Continue to work on GUI for the testbed application

testbed/common/Box.cpp

@@ -60,7 +60,7 @@ GLuint Box::mCubeIndices[36] = { 0, 1, 2,
 // Constructor
 Box::Box(const openglframework::Vector3& size, const openglframework::Vector3 &position,
          reactphysics3d::CollisionWorld* world, openglframework::Shader& shader)
-    : openglframework::Object3D(), mColor(0.5f, 0.5f, 0.5f, 1.0f) {
+    : openglframework::Object3D(), mColor(0.01f, 0.62f, 0.39f, 1.0f) {
 
     // Initialize the size of the box
     mSize[0] = size.x * 0.5f;
@@ -107,7 +107,7 @@ Box::Box(const openglframework::Vector3& size, const openglframework::Vector3 &p
 // Constructor
 Box::Box(const openglframework::Vector3& size, const openglframework::Vector3 &position,
          float mass, reactphysics3d::DynamicsWorld* world, openglframework::Shader& shader)
-    : openglframework::Object3D(), mColor(0.5f, 0.5f, 0.5f, 1.0f) {
+    : openglframework::Object3D(), mColor(0.01f, 0.62f, 0.39f, 1.0f) {
 
     // Initialize the size of the box
     mSize[0] = size.x * 0.5f;

testbed/common/Capsule.cpp

@@ -32,7 +32,7 @@ Capsule::Capsule(float radius, float height, const openglframework::Vector3& pos
                  const std::string& meshFolderPath, openglframework::Shader& shader)
         : openglframework::Mesh(), mRadius(radius), mHeight(height), mVBOVertices(GL_ARRAY_BUFFER),
           mVBONormals(GL_ARRAY_BUFFER), mVBOTextureCoords(GL_ARRAY_BUFFER),
-          mVBOIndices(GL_ELEMENT_ARRAY_BUFFER), mColor(1.0f, 0.5f, 0.5f, 1.0f) {
+          mVBOIndices(GL_ELEMENT_ARRAY_BUFFER), mColor(0.5f, 0.5f, 0.5f, 1.0f) {
 
     // Load the mesh from a file
     openglframework::MeshReaderWriter::loadMeshFromFile(meshFolderPath + "capsule.obj", *this);

testbed/opengl-framework/src/VertexArrayObject.cpp

@@ -0,0 +1,70 @@
+/********************************************************************************
+* OpenGL-Framework                                                              *
+* Copyright (c) 2015 Daniel Chappuis                                            *
+*********************************************************************************
+*                                                                               *
+* This software is provided 'as-is', without any express or implied warranty.   *
+* In no event will the authors be held liable for any damages arising from the  *
+* use of this software.                                                         *
+*                                                                               *
+* Permission is granted to anyone to use this software for any purpose,         *
+* including commercial applications, and to alter it and redistribute it        *
+* freely, subject to the following restrictions:                                *
+*                                                                               *
+* 1. The origin of this software must not be misrepresented; you must not claim *
+*    that you wrote the original software. If you use this software in a        *
+*    product, an acknowledgment in the product documentation would be           *
+*    appreciated but is not required.                                           *
+*                                                                               *
+* 2. Altered source versions must be plainly marked as such, and must not be    *
+*    misrepresented as being the original software.                             *
+*                                                                               *
+* 3. This notice may not be removed or altered from any source distribution.    *
+*                                                                               *
+********************************************************************************/
+
+// Libraries
+#include "VertexArrayObject.h"
+
+using namespace openglframework;
+
+// Constructor
+VertexArrayObject::VertexArrayObject() : mVertexArrayID(0) {
+
+}
+
+// Destructor
+VertexArrayObject::~VertexArrayObject() {
+
+}
+
+// Create the vertex buffer object
+bool VertexArrayObject::create() {
+
+    // Destroy the current VAO
+    destroy();
+
+    // Check that the needed OpenGL extensions are available
+    bool isExtensionOK = checkOpenGLExtensions();
+    if (!isExtensionOK) {
+        std::cerr << "Error : Impossible to use Vertex Array Object on this platform" << std::endl;
+        assert(false);
+        return false;
+    }
+
+    // Generate a new VAO
+    glGenVertexArrays(1, &mVertexArrayID);
+    assert(mVertexArrayID != 0);
+
+    return true;
+}
+
+// Destroy the VAO
+void VertexArrayObject::destroy() {
+
+    // Delete the vertex buffer object
+    if (mVertexArrayID) {
+        glDeleteVertexArrays(1, &mVertexArrayID);
+        mVertexArrayID = 0;
+    }
+}

