//===========================================================================
/*
    This file is part of the CHAI 3D visualization and haptics libraries.
    Copyright (C) 2003-2009 by CHAI 3D. All rights reserved.

    This library is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License("GPL") version 2
    as published by the Free Software Foundation.

    For using the CHAI 3D libraries with software that can not be combined
    with the GNU GPL, and for taking advantage of the additional benefits
    of our support services, please contact CHAI 3D about acquiring a
    Professional Edition License.

    \author    <http://www.chai3d.org>
    \author    Francois Conti
    \version   2.0.0 $Rev: 269 $
*/
//===========================================================================

//---------------------------------------------------------------------------
#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//---------------------------------------------------------------------------
#include "chai3d.h"
//---------------------------------------------------------------------------

//---------------------------------------------------------------------------
// DECLARED CONSTANTS
//---------------------------------------------------------------------------

// initial size (width/height) in pixels of the display window
const int WINDOW_SIZE_W         = 600;
const int WINDOW_SIZE_H         = 600;

// mouse menu options (right button)
const int OPTION_FULLSCREEN     = 1;
const int OPTION_WINDOWDISPLAY  = 2;


//---------------------------------------------------------------------------
// DECLARED VARIABLES
//---------------------------------------------------------------------------

// a world that contains all objects of the virtual environment
cWorld* world;

// a camera that renders the world in a window display
cCamera* camera;

// a light source to illuminate the objects in the virtual scene
cLight *light;

// a little "chai3d" bitmap logo at the bottom of the screen
cBitmap* logo;

// width and height of the current window display
int displayW  = 0;
int displayH  = 0;

// a haptic device handler
cHapticDeviceHandler* handler;

// a virtual tool representing the haptic device in the scene
cGeneric3dofPointer* tool;

// radius of the tool proxy
double proxyRadius;

// a virtual object
cMesh* object;

// rotational velocity of the object
cVector3d rotVel;

// display level for collision tree
int collisionTreeDisplayLevel = 1;

// status of the main simulation haptics loop
bool simulationRunning = false;

// simulation clock
cPrecisionClock simClock;

// root resource path
string resourceRoot;

// has exited haptics simulation thread
bool simulationFinished = false;

//---------------------------------------------------------------------------
// DECLARED MACROS
//---------------------------------------------------------------------------
// convert to resource path
#define RESOURCE_PATH(p)    (char*)((resourceRoot+string(p)).c_str())


//---------------------------------------------------------------------------
// DECLARED FUNCTIONS
//---------------------------------------------------------------------------

// callback when the window display is resized
void resizeWindow(int w, int h);

// callback when a keyboard key is pressed
void keySelect(unsigned char key, int x, int y);

// callback when the right mouse button is pressed to select a menu item
void menuSelect(int value);

// function called before exiting the application
void close(void);

// main graphics callback
void updateGraphics(void);

// main haptics loop
void updateHaptics(void);


//===========================================================================
/*
    DEMO:    object.cpp

    This demonstration loads a 3D mesh file by using the file loader
    functionality of the cMesh class. A finger-proxy algorithm is used to
    render the forces. Take a look at this example to understand the
    different functionalities offered by the tool force renderer.

    In the main haptics loop function  "updateHaptics()" , the position
    of the haptic device is retrieved at each simulation iteration.
    The interaction forces are then computed and sent to the device.
    Finally, a simple dynamics model is used to simulate the behavior
    of the object.
*/
//===========================================================================

int main(int argc, char* argv[])
{
    //-----------------------------------------------------------------------
    // INITIALIZATION
    //-----------------------------------------------------------------------

    printf ("\n");
    printf ("-----------------------------------\n");
    printf ("CHAI 3D\n");
    printf ("Demo: 21-object\n");
    printf ("Copyright 2003-2009\n");
    printf ("-----------------------------------\n");
    printf ("\n\n");
    printf ("Keyboard Options:\n\n");
    printf ("[1] - Texture   (ON/OFF)\n");
    printf ("[2] - Wireframe (ON/OFF)\n");
    printf ("[3] - Collision tree (ON/OFF)\n");
    printf ("[+] - Increase collision tree tisplay depth\n");
    printf ("[-] - Decrease collision tree tisplay depth\n");
    printf ("[x] - Exit application\n");
    printf ("\n\n");

    // parse first arg to try and locate resources
    resourceRoot = string(argv[0]).substr(0,string(argv[0]).find_last_of("/\\")+1);


    //-----------------------------------------------------------------------
    // 3D - SCENEGRAPH
    //-----------------------------------------------------------------------

    // create a new world.
    world = new cWorld();

    // set the background color of the environment
    // the color is defined by its (R,G,B) components.
    world->setBackgroundColor(0.0, 0.0, 0.0);

    // create a camera and insert it into the virtual world
    camera = new cCamera(world);
    world->addChild(camera);

    // position and oriente the camera
    camera->set( cVector3d (3.0, 0.0, 0.0),    // camera position (eye)
                 cVector3d (0.0, 0.0, 0.0),    // lookat position (target)
                 cVector3d (0.0, 0.0, 1.0));   // direction of the "up" vector

    // set the near and far clipping planes of the camera
    // anything in front/behind these clipping planes will not be rendered
    camera->setClippingPlanes(0.01, 10.0);

    // create a light source and attach it to the camera
    light = new cLight(world);
    camera->addChild(light);                   // attach light to camera
    light->setEnabled(true);                   // enable light source
    light->setPos(cVector3d( 2.0, 0.5, 1.0));  // position the light source
    light->setDir(cVector3d