From fb0da7f2debf1a11de9cadc90726a56ac7c4c3d6 Mon Sep 17 00:00:00 2001
From: Robert Maynard <robert.maynard@kitware.com>
Date: Fri, 4 May 2018 14:58:11 -0400
Subject: [PATCH] Allow vtkm_find_gl CMake function to be used no matter vtk-m
 settings

Previously vtkm_find_gl was only usable when rendering was enabled.
This is problematic as examples would use vtkm_find_gl even if
they didn't use vtkm rendering library.
---
 CMake/VTKmConfig.cmake.in         | 5 +----
 CMake/VTKmRenderingContexts.cmake | 9 +++++----
 vtkm/rendering/CMakeLists.txt     | 5 ++++-
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/CMake/VTKmConfig.cmake.in b/CMake/VTKmConfig.cmake.in
index f98dbd832..eb513f895 100644
--- a/CMake/VTKmConfig.cmake.in
+++ b/CMake/VTKmConfig.cmake.in
@@ -92,7 +92,4 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${VTKm_CMAKE_MODULE_PATH})
 
 # This includes a host of functions used by VTK-m CMake.
 include(VTKmWrappers)
-
-if(VTKm_ENABLE_RENDERING)
-  include(VTKmRenderingContexts)
-endif()
+include(VTKmRenderingContexts)
diff --git a/CMake/VTKmRenderingContexts.cmake b/CMake/VTKmRenderingContexts.cmake
index 411847cdc..e3362de77 100644
--- a/CMake/VTKmRenderingContexts.cmake
+++ b/CMake/VTKmRenderingContexts.cmake
@@ -94,12 +94,13 @@ if(VTKm_ENABLE_GL_CONTEXT OR
 endif()
 
 #-----------------------------------------------------------------------------
-if(TARGET vtkm_rendering_gl_context)
-  return()
+if(VTKm_ENABLE_RENDERING)
+  if(TARGET vtkm_rendering_gl_context)
+    return()
+  endif()
+  add_library(vtkm_rendering_gl_context INTERFACE)
 endif()
 
-add_library(vtkm_rendering_gl_context INTERFACE)
-
 #-----------------------------------------------------------------------------
 if(VTKm_ENABLE_GL_CONTEXT)
   if(TARGET OpenGL::GLX)
diff --git a/vtkm/rendering/CMakeLists.txt b/vtkm/rendering/CMakeLists.txt
index a148d3bd6..b0e38a5de 100644
--- a/vtkm/rendering/CMakeLists.txt
+++ b/vtkm/rendering/CMakeLists.txt
@@ -18,6 +18,10 @@
 ##  this software.
 ##============================================================================
 
+#unconditionally include rendering contexts so that the helper functions
+#are around even if rendering isn't enabled
+include(VTKmRenderingContexts)
+
 if(NOT VTKm_ENABLE_RENDERING)
   return()
 endif()
@@ -190,7 +194,6 @@ if(UNIX AND NOT APPLE)
 endif()
 
 #-----------------------------------------------------------------------------
-include(VTKmRenderingContexts)
 target_link_libraries(vtkm_rendering PUBLIC vtkm_rendering_gl_context)
 
 if(NOT VTKm_INSTALL_ONLY_LIBRARIES)