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#include "geoData.h"
#include "collections.h"
#include "geometricPlane.h"
#include <fstream>
#include <glm/gtx/intersect.hpp>
#include <maths.h>
#include <set>
GeoData
GeoData::loadFromAsciiGrid(const std::filesystem::path & input)
{
size_t ncols = 0, nrows = 0, xllcorner = 0, yllcorner = 0, cellsize = 0;
std::map<std::string_view, size_t *> properties {
{"ncols", &ncols},
{"nrows", &nrows},
{"xllcorner", &xllcorner},
{"yllcorner", &yllcorner},
{"cellsize", &cellsize},
};
std::ifstream f {input};
while (!properties.empty()) {
std::string property;
f >> property;
f >> *properties.at(property);
properties.erase(property);
}
xllcorner *= 1000;
yllcorner *= 1000;
cellsize *= 1000;
std::vector<VertexHandle> vertices;
vertices.reserve(ncols * nrows);
GeoData mesh;
mesh.lowerExtent = {xllcorner, yllcorner, std::numeric_limits<GlobalDistance>::max()};
mesh.upperExtent = {xllcorner + (cellsize * (ncols - 1)), yllcorner + (cellsize * (nrows - 1)),
std::numeric_limits<GlobalDistance>::min()};
for (size_t row = 0; row < nrows; ++row) {
for (size_t col = 0; col < ncols; ++col) {
float heightf = 0;
f >> heightf;
const auto height = static_cast<GlobalDistance>(std::round(heightf * 1000.F));
mesh.upperExtent.z = std::max(mesh.upperExtent.z, height);
mesh.lowerExtent.z = std::min(mesh.lowerExtent.z, height);
vertices.push_back(mesh.add_vertex({xllcorner + (col * cellsize), yllcorner + (row * cellsize), height}));
}
}
if (!f.good()) {
throw std::runtime_error("Couldn't read terrain file");
}
for (size_t row = 1; row < nrows; ++row) {
for (size_t col = 1; col < ncols; ++col) {
mesh.add_face({
vertices[ncols * (row - 1) + (col - 1)],
vertices[ncols * (row - 0) + (col - 0)],
vertices[ncols * (row - 0) + (col - 1)],
});
mesh.add_face({
vertices[ncols * (row - 1) + (col - 1)],
vertices[ncols * (row - 1) + (col - 0)],
vertices[ncols * (row - 0) + (col - 0)],
});
}
}
mesh.update_vertex_normals_only();
return mesh;
};
template<typename T> constexpr static T GRID_SIZE = 10'000;
GeoData
GeoData::createFlat(GlobalPosition2D lower, GlobalPosition2D upper, GlobalDistance h)
{
GeoData mesh;
mesh.lowerExtent = {lower, h};
mesh.upperExtent = {upper, h};
std::vector<VertexHandle> vertices;
for (GlobalDistance row = lower.x; row < upper.x; row += GRID_SIZE<GlobalDistance>) {
for (GlobalDistance col = lower.y; col < upper.y; col += GRID_SIZE<GlobalDistance>) {
vertices.push_back(mesh.add_vertex({col, row, h}));
}
}
const auto nrows = static_cast<size_t>(std::ceil(float(upper.x - lower.x) / GRID_SIZE<RelativeDistance>));
const auto ncols = static_cast<size_t>(std::ceil(float(upper.y - lower.y) / GRID_SIZE<RelativeDistance>));
for (size_t row = 1; row < nrows; ++row) {
for (size_t col = 1; col < ncols; ++col) {
mesh.add_face({
vertices[ncols * (row - 1) + (col - 1)],
vertices[ncols * (row - 0) + (col - 0)],
vertices[ncols * (row - 0) + (col - 1)],
});
mesh.add_face({
vertices[ncols * (row - 1) + (col - 1)],
vertices[ncols * (row - 1) + (col - 0)],
vertices[ncols * (row - 0) + (col - 0)],
});
}
}
mesh.update_vertex_normals_only();
return mesh;
}
OpenMesh::FaceHandle
GeoData::findPoint(GlobalPosition2D p) const
{
return findPoint(p, *faces_begin());
}
GeoData::PointFace::PointFace(const GlobalPosition2D p, const GeoData * mesh) :
PointFace {p, mesh, *mesh->faces_begin()}
{
}
GeoData::PointFace::PointFace(const GlobalPosition2D p, const GeoData * mesh, FaceHandle start) :
PointFace {p, mesh->findPoint(p, start)}
{
}
GeoData::FaceHandle
GeoData::PointFace::face(const GeoData * mesh, FaceHandle start) const