testbed/opengl-framework/src/VertexArrayObject.h

@@ -0,0 +1,99 @@
+/********************************************************************************
+* OpenGL-Framework                                                              *
+* Copyright (c) 2013 Daniel Chappuis                                            *
+*********************************************************************************
+*                                                                               *
+* This software is provided 'as-is', without any express or implied warranty.   *
+* In no event will the authors be held liable for any damages arising from the  *
+* use of this software.                                                         *
+*                                                                               *
+* Permission is granted to anyone to use this software for any purpose,         *
+* including commercial applications, and to alter it and redistribute it        *
+* freely, subject to the following restrictions:                                *
+*                                                                               *
+* 1. The origin of this software must not be misrepresented; you must not claim *
+*    that you wrote the original software. If you use this software in a        *
+*    product, an acknowledgment in the product documentation would be           *
+*    appreciated but is not required.                                           *
+*                                                                               *
+* 2. Altered source versions must be plainly marked as such, and must not be    *
+*    misrepresented as being the original software.                             *
+*                                                                               *
+* 3. This notice may not be removed or altered from any source distribution.    *
+*                                                                               *
+********************************************************************************/
+
+#ifndef VERTEX_ARRAY_OBJECT_H
+#define VERTEX_ARRAY_OBJECT_H
+
+// Libraries
+#include <GL/glew.h>
+#include <cassert>
+#include <iostream>
+
+namespace openglframework {
+
+
+// Class VertexArrayObject
+class VertexArrayObject {
+
+    private :
+
+        // -------------------- Attributes -------------------- //
+
+        /// ID of the Vertex Array Object
+        GLuint mVertexArrayID;
+
+    public :
+
+        // -------------------- Methods -------------------- //
+
+        /// Constructor
+        VertexArrayObject();
+
+        /// Destructor
+        ~VertexArrayObject();
+
+        /// Create the vertex buffer object
+        bool create();
+
+        /// Bind the VAO
+        void bind() const;
+
+        /// Unbind the VAO
+        void unbind() const;
+
+        /// Return true if the needed OpenGL extensions are available for VAO
+        static bool checkOpenGLExtensions();
+
+        /// Destroy the VAO
+        void destroy();
+};
+
+// Bind the VAO
+inline void VertexArrayObject::bind() const {
+    assert(mVertexArrayID != 0);
+
+    // Bind the VAO
+    glBindVertexArray(mVertexArrayID);
+}
+
+// Unbind the VAO
+inline void VertexArrayObject::unbind() const {
+    assert(mVertexArrayID != 0);
+
+    // Unbind the VAO
+    glBindVertexArray(0);
+}
+
+// Return true if the needed OpenGL extensions are available for VAO
+inline bool VertexArrayObject::checkOpenGLExtensions() {
+
+    // Check that OpenGL version is at least 3.0 or there the vertex array object extension exists
+    return (GLEW_VERSION_3_0 || GL_ARB_vertex_array_object);
+}
+
+}
+
+#endif
+

testbed/shaders/gui.frag

@@ -0,0 +1,10 @@
+#version 330
+uniform sampler2D Texture;
+in vec2 Frag_UV;
+in vec4 Frag_Color;
+out vec4 Out_Color;
+
+void main()
+{
+    Out_Color = Frag_Color * texture( Texture, Frag_UV.st);
+}

testbed/shaders/gui.vert

@@ -0,0 +1,15 @@
+#version 330
+
+uniform mat4 ProjMtx;
+in vec2 Position;
+in vec2 UV;
+in vec4 Color;
+out vec2 Frag_UV;
+out vec4 Frag_Color;
+
+void main()
+{
+    Frag_UV = UV;
+    Frag_Color = Color;
+    gl_Position = ProjMtx * vec4(Position.xy,0,1);
+}

testbed/src/Gui.cpp

@@ -26,6 +26,7 @@
 // Libraries
 #include "Gui.h"
 #include <GLFW/glfw3.h>
+#include "TestbedApplication.h"
 
