Building igl statically and moving to the dep scripts

Fixing dep build script on Windows and removing some warnings.

Use bundled igl by default.

Not building with the dependency scripts if not explicitly stated. This way, it will stay in
Fix the libigl patch to include C source files in header only mode.

src/libigl/igl/lexicographic_triangulation.cpp

@@ -0,0 +1,132 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2016 Alec Jacobson <alecjacobson@gmail.com>
+//                    Qingan Zhou <qnzhou@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+
+#include "lexicographic_triangulation.h"
+#include "sortrows.h"
+
+#include <vector>
+#include <list>
+
+template<
+  typename DerivedP,
+  typename Orient2D,
+  typename DerivedF
+  >
+IGL_INLINE void igl::lexicographic_triangulation(
+    const Eigen::PlainObjectBase<DerivedP>& P,
+    Orient2D orient2D,
+    Eigen::PlainObjectBase<DerivedF>& F)
+{
+  typedef typename DerivedP::Scalar Scalar;
+  const size_t num_pts = P.rows();
+  if (num_pts < 3) {
+    throw "At least 3 points are required for triangulation!";
+  }
+
+  // Sort points in lexicographic order.
+  DerivedP ordered_P;
+  Eigen::VectorXi order;
+  igl::sortrows(P, true, ordered_P, order);
+
+  std::vector<Eigen::Vector3i> faces;
+  std::list<int> boundary;
+  const Scalar p0[] = {ordered_P(0, 0), ordered_P(0, 1)};
+  const Scalar p1[] = {ordered_P(1, 0), ordered_P(1, 1)};
+  for (size_t i=2; i<num_pts; i++) {
+    const Scalar curr_p[] = {ordered_P(i, 0), ordered_P(i, 1)};
+    if (faces.size() == 0) {
+      // All points processed so far are collinear.
+      // Check if the current point is collinear with every points before it.
+      auto orientation = orient2D(p0, p1, curr_p);
+      if (orientation != 0) {
+        // Add a fan of triangles eminating from curr_p.
+        if (orientation > 0) {
+          for (size_t j=0; j<=i-2; j++) {
+            faces.push_back({order[j], order[j+1], order[i]});
+          }
+        } else if (orientation < 0) {
+          for (size_t j=0; j<=i-2; j++) {
+            faces.push_back({order[j+1], order[j], order[i]});
+          }
+        }
+        // Initialize current boundary.
+        boundary.insert(boundary.end(), order.data(), order.data()+i+1);
+        if (orientation < 0) {
+          boundary.reverse();
+        }
+      }
+    } else {
+      const size_t bd_size = boundary.size();
+      assert(bd_size >= 3);
+      std::vector<short> orientations;
+      for (auto itr=boundary.begin(); itr!=boundary.end(); itr++) {
+        auto next_itr = std::next(itr, 1);
+        if (next_itr == boundary.end()) {
+          next_itr = boundary.begin();
+        }
+        const Scalar bd_p0[] = {P(*itr, 0), P(*itr, 1)};
+        const Scalar bd_p1[] = {P(*next_itr, 0), P(*next_itr, 1)};
+        auto orientation = orient2D(bd_p0, bd_p1, curr_p);
+        if (orientation < 0) {
+          faces.push_back({*next_itr, *itr, order[i]});
+        }
+        orientations.push_back(orientation);
+      }
+
+      auto left_itr = boundary.begin();
+      auto right_itr = boundary.begin();
+      auto curr_itr = boundary.begin();
+      for (size_t j=0; j<bd_size; j++, curr_itr++) {
+        size_t prev = (j+bd_size-1) % bd_size;
+        if (orientations[j] >= 0 && orientations[prev] < 0) {
+          right_itr = curr_itr;
+        } else if (orientations[j] < 0 && orientations[prev] >= 0) {
+          left_itr = curr_itr;
+        }
+      }
+      assert(left_itr != right_itr);
+
+      for (auto itr=left_itr; itr!=right_itr; itr++) {
+        if (itr == boundary.end()) itr = boundary.begin();
+        if (itr == right_itr) break;
+        if (itr == left_itr || itr == right_itr) continue;
+        itr = boundary.erase(itr);
+        if (itr == boundary.begin()) {
+            itr = boundary.end();
+        } else {
+            itr--;
+        }
+      }
+
+      if (right_itr == boundary.begin()) {
+        assert(std::next(left_itr, 1) == boundary.end());
+        boundary.insert(boundary.end(), order[i]);
+      } else {
+        assert(std::next(left_itr, 1) == right_itr);
+        boundary.insert(right_itr, order[i]);
+      }
+    }
+  }
+
+  const size_t num_faces = faces.size();
+  if (num_faces == 0) {
+      // All input points are collinear.
+      // Do nothing here.
+  } else {
+      F.resize(num_faces, 3);
+      for (size_t i=0; i<num_faces; i++) {
+          F.row(i) = faces[i];
+      }
+  }
+}
+
+
+#ifdef IGL_STATIC_LIBRARY
+template void igl::lexicographic_triangulation<Eigen::Matrix<double, -1, -1, 0, -1, -1>, short (*)(double const*, double const*, double const*), Eigen::Matrix<int, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, short (*)(double const*, double const*, double const*), Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&);
+#endif