godot-module-template/engine/thirdparty/manifold/src/boolean3.cpp

600 lines
19 KiB
C++

// Copyright 2021 The Manifold Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "./boolean3.h"
#include <limits>
#include "./parallel.h"
using namespace manifold;
namespace {
// These two functions (Interpolate and Intersect) are the only places where
// floating-point operations take place in the whole Boolean function. These
// are carefully designed to minimize rounding error and to eliminate it at edge
// cases to ensure consistency.
vec2 Interpolate(vec3 pL, vec3 pR, double x) {
const double dxL = x - pL.x;
const double dxR = x - pR.x;
DEBUG_ASSERT(dxL * dxR <= 0, logicErr,
"Boolean manifold error: not in domain");
const bool useL = fabs(dxL) < fabs(dxR);
const vec3 dLR = pR - pL;
const double lambda = (useL ? dxL : dxR) / dLR.x;
if (!std::isfinite(lambda) || !std::isfinite(dLR.y) || !std::isfinite(dLR.z))
return vec2(pL.y, pL.z);
vec2 yz;
yz[0] = fma(lambda, dLR.y, useL ? pL.y : pR.y);
yz[1] = fma(lambda, dLR.z, useL ? pL.z : pR.z);
return yz;
}
vec4 Intersect(const vec3 &pL, const vec3 &pR, const vec3 &qL, const vec3 &qR) {
const double dyL = qL.y - pL.y;
const double dyR = qR.y - pR.y;
DEBUG_ASSERT(dyL * dyR <= 0, logicErr,
"Boolean manifold error: no intersection");
const bool useL = fabs(dyL) < fabs(dyR);
const double dx = pR.x - pL.x;
double lambda = (useL ? dyL : dyR) / (dyL - dyR);
if (!std::isfinite(lambda)) lambda = 0.0;
vec4 xyzz;
xyzz.x = fma(lambda, dx, useL ? pL.x : pR.x);
const double pDy = pR.y - pL.y;
const double qDy = qR.y - qL.y;
const bool useP = fabs(pDy) < fabs(qDy);
xyzz.y = fma(lambda, useP ? pDy : qDy,
useL ? (useP ? pL.y : qL.y) : (useP ? pR.y : qR.y));
xyzz.z = fma(lambda, pR.z - pL.z, useL ? pL.z : pR.z);
xyzz.w = fma(lambda, qR.z - qL.z, useL ? qL.z : qR.z);
return xyzz;
}
template <const bool inverted>
struct CopyFaceEdges {
const SparseIndices &p1q1;
// x can be either vert or edge (0 or 1).
SparseIndices &pXq1;
VecView<const Halfedge> halfedgesQ;
const size_t offset;
void operator()(const size_t i) {
int idx = 3 * (i + offset);
int pX = p1q1.Get(i, inverted);
int q2 = p1q1.Get(i, !inverted);
for (const int j : {0, 1, 2}) {
const int q1 = 3 * q2 + j;
const Halfedge edge = halfedgesQ[q1];
int a = pX;
int b = edge.IsForward() ? q1 : edge.pairedHalfedge;
if (inverted) std::swap(a, b);
pXq1.Set(idx + static_cast<size_t>(j), a, b);
}
}
};
SparseIndices Filter11(const Manifold::Impl &inP, const Manifold::Impl &inQ,
const SparseIndices &p1q2, const SparseIndices &p2q1) {
ZoneScoped;
SparseIndices p1q1(3 * p1q2.size() + 3 * p2q1.size());
for_each_n(autoPolicy(p1q2.size(), 1e5), countAt(0_uz), p1q2.size(),
CopyFaceEdges<false>({p1q2, p1q1, inQ.halfedge_, 0_uz}));
for_each_n(autoPolicy(p2q1.size(), 1e5), countAt(0_uz), p2q1.size(),
CopyFaceEdges<true>({p2q1, p1q1, inP.halfedge_, p1q2.size()}));
p1q1.Unique();
return p1q1;
}
inline bool Shadows(double p, double q, double dir) {
return p == q ? dir < 0 : p < q;
}
inline std::pair<int, vec2> Shadow01(
const int p0, const int q1, VecView<const vec3> vertPosP,
VecView<const vec3> vertPosQ, VecView<const Halfedge> halfedgeQ,