{
if (_face.is_valid()) {
assert(mesh->triangleContainsPoint(point, _face));
return _face;
}
else {
return (_face = mesh->findPoint(point, start));
}
}
GeoData::FaceHandle
GeoData::PointFace::face(const GeoData * mesh) const
{
return face(mesh, *mesh->faces_begin());
}
namespace {
template<template<typename> typename Op>
[[nodiscard]] constexpr inline auto
pointLineOp(const GlobalPosition2D p, const GlobalPosition2D e1, const GlobalPosition2D e2)
{
return Op {}(CalcDistance(e2.x - e1.x) * CalcDistance(p.y - e1.y),
CalcDistance(e2.y - e1.y) * CalcDistance(p.x - e1.x));
}
constexpr auto pointLeftOfLine = pointLineOp<std::greater>;
constexpr auto pointLeftOfOrOnLine = pointLineOp<std::greater_equal>;
static_assert(pointLeftOfLine({1, 2}, {1, 1}, {2, 2}));
static_assert(pointLeftOfLine({2, 1}, {2, 2}, {1, 1}));
static_assert(pointLeftOfLine({2, 2}, {1, 2}, {2, 1}));
static_assert(pointLeftOfLine({1, 1}, {2, 1}, {1, 2}));
static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310000000, 490000000}, {310050000, 490050000}));
static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310050000, 490050000}, {310000000, 490050000}));
static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310000000, 490050000}, {310000000, 490000000}));
[[nodiscard]] constexpr inline bool
linesCross(
const GlobalPosition2D a1, const GlobalPosition2D a2, const GlobalPosition2D b1, const GlobalPosition2D b2)
{
return (pointLeftOfLine(a2, b1, b2) == pointLeftOfLine(a1, b2, b1))
&& (pointLeftOfLine(b1, a1, a2) == pointLeftOfLine(b2, a2, a1));
}
static_assert(linesCross({1, 1}, {2, 2}, {1, 2}, {2, 1}));
static_assert(linesCross({2, 2}, {1, 1}, {1, 2}, {2, 1}));
[[nodiscard]] constexpr inline bool
linesCrossLtR(
const GlobalPosition2D a1, const GlobalPosition2D a2, const GlobalPosition2D b1, const GlobalPosition2D b2)
{
return pointLeftOfLine(a2, b1, b2) && pointLeftOfLine(a1, b2, b1) && pointLeftOfLine(b1, a1, a2)
&& pointLeftOfLine(b2, a2, a1);
}
static_assert(linesCrossLtR({1, 1}, {2, 2}, {1, 2}, {2, 1}));
static_assert(!linesCrossLtR({2, 2}, {1, 1}, {1, 2}, {2, 1}));
constexpr GlobalPosition3D
positionOnTriangle(const GlobalPosition2D point, const GeoData::Triangle<3> & t)
{
const CalcPosition3D a = t[1] - t[0], b = t[2] - t[0];
const auto n = crossProduct(a, b);
return {point, ((n.x * t[0].x) + (n.y * t[0].y) + (n.z * t[0].z) - (n.x * point.x) - (n.y * point.y)) / n.z};
}
static_assert(positionOnTriangle({7, -2}, {{1, 2, 3}, {1, 0, 1}, {-2, 1, 0}}) == GlobalPosition3D {7, -2, 3});
}
OpenMesh::FaceHandle
GeoData::findPoint(GlobalPosition2D p, OpenMesh::FaceHandle f) const
{
while (f.is_valid() && !triangleContainsPoint(p, triangle<2>(f))) {
for (auto next = cfh_iter(f); next.is_valid(); ++next) {
f = opposite_face_handle(*next);
if (f.is_valid()) {
const auto e1 = point(to_vertex_handle(*next));
const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(*next)));
if (pointLeftOfLine(p, e1, e2)) {
break;
}
}
f.reset();
}
}
return f;
}
GlobalPosition3D
GeoData::positionAt(const PointFace & p) const
{
return positionOnTriangle(p.point, triangle<3>(p.face(this)));
}
[[nodiscard]] GeoData::IntersectionResult
GeoData::intersectRay(const Ray<GlobalPosition3D> & ray) const
{
return intersectRay(ray, findPoint(ray.start));
}
[[nodiscard]] GeoData::IntersectionResult
GeoData::intersectRay(const Ray<GlobalPosition3D> & ray, FaceHandle face) const
{
GeoData::IntersectionResult out;
walkUntil(PointFace {ray.start, face},
ray.start.xy() + (ray.direction.xy() * RelativePosition2D(upperExtent.xy() - lowerExtent.xy())),
