(*edge->q, *node.prev->prev->point, *edge->p) == CW) {
// Below
FillLeftConvexEdgeEvent(tcx, edge, *node.prev);
} else{
} else {
// Above
}
}
@ -686,17 +688,22 @@ void Sweep::FillLeftConcaveEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
if (Orient2d(*node.point, *node.prev->point, *node.prev->prev->point) == CW) {
// Next is concave
FillLeftConcaveEdgeEvent(tcx, edge, node);
} else{
} else {
// Next is convex
}
}
}
}
void Sweep::FlipEdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* t, Point& p)
{
Triangle& ot = t->NeighborAcross(p);
assert(t);
Triangle* ot_ptr = t->NeighborAcross(p);
if (ot_ptr == nullptr)
{
throw std::runtime_error("FlipEdgeEvent - null neighbor across");
}
Triangle& ot = *ot_ptr;
Point& op = *ot.OppositePoint(*t, p);
if (InScanArea(p, *t->PointCCW(p), *t->PointCW(p), op)) {
@ -762,7 +769,11 @@ Point& Sweep::NextFlipPoint(Point& ep, Point& eq, Triangle& ot, Point& op)
void Sweep::FlipScanEdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle& flip_triangle,
Triangle& t, Point& p)
{
Triangle& ot = t.NeighborAcross(p);
Triangle* ot_ptr = t.NeighborAcross(p);
if (ot_ptr == nullptr) {
throw std::runtime_error("FlipScanEdgeEvent - null neighbor across");
}
Triangle& ot = *ot_ptr;
Point& op = *ot.OppositePoint(t, p);
if (InScanArea(eq, *flip_triangle.PointCCW(eq), *flip_triangle.PointCW(eq), op)) {
@ -775,7 +786,7 @@ void Sweep::FlipScanEdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle&
// also need to set a new flip_triangle first
// Turns out at first glance that this is somewhat complicated
// so it will have to wait.
} else{
} else {
Point& newP = NextFlipPoint(ep, eq, ot, op);
FlipScanEdgeEvent(tcx, ep, eq, flip_triangle, ot, newP);
}
@ -790,5 +801,4 @@ Sweep::~Sweep() {
}
}
} // namespace p2t

8
unittest/main.cpp
View File

@ -21,7 +21,7 @@ BOOST_AUTO_TEST_CASE(BasicTest)
new p2t::Point(1, 1),
};
p2t::CDT cdt{ polyline };
cdt.Triangulate();
BOOST_CHECK_NO_THROW(cdt.Triangulate());
const auto result = cdt.GetTriangles();
BOOST_REQUIRE_EQUAL(result.size(), 1);
BOOST_CHECK_EQUAL(*result[0]->GetPoint(0), *polyline[0]);
@ -38,7 +38,7 @@ BOOST_AUTO_TEST_CASE(QuadTest)
std::vector<p2t::Point*> polyline{ new p2t::Point(0, 0), new p2t::Point(0, 1),
new p2t::Point(1, 1), new p2t::Point(1, 0) };
p2t::CDT cdt{ polyline };
cdt.Triangulate();
BOOST_CHECK_NO_THROW(cdt.Triangulate());
const auto result = cdt.GetTriangles();
BOOST_REQUIRE_EQUAL(result.size(), 2);
BOOST_CHECK(p2t::IsDelaunay(result));
@ -47,7 +47,7 @@ BOOST_AUTO_TEST_CASE(QuadTest)
}
}
BOOST_AUTO_TEST_CASE(QuadTestThrow)
BOOST_AUTO_TEST_CASE(NarrowQuadTest)
{
// Very narrow quad that demonstrates a failure case during triangulation
std::vector<p2t::Point*> polyline {
@ -92,7 +92,7 @@ BOOST_AUTO_TEST_CASE(TestbedFilesTest)
polyline.push_back(new p2t::Point(x, y));
}
p2t::CDT cdt{ polyline };
cdt.Triangulate();
BOOST_CHECK_NO_THROW(cdt.Triangulate());
const auto result = cdt.GetTriangles();
BOOST_REQUIRE(result.size() * 3 > polyline.size());
BOOST_CHECK_MESSAGE(p2t::IsDelaunay(result), filename + std::to_string(polyline.size()));