title: GLFW directory not found with CMake and vcpkg
body: <p>I have been unable to figure out how to get CMake to find and set correct GLFW CMake constants when using CMake in VS2017. Any help will be greatly appreciated :).</p>
  
  <p>I downloaded <code>glfw3</code> through Microsoft's <code>vcpkg</code> tool. I have checked that files do physically exist in the directory that <code>vcpkg</code> puts them in (<code>~\vcpkg\installed\x86-windows\include</code>). I set up my <code>CMakeSettings.json</code> as per their docs <a href="https://github.com/Microsoft/vcpkg/blob/master/docs/examples/using-sqlite.md" rel="nofollow noreferrer">here</a>. I used that tutorial as a basis for getting GLFW to be set up correctly.</p>
  
  <p>I then use <code>find_package(glfw3 REQUIRED)</code> to find the <code>glfw3</code> library. This does not spit out any errors. Actually the <code>CMakeLists.txt</code> doesn't complain at all. It's at the compile stage where it complains. </p>
  
  <p>After that I add <code>glfw3</code> with <code>target_link_libraries(exe ${GLFW3_LIBRARIES})</code> to the executable. </p>
  
  <p>Then when I try and build a simple example (including the header file), the compilation fails because it cannot find <code>GLFW/glfw3.h</code>. </p>
  
  <p>The error from MSVC:</p>
  
  <pre><code>fatal error C1083: Cannot open include file: 'GLFW/glfw3.h': No such file or directory 
  </code></pre>
  
  <p>Here is my <code>CMakeLists.txt</code> for added reference:</p>
  
  <pre><code>cmake_minimum_required(VERSION 3.7)
  project(learn-opengl)
  find_package(glfw3 REQUIRED)
  
  add_executable(learn-opengl main.cpp)
  target_link_libraries(learn-opengl ${GLFW3_LIBRARIES})
  </code></pre>
  
  <p><code>GLFW3_LIBRARIES</code> I got from <code>glfw3Config.cmake</code> by snooping around what <code>vcpkg</code> puts in the installed directory (<code>~\vcpkg\installed\x86-windows\share\glfw3</code>)</p>
  
  <p>And just in case, the <code>main.cpp</code>:</p>
  
  <pre><code>#include &lt;GLFW/glfw3.h&gt;
  
  int main()
  {
      return 0;
  }
  </code></pre>
  
  <p>I have tried calling <code>cmake</code> from the command line as well, but to no avail that didn't work either.</p>
  
  <p>Am I missing something? Did I perhaps misunderstand something in <code>vcpkg</code> documentation? I have really no idea what I am missing... :/ I should say, in addition, that I am fairly new to CMake as well.</p>