[&out, &ray, this](FaceHandle face) {
BaryPosition bari {};
RelativeDistance dist {};
const auto t = triangle<3>(face);
if (ray.intersectTriangle(t.x, t.y, t.z, bari, dist)) {
out.emplace(t * bari, face);
return true;
}
return false;
});
return out;
}
void
GeoData::walk(const PointFace & from, const GlobalPosition2D to, const std::function<void(FaceHandle)> & op) const
{
walkUntil(from, to, [&op](const auto & fh) {
op(fh);
return false;
});
}
void
GeoData::walkUntil(const PointFace & from, const GlobalPosition2D to, const std::function<bool(FaceHandle)> & op) const
{
auto f = from.face(this);
if (!f.is_valid()) {
const auto entryEdge = findEntry(from.point, to);
if (!entryEdge.is_valid()) {
return;
}
f = opposite_face_handle(entryEdge);
}
FaceHandle previousFace;
while (f.is_valid() && !op(f)) {
for (auto next = cfh_iter(f); next.is_valid(); ++next) {
f = opposite_face_handle(*next);
if (f.is_valid() && f != previousFace) {
const auto e1 = point(to_vertex_handle(*next));
const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(*next)));
if (linesCrossLtR(from.point, to, e1, e2)) {
previousFace = f;
break;
}
}
f.reset();
}
}
}
void
GeoData::boundaryWalk(const std::function<void(HalfedgeHandle)> & op) const
{
boundaryWalk(op, findBoundaryStart());
}
void
GeoData::boundaryWalk(const std::function<void(HalfedgeHandle)> & op, HalfedgeHandle start) const
{
assert(is_boundary(start));
boundaryWalkUntil(
[&op](auto heh) {
op(heh);
return false;
},
start);
}
void
GeoData::boundaryWalkUntil(const std::function<bool(HalfedgeHandle)> & op) const
{
boundaryWalkUntil(op, findBoundaryStart());
}
void
GeoData::boundaryWalkUntil(const std::function<bool(HalfedgeHandle)> & op, HalfedgeHandle start) const
{
assert(is_boundary(start));
if (!op(start)) {
for (auto heh = next_halfedge_handle(start); heh != start; heh = next_halfedge_handle(heh)) {
if (op(heh)) {
break;
}
}
}
}
GeoData::HalfedgeHandle
GeoData::findEntry(const GlobalPosition2D from, const GlobalPosition2D to) const
{
HalfedgeHandle entry;
boundaryWalkUntil([this, from, to, &entry](auto he) {
const auto e1 = point(to_vertex_handle(he));
const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(he)));
if (linesCrossLtR(from, to, e1, e2)) {
entry = he;
return true;
}
return false;
});
return entry;
}
bool
GeoData::triangleContainsPoint(const GlobalPosition2D p, const Triangle<2> & t)
{
return pointLeftOfOrOnLine(p, t[0], t[1]) && pointLeftOfOrOnLine(p, t[1], t[2])
&& pointLeftOfOrOnLine(p, t[2], t[0]);
}
bool
GeoData::triangleContainsPoint(const GlobalPosition2D p, FaceHandle face) const
{
return triangleContainsPoint(p, triangle<2>(face));
}
GeoData::HalfedgeHandle
GeoData::findBoundaryStart() const
{
return *std::find_if(halfedges_begin(), halfedges_end(), [this](const auto heh) {
return is_boundary(heh);
});
}
void
GeoData::update_vertex_normals_only()
{
for (auto vh : all_vertices()) {
Normal3D n;
calc_vertex_normal_correct(vh, n);
this->set_normal(vh, glm::normalize(n));
}
}
bool
GeoData::triangleOverlapsTriangle(const Triangle<2> & a, const Triangle<2> & b)
{
return triangleContainsPoint(a.x, b) || triangleContainsPoint(a.y, b) || triangleContainsPoint(a.z, b)
|| triangleContainsPoint(b.x, a) || triangleContainsPoint(b.y, a) || triangleContainsPoint(b.z, a)
|| linesCross(a.x, a.y, b.x, b.y) || linesCross(a.x, a.y, b.y, b.z) || linesCross(a.x, a.y, b.z, b.x)
|| linesCross(a.y, a.z, b.x, b.y) || linesCross(a.y, a.z, b.y, b.z) || linesCross(a.y, a.z, b.z, b.x)
|| linesCross(a.z, a.x, b.x, b.y) || linesCross(a.z, a.x, b.y, b.z) || linesCross(a.z, a.x, b.z, b.x);
}
bool
