From 2df6b00f1d6f3e8bdfab0e047bb8a83eebc5245c Mon Sep 17 00:00:00 2001
From: Joseph Lenox <lenox.joseph@gmail.com>
Date: Thu, 17 Nov 2016 13:10:22 -0600
Subject: [PATCH] Significant code cleanup; remember to turn off VBOs after
 done with use to not interfere with other code.

---
 lib/Slic3r/GUI/3DScene.pm | 62 ++++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 23 deletions(-)

diff --git a/lib/Slic3r/GUI/3DScene.pm b/lib/Slic3r/GUI/3DScene.pm
index 715be6402..7f6f7ae97 100644
--- a/lib/Slic3r/GUI/3DScene.pm
+++ b/lib/Slic3r/GUI/3DScene.pm
@@ -1,9 +1,9 @@
 package Slic3r::GUI::3DScene::Base;
 use strict;
 use warnings;
-
 use Wx::Event qw(EVT_PAINT EVT_SIZE EVT_ERASE_BACKGROUND EVT_IDLE EVT_MOUSEWHEEL EVT_MOUSE_EVENTS);
 # must load OpenGL *before* Wx::GLCanvas
+
 use OpenGL qw(:glconstants :glfunctions :glufunctions :gluconstants);
 use base qw(Wx::GLCanvas Class::Accessor);
 use Math::Trig qw(asin);
@@ -46,6 +46,8 @@ use constant GROUND_Z       => -0.02;
 use constant DEFAULT_COLOR  => [1,1,0];
 use constant SELECTED_COLOR => [0,1,0,1];
 use constant HOVER_COLOR    => [0.4,0.9,0,1];
+use constant HAS_VBO        => 1;
+
 
 # make OpenGL::Array thread-safe
 {
@@ -56,6 +58,7 @@ use constant HOVER_COLOR    => [0.4,0.9,0,1];
 sub new {
     my ($class, $parent) = @_;
     
+
     # We can only enable multi sample anti aliasing wih wxWidgets 3.0.3 and with a hacked Wx::GLCanvas,
     # which exports some new WX_GL_XXX constants, namely WX_GL_SAMPLE_BUFFERS and WX_GL_SAMPLES.
     my $can_multisample =
@@ -74,6 +77,7 @@ sub new {
     # we request a depth buffer explicitely because it looks like it's not created by 
     # default on Linux, causing transparency issues
     my $self = $class->SUPER::new($parent, -1, Wx::wxDefaultPosition, Wx::wxDefaultSize, 0, "", $attrib);
+
     if (Wx::wxVERSION >= 3.000003) {
         # Wx 3.0.3 contains an ugly hack to support some advanced OpenGL attributes through the attribute list.
         # The attribute list is transferred between the wxGLCanvas and wxGLContext constructors using a single static array s_wglContextAttribs.
@@ -133,6 +137,7 @@ sub new {
         $self->Refresh;
     });
     EVT_MOUSE_EVENTS($self, \&mouse_event);
+
     
     return $self;
 }
@@ -750,26 +755,27 @@ sub Render {
     # draw ground
     my $ground_z = GROUND_Z;
     if ($self->bed_triangles) {
-        my($VertexObjID,$NormalObjID,$ColorObjID);
-        my $colors = OpenGL::Array->new_list(GL_FLOAT,(0.8,0.6,0.5,0.4));
-        my $norms = OpenGL::Array->new_list(GL_FLOAT,(0,0,1));
-        ($VertexObjID,$NormalObjID,$ColorObjID) =
-            glGenBuffersARB_p(3);
-        $self->bed_triangles->bind($VertexObjID);
-        glBufferDataARB_p(GL_ARRAY_BUFFER_ARB, $self->bed_triangles, GL_STATIC_DRAW_ARB);
-        glVertexPointer_c(3, GL_FLOAT, 0, 0);
-        $norms->bind($NormalObjID);
-        glBufferDataARB_p(GL_ARRAY_BUFFER_ARB, $norms, GL_STATIC_DRAW_ARB);
-        glNormalPointer_c(GL_FLOAT, 0, 0);
+        my $norms = OpenGL::Array->new_list(GL_FLOAT,(0.0, 0.0, 1.0)); # common normal for both
 
         glDisable(GL_DEPTH_TEST);
-
+        
         glEnable(GL_BLEND);
         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
         
         glEnableClientState(GL_VERTEX_ARRAY);
-        #glNormal3d(0,0,1);
-        #glVertexPointer_p(3, $self->bed_triangles);
+        if (HAS_VBO) {
+            my ($triangle_vertex);
+            ($triangle_vertex) =
+                glGenBuffersARB_p(1);
+            $self->bed_triangles->bind($triangle_vertex);
+            glBufferDataARB_p(GL_ARRAY_BUFFER_ARB, $self->bed_triangles, GL_STATIC_DRAW_ARB);
+            glVertexPointer_c(3, GL_FLOAT, 0, 0);
+        } else {
+            # fall back on old behavior
+            glVertexPointer_p(3, $self->bed_triangles);
+        }
+        glColor4f(0.8, 0.6, 0.5, 0.4);
+        glNormal3d(0,0,1);
         glDrawArrays(GL_TRIANGLES, 0, $self->bed_triangles->elements / 3);
         glDisableClientState(GL_VERTEX_ARRAY);
         
@@ -777,21 +783,31 @@ sub Render {
         # the object from below
         glEnable(GL_DEPTH_TEST);
     
-        my($GridVertexObjID,$GridNormalObjID,$GridColorObjID);
-        ($GridVertexObjID,$GridNormalObjID,$GridColorObjID) =
-            glGenBuffersARB_p(3);
-        glBufferDataARB_p(GL_ARRAY_BUFFER_ARB, $self->bed_grid_lines, GL_STATIC_DRAW_ARB);
-        glVertexPointer_c(3, GL_FLOAT, 0, 0);
         # draw grid
         glLineWidth(3);
-        glColor4f(0.2, 0.2, 0.2, 0.4);
         glEnableClientState(GL_VERTEX_ARRAY);
-
-        #glVertexPointer_p(3, $self->bed_grid_lines);
+        if (HAS_VBO) {
+            my ($grid_vertex);
+            ($grid_vertex) =
+                glGenBuffersARB_p(1);
+            $self->bed_grid_lines->bind($grid_vertex);
+            glBufferDataARB_p(GL_ARRAY_BUFFER_ARB, $self->bed_grid_lines, GL_STATIC_DRAW_ARB);
+            glVertexPointer_c(3, GL_FLOAT, 0, 0);
+        } else {
+            # fall back on old behavior
+            glVertexPointer_p(3, $self->bed_grid_lines);
+        }
+        glColor4f(0.2, 0.2, 0.2, 0.4);
+        glNormal3d(0,0,1);
         glDrawArrays(GL_LINES, 0, $self->bed_grid_lines->elements / 3);
         glDisableClientState(GL_VERTEX_ARRAY);
         
         glDisable(GL_BLEND);
+        if (HAS_VBO) { 
+            # Turn off buffer objects to let the rest of the draw code work.
+            glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
+            glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
+        }
     }
     
     my $volumes_bb = $self->volumes_bounding_box;