From 5a9c163a2e65d46b952366a0f97fc4b4fd86c83f Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Mon, 16 Sep 2013 10:18:42 +0200
Subject: [PATCH] Meaningful error when user wants to use 3D preview but didn't
 install the required modules.

---
 Build.PL                 | 13 +++++++++----
 lib/Slic3r/GUI/Plater.pm |  5 +++++
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/Build.PL b/Build.PL
index f75f71559..7fac4c2fe 100644
--- a/Build.PL
+++ b/Build.PL
@@ -124,10 +124,15 @@ EOF
     system $cpanm, '--reinstall', './xs';
 }
 
-if (eval "use App::Prove; 1" && !$missing_prereqs) {
-    App::Prove->new->run;
+if ($missing_prereqs) {
+    exit 1;
+} else {
+    if (eval "use App::Prove; 1") {
+        App::Prove->new->run;
+    }
+    if (!defined $ARGV[0] && $ARGV[0] ne '--gui') {
+        print "If you also want to use the GUI you can now run `perl Build.PL --gui` to install the required modules.\n";
+    }
 }
 
-exit 1 if $missing_prereqs;
-
 __END__
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index 207750eaa..bc002af37 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -1079,6 +1079,11 @@ sub object_preview_dialog {
         ($obj_idx, undef) = $self->selected_object;
     }
     
+    if (!$Slic3r::GUI::have_OpenGL) {
+        Slic3r::GUI::show_error($self, "Please install the OpenGL modules to use this feature (see build instructions).");
+        return;
+    }
+    
     my $dlg = Slic3r::GUI::Plater::ObjectPreviewDialog->new($self,
 		object => $self->{objects}[$obj_idx],
 	);