GeoData::triangleContainsTriangle(const Triangle<2> & a, const Triangle<2> & b)
{
return triangleContainsPoint(a.x, b) && triangleContainsPoint(a.y, b) && triangleContainsPoint(a.z, b);
}
void
GeoData::setHeights(const std::span<const GlobalPosition3D> triangleStrip)
{
static const RelativeDistance MAX_SLOPE = 1.5F;
if (triangleStrip.size() < 3) {
return;
}
// Create new vertices
std::vector<VertexHandle> newVerts;
newVerts.reserve(newVerts.size());
std::transform(triangleStrip.begin(), triangleStrip.end(), std::back_inserter(newVerts), [this](const auto tsVert) {
return add_vertex(tsVert);
});
// Create new faces
std::vector<FaceHandle> newFaces;
newFaces.reserve(newVerts.size() - 2);
std::transform(
strip_begin(newVerts), strip_end(newVerts), std::back_inserter(newFaces), [this](const auto & newVert) {
const auto [a, b, c] = newVert;
auto faceHandle = add_face(a, b, c);
return faceHandle;
});
std::vector<HalfedgeHandle> boundary;
boundaryWalk(
[out = std::back_inserter(boundary)](const auto boundaryHeh) mutable {
out = boundaryHeh;
},
*voh_begin(newVerts.front()));
// Extrude corners
struct Extrusion {
VertexHandle boundaryVertex, extrusionVertex;
Direction3D lowerLimit, upperLimit;
};
std::vector<Extrusion> extrusionExtents;
std::for_each(boundary.begin(), boundary.end(), [this, &extrusionExtents](const auto boundaryHeh) {
const auto vectorNormal = []<typename T, glm::qualifier Q>(const glm::vec<2, T, Q> & v) -> glm::vec<2, T, Q> {
return {-v.y, v.x};
};
const auto boundaryVertex = from_vertex_handle(boundaryHeh);
const auto nextBoundaryVertex = to_vertex_handle(boundaryHeh);
const auto p0 = point(from_vertex_handle(prev_halfedge_handle(boundaryHeh)));
const auto p1 = point(boundaryVertex);
const auto p2 = point(nextBoundaryVertex);
const auto e0 = glm::normalize(vectorNormal(RelativePosition2D(p1 - p0)));
const auto e1 = glm::normalize(vectorNormal(RelativePosition2D(p2 - p1)));
const auto doExtrusion = [this](VertexHandle & extrusionVertex, Direction2D direction,
GlobalPosition3D boundaryVertex, RelativeDistance vert) {
const auto extrusionDir = glm::normalize(direction || vert);
if (!extrusionVertex.is_valid()) {
if (const auto intersect = intersectRay({boundaryVertex, extrusionDir})) {
auto splitVertex = split(intersect->second, intersect->first);
extrusionVertex = splitVertex;
}
else if (const auto intersect
= intersectRay({boundaryVertex + GlobalPosition3D {1, 1, 0}, extrusionDir})) {
auto splitVertex = split(intersect->second, intersect->first);
extrusionVertex = splitVertex;
}
else if (const auto intersect
= intersectRay({boundaryVertex + GlobalPosition3D {1, 0, 0}, extrusionDir})) {
auto splitVertex = split(intersect->second, intersect->first);
extrusionVertex = splitVertex;
}
}
return extrusionDir;
};
// Previous half edge end to current half end start arc tangents
const Arc arc {e0, e1};
const auto limit = std::floor((arc.second - arc.first) * 5.F / pi);
const auto inc = (arc.second - arc.first) / limit;
for (float step = 1; step < limit; step += 1.F) {
const auto direction = sincosf(arc.first + (step * inc));
VertexHandle extrusionVertex;
extrusionExtents.emplace_back(boundaryVertex, extrusionVertex,
doExtrusion(extrusionVertex, direction, p1, -MAX_SLOPE),
doExtrusion(extrusionVertex, direction, p1, MAX_SLOPE));
assert(extrusionVertex.is_valid());
}
// Half edge start/end tangents
for (const auto p : {boundaryVertex, nextBoundaryVertex}) {
VertexHandle extrusionVertex;
extrusionExtents.emplace_back(p, extrusionVertex, doExtrusion(extrusionVertex, e1, point(p), -MAX_SLOPE),
doExtrusion(extrusionVertex, e1, point(p), MAX_SLOPE));
