From a209081cf697bf58079010d29de1affa355811fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophile=20Bastian?= <contact@tobast.fr>
Date: Mon, 12 Feb 2018 13:40:06 +0100
Subject: [PATCH] Begin hints integration -- WIP

---
 MarchingCubes.cpp | 59 +++++++++++++++++++++++++++++++++++++++++++----
 MarchingCubes.hpp |  6 +++++
 2 files changed, 61 insertions(+), 4 deletions(-)

diff --git a/MarchingCubes.cpp b/MarchingCubes.cpp
index 22cd064..bc76de0 100644
--- a/MarchingCubes.cpp
+++ b/MarchingCubes.cpp
@@ -18,7 +18,12 @@ void MarchingCubes::add_hint(const Cuboid& hint) {
 Mesh MarchingCubes::operator()() {
     Mesh output;
 
-    without_hints(output);
+    if(hints.empty()) {
+        without_hints(output);
+    }
+    else {
+        with_hints(output);
+    }
 
     return output;
 }
@@ -36,6 +41,39 @@ void MarchingCubes::without_hints(Mesh& output) {
     }
 }
 
+void MarchingCubes::with_hints(Mesh& output) {
+    auto fmod = [](double x, double mod) {
+        return x - floor(x/mod) * mod;
+    };
+
+    LocSet visited;
+    for(const Cuboid& hint: hints) {
+        Intersections inters = mk_intersection_cuboid(
+                hint.low(0), hint.low(1), hint.low(2),
+                hint.length(0), hint.length(1), hint.length(2));
+
+        const std::vector<CubeTri> triangles =
+            edges_of_intersection[inters.value()];
+        if(triangles.size() == 0)
+            continue; // this hint does not intersect anything.
+        const CubeEdge& edge = triangles[0].edge[0];
+        double edge_len = 0;
+        if(edge.x[0] != edge.x[1])
+            edge_len = hint.length(0);
+        else if(edge.y[0] != edge.y[1])
+            edge_len = hint.length(1);
+        else
+            edge_len = hint.length(2);
+
+        Point intersect_loc = intersect_location(
+                edge, hint.low(0), hint.low(1), hint.low(1), edge_len);
+        int cube_x = floor(intersect_loc.x / resolution),
+            cube_y = floor(intersect_loc.y / resolution),
+            cube_z = floor(intersect_loc.z / resolution);
+        //TODO
+    }
+}
+
 Point MarchingCubes::CubeEdge::at(double pos,
         double bx, double by, double bz, double resolution) const
 {
@@ -102,14 +140,21 @@ bool MarchingCubes::march_at(double x, double y, double z, Mesh& output) {
 
 MarchingCubes::Intersections MarchingCubes::mk_intersection_cube(
         double bx, double by, double bz, double side_len) const
+{
+    return mk_intersection_cuboid(bx, by, bz, side_len, side_len, side_len);
+}
+
+MarchingCubes::Intersections MarchingCubes::mk_intersection_cuboid(
+        double bx, double by, double bz,
+        double x_len, double y_len, double z_len) const
 {
     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;
+                double cx = bx + x_len * dx;
+                double cy = by + y_len * dy;
+                double cz = bz + z_len * dz;
                 intersections.set_corner(dx, dy, dz,
                         surface(cx, cy, cz) > 0);
             }
@@ -120,6 +165,12 @@ MarchingCubes::Intersections MarchingCubes::mk_intersection_cube(
 
 Point MarchingCubes::intersect_location(const CubeEdge& edge,
         double bx, double by, double bz) const
+{
+    return intersect_location(edge, bx, by, bz, this->resolution);
+}
+
+Point MarchingCubes::intersect_location(const CubeEdge& edge,
+        double bx, double by, double bz, double resolution) const
 {
     std::function<Point(double, double)> compute =
         [&](double low_prop, double high_prop)
diff --git a/MarchingCubes.hpp b/MarchingCubes.hpp
index cd4fb28..2d61ecb 100644
--- a/MarchingCubes.hpp
+++ b/MarchingCubes.hpp
@@ -120,12 +120,18 @@ class MarchingCubes {
         /// triangle was added.
 
         void without_hints(Mesh& output);
+        void with_hints(Mesh& output);
 
         Intersections mk_intersection_cube(double bx, double by, double bz,
                 double side_len) const;
+        Intersections mk_intersection_cuboid(double bx, double by, double bz,
+                double x_len, double y_len, double z_len) const;
 
         Point intersect_location(const CubeEdge& edge,
                 double bx, double by, double bz) const;
+        Point intersect_location(const CubeEdge& edge,
+                double bx, double by, double bz,
+                double resolution) const;
 
     private:
         static const std::vector<CubeTri> edges_of_intersection[256];