Continue to implement the examples using the openg-framework

examples/CMakeLists.txt

@@ -1,5 +1,5 @@
 # Minimum cmake version required
 CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
 
-add_subdirectory(opengl-framework/)
+add_subdirectory(common/)
 add_subdirectory(fallingcubes/)

examples/common/Box.cpp

@@ -0,0 +1,180 @@
+/********************************************************************************
+* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/      *
+* Copyright (c) 2010-2013 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.    *
+*                                                                               *
+********************************************************************************/
+
+// Libraries
+#include "Box.h"
+
+// Macros
+#define MEMBER_OFFSET(s,m) ((char *)NULL + (offsetof(s,m)))
+
+// Initialize static variables
+openglframework::VertexBufferObject Box::mVBOVertices(GL_ARRAY_BUFFER);
+openglframework::VertexBufferObject Box::mVBOIndices(GL_ELEMENT_ARRAY_BUFFER);
+bool Box::areVBOsCreated = false;
+VertexData Box::mCubeVertices[8] = {
+ {openglframework::Vector3(1,1,1),openglframework::Vector3(1,1,1),openglframework::Color(0,0,1,1)},
+ {openglframework::Vector3(-1,1,1),openglframework::Vector3(-1,1,1),openglframework::Color(0,0,1,1)},
+ {openglframework::Vector3(-1,-1,1),openglframework::Vector3(-1,-1,1),openglframework::Color(0,0,1,1)},
+ {openglframework::Vector3(1,-1,1),openglframework::Vector3(1,-1,1),openglframework::Color(0,0,1,1)},
+ {openglframework::Vector3(1,-1,-1),openglframework::Vector3(1,-1,-1),openglframework::Color(0,0,1,1)},
+ {openglframework::Vector3(-1,-1,-1),openglframework::Vector3(-1,-1,-1),openglframework::Color(0,0,1,1)},
+ {openglframework::Vector3(-1,1,-1),openglframework::Vector3(-1,1,-1),openglframework::Color(0,0,1,1)},
+ {openglframework::Vector3(1,1,-1),openglframework::Vector3(1,1,-1),openglframework::Color(0,0,1,1)}
+};
+GLuint Box::mCubeIndices[36] = { 0, 1, 2,
+                                 2, 3, 0,
+                                 7, 4, 5,
+                                 5, 6, 7,
+                                 6, 5, 2,
+                                 2, 1, 6,
+                                 7, 0, 3,
+                                 3, 4, 7,
+                                 7, 6, 1,
+                                 1, 0, 7,
+                                 3, 2, 5,
+                                 5, 4, 3};
+
+// Constructor
+Box::Box(const openglframework::Vector3& size, const openglframework::Vector3 &position,
+         float mass, reactphysics3d::DynamicsWorld* dynamicsWorld)
+     : openglframework::Object3D() {
+
+    // Initialize the size of the box
+    mSize[0] = size.x * 0.5f;
+    mSize[1] = size.y * 0.5f;
+    mSize[2] = size.z * 0.5f;
+
+    // Compute the scaling matrix
+    mScalingMatrix = openglframework::Matrix4(mSize[0], 0, 0, 0,
+                                              0, mSize[1], 0, 0,
+                                              0, 0, mSize[2], 0,
+                                              0, 0, 0, 1);
+
+    // Initialize the position where the cube will be rendered
+    translateWorld(position);
+
+    // Create the collision shape for the rigid body (box shape)
+    mCollisionShape = new rp3d::BoxShape(rp3d::Vector3(mSize[0], mSize[1], mSize[2]));
+
+    // Compute the inertia tensor of the body using its collision shape