const double expandP, VecView<const vec3> normalP, const bool reverse) {
const int q1s = halfedgeQ[q1].startVert;
const int q1e = halfedgeQ[q1].endVert;
const double p0x = vertPosP[p0].x;
const double q1sx = vertPosQ[q1s].x;
const double q1ex = vertPosQ[q1e].x;
int s01 = reverse ? Shadows(q1sx, p0x, expandP * normalP[q1s].x) -
Shadows(q1ex, p0x, expandP * normalP[q1e].x)
: Shadows(p0x, q1ex, expandP * normalP[p0].x) -
Shadows(p0x, q1sx, expandP * normalP[p0].x);
vec2 yz01(NAN);
if (s01 != 0) {
yz01 = Interpolate(vertPosQ[q1s], vertPosQ[q1e], vertPosP[p0].x);
if (reverse) {
vec3 diff = vertPosQ[q1s] - vertPosP[p0];
const double start2 = la::dot(diff, diff);
diff = vertPosQ[q1e] - vertPosP[p0];
const double end2 = la::dot(diff, diff);
const double dir = start2 < end2 ? normalP[q1s].y : normalP[q1e].y;
if (!Shadows(yz01[0], vertPosP[p0].y, expandP * dir)) s01 = 0;
} else {
if (!Shadows(vertPosP[p0].y, yz01[0], expandP * normalP[p0].y)) s01 = 0;
}
}
return std::make_pair(s01, yz01);
}
// https://github.com/scandum/binary_search/blob/master/README.md
// much faster than standard binary search on large arrays
size_t monobound_quaternary_search(VecView<const int64_t> array, int64_t key) {
if (array.size() == 0) {
return std::numeric_limits<size_t>::max();
}
size_t bot = 0;
size_t top = array.size();
while (top >= 65536) {
size_t mid = top / 4;
top -= mid * 3;
if (key < array[bot + mid * 2]) {
if (key >= array[bot + mid]) {
bot += mid;
}
} else {
bot += mid * 2;
if (key >= array[bot + mid]) {
bot += mid;
}
}
}
while (top > 3) {
size_t mid = top / 2;
if (key >= array[bot + mid]) {
bot += mid;
}
top -= mid;
}
while (top--) {
if (key == array[bot + top]) {
return bot + top;
}
}
return -1;
}
struct Kernel11 {
VecView<vec4> xyzz;
VecView<int> s;
VecView<const vec3> vertPosP;
VecView<const vec3> vertPosQ;
VecView<const Halfedge> halfedgeP;
VecView<const Halfedge> halfedgeQ;
const double expandP;
VecView<const vec3> normalP;
const SparseIndices &p1q1;
void operator()(const size_t idx) {
const int p1 = p1q1.Get(idx, false);
const int q1 = p1q1.Get(idx, true);
vec4 &xyzz11 = xyzz[idx];
int &s11 = s[idx];
// For pRL[k], qRL[k], k==0 is the left and k==1 is the right.
int k = 0;
vec3 pRL[2], qRL[2];
// Either the left or right must shadow, but not both. This ensures the
// intersection is between the left and right.
bool shadows = false;
s11 = 0;
const int p0[2] = {halfedgeP[p1].startVert, halfedgeP[p1].endVert};
for (int i : {0, 1}) {
const auto syz01 = Shadow01(p0[i], q1, vertPosP, vertPosQ, halfedgeQ,
expandP, normalP, false);
const int s01 = syz01.first;
const vec2 yz01 = syz01.second;
// If the value is NaN, then these do not overlap.
if (std::isfinite(yz01[0])) {
s11 += s01 * (i == 0 ? -1 : 1);
if (k < 2 && (k == 0 || (s01 != 0) != shadows)) {
shadows = s01 != 0;
pRL[k] = vertPosP[p0[i]];
qRL[k] = vec3(pRL[k].x, yz01.x, yz01.y);
++k;
}
}
}
const int q0[2] = {halfedgeQ[q1].startVert, halfedgeQ[q1].endVert};
for (int i : {0, 1}) {
const auto syz10 = Shadow01(q0[i], p1, vertPosQ, vertPosP, halfedgeP,
expandP, normalP, true);
const int s10 = syz10.first;
const vec2 yz10 = syz10.second;
// If the value is NaN, then these do not overlap.