assert(extrusionVertex.is_valid());
}
});
// Cut existing terrain
extrusionExtents.emplace_back(extrusionExtents.front()); // Circular next
std::vector<std::vector<VertexHandle>> boundaryFaces;
std::adjacent_find(extrusionExtents.begin(), extrusionExtents.end(),
[this, &boundaryFaces](const auto & first, const auto & second) {
const auto p0 = point(first.boundaryVertex);
const auto p1 = point(second.boundaryVertex);
const auto bdir = RelativePosition3D(p1 - p0);
const auto make_plane = [p0](auto y, auto z) {
return GeometricPlaneT<GlobalPosition3D> {p0, crossProduct(y, z)};
};
const auto planes = ((first.boundaryVertex == second.boundaryVertex)
? std::array {make_plane(second.lowerLimit, first.lowerLimit),
make_plane(second.upperLimit, first.upperLimit),
}
: std::array {
make_plane(bdir, second.lowerLimit),
make_plane(bdir, second.upperLimit),
});
assert(planes.front().normal.z > 0.F);
assert(planes.back().normal.z > 0.F);
auto & out = boundaryFaces.emplace_back();
out.emplace_back(first.boundaryVertex);
out.emplace_back(first.extrusionVertex);
for (auto currentVertex = first.extrusionVertex;
!find_halfedge(currentVertex, second.extrusionVertex).is_valid();) {
[[maybe_unused]] const auto n = std::any_of(
voh_begin(currentVertex), voh_end(currentVertex), [&](const auto currentVertexOut) {
const auto next = next_halfedge_handle(currentVertexOut);
const auto nextVertex = to_vertex_handle(next);
const auto startVertex = from_vertex_handle(next);
if (nextVertex == *++out.rbegin()) {
// This half edge goes back to the previous vertex
return false;
}
const auto edge = edge_handle(next);
const auto ep0 = point(startVertex);
const auto ep1 = point(nextVertex);
if (planes.front().getRelation(ep1) == GeometricPlane::PlaneRelation::Below
|| planes.back().getRelation(ep1) == GeometricPlane::PlaneRelation::Above) {
return false;
}
const auto diff = RelativePosition3D(ep1 - ep0);
const auto length = glm::length(diff);
const auto dir = diff / length;
const Ray r {ep1, -dir};
const auto dists = planes * [r](const auto & plane) {
RelativeDistance dist {};
if (r.intersectPlane(plane.origin, plane.normal, dist)) {
return dist;
}
return INFINITY;
};
const auto dist = *std::min_element(dists.begin(), dists.end());
const auto splitPos = ep1 - (dir * dist);
if (dist <= length) {
currentVertex = split(edge, splitPos);
out.emplace_back(currentVertex);
return true;
}
return false;
});
assert(n);
}
out.emplace_back(second.extrusionVertex);
if (first.boundaryVertex != second.boundaryVertex) {
out.emplace_back(second.boundaryVertex);
}
return false;
});
// Remove old faces
std::set<FaceHandle> visited;
auto removeOld = [&](auto & self, const auto face) -> void {
if (visited.insert(face).second) {
std::for_each(fh_begin(face), fh_end(face), [&](const auto fh) {
const auto b1 = to_vertex_handle(fh);
const auto b2 = from_vertex_handle(fh);
if (opposite_face_handle(fh).is_valid()
&& std::none_of(boundaryFaces.begin(), boundaryFaces.end(), [b2, b1](const auto & bf) {
return std::adjacent_find(bf.begin(), bf.end(), [b2, b1](const auto v1, const auto v2) {
return b1 == v1 && b2 == v2;
}) != bf.end();
})) {
self(self, opposite_face_handle(fh));
}
});
delete_face(face, false);
}
};
removeOld(removeOld, findPoint(triangleStrip.front()));
std::for_each(boundaryFaces.begin(), boundaryFaces.end(), [&](auto & boundaryFace) {
std::reverse(boundaryFace.begin(), boundaryFace.end());
add_face(boundaryFace);
});
// Tidy up
garbage_collection();
update_vertex_normals_only();
}
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