+    rp3d::Matrix3x3 inertiaTensor;
+    mCollisionShape->computeLocalInertiaTensor(inertiaTensor, mass);
+
+    // Initial position and orientation of the rigid body
+    rp3d::Vector3 initPosition(position.x, position.y, position.z);
+    rp3d::Quaternion initOrientation = rp3d::Quaternion::identity();
+    rp3d::Transform transform(initPosition, initOrientation);
+
+    // Create a rigid body corresponding to the cube in the dynamics world
+    mRigidBody = dynamicsWorld->createRigidBody(transform, mass, inertiaTensor, mCollisionShape);
+
+    // If the Vertex Buffer object has not been created yet
+    if (!areVBOsCreated) {
+        // Create the Vertex Buffer
+        createVBO();
+    }
+}
+
+// Destructor
+Box::~Box() {
+
+    // Destroy the collision shape
+    delete mCollisionShape;
+}
+
+// Render the cube at the correct position and with the correct orientation
+void Box::render(openglframework::Shader& shader) {
+
+    // Bind the shader
+    shader.bind();
+
+    // Set the model to World matrix
+    shader.setMatrix4x4Uniform("modelToWorldMatrix", mTransformMatrix);
+
+    // Bind the vertices VBO
+    mVBOVertices.bind();
+
+    // Enable the vertex, normal and color arrays
+    glEnableClientState(GL_VERTEX_ARRAY);
+    glEnableClientState(GL_COLOR_ARRAY);
+    glEnableClientState(GL_NORMAL_ARRAY);
+
+    // Set the arrays pointers
+    glVertexPointer(3, GL_FLOAT, sizeof(VertexData), MEMBER_OFFSET(VertexData, position));
+    glNormalPointer(GL_FLOAT, sizeof(VertexData), MEMBER_OFFSET(VertexData, normal));
+    glColorPointer(3, GL_FLOAT, sizeof(VertexData), MEMBER_OFFSET(VertexData, color));
+
+    // Bind the indices VBO
+    mVBOIndices.bind();
+
+    // Draw the geometry of the box
+    glDrawElements(GL_TRIANGLES, 36, GL_UNSIGNED_INT, (char*)NULL);
+
+    // Unbind the VBOs
+    mVBOVertices.unbind();
+    mVBOIndices.unbind();
+
+    // Disable the arrays
+    glDisableClientState(GL_VERTEX_ARRAY);
+    glDisableClientState(GL_COLOR_ARRAY);
+    glDisableClientState(GL_NORMAL_ARRAY);
+
+    // Unbind the shader
+    shader.unbind();
+}
+
+// Update the transform matrix of the box
+void Box::updateTransform() {
+
+    // Get the interpolated transform of the rigid body
+    rp3d::Transform transform = mRigidBody->getInterpolatedTransform();
+
+    // Compute the transform used for rendering the box
+    float matrix[16];
+    transform.getOpenGLMatrix(matrix);
+    openglframework::Matrix4 newMatrix(matrix[0], matrix[4], matrix[8], matrix[12],
+                                       matrix[1], matrix[5], matrix[9], matrix[13],
+                                       matrix[2], matrix[6], matrix[10], matrix[14],
+                                       matrix[3], matrix[7], matrix[11], matrix[15]);
+
+    // Apply the scaling matrix to have the correct box dimensions
+    mTransformMatrix = newMatrix * mScalingMatrix;
+}
+
+// Create the Vertex Buffer Objects used to render to box with OpenGL.
+/// We create two VBOs (one for vertices and one for indices) to render all the boxes
+/// in the simulation.
+void Box::createVBO() {
+
+    // Create the VBOs
+    mVBOVertices.create();
+    mVBOIndices.create();
+
+    // Copy the data into the VBOs
+    mVBOVertices.copyDataIntoVBO(sizeof(mCubeVertices), mCubeVertices, GL_STATIC_DRAW);
+    mVBOIndices.copyDataIntoVBO(sizeof(mCubeIndices), mCubeIndices, GL_STATIC_DRAW);
+
+    areVBOsCreated = true;
+}

