Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/unproject_onto_mesh.h

@@ -0,0 +1,74 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2016 Alec Jacobson <alecjacobson@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/.
+#ifndef IGL_UNPROJECT_ONTO_MESH
+#define IGL_UNPROJECT_ONTO_MESH
+#include "igl_inline.h"
+#include "Hit.h"
+#include <Eigen/Core>
+#include <functional>
+
+namespace igl
+{
+  // Unproject a screen location (using current opengl viewport, projection, and
+  // model view) to a 3D position _onto_ a given mesh, if the ray through the
+  // given screen location (x,y) _hits_ the mesh.
+  //
+  // Inputs:
+  //    pos        screen space coordinates
+  //    model      model matrix
+  //    proj       projection matrix
+  //    viewport   vieweport vector
+  //    V   #V by 3 list of mesh vertex positions
+  //    F   #F by 3 list of mesh triangle indices into V
+  // Outputs:
+  //    fid  id of the first face hit
+  //    bc  barycentric coordinates of hit
+  // Returns true if there's a hit
+  template < typename DerivedV, typename DerivedF, typename Derivedbc>
+  IGL_INLINE bool unproject_onto_mesh(
+    const Eigen::Vector2f& pos,
+    const Eigen::Matrix4f& model,
+    const Eigen::Matrix4f& proj,
+    const Eigen::Vector4f& viewport,
+    const Eigen::PlainObjectBase<DerivedV> & V,
+    const Eigen::PlainObjectBase<DerivedF> & F,
+    int & fid,
+    Eigen::PlainObjectBase<Derivedbc> & bc);
+  //
+  // Inputs:
+  //    pos        screen space coordinates
+  //    model      model matrix
+  //    proj       projection matrix
+  //    viewport   vieweport vector
+  //    shoot_ray  function handle that outputs hits of a given ray against a
+  //      mesh (embedded in function handles as captured variable/data)
+  // Outputs:
+  //    fid  id of the first face hit
+  //    bc  barycentric coordinates of hit
+  // Returns true if there's a hit
+  template <typename Derivedbc>
+  IGL_INLINE bool unproject_onto_mesh(
+    const Eigen::Vector2f& pos,
+    const Eigen::Matrix4f& model,
+    const Eigen::Matrix4f& proj,
+    const Eigen::Vector4f& viewport,
+    const std::function<
+      bool(
+        const Eigen::Vector3f&,
+        const Eigen::Vector3f&,
+        igl::Hit  &)
+        > & shoot_ray,
+    int & fid,
+    Eigen::PlainObjectBase<Derivedbc> & bc);
+}
+#ifndef IGL_STATIC_LIBRARY
+#  include "unproject_onto_mesh.cpp"
+#endif
+#endif
+
+