freeglut: require GL/glu.h

Freeglut requires GL/glu.h, which isn't always installed. Make sure we
check for it, so we can get a meaningful error message early on instead
of just failing to compile.

Because not all platforms has glu as a dependency, we also need to fall
back to searching for the library. This search is copied from Mesa's
demos project.

Author: kusma

releases.json

@@ -931,6 +931,7 @@
       "glut"
     ],
     "versions": [
+      "3.4.0-4",
       "3.4.0-3",
       "3.4.0-2",
       "3.4.0-1"

subprojects/packagefiles/freeglut/meson.build

@@ -67,12 +67,29 @@ freeglut_sources = files(
   'src/fg_window.c',
 )
 
+dep_glu = dependency(
+  'glu',
+  required: false,
+)
+# GLU is part of OpenGL.Framework
+if not dep_glu.found() and host_machine.system() != 'darwin'
+  _glu_name = 'GLU'
+  if host_machine.system() == 'windows'
+    _glu_name = 'glu32'
+  endif
+  dep_glu = cc.find_library(
+    _glu_name,
+    has_headers: 'GL/glu.h',
+  )
+endif
+
 freeglut_deps = [
   cc.find_library(
     'm',
     required: false,
   ),
   dependency('gl'),
+  dep_glu,
 ]
 
 if host_system == 'windows'