examples/common/Box.h

@@ -0,0 +1,111 @@
+/********************************************************************************
+* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/      *
+* Copyright (c) 2010-2013 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 BOX_H
+#define BOX_H
+
+// Libraries
+#include "openglframework.h"
+#include "reactphysics3d.h"
+
+// Structure VertexData
+struct VertexData {
+
+    /// Vertex position
+    openglframework::Vector3 position;
+
+    /// Vertex normal
+    openglframework::Vector3 normal;
+
+    // Vertex color
+    openglframework::Color color;
+};
+
+// Class Box
+class Box : public openglframework::Object3D {
+
+    private :
+
+        // -------------------- Attributes -------------------- //
+
+        /// Size of each side of the box
+        float mSize[3];
+
+        /// Rigid body used to simulate the dynamics of the box
+        rp3d::RigidBody* mRigidBody;
+
+        /// Collision shape of the rigid body
+        rp3d::BoxShape* mCollisionShape;
+
+        /// Scaling matrix (applied to a cube to obtain the correct box dimensions)
+        openglframework::Matrix4 mScalingMatrix;
+
+        /// Vertex Buffer Object for the vertices data used to render the box with OpenGL
+        static openglframework::VertexBufferObject mVBOVertices;
+
+        /// Vertex Buffer Object for the indices used to render the box with OpenGL
+        static openglframework::VertexBufferObject mVBOIndices;
+
+        /// Vertex data for each vertex of the cube (used to render the box)
+        static VertexData mCubeVertices[8];
+
+        /// Indices of the cube (used to render the box)
+        static GLuint mCubeIndices[36];
+
+        /// True if the VBOs have already been created
+        static bool areVBOsCreated;
+
+        // -------------------- Methods -------------------- //
+
+        /// Create a Vertex Buffer Object to render to box with OpenGL
+        static void createVBO();
+
+    public :
+
+        // -------------------- Methods -------------------- //
+
+        /// Constructor
+        Box(const openglframework::Vector3& size, const openglframework::Vector3& position,
+            float mass, rp3d::DynamicsWorld* dynamicsWorld);
+
+        /// Destructor
+        ~Box();
+
+        /// Return a pointer to the rigid body of the box
+        rp3d::RigidBody* getRigidBody();
+
+        /// Update the transform matrix of the box
+        void updateTransform();
+
+        /// Render the cube at the correct position and with the correct orientation
+        void render(openglframework::Shader& shader);
+};
+
+// Return a pointer to the rigid body of the box
+inline rp3d::RigidBody* Box::getRigidBody() {
+    return mRigidBody;
+}
+
+#endif

examples/common/CMakeLists.txt

@@ -0,0 +1,4 @@
+# Minimum cmake version required
+CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+
+add_subdirectory(opengl-framework/)

examples/common/Viewer.cpp

@@ -0,0 +1,83 @@
+/********************************************************************************
+* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/      *
+* Copyright (c) 2010-2013 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.    *
+*                                                                               *
+********************************************************************************/
+
+// Libraries
+#include "Viewer.h"
+#include "openglframework.h"
+#include <sstream>
+
+// Constructor
+Viewer::Viewer() : openglframework::GlutViewer(), fps(0), nbFrames(0) {
+
+}
+
+// Compute the FPS
+void Viewer::computeFPS() {
+
+    nbFrames++;
+
+    //  Get the number of milliseconds since glutInit called
+    currentTime = glutGet(GLUT_ELAPSED_TIME);
+
+    //  Calculate time passed
+    int timeInterval = currentTime - previousTime;
+
+    // Update the FPS counter each second
+    if(timeInterval > 1000){
+
+        //  calculate the number of frames per second
+        fps = nbFrames / (timeInterval / 1000.0f);
+
+         //  Set time
+         previousTime = currentTime;
+
+         //  Reset frame count
+         nbFrames = 0;
+    }
+}
+
+// Display the GUI
+void Viewer::displayGUI() {
+
+    // Display the FPS
+    displayFPS();
+}
+
+// Display the FPS
+void Viewer::displayFPS() {
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glOrtho(0, mCamera.getWidth(), mCamera.getHeight(), 0, -1, 1);
+
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+
+    glRasterPos2i(10, 20);
+    glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
+    std::stringstream ss;
+    ss << "FPS : " << fps;
+    glutBitmapString(GLUT_BITMAP_HELVETICA_12, (const unsigned char*)ss.str().c_str());
+}

examples/common/Viewer.h

@@ -0,0 +1,71 @@
+/********************************************************************************
+* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/      *
+* Copyright (c) 2010-2013 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 VIEWER_H
+#define VIEWER_H
+
+// Libraries
+#include "openglframework.h"
+
+// Class Viewer
+class Viewer : public openglframework::GlutViewer {
+
+    private :
+
+        // -------------------- Attributes -------------------- //
+
+        /// Current number of frames per seconds
+        int fps;
+
+        /// Number of frames during the last second
+        int nbFrames;
+
+        /// Current time for fps computation
+        int currentTime;
+
+        /// Previous time for fps computation
+        int previousTime;
+
+        // -------------------- Methods -------------------- //
+
+        /// Display the FPS
+        void displayFPS();
+
+    public :
+
+        // -------------------- Methods -------------------- //
+
+        /// Constructor
+        Viewer();
+
+        /// Compute the FPS
+        void computeFPS();
+
+        /// Display the GUI
+        void displayGUI();
+
+};
+
+#endif

examples/common/opengl-framework/src/GlutViewer.cpp

@@ -168,6 +168,16 @@ void GlutViewer::mouseMotionEvent(int xMouse, int yMouse) {
     glutPostRedisplay();
 }
 