 GLFWwindow* Gui::mWindow = NULL;
 double Gui::g_Time = 0.0f;
@@ -33,14 +34,16 @@ bool Gui::g_MousePressed[3] = {false, false, false};
 float Gui::g_MouseWheel = 0.0f;
 GLuint Gui::g_FontTexture = 0;
 size_t Gui::g_VboSize = 0;
-unsigned int Gui::g_VboHandle = 0;
-unsigned int Gui::g_VaoHandle = 0;
 int Gui::g_AttribLocationTex = 0, Gui::g_AttribLocationProjMtx = 0;
 int Gui::g_AttribLocationPosition = 0, Gui::g_AttribLocationUV = 0, Gui::g_AttribLocationColor = 0;
 Shader Gui::mShader;
+openglframework::VertexBufferObject Gui::mVBO(GL_ARRAY_BUFFER);
+openglframework::VertexArrayObject Gui::mVAO;
+Gui::LeftPane Gui::mLeftPane = SCENES;
 
 // Constructor
 Gui::Gui() {
+
     g_Time = 0.0f;
     g_MousePressed[0] = false;
     g_MousePressed[1] = false;
@@ -48,16 +51,13 @@ Gui::Gui() {
     g_MouseWheel = 0.0f;
     g_FontTexture = 0;
     g_VboSize = 0;
-    g_VboHandle = 0, g_VaoHandle = 0;
 }
 
 // Destructor
 Gui::~Gui() {
 
-    if (g_VaoHandle) glDeleteVertexArrays(1, &g_VaoHandle);
+    mVAO.destroy();
-    if (g_VboHandle) glDeleteBuffers(1, &g_VboHandle);
+    mVBO.destroy();
-    g_VaoHandle = 0;
-    g_VboHandle = 0;
 
     mShader.destroy();
 
@@ -101,11 +101,111 @@ void Gui::init() {
     io.RenderDrawListsFn = renderDrawLists;
     io.SetClipboardTextFn = setClipboardText;
     io.GetClipboardTextFn = getClipboardText;
+
+    io.FontGlobalScale = GUI_SCALING;
+}
+
+void Gui::displayHeader() {
+
+    ImVec2 buttonSize(120, 40);
+
+    int display_w, display_h;
+    glfwGetFramebufferSize(mWindow, &display_w, &display_h);
+
+    ImGuiWindowFlags window_flags = 0;
+    window_flags |= ImGuiWindowFlags_NoTitleBar;
+    window_flags |= ImGuiWindowFlags_NoResize;
+    window_flags |= ImGuiWindowFlags_NoMove;
+
+    ImGui::PushID("Header");
+    ImGui::PushStyleColor(ImGuiCol_WindowBg, BACKGROUND_COLOR);
+
+        ImGui::Begin("Header", NULL, ImVec2(display_w, HEADER_HEIGHT), 1.0f, window_flags);
+        ImGui::SetWindowPos(ImVec2(0, 0));
+        ImGui::Button("Play", buttonSize); ImGui::SameLine();
+        ImGui::Button("Pause", buttonSize); ImGui::SameLine();
+        ImGui::Button("Step", buttonSize); ImGui::SameLine();
+        ImGui::Button("Restart", buttonSize); ImGui::SameLine();
+        ImGui::End();
+
+    ImGui::PopStyleColor(1);
+    ImGui::PopID();
+}
+
+void Gui::displayLeftPane() {
+
+    const int nbButtonsHeader = 4;
+    ImVec2 buttonSize(LEFT_PANE_WIDTH / nbButtonsHeader - 9, LEFT_PANE_HEADER_HEIGHT);
+
+    int display_w, display_h;
+    glfwGetFramebufferSize(mWindow, &display_w, &display_h);
+
+    ImGuiWindowFlags window_flags = 0;
+    window_flags |= ImGuiWindowFlags_NoTitleBar;
+    window_flags |= ImGuiWindowFlags_NoResize;
+    window_flags |= ImGuiWindowFlags_NoMove;
+
+    ImGui::PushID("LeftPane");
+    ImGui::PushStyleColor(ImGuiCol_WindowBg, BACKGROUND_COLOR);
+
+        ImGui::Begin("LeftPane", NULL, ImVec2(LEFT_PANE_WIDTH, display_h - HEADER_HEIGHT), 1.0f, window_flags);
+        ImGui::SetWindowPos(ImVec2(0, HEADER_HEIGHT));
+
+        // ----- Left Pane Header ----- //
+        ImGui::Button("Scenes", buttonSize); ImGui::SameLine();
+        ImGui::Button("Physics", buttonSize); ImGui::SameLine();
+        ImGui::Button("Rendering", buttonSize); ImGui::SameLine();
+        ImGui::Button("Profiling", buttonSize);
+
+        // Display the left pane content
+        switch(mLeftPane) {
+            case SCENES: displayScenesPane(); break;
+            case PHYSICS: displayPhysicsPane(); break;
+            case RENDERING: displayRenderingPane(); break;
+            case PROFILING: displayProfilingPane(); break;
+        }
+
+        ImGui::End();
+
+    ImGui::PopStyleColor(1);
+    ImGui::PopID();
+}
+
+// Display the list of scenes
+void Gui::displayScenesPane() {
+
+    static int choice = 0;
+    int startChoice = choice;
+    TestbedApplication& app = TestbedApplication::getInstance();
+    std::vector<Scene*> scenes = app.getScenes();
+
+    // For each scene
+    for (int i=0; i<scenes.size(); i++) {
+
+        // Display a radio button
+        ImGui::RadioButton(scenes[i]->getName().c_str(), &choice, i);
+    }
+
+    // If the user changed scene
+    if (choice != startChoice) {
+        app.switchScene(scenes[choice]);
+    }
+}
+
+void Gui::displayPhysicsPane() {
+
+}
+
+void Gui::displayRenderingPane() {
+
+}
+
+void Gui::displayProfilingPane() {
+
 }
 
