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Merge commit 'cf0d7af'

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This commit is contained in:
Théophile Bastian 2018-02-12 13:40:49 +01:00
commit 97966377f5
4 changed files with 122 additions and 58 deletions
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98
MarchingCubes.cpp
View file

@ -18,15 +18,47 @@ void MarchingCubes::add_hint(const Cuboid& hint) {
Mesh MarchingCubes::operator()() {
Mesh output;
for(double x = box.low(0); x < box.high(0) + resolution; x += resolution)
{
without_hints(output);
return output;
}
void MarchingCubes::without_hints(Mesh& output) {
for(double x = box.low(0); x < box.high(0) + resolution;
x += resolution) {
for(double y = box.low(1); y < box.high(1) + resolution;
y += resolution)
{
y += resolution) {
for(double z = box.low(2); z < box.high(2) + resolution;
z += resolution)
z += resolution) {
march_at(x, y, z, output);
}
}
}
}
Point MarchingCubes::CubeEdge::at(double pos,
double bx, double by, double bz, double resolution) const
{
Intersections intersections;
auto bary = [pos](double x, double y) {
return pos * x + (1.-pos) * y;
};
Point p1(
bx + x[0] * resolution,
by + y[0] * resolution,
bz + z[0] * resolution);
Point p2(
bx + x[1] * resolution,
by + y[1] * resolution,
bz + z[1] * resolution);
return Point(
bary(p1.x, p2.x),
bary(p1.y, p2.y),
bary(p1.z, p2.z));
}
bool MarchingCubes::march_at(double x, double y, double z, Mesh& output) {
/* =====
* NOTE: this code currently computes 8 times the surface value
* at each corner point of the inspected space. This is okay
@ -36,17 +68,8 @@ Mesh MarchingCubes::operator()() {
* are looking at more complex implicit surfaces,
* IT WILL BE NECESSARY TO ENHANCE THIS CODE!
* ==== */
for(int dx=0; dx <= 1; dx++) {
for(int dy=0; dy <= 1; dy++) {
for(int dz=0; dz <= 1; dz++) {
double cx = x + resolution * dx;
double cy = y + resolution * dy;
double cz = z + resolution * dz;
intersections.set_corner(dx, dy, dz,
surface(cx, cy, cz) > 0);
}
}
}
Intersections intersections = mk_intersection_cube(x, y, z, resolution);
const std::vector<CubeTri>& cur_triangles =
edges_of_intersection[intersections.value()];
@ -73,33 +96,26 @@ Mesh MarchingCubes::operator()() {
}
}
}
}
return !cur_triangles.empty();
}
return output;
}
Point MarchingCubes::CubeEdge::at(double pos,
double bx, double by, double bz, double resolution) const
MarchingCubes::Intersections MarchingCubes::mk_intersection_cube(
double bx, double by, double bz, double side_len) const
{
auto bary = [pos](double x, double y) {
return pos * x + (1.-pos) * y;
};
Point p1(
bx + x[0] * resolution,
by + y[0] * resolution,
bz + z[0] * resolution);
Point p2(
bx + x[1] * resolution,
by + y[1] * resolution,
bz + z[1] * resolution);
return Point(
bary(p1.x, p2.x),
bary(p1.y, p2.y),
bary(p1.z, p2.z));
Intersections intersections;
for(int dx=0; dx <= 1; dx++) {
for(int dy=0; dy <= 1; dy++) {
for(int dz=0; dz <= 1; dz++) {
double cx = bx + side_len * dx;
double cy = by + side_len * dy;
double cz = bz + side_len * dz;
intersections.set_corner(dx, dy, dz,
surface(cx, cy, cz) > 0);
}
}
}
return intersections;
}
Point MarchingCubes::intersect_location(const CubeEdge& edge,

12
MarchingCubes.hpp
View file

@ -9,12 +9,15 @@
*/
#include <vector>
#include <set>
#include "Mesh.hpp"
#include "Implicit.hpp"
#include "common_structures.hpp"
class MarchingCubes {
private:
typedef std::set<PointLoc> LocSet;
class Intersections {
public:
typedef unsigned char intersect_t;
@ -112,6 +115,15 @@ class MarchingCubes {
};
private: //methods
bool march_at(double x, double y, double z, Mesh& output);
/// ^ Adds triangles for the given location. Returns true if any
/// triangle was added.
void without_hints(Mesh& output);
Intersections mk_intersection_cube(double bx, double by, double bz,
double side_len) const;
Point intersect_location(const CubeEdge& edge,
double bx, double by, double bz) const;

9
common_structures.cpp
View file

@ -23,10 +23,13 @@ double Cuboid::high(unsigned dim) const {
return highBound[dim];
}
double Cuboid::length(unsigned dim) const {
assert(dim < 3);
return high(dim) - low(dim);
}
double Cuboid::volume() const {
return (high(0) - low(0))
* (high(1) - low(1))
* (high(2) - low(2));
return length(0) * length(1) * length(2);
}
bool Cuboid::is_empty() const {

33
common_structures.hpp
View file

@ -7,6 +7,7 @@
#include <functional> // Hash
#include <vector>
#include <cassert>
#include <cmath>
struct Point {
Point(double x, double y, double z) : x(x), y(y), z(z) {}
@ -22,6 +23,12 @@ struct Point {
}
}
bool operator==(const Point& pt) const {
return fabs(x - pt.x) < 1e-9
&& fabs(y - pt.y) < 1e-9
&& fabs(z - pt.z) < 1e-9;
}
Point operator+(const Point& pt) const {
return Point(
x + pt.x,
@ -57,6 +64,31 @@ struct Point {
}
};
struct PointLoc {
/// Point location: a point with integer coordinates, used to index Points
PointLoc(int x, int y, int z): x(x), y(y), z(z) {}
int x, y, z;
bool operator<(const PointLoc& pt) const {
if(x == pt.x) {
if(y == pt.y)
return z < pt.z;
return y < pt.y;
}
return x < pt.x;
}
bool operator==(const PointLoc& pt) const {
return x == pt.x && y == pt.y && z == pt.z;
}
PointLoc operator+(const PointLoc& pt) const {
return PointLoc(x + pt.x, y + pt.y, z + pt.z);
}
};
struct Face {
Face(int v0, int v1, int v2) {
vert[0] = v0;
@ -87,6 +119,7 @@ class Cuboid {
double low(unsigned dim) const; ///< Lower bound for a dimension
double high(unsigned dim) const; ///< Higher bound for a dimension
double length(unsigned dim) const;
double volume() const;
bool is_empty() const;