+// Called when a GLUT keyboard event occurs
+void GlutViewer::keyboardEvent(int key, int xMouse, int yMouse) {
+
+}
+
+// Called when a GLUT special keyboard event occurs
+void GlutViewer::keyboardSpecialEvent(int key, int xMouse, int yMouse) {
+
+}
+
 // Map the mouse x,y coordinates to a point on a sphere
 bool GlutViewer::mapMouseCoordinatesToSphere(int xMouse, int yMouse, Vector3& spherePoint) const {
 

examples/common/opengl-framework/src/GlutViewer.h

@@ -39,7 +39,7 @@ namespace openglframework {
 // Class Renderer
 class GlutViewer {
 
-    private:
+    protected :
 
         // -------------------- Attributes -------------------- //
 
@@ -81,7 +81,7 @@ class GlutViewer {
         GlutViewer();
 
         // Destructor
-        ~GlutViewer();
+        virtual ~GlutViewer();
 
         // Initialize the viewer
         bool init(int argc, char** argv, const std::string& windowsTitle,
@@ -112,16 +112,17 @@ class GlutViewer {
         // Get the camera
         Camera& getCamera();
 
-        void motion(int x, int y);
-
         // Called when a GLUT mouse button event occurs
         void mouseButtonEvent(int button, int state, int x, int y);
 
         // Called when a GLUT mouse motion event occurs
         void mouseMotionEvent(int xMouse, int yMouse);
 
-        void keyboard(int key, int x, int y);
+        // Called when a GLUT keyboard event occurs
-        void special(int key, int x, int y);
+        void keyboardEvent(int key, int xMouse, int yMouse);
+
+        // Called when a GLUT special keyboard event occurs
+        void keyboardSpecialEvent(int key, int xMouse, int yMouse);
 
         // Check the OpenGL errors
         static void checkOpenGLErrors();

examples/fallingcubes/CMakeLists.txt

@@ -5,13 +5,13 @@ cmake_minimum_required(VERSION 2.6)
 PROJECT(FallingCubes)
 
 # Copy the shaders used for the demo into the build directory
-FILE(COPY "../opengl-framework/src/shaders/" DESTINATION "${CMAKE_CURRENT_BINARY_DIR}/shaders/")
+FILE(COPY "../common/opengl-framework/src/shaders/" DESTINATION "${CMAKE_CURRENT_BINARY_DIR}/shaders/")
 
 # Headers
-INCLUDE_DIRECTORIES("../opengl-framework/src/")
+INCLUDE_DIRECTORIES("../common/opengl-framework/src/" "../common/")
 
 # Create the example executable using the
 # compiled reactphysics3d static library
-ADD_EXECUTABLE(fallingcubes main.cpp Scene.cpp Scene.h Box.cpp Box.h)
+ADD_EXECUTABLE(fallingcubes FallingCubes.cpp Scene.cpp Scene.h "../common/Box.cpp" "../common/Box.h" "../common/Viewer.cpp" "../common/Viewer.h")
 
 TARGET_LINK_LIBRARIES(fallingcubes reactphysics3d openglframework)

examples/fallingcubes/FallingCubes.cpp

@@ -25,40 +25,32 @@
 
 // Libraries
 #include "Scene.h"
-#include <sstream>
+#include "Viewer.h"
 
 // Declarations
 void simulate();
 void display();
-void displayFPS();
+void finish();
-void computeFPS();
 void reshape(int width, int height);
 void mouseButton(int button, int state, int x, int y);
 void mouseMotion(int x, int y);
-void keyboardSpecial(int key, int x, int y);
+void keyboard(unsigned char key, int x, int y);
 void init();
 
 // Namespaces
 using namespace openglframework;
 
 // Global variables
-GlutViewer* viewer;
+Viewer* viewer;
 Scene* scene;
-int fps;
-int nbFrames;
-int currentTime;
-int previousTime;
-int width, height;
 
 // Main function
 int main(int argc, char** argv) {
 
     // Create and initialize the Viewer
-    viewer = new GlutViewer();
+    viewer = new Viewer();
     Vector2 windowsSize = Vector2(800, 600);
     Vector2 windowsPosition = Vector2(100, 100);
-    width = windowsSize.x;
-    height = windowsSize.y;
     bool initOK = viewer->init(argc, argv, "ReactPhysics3D Examples - Falling Cubes", windowsSize, windowsPosition);
     if (!initOK) return 1;
 
@@ -67,21 +59,18 @@ int main(int argc, char** argv) {
 
     init();
 