 void Gui::createDeviceObjects() {
 
-    /*
     mShader.create("shaders/gui.vert", "shaders/gui.frag");
 
     GLuint shaderID = mShader.getProgramObjectId();
@@ -115,11 +215,11 @@ void Gui::createDeviceObjects() {
     g_AttribLocationUV = glGetAttribLocation(shaderID, "UV");
     g_AttribLocationColor = glGetAttribLocation(shaderID, "Color");
 
-        glGenBuffers(1, &g_VboHandle);
+    mVBO.create();
 
-        glGenVertexArrays(1, &g_VaoHandle);
+    mVAO.create();
-        glBindVertexArray(g_VaoHandle);
+    mVAO.bind();
-        glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
+    mVBO.bind();
     glEnableVertexAttribArray(g_AttribLocationPosition);
     glEnableVertexAttribArray(g_AttribLocationUV);
     glEnableVertexAttribArray(g_AttribLocationColor);
@@ -128,45 +228,37 @@ void Gui::createDeviceObjects() {
     glVertexAttribPointer(g_AttribLocationUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, uv));
     glVertexAttribPointer(g_AttribLocationColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, col));
 #undef OFFSETOF
-        glBindVertexArray(0);
+    mVAO.unbind();
-        glBindBuffer(GL_ARRAY_BUFFER, 0);
+    mVBO.unbind();
 
     createFontTextures();
-        */
 }
 
 // Display the GUI
 void Gui::render() {
 
-/*
     ImGuiIO& io = ImGui::GetIO();
     //glfwPollEvents();
     beginNewFrame();
 
-
     bool show_test_window = true;
     bool show_another_window = false;
     ImVec4 clear_color = ImColor(255, 255, 255);
 
-    // 1. Show a simple window
+    displayHeader();
-    // Tip: if we don't call ImGui::Begin()/ImGui::End() the widgets appears in a window automatically called "Debug"
+    displayLeftPane();
-    {
-        ImGui::Text("Hello, world!");
-    }
 
+    ImGui::ShowTestWindow();
 
     // Render the GUI
     ImGui::Render();
-    */
 }
 
 void Gui::beginNewFrame() {
 
-    /*
     if (!g_FontTexture)
         createDeviceObjects();
 
-
     ImGuiIO& io = ImGui::GetIO();
 
     // Setup display size (every frame to accommodate for window resizing)
@@ -210,7 +302,6 @@ void Gui::beginNewFrame() {
 
     // Start the frame
     ImGui::NewFrame();
-    */
 }
 
 void Gui::createFontTextures()
@@ -236,7 +327,6 @@ void Gui::createFontTextures()
 // - in your Render function, try translating your projection matrix by (0.5f,0.5f) or (0.375f,0.375f)
 void Gui::renderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count)
 {
-    std::cout << "OpenGLVersion : " << glGetString(GL_VERSION) << std::endl;
     if (cmd_lists_count == 0)
         return;
 