if (std::isfinite(yz10[0])) {
s11 += s10 * (i == 0 ? -1 : 1);
if (k < 2 && (k == 0 || (s10 != 0) != shadows)) {
shadows = s10 != 0;
qRL[k] = vertPosQ[q0[i]];
pRL[k] = vec3(qRL[k].x, yz10.x, yz10.y);
++k;
}
}
}
if (s11 == 0) { // No intersection
xyzz11 = vec4(NAN);
} else {
DEBUG_ASSERT(k == 2, logicErr, "Boolean manifold error: s11");
xyzz11 = Intersect(pRL[0], pRL[1], qRL[0], qRL[1]);
const int p1s = halfedgeP[p1].startVert;
const int p1e = halfedgeP[p1].endVert;
vec3 diff = vertPosP[p1s] - vec3(xyzz11);
const double start2 = la::dot(diff, diff);
diff = vertPosP[p1e] - vec3(xyzz11);
const double end2 = la::dot(diff, diff);
const double dir = start2 < end2 ? normalP[p1s].z : normalP[p1e].z;
if (!Shadows(xyzz11.z, xyzz11.w, expandP * dir)) s11 = 0;
}
}
};
std::tuple<Vec<int>, Vec<vec4>> Shadow11(SparseIndices &p1q1,
const Manifold::Impl &inP,
const Manifold::Impl &inQ,
double expandP) {
ZoneScoped;
Vec<int> s11(p1q1.size());
Vec<vec4> xyzz11(p1q1.size());
for_each_n(autoPolicy(p1q1.size(), 1e4), countAt(0_uz), p1q1.size(),
Kernel11({xyzz11, s11, inP.vertPos_, inQ.vertPos_, inP.halfedge_,
inQ.halfedge_, expandP, inP.vertNormal_, p1q1}));
p1q1.KeepFinite(xyzz11, s11);
return std::make_tuple(s11, xyzz11);
};
struct Kernel02 {
VecView<int> s;
VecView<double> z;
VecView<const vec3> vertPosP;
VecView<const Halfedge> halfedgeQ;
VecView<const vec3> vertPosQ;
const double expandP;
VecView<const vec3> vertNormalP;
const SparseIndices &p0q2;
const bool forward;
void operator()(const size_t idx) {
const int p0 = p0q2.Get(idx, !forward);
const int q2 = p0q2.Get(idx, forward);
int &s02 = s[idx];
double &z02 = z[idx];
// For yzzLR[k], k==0 is the left and k==1 is the right.
int k = 0;
vec3 yzzRL[2];
// Either the left or right must shadow, but not both. This ensures the
// intersection is between the left and right.
bool shadows = false;
int closestVert = -1;
double minMetric = std::numeric_limits<double>::infinity();
s02 = 0;
const vec3 posP = vertPosP[p0];
for (const int i : {0, 1, 2}) {
const int q1 = 3 * q2 + i;
const Halfedge edge = halfedgeQ[q1];
const int q1F = edge.IsForward() ? q1 : edge.pairedHalfedge;
if (!forward) {
const int qVert = halfedgeQ[q1F].startVert;
const vec3 diff = posP - vertPosQ[qVert];
const double metric = la::dot(diff, diff);
if (metric < minMetric) {
minMetric = metric;
closestVert = qVert;
}
}
const auto syz01 = Shadow01(p0, q1F, vertPosP, vertPosQ, halfedgeQ,
expandP, vertNormalP, !forward);
const int s01 = syz01.first;
const vec2 yz01 = syz01.second;
// If the value is NaN, then these do not overlap.
if (std::isfinite(yz01[0])) {
s02 += s01 * (forward == edge.IsForward() ? -1 : 1);
if (k < 2 && (k == 0 || (s01 != 0) != shadows)) {
shadows = s01 != 0;
yzzRL[k++] = vec3(yz01[0], yz01[1], yz01[1]);
}
}
}
if (s02 == 0) { // No intersection
z02 = NAN;
} else {
DEBUG_ASSERT(k == 2, logicErr, "Boolean manifold error: s02");
vec3 vertPos = vertPosP[p0];
z02 = Interpolate(yzzRL[0], yzzRL[1], vertPos.y)[1];
if (forward) {
if (!Shadows(vertPos.z, z02, expandP * vertNormalP[p0].z)) s02 = 0;
} else {
// DEBUG_ASSERT(closestVert != -1, topologyErr, "No closest vert");
if (!Shadows(z02, vertPos.z, expandP * vertNormalP[closestVert].z))
s02 = 0;
}
}
}
};
std::tuple<Vec<int>, Vec<double>> Shadow02(const Manifold::Impl &inP,
const Manifold::Impl &inQ,
SparseIndices &p0q2, bool forward,
double expandP) {
ZoneScoped;
Vec<int> s02(p0q2.size());
Vec<double> z02(p0q2.size());
auto vertNormalP = forward ? inP.vertNormal_ : inQ.vertNormal_;
for_each_n(autoPolicy(p0q2.size(), 1e4), countAt(0_uz), p0q2.size(),
Kernel02({s02, z02, inP.vertPos_, inQ.halfedge_, inQ.vertPos_,
expandP, vertNormalP, p0q2, forward}));
p0q2.KeepFinite(z02, s02);
return std::make_tuple(s02, z02);
};
struct Kernel12 {
VecView<int> x;
VecView<vec3> v;
VecView<const int64_t> p0q2;
VecView<const int> s02;
VecView<const double> z02;
VecView<const int64_t> p1q1;
VecView<const int> s11;
VecView<const vec4> xyzz11;
VecView<const Halfedge> halfedgesP;
VecView<const Halfedge> halfedgesQ;
VecView<const vec3> vertPosP;
const bool forward;
const SparseIndices &p1q2;
void operator()(const size_t idx) {
int p1 = p1q2.Get(idx, !forward);
int q2 = p1q2.Get(idx, forward);
int &x12 = x[idx];
vec3 &v12 = v[idx];
// For xzyLR-[k], k==0 is the left and k==1 is the right.