-    nbFrames = 0;
-
     // Glut Idle function that is continuously called
     glutIdleFunc(simulate);
     glutDisplayFunc(display);
     glutReshapeFunc(reshape);
     glutMouseFunc(mouseButton);
     glutMotionFunc(mouseMotion);
-    glutSpecialFunc(keyboardSpecial);
+    glutKeyboardFunc(keyboard);
 
     // Glut main looop
     glutMainLoop();
 
-    delete viewer;
+    finish();
-    delete scene;
 
     return 0;
 }
@@ -92,7 +81,7 @@ void simulate() {
     // Physics simulation
     scene->simulate();
 
-    computeFPS();
+    viewer->computeFPS();
 
     // Ask GLUT to render the scene
     glutPostRedisplay ();
@@ -108,8 +97,6 @@ void init() {
 // Reshape function
 void reshape(int newWidth, int newHeight) {
     viewer->reshape(newWidth, newHeight);
-    width = newWidth;
-    height = newHeight;
 }
 
 // Called when a mouse button event occurs
@@ -123,12 +110,28 @@ void mouseMotion(int x, int y) {
 }
 
 // Called when the user hits a special key on the keyboard
-void keyboardSpecial(int key, int x, int y) {
+void keyboard(unsigned char key, int x, int y) {
-   /*
+    switch(key) {
-    if(key=='0')
+
+        // Escape key
+        case 27:
+            finish();
             exit(0);
-    if(key== GLUT_KEY_RIGHT) {
+            break;
-    */
+
+        // Space bar
+        case 32:
+            scene->pauseContinueSimulation();
+            break;
+    }
+}
+
+// End of the application
+void finish() {
+
+    // Destroy the viewer and the scene
+    delete viewer;
+    delete scene;
 }
 
 // Display the scene
@@ -138,7 +141,7 @@ void display() {
     scene->render();
 
     // Display the FPS
-    displayFPS();
+    viewer->displayGUI();
 
     // Swap the buffers
     glutSwapBuffers();
@@ -147,43 +150,4 @@ void display() {
     GlutViewer::checkOpenGLErrors();
 }
 
-// Compute the FPS
-void computeFPS() {
-    nbFrames++;
 
-    //  Get the number of milliseconds since glutInit called
-    currentTime = glutGet(GLUT_ELAPSED_TIME);
-
-    //  Calculate time passed
-    int timeInterval = currentTime - previousTime;
-
-    // Update the FPS counter each second
-    if(timeInterval > 1000){
-
-        //  calculate the number of frames per second
-        fps = nbFrames / (timeInterval / 1000.0f);
-
-         //  Set time
-         previousTime = currentTime;
-
-         //  Reset frame count
-         nbFrames = 0;
-    }
-}
-
-// Display the FPS
-void displayFPS() {
-
-    glMatrixMode(GL_PROJECTION);
-    glLoadIdentity();
-    glOrtho(0, width, height, 0, -1, 1);
-
-    glMatrixMode(GL_MODELVIEW);
-    glLoadIdentity();
-
-    glRasterPos2i(10, 20);
-    glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
-    std::stringstream ss;
-    ss << "FPS : " << fps;
-    glutBitmapString(GLUT_BITMAP_HELVETICA_12, (const unsigned char*)ss.str().c_str());
-}

examples/fallingcubes/Scene.cpp

@@ -32,32 +32,40 @@ using namespace openglframework;
 // Constructor
 Scene::Scene(GlutViewer* viewer) : mViewer(viewer), mLight0(0),
                                mPhongShader("shaders/phong.vert",
-                                            "shaders/phong.frag"){
+                                            "shaders/phong.frag"), mIsRunning(false) {
 
     // Move the light 0
     mLight0.translateWorld(Vector3(7, 15, 15));
 
     // Compute the radius and the center of the scene
-    float radius = 10.0f;
+    float radiusScene = 10.0f;
     openglframework::Vector3 center(0, 5, 0);
 
     // Set the center of the scene
-    mViewer->setScenePosition(center, radius);
+    mViewer->setScenePosition(center, radiusScene);
 
     // Gravity vector in the dynamics world
     rp3d::Vector3 gravity(0, -9.81, 0);
 
     // Time step for the physics simulation
-    rp3d::decimal timeStep = 1.0f / 80.0f;
+    rp3d::decimal timeStep = 1.0f / 60.0f;
 
     // Create the dynamics world for the physics simulation
     mDynamicsWorld = new rp3d::DynamicsWorld(gravity, timeStep);
 