@@ -252,7 +342,7 @@ void Gui::renderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count)
     glEnable(GL_SCISSOR_TEST);
     glActiveTexture(GL_TEXTURE0);
 
-    /*
+
     // Setup orthographic projection matrix
     const float width = ImGui::GetIO().DisplaySize.x;
     const float height = ImGui::GetIO().DisplaySize.y;
@@ -279,12 +369,13 @@ void Gui::renderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count)
     size_t total_vtx_count = 0;
     for (int n = 0; n < cmd_lists_count; n++)
         total_vtx_count += cmd_lists[n]->vtx_buffer.size();
-    glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
+    mVBO.bind();
     size_t needed_vtx_size = total_vtx_count * sizeof(ImDrawVert);
     if (g_VboSize < needed_vtx_size)
     {
         g_VboSize = needed_vtx_size + 5000 * sizeof(ImDrawVert);  // Grow buffer
-        glBufferData(GL_ARRAY_BUFFER, g_VboSize, NULL, GL_STREAM_DRAW);
+        mVBO.copyDataIntoVBO(g_VboSize, NULL, GL_STREAM_DRAW);
+        //glBufferData(GL_ARRAY_BUFFER, g_VboSize, NULL, GL_STREAM_DRAW);
     }
 
     // Copy and convert all vertices into a single contiguous buffer
@@ -298,8 +389,8 @@ void Gui::renderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count)
         buffer_data += cmd_list->vtx_buffer.size() * sizeof(ImDrawVert);
     }
     glUnmapBuffer(GL_ARRAY_BUFFER);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    mVBO.unbind();
-    glBindVertexArray(g_VaoHandle);
+    mVAO.bind();
 
     int cmd_offset = 0;
     for (int n = 0; n < cmd_lists_count; n++)
@@ -324,14 +415,11 @@ void Gui::renderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count)
         cmd_offset = vtx_offset;
     }
 
-
-
     // Restore modified state
-    glBindVertexArray(0);
+    mVAO.unbind();
     glUseProgram(last_program);
     glDisable(GL_SCISSOR_TEST);
     glBindTexture(GL_TEXTURE_2D, last_texture);
-    */
 }
 
 const char* Gui::getClipboardText() {

testbed/src/Gui.h

@@ -32,13 +32,25 @@
 #include <GLFW/glfw3.h>
 #include "openglframework.h"
 
+// Constants
+const float GUI_SCALING = 2.0f;
+const int HEADER_HEIGHT = 80;
+const int LEFT_PANE_WIDTH = 700;
+const int LEFT_PANE_HEADER_HEIGHT = 60;
+const ImColor BACKGROUND_COLOR = ImColor(41, 41, 41, 255);
+
 using namespace openglframework;
 
+// Declarations
+class TestbedApplication;
+
 // Class Gui
 class Gui {
 
     protected :
 
+        enum LeftPane {SCENES, PHYSICS, RENDERING, PROFILING};
+
         // -------------------- Constants -------------------- //
 
 
@@ -48,7 +60,6 @@ class Gui {
         static GLFWwindow* mWindow;
 
         static Shader mShader;
-
         static double       g_Time;
         static bool         g_MousePressed[3];
         static float        g_MouseWheel;
@@ -57,7 +68,9 @@ class Gui {
         static int          g_AttribLocationTex, g_AttribLocationProjMtx;
         static int          g_AttribLocationPosition, g_AttribLocationUV, g_AttribLocationColor;
         static size_t       g_VboSize;
-        static unsigned int g_VboHandle, g_VaoHandle;
+        static openglframework::VertexBufferObject mVBO;
+        static openglframework::VertexArrayObject mVAO;
+        static LeftPane mLeftPane;
 
 
         // -------------------- Methods -------------------- //
@@ -74,6 +87,16 @@ class Gui {
 
         static void setClipboardText(const char* text);
 
+        static void displayHeader();
+        static void displayLeftPane();
+
+        /// Display the list of scenes
+        static void displayScenesPane();
+
+        static void displayPhysicsPane();
+        static void displayRenderingPane();
+        static void displayProfilingPane();
+
     public :
 
