From a72fb79f72d60570b23081903fb596dcb7ebe18a Mon Sep 17 00:00:00 2001
From: enricoturri1966 <enricoturri@seznam.cz>
Date: Mon, 9 Nov 2020 14:27:00 +0100
Subject: [PATCH] #5098 - Fixed no preview after language change

---
 src/slic3r/GUI/GCodeViewer.cpp | 75 ++++++++++++++++------------------
 src/slic3r/GUI/GCodeViewer.hpp |  1 +
 2 files changed, 37 insertions(+), 39 deletions(-)

diff --git a/src/slic3r/GUI/GCodeViewer.cpp b/src/slic3r/GUI/GCodeViewer.cpp
index 5dd728284a..0b5bb23aac 100644
--- a/src/slic3r/GUI/GCodeViewer.cpp
+++ b/src/slic3r/GUI/GCodeViewer.cpp
@@ -412,6 +412,9 @@ void GCodeViewer::refresh(const GCodeProcessor::Result& gcode_result, const std:
 
 void GCodeViewer::reset()
 {
+    m_initialized = false;
+    m_gl_data_initialized = false;
+
     m_moves_count = 0;
     for (TBuffer& buffer : m_buffers) {
         buffer.reset();
@@ -439,46 +442,39 @@ void GCodeViewer::reset()
 void GCodeViewer::render() const
 {
     auto init_gl_data = [this]() {
-        static bool first_run = true;
-        if (first_run) {
-            // initializes opengl data of TBuffers
-            for (size_t i = 0; i < m_buffers.size(); ++i) {
-                TBuffer& buffer = m_buffers[i];
-                switch (buffer_type(i))
-                {
-                default: { break; }
-                case EMoveType::Tool_change:
-                case EMoveType::Color_change:
-                case EMoveType::Pause_Print:
-                case EMoveType::Custom_GCode:
-                case EMoveType::Retract:
-                case EMoveType::Unretract:
-                {
-                    buffer.shader = wxGetApp().is_glsl_version_greater_or_equal_to(1, 20) ? "options_120" : "options_110";
-                    break;
-                }
-                case EMoveType::Extrude:
-                {
-                    buffer.shader = "gouraud_light";
-                    break;
-                }
-                case EMoveType::Travel:
-                {
-                    buffer.shader = "toolpaths_lines";
-                    break;
-                }
-                }
+        // initializes opengl data of TBuffers
+        for (size_t i = 0; i < m_buffers.size(); ++i) {
+            TBuffer& buffer = m_buffers[i];
+            switch (buffer_type(i)) {
+            default: { break; }
+            case EMoveType::Tool_change:
+            case EMoveType::Color_change:
+            case EMoveType::Pause_Print:
+            case EMoveType::Custom_GCode:
+            case EMoveType::Retract:
+            case EMoveType::Unretract: {
+                buffer.shader = wxGetApp().is_glsl_version_greater_or_equal_to(1, 20) ? "options_120" : "options_110";
+                break;
+            }
+            case EMoveType::Extrude: {
+                buffer.shader = "gouraud_light";
+                break;
+            }
+            case EMoveType::Travel: {
+                buffer.shader = "toolpaths_lines";
+                break;
+            }
             }
-
-            // initializes tool marker
-            m_sequential_view.marker.init();
-
-            // initializes point sizes
-            std::array<int, 2> point_sizes;
-            ::glGetIntegerv(GL_ALIASED_POINT_SIZE_RANGE, point_sizes.data());
-            m_detected_point_sizes = { static_cast<float>(point_sizes[0]), static_cast<float>(point_sizes[1]) };
-            first_run = false;
         }
+
+        // initializes tool marker
+        m_sequential_view.marker.init();
+
+        // initializes point sizes
+        std::array<int, 2> point_sizes;
+        ::glGetIntegerv(GL_ALIASED_POINT_SIZE_RANGE, point_sizes.data());
+        m_detected_point_sizes = { static_cast<float>(point_sizes[0]), static_cast<float>(point_sizes[1]) };
+        m_gl_data_initialized = true;
     };
 
 #if ENABLE_GCODE_VIEWER_STATISTICS
@@ -487,7 +483,8 @@ void GCodeViewer::render() const
 
     // OpenGL data must be initialized after the glContext has been created.
     // This is ensured when this method is called by GLCanvas3D::_render_gcode().
-    init_gl_data();
+    if (!m_gl_data_initialized)
+        init_gl_data();
 
     if (m_roles.empty())
         return;
diff --git a/src/slic3r/GUI/GCodeViewer.hpp b/src/slic3r/GUI/GCodeViewer.hpp
index fb805da4ac..93eb86932a 100644
--- a/src/slic3r/GUI/GCodeViewer.hpp
+++ b/src/slic3r/GUI/GCodeViewer.hpp
@@ -388,6 +388,7 @@ public:
 
 private:
     bool m_initialized{ false };
+    mutable bool m_gl_data_initialized{ false };
     unsigned int m_last_result_id{ 0 };
     size_t m_moves_count{ 0 };
     mutable std::vector<TBuffer> m_buffers{ static_cast<size_t>(EMoveType::Extrude) };