From ed9a924880a0eb12a5d0e6e29108d211da953a66 Mon Sep 17 00:00:00 2001
From: bubnikv <bubnikv@gmail.com>
Date: Wed, 30 Jan 2019 19:02:30 +0100
Subject: [PATCH] Added missing GL context "Set Current" calls before loading
 data into vertex buffers.

Changed behavior of Canvas3D::on_render() to postpone rendering to idle,
as on OSX the paint events happen directly from control updates,
if the control update triggers Canvas3D window rescaling. With this change,
rendering only happens from idle handler consistently.
---
 src/slic3r/GUI/GLCanvas3D.cpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index de3c2e6aab..299341cd80 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -4627,6 +4627,8 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
     if ((m_canvas == nullptr) || (m_config == nullptr) || (m_model == nullptr))
         return;
 
+    _set_current();
+
     struct ModelVolumeState {
         ModelVolumeState(const GLVolume *volume) : 
 			model_volume(nullptr), geometry_id(volume->geometry_id), volume_idx(-1) {}
@@ -4933,6 +4935,8 @@ void GLCanvas3D::load_gcode_preview(const GCodePreviewData& preview_data, const
     const Print *print = this->fff_print();
     if ((m_canvas != nullptr) && (print != nullptr))
     {
+        _set_current();
+
         std::vector<float> tool_colors = _parse_colors(str_tool_colors);
 
         if (m_volumes.empty())
@@ -4970,6 +4974,7 @@ void GLCanvas3D::load_sla_preview()
     const SLAPrint* print = this->sla_print();
     if ((m_canvas != nullptr) && (print != nullptr))
     {
+        _set_current();
         _load_shells_sla();
     }
 }
@@ -4980,6 +4985,8 @@ void GLCanvas3D::load_preview(const std::vector<std::string>& str_tool_colors, c
     if (print == nullptr)
         return;
 
+    _set_current();
+
     _load_print_toolpaths();
     _load_wipe_tower_toolpaths(str_tool_colors);
     for (const PrintObject* object : print->objects())
@@ -5650,7 +5657,7 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
 
 void GLCanvas3D::on_paint(wxPaintEvent& evt)
 {
-    render();
+    m_dirty = true;
 }
 
 void GLCanvas3D::on_key_down(wxKeyEvent& evt)