new stuff

vendor/assimp/contrib/poly2tri/README.md

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+Since there are no Input validation of the data given for triangulation you need
+to think about this. Poly2Tri does not support repeat points within epsilon.
+
+* If you have a cyclic function that generates random points make sure you don't
+  add the same coordinate twice.
+* If you are given input and aren't sure same point exist twice you need to
+  check for this yourself.
+* Only simple polygons are supported. You may add holes or interior Steiner points
+* Interior holes must not touch other holes, nor touch the polyline boundary
+* Use the library in this order:
+  1. Initialize CDT with a simple polyline (this defines the constrained edges)
+  2. Add holes if necessary (also simple polylines)
+  3. Add Steiner points
+  4. Triangulate
+
+Make sure you understand the preceding notice before posting an issue. If you have
+an issue not covered by the above, include your data-set with the problem.
+The only easy day was yesterday; have a nice day. <Mason Green>
+
+TESTBED INSTALLATION GUIDE
+==========================
+
+Dependencies
+------------
+
+Core poly2tri lib:
+
+* Standard Template Library (STL)
+
+Unit tests:
+* Boost (filesystem, test framework)
+
+Testbed:
+
+* OpenGL
+* [GLFW](http://glfw.sf.net)
+
+Build the library
+-----------------
+
+With the ninja build system installed:
+
+```
+mkdir build && cd build
+cmake -GNinja ..
+cmake --build .
+```
+
+Build and run with unit tests
+----------------------------
+
+With the ninja build system:
+
+```
+mkdir build && cd build
+cmake -GNinja -DP2T_BUILD_TESTS=ON ..
+cmake --build .
+ctest --output-on-failure
+```
+
+Build with the testbed
+-----------------
+
+```
+mkdir build && cd build
+cmake -GNinja -DP2T_BUILD_TESTBED=ON ..
+cmake --build .
+```
+
+Running the Examples
+--------------------
+
+Load data points from a file:
+```
+build/testbed/p2t <filename> <center_x> <center_y> <zoom>
+```
+Load data points from a file and automatically fit the geometry to the window:
+```
+build/testbed/p2t <filename>
+```
+Random distribution of points inside a constrained box:
+```
+build/testbed/p2t random <num_points> <box_radius> <zoom>
+```
+Examples:
+```
+build/testbed/p2t testbed/data/dude.dat 350 500 3
+
+build/testbed/p2t testbed/data/nazca_monkey.dat
+
+build/testbed/p2t random 10 100 5.0
+build/testbed/p2t random 1000 20000 0.025
+```
+
+References
+==========
+
+- Domiter V. and Zalik B. (2008) Sweep‐line algorithm for constrained Delaunay triangulation
+- FlipScan by library author Thomas Åhlén
+
+![FlipScan](doc/FlipScan.png)