int k = 0;
vec3 xzyLR0[2];
vec3 xzyLR1[2];
// Either the left or right must shadow, but not both. This ensures the
// intersection is between the left and right.
bool shadows = false;
x12 = 0;
const Halfedge edge = halfedgesP[p1];
for (int vert : {edge.startVert, edge.endVert}) {
const int64_t key = forward ? SparseIndices::EncodePQ(vert, q2)
: SparseIndices::EncodePQ(q2, vert);
const size_t idx = monobound_quaternary_search(p0q2, key);
if (idx != std::numeric_limits<size_t>::max()) {
const int s = s02[idx];
x12 += s * ((vert == edge.startVert) == forward ? 1 : -1);
if (k < 2 && (k == 0 || (s != 0) != shadows)) {
shadows = s != 0;
xzyLR0[k] = vertPosP[vert];
std::swap(xzyLR0[k].y, xzyLR0[k].z);
xzyLR1[k] = xzyLR0[k];
xzyLR1[k][1] = z02[idx];
k++;
}
}
}
for (const int i : {0, 1, 2}) {
const int q1 = 3 * q2 + i;
const Halfedge edge = halfedgesQ[q1];
const int q1F = edge.IsForward() ? q1 : edge.pairedHalfedge;
const int64_t key = forward ? SparseIndices::EncodePQ(p1, q1F)
: SparseIndices::EncodePQ(q1F, p1);
const size_t idx = monobound_quaternary_search(p1q1, key);
if (idx !=
std::numeric_limits<size_t>::max()) { // s is implicitly zero for
// anything not found
const int s = s11[idx];
x12 -= s * (edge.IsForward() ? 1 : -1);
if (k < 2 && (k == 0 || (s != 0) != shadows)) {
shadows = s != 0;
const vec4 xyzz = xyzz11[idx];
xzyLR0[k][0] = xyzz.x;
xzyLR0[k][1] = xyzz.z;
xzyLR0[k][2] = xyzz.y;
xzyLR1[k] = xzyLR0[k];
xzyLR1[k][1] = xyzz.w;
if (!forward) std::swap(xzyLR0[k][1], xzyLR1[k][1]);
k++;
}
}
}
if (x12 == 0) { // No intersection
v12 = vec3(NAN);
} else {
DEBUG_ASSERT(k == 2, logicErr, "Boolean manifold error: v12");
const vec4 xzyy = Intersect(xzyLR0[0], xzyLR0[1], xzyLR1[0], xzyLR1[1]);
v12.x = xzyy[0];
v12.y = xzyy[2];
v12.z = xzyy[1];
}
}
};
std::tuple<Vec<int>, Vec<vec3>> Intersect12(
const Manifold::Impl &inP, const Manifold::Impl &inQ, const Vec<int> &s02,
const SparseIndices &p0q2, const Vec<int> &s11, const SparseIndices &p1q1,
const Vec<double> &z02, const Vec<vec4> &xyzz11, SparseIndices &p1q2,
bool forward) {
ZoneScoped;
Vec<int> x12(p1q2.size());
Vec<vec3> v12(p1q2.size());
for_each_n(
autoPolicy(p1q2.size(), 1e4), countAt(0_uz), p1q2.size(),
Kernel12({x12, v12, p0q2.AsVec64(), s02, z02, p1q1.AsVec64(), s11, xyzz11,
inP.halfedge_, inQ.halfedge_, inP.vertPos_, forward, p1q2}));
p1q2.KeepFinite(v12, x12);
return std::make_tuple(x12, v12);
};
Vec<int> Winding03(const Manifold::Impl &inP, Vec<int> &vertices, Vec<int> &s02,
bool reverse) {
ZoneScoped;
// verts that are not shadowed (not in p0q2) have winding number zero.