+    // Set the number of iterations of the constraint solver
+    mDynamicsWorld->setNbIterationsSolver(15);
+
+    float radius = 2.0f;
+
     // Create all the cubes of the scene
     for (int i=0; i<NB_BOXES; i++) {
 
         // Position of the cubes
-        openglframework::Vector3 position(0, 5 + i * (BOX_SIZE.y + 0.5f), 0);
+        float angle = i * 30.0f;
+        openglframework::Vector3 position(radius * cos(angle),
+                                          1 + i * (BOX_SIZE.y + 0.3f),
+                                          radius * sin(angle));
 
         // Create a cube and a corresponding rigid in the dynamics world
         Box* cube = new Box(BOX_SIZE, position , BOX_MASS, mDynamicsWorld);
@@ -83,14 +91,14 @@ Scene::Scene(GlutViewer* viewer) : mViewer(viewer), mLight0(0),
     mFloor->getRigidBody()->setRestitution(0.3);
 
     // Start the simulation
-    mDynamicsWorld->start();
+    startSimulation();
 }
 
 // Destructor
 Scene::~Scene() {
 
     // Stop the physics simulation
-    mDynamicsWorld->stop();
+    stopSimulation();
 
     // Destroy the shader
     mPhongShader.destroy();
@@ -118,17 +126,22 @@ Scene::~Scene() {
 // Take a step for the simulation
 void Scene::simulate() {
 
-    // Take a simulation step
+    // If the physics simulation is running
-    mDynamicsWorld->update();
+    if (mIsRunning) {
 
-    // Update the position and orientation of the boxes
+        // Take a simulation step
-    for (std::vector<Box*>::iterator it = mBoxes.begin(); it != mBoxes.end(); ++it) {
+        mDynamicsWorld->update();
+
+        // Update the position and orientation of the boxes
+        for (std::vector<Box*>::iterator it = mBoxes.begin(); it != mBoxes.end(); ++it) {
+
+            // Update the transform used for the rendering
+            (*it)->updateTransform();
+        }
+
+        mFloor->updateTransform();
 
-        // Update the transform used for the rendering
-        (*it)->updateTransform();
     }
-
-    mFloor->updateTransform();
 }
 
 // Render the scene
@@ -136,7 +149,7 @@ void Scene::render() {
 
     glEnable(GL_DEPTH_TEST);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-    glDisable(GL_CULL_FACE);
+    glEnable(GL_CULL_FACE);
 
     // Bind the shader
     mPhongShader.bind();

examples/fallingcubes/Scene.h

@@ -32,7 +32,7 @@
 #include "Box.h"
 
 // Constants
-const int NB_BOXES = 10;                                     // Number of boxes in the scene
+const int NB_BOXES = 20;                                    // Number of boxes in the scene
 const openglframework::Vector3 BOX_SIZE(2, 2, 2);           // Box dimensions in meters
 const openglframework::Vector3 FLOOR_SIZE(20, 0.5f, 20);    // Floor dimensions in meters
 const float BOX_MASS = 1.0f;                                // Box mass in kilograms
@@ -63,6 +63,9 @@ class Scene {
         /// Dynamics world used for the physics simulation
         rp3d::DynamicsWorld* mDynamicsWorld;
 
+        /// True if the physics simulation is running
+        bool mIsRunning;
+
     public:
 
         // -------------------- Methods -------------------- //
@@ -76,8 +79,39 @@ class Scene {
         /// Take a step for the simulation
         void simulate();
 
+        /// Stop the simulation
+        void stopSimulation();
+
+        /// Start the simulation
+        void startSimulation();
+
+        /// Pause or continue simulation
+        void pauseContinueSimulation();
+
         /// Render the scene
         void render();
 };
 
+// Stop the simulation
+inline void Scene::stopSimulation() {
+    mDynamicsWorld->stop();
+    mIsRunning = false;
+}
+
+// Start the simulation
+inline void Scene::startSimulation() {
+    mDynamicsWorld->start();
+    mIsRunning = true;
+}
+
+// Pause or continue simulation
+inline void Scene::pauseContinueSimulation() {
+    if (mIsRunning) {
+        stopSimulation();
+    }
+    else {
+        startSimulation();
+    }
+}
+
 #endif

src/engine/DynamicsWorld.h

@@ -215,7 +215,6 @@ inline void DynamicsWorld::start() {
 }
 
 inline void DynamicsWorld::stop() {
-    std::cout << "Stop Simulation" << std::endl;
     mTimer.stop();
 }