Remove a mistake, GLEW is not required when including the correct headers

CMakeLists.txt

@@ -95,7 +95,7 @@ option(ENABLE_RTI       "Set to ON to build SimGear with RTI support" OFF)
 option(ENABLE_GDAL      "Set to ON to build SimGear with GDAL support" OFF)
 option(ENABLE_TESTS     "Set to OFF to disable building SimGear's test applications" ON)
 option(ENABLE_SOUND     "Set to OFF to disable building SimGear's sound support" ON)
-option(USE_SHADERVG     "Set to ON to use SHaderVG instead of ShivaVG" OFF)
+option(USE_SHADERVG     "Set to ON to use SHaderVG instead of ShivaVG" ON)
 option(USE_AEONWAVE     "Set to ON to use AeonWave instead of OpenAL" ON)
 option(USE_OPENALSOFT   "Set to ON to use OpenAL from OpenAL-soft" OFF)
 
@@ -111,7 +111,6 @@ endif()
 
 if (USE_SHADERVG)
   set(OPENVG ShaderVG)
-  find_package(GLEW REQUIRED)
 else()
   set(OPENVG ShivaVG)
 endif()

SimGearConfig.cmake.in

@@ -14,7 +14,6 @@ set(SG_SOUND_USES_OPENALSOFT @SG_SOUND_USES_OPENALSOFT@)
 
 set(USE_SHADERVG @USE_SHADERVG@)
 if (USE_SHADERVG)
-  find_dependency(GLEW REQUIRED)
 endif()
 
 set(ENABLE_ASAN @ENABLE_ASAN@)

simgear/CMakeLists.txt

@@ -173,10 +173,6 @@ if(NOT SIMGEAR_HEADLESS)
         ${FFMPEG_LIBRARIES}
         FGTinyGLTF)
 
-    if (USE_SHADERVG)
-      target_link_libraries(SimGearScene PRIVATE GLEW::GLEW)
-    endif()
-
     # ToDo: define an ALIAS target for the sound backend, to get
     # rid of this logic here
     if (ENABLE_SOUND)