Vec<int> w03(inP.NumVert(), 0);
if (vertices.size() <= 1e5) {
for_each_n(ExecutionPolicy::Seq, countAt(0), s02.size(),
[&w03, &vertices, &s02, reverse](const int i) {
w03[vertices[i]] += s02[i] * (reverse ? -1 : 1);
});
} else {
for_each_n(ExecutionPolicy::Par, countAt(0), s02.size(),
[&w03, &vertices, &s02, reverse](const int i) {
AtomicAdd(w03[vertices[i]], s02[i] * (reverse ? -1 : 1));
});
}
return w03;
};
} // namespace
namespace manifold {
Boolean3::Boolean3(const Manifold::Impl &inP, const Manifold::Impl &inQ,
OpType op)
: inP_(inP), inQ_(inQ), expandP_(op == OpType::Add ? 1.0 : -1.0) {
// Symbolic perturbation:
// Union -> expand inP
// Difference, Intersection -> contract inP
#ifdef MANIFOLD_DEBUG
Timer broad;
broad.Start();
#endif
if (inP.IsEmpty() || inQ.IsEmpty() || !inP.bBox_.DoesOverlap(inQ.bBox_)) {
PRINT("No overlap, early out");
w03_.resize(inP.NumVert(), 0);
w30_.resize(inQ.NumVert(), 0);
return;
}
// Level 3
// Find edge-triangle overlaps (broad phase)
p1q2_ = inQ_.EdgeCollisions(inP_);
p2q1_ = inP_.EdgeCollisions(inQ_, true); // inverted
p1q2_.Sort();
PRINT("p1q2 size = " << p1q2_.size());
p2q1_.Sort();
PRINT("p2q1 size = " << p2q1_.size());
// Level 2
// Find vertices that overlap faces in XY-projection
SparseIndices p0q2 = inQ.VertexCollisionsZ(inP.vertPos_);
p0q2.Sort();
PRINT("p0q2 size = " << p0q2.size());
SparseIndices p2q0 = inP.VertexCollisionsZ(inQ.vertPos_, true); // inverted
p2q0.Sort();
PRINT("p2q0 size = " << p2q0.size());
// Find involved edge pairs from Level 3
SparseIndices p1q1 = Filter11(inP_, inQ_, p1q2_, p2q1_);
PRINT("p1q1 size = " << p1q1.size());
#ifdef MANIFOLD_DEBUG
broad.Stop();
Timer intersections;
intersections.Start();
#endif
// Level 2
// Build up XY-projection intersection of two edges, including the z-value for
// each edge, keeping only those whose intersection exists.
Vec<int> s11;
Vec<vec4> xyzz11;
std::tie(s11, xyzz11) = Shadow11(p1q1, inP, inQ, expandP_);
PRINT("s11 size = " << s11.size());
// Build up Z-projection of vertices onto triangles, keeping only those that
// fall inside the triangle.
Vec<int> s02;
Vec<double> z02;
std::tie(s02, z02) = Shadow02(inP, inQ, p0q2, true, expandP_);
PRINT("s02 size = " << s02.size());
Vec<int> s20;
Vec<double> z20;
std::tie(s20, z20) = Shadow02(inQ, inP, p2q0, false, expandP_);
PRINT("s20 size = " << s20.size());
// Level 3
// Build up the intersection of the edges and triangles, keeping only those
// that intersect, and record the direction the edge is passing through the
// triangle.
std::tie(x12_, v12_) =
Intersect12(inP, inQ, s02, p0q2, s11, p1q1, z02, xyzz11, p1q2_, true);
PRINT("x12 size = " << x12_.size());
std::tie(x21_, v21_) =
Intersect12(inQ, inP, s20, p2q0, s11, p1q1, z20, xyzz11, p2q1_, false);
PRINT("x21 size = " << x21_.size());
s11.clear();
xyzz11.clear();
z02.clear();
z20.clear();
Vec<int> p0 = p0q2.Copy(false);
p0q2.Resize(0);
Vec<int> q0 = p2q0.Copy(true);
p2q0.Resize(0);
// Sum up the winding numbers of all vertices.
w03_ = Winding03(inP, p0, s02, false);
w30_ = Winding03(inQ, q0, s20, true);
#ifdef MANIFOLD_DEBUG
intersections.Stop();
if (ManifoldParams().verbose) {
broad.Print("Broad phase");
intersections.Print("Intersections");
}
#endif
}
} // namespace manifold