         // -------------------- Methods -------------------- //

testbed/src/Scene.h

@@ -152,6 +152,9 @@ class Scene {
 
         /// Set the interpolation factor
         void setInterpolationFactor(float interpolationFactor);
+
+        /// Return the name of the scene
+        std::string getName() const;
 };
 
 // Called when a keyboard event occurs
@@ -185,4 +188,9 @@ inline void Scene::setInterpolationFactor(float interpolationFactor) {
     mInterpolationFactor = interpolationFactor;
 }
 
+// Return the name of the scene
+inline std::string Scene::getName() const {
+    return mName;
+}
+
 #endif

testbed/src/TestbedApplication.cpp

@@ -137,7 +137,7 @@ void TestbedApplication::init() {
     Gui::getInstance().setWindow(mWindow);
 
     // Init the GUI
-    //Gui::getInstance().init();
+    Gui::getInstance().init();
 
     mTimer.start();
 }
@@ -149,21 +149,17 @@ void TestbedApplication::createScenes() {
     CubesScene* cubeScene = new CubesScene("Cubes");
     mScenes.push_back(cubeScene);
 
-    /*
     // Joints scene
     JointsScene* jointsScene = new JointsScene("Joints");
     mScenes.push_back(jointsScene);
-    */
 
     // Collision shapes scene
     CollisionShapesScene* collisionShapesScene = new CollisionShapesScene("Collision Shapes");
     mScenes.push_back(collisionShapesScene);
 
-    /*
     // Raycast scene
     RaycastScene* raycastScene = new RaycastScene("Raycast");
     mScenes.push_back(raycastScene);
-    */
 
     assert(mScenes.size() > 0);
     mCurrentScene = mScenes[1];
@@ -225,11 +221,22 @@ void TestbedApplication::update() {
 // Render
 void TestbedApplication::render() {
 
+    // Get the framebuffer dimension
+    int width, height;
+    glfwGetFramebufferSize(mWindow, &width, &height);
+
+    // Resize the OpenGL viewport
+    glViewport(LEFT_PANE_WIDTH, HEADER_HEIGHT,
+               width - LEFT_PANE_WIDTH, height - HEADER_HEIGHT);
+
     // Render the scene
     mCurrentScene->render();
 
+    // Resize the OpenGL viewport
+    glViewport(0, 0, width, height);
+
     // Display the GUI
-    //Gui::getInstance().render();
+    Gui::getInstance().render();
 
     // Check the OpenGL errors
     checkOpenGLErrors();
@@ -243,10 +250,11 @@ void TestbedApplication::reshape() {
     glfwGetFramebufferSize(mWindow, &width, &height);
 
     // Resize the camera viewport
-    mCurrentScene->reshape(width, height);
+    mCurrentScene->reshape(width - LEFT_PANE_WIDTH, height - HEADER_HEIGHT);
 
     // Resize the OpenGL viewport
-    glViewport(0, 0, width, height);
+    //glViewport(LEFT_PANE_WIDTH, HEADER_HEIGHT,
+    //           width - LEFT_PANE_WIDTH, height - HEADER_HEIGHT);
 
     // Update the window size of the scene
     int windowWidth, windowHeight;
@@ -281,6 +289,17 @@ void TestbedApplication::startMainLoop() {
     }
 }
 
+// Change the current scene
+void TestbedApplication::switchScene(Scene* newScene) {
+
+    if (newScene == mCurrentScene) return;
+
+    mCurrentScene = newScene;
+
+    // Reset the scene
+    mCurrentScene->reset();
+}
+
 // Check the OpenGL errors
 void TestbedApplication::checkOpenGLErrors() {
     GLenum glError;

testbed/src/TestbedApplication.h

@@ -137,6 +137,9 @@ class TestbedApplication {
         /// Remove all the scenes
         void destroyScenes();
 
+        /// Return the list of the scenes
+        std::vector<Scene*> getScenes();
+
     public :
 
         // -------------------- Methods -------------------- //
@@ -152,8 +155,19 @@ class TestbedApplication {
 
         /// Start the main loop where rendering occur
         void startMainLoop();
+
+        /// Change the current scene
+        void switchScene(Scene* newScene);
+
+        // -------------------- Friendship -------------------- //
+
+        friend class Gui;
 };
 
+// Return the list of the scenes
+inline std::vector<Scene*> TestbedApplication::getScenes() {
+    return mScenes;
+}
 
 
 #endif