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.

deps/deps-windows.cmake

@@ -252,6 +252,51 @@ else ()
     set(DEP_WXWIDGETS_LIBDIR "vc_x64_lib")
 endif ()
 
+find_package(Git REQUIRED)
+
+ExternalProject_Add(dep_libigl
+    EXCLUDE_FROM_ALL 1
+    URL "https://github.com/libigl/libigl/archive/v2.0.0.tar.gz"
+    URL_HASH SHA256=42518e6b106c7209c73435fd260ed5d34edeb254852495b4c95dce2d95401328
+    CMAKE_GENERATOR "${DEP_MSVC_GEN}"
+    CMAKE_ARGS
+        -DCMAKE_INSTALL_PREFIX=${DESTDIR}/usr/local
+        -DLIBIGL_BUILD_PYTHON=OFF
+        -DLIBIGL_BUILD_TESTS=OFF
+        -DLIBIGL_BUILD_TUTORIALS=OFF
+        -DLIBIGL_USE_STATIC_LIBRARY=${DEP_BUILD_IGL_STATIC}
+        -DLIBIGL_WITHOUT_COPYLEFT=OFF
+        -DLIBIGL_WITH_CGAL=OFF
+        -DLIBIGL_WITH_COMISO=OFF
+        -DLIBIGL_WITH_CORK=OFF
+        -DLIBIGL_WITH_EMBREE=OFF
+        -DLIBIGL_WITH_MATLAB=OFF
+        -DLIBIGL_WITH_MOSEK=OFF
+        -DLIBIGL_WITH_OPENGL=OFF
+        -DLIBIGL_WITH_OPENGL_GLFW=OFF
+        -DLIBIGL_WITH_OPENGL_GLFW_IMGUI=OFF
+        -DLIBIGL_WITH_PNG=OFF
+        -DLIBIGL_WITH_PYTHON=OFF
+        -DLIBIGL_WITH_TETGEN=OFF
+        -DLIBIGL_WITH_TRIANGLE=OFF
+        -DLIBIGL_WITH_XML=OFF
+        -DCMAKE_POSITION_INDEPENDENT_CODE=ON
+        -DCMAKE_DEBUG_POSTFIX=d
+    PATCH_COMMAND ${GIT_EXECUTABLE} apply --ignore-space-change --ignore-whitespace ${CMAKE_CURRENT_SOURCE_DIR}/igl-fixes.patch
+    BUILD_COMMAND msbuild /m /P:Configuration=Release INSTALL.vcxproj
+    INSTALL_COMMAND ""
+)
+
+if (${DEP_DEBUG})
+    ExternalProject_Get_Property(dep_libigl BINARY_DIR)
+    ExternalProject_Add_Step(dep_libigl build_debug
+        DEPENDEES build
+        DEPENDERS install
+        COMMAND msbuild /m /P:Configuration=Debug INSTALL.vcxproj
+        WORKING_DIRECTORY "${BINARY_DIR}"
+    )
+endif ()
+
 ExternalProject_Add(dep_wxwidgets
     EXCLUDE_FROM_ALL 1
     GIT_REPOSITORY "https://github.com/prusa3d/wxWidgets"