/********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com                 *
* Copyright (c) 2010-2015 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 "CubesScene.h"

// Namespaces
using namespace openglframework;
using namespace cubesscene;

// Constructor
CubesScene::CubesScene(const std::string& name)
      : SceneDemo(name, SCENE_RADIUS) {

    // Compute the radius and the center of the scene
    openglframework::Vector3 center(0, 5, 0);

    // Set the center of the scene
    setScenePosition(center, SCENE_RADIUS);

    // Gravity vector in the dynamics world
    rp3d::Vector3 gravity(0, rp3d::decimal(-9.81), 0);

    // Time step for the physics simulation
    rp3d::decimal timeStep = 1.0f / 60.0f;

    // Create the dynamics world for the physics simulation
    mDynamicsWorld = new rp3d::DynamicsWorld(gravity);

    // Set the number of iterations of the constraint solver
    mDynamicsWorld->setNbIterationsVelocitySolver(15);

    float radius = 2.0f;

    // Create all the cubes of the scene
    for (int i=0; i<NB_CUBES; i++) {

        // Position of the cubes
        float angle = i * 30.0f;
        openglframework::Vector3 position(radius * cos(angle),
                                          30 + i * (BOX_SIZE.y + 0.3f),
                                          0);

        // Create a cube and a corresponding rigid in the dynamics world
        Box* cube = new Box(BOX_SIZE, position , BOX_MASS, mDynamicsWorld);

        // Set the box color
        cube->setColor(mDemoColors[i % mNbDemoColors]);
        cube->setSleepingColor(mRedColorDemo);

        // Change the material properties of the rigid body
        rp3d::Material& material = cube->getRigidBody()->getMaterial();
        material.setBounciness(rp3d::decimal(0.4));

        // Add the box the list of box in the scene
        mBoxes.push_back(cube);
    }

    // Create the floor
    openglframework::Vector3 floorPosition(0, 0, 0);
    mFloor = new Box(FLOOR_SIZE, floorPosition, FLOOR_MASS, mDynamicsWorld);
    mFloor->setColor(mGreyColorDemo);
    mFloor->setSleepingColor(mGreyColorDemo);

    // The floor must be a static rigid body
    mFloor->getRigidBody()->setType(rp3d::STATIC);

    // Change the material properties of the floor rigid body
    rp3d::Material& material = mFloor->getRigidBody()->getMaterial();
    material.setBounciness(rp3d::decimal(0.3));

    // Get the physics engine parameters
    mEngineSettings.isGravityEnabled = mDynamicsWorld->isGravityEnabled();
    rp3d::Vector3 gravityVector = mDynamicsWorld->getGravity();
    mEngineSettings.gravity = openglframework::Vector3(gravityVector.x, gravityVector.y, gravityVector.z);
    mEngineSettings.isSleepingEnabled = mDynamicsWorld->isSleepingEnabled();
    mEngineSettings.sleepLinearVelocity = mDynamicsWorld->getSleepLinearVelocity();
    mEngineSettings.sleepAngularVelocity = mDynamicsWorld->getSleepAngularVelocity();
    mEngineSettings.nbPositionSolverIterations = mDynamicsWorld->getNbIterationsPositionSolver();
    mEngineSettings.nbVelocitySolverIterations = mDynamicsWorld->getNbIterationsVelocitySolver();
    mEngineSettings.timeBeforeSleep = mDynamicsWorld->getTimeBeforeSleep();
}

// Destructor
CubesScene::~CubesScene() {

    // Destroy all the cubes of the scene
    for (std::vector<Box*>::iterator it = mBoxes.begin(); it != mBoxes.end(); ++it) {

        // Destroy the corresponding rigid body from the dynamics world
        mDynamicsWorld->destroyRigidBody((*it)->getRigidBody());

        // Destroy the cube
        delete (*it);
    }

    // Destroy the rigid body of the floor
    mDynamicsWorld->destroyRigidBody(mFloor->getRigidBody());

    // Destroy the floor
    delete mFloor;

    // Destroy the dynamics world
    delete mDynamicsWorld;
}

// Update the physics world (take a simulation step)
void CubesScene::updatePhysics() {


    // Update the physics engine parameters
    mDynamicsWorld->setIsGratityEnabled(mEngineSettings.isGravityEnabled);
    rp3d::Vector3 gravity(mEngineSettings.gravity.x, mEngineSettings.gravity.y,
                                     mEngineSettings.gravity.z);
    mDynamicsWorld->setGravity(gravity);
    mDynamicsWorld->enableSleeping(mEngineSettings.isSleepingEnabled);
    mDynamicsWorld->setSleepLinearVelocity(mEngineSettings.sleepLinearVelocity);
    mDynamicsWorld->setSleepAngularVelocity(mEngineSettings.sleepAngularVelocity);
    mDynamicsWorld->setNbIterationsPositionSolver(mEngineSettings.nbPositionSolverIterations);
    mDynamicsWorld->setNbIterationsVelocitySolver(mEngineSettings.nbVelocitySolverIterations);
    mDynamicsWorld->setTimeBeforeSleep(mEngineSettings.timeBeforeSleep);

    // Take a simulation step
    mDynamicsWorld->update(mEngineSettings.timeStep);
}

// Update the scene
void CubesScene::update() {

    SceneDemo::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(mInterpolationFactor);
    }

    mFloor->updateTransform(mInterpolationFactor);
}

// Render the scene in a single pass
void CubesScene::renderSinglePass(Shader& shader, const openglframework::Matrix4& worldToCameraMatrix) {

    // Bind the shader
    shader.bind();

    // Render all the cubes of the scene
    for (std::vector<Box*>::iterator it = mBoxes.begin(); it != mBoxes.end(); ++it) {
        (*it)->render(shader, worldToCameraMatrix);
    }

    // Render the floor
    mFloor->render(shader, worldToCameraMatrix);

    // Unbind the shader
    shader.unbind();
}

// Reset the scene
void CubesScene::reset() {

    float radius = 2.0f;

    for (int i=0; i<NB_CUBES; i++) {

        // Position of the cubes
        float angle = i * 30.0f;
        openglframework::Vector3 position(radius * cos(angle),
                                          10 + i * (BOX_SIZE.y + 0.3f),
                                          0);

        // 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);

        mBoxes[i]->resetTransform(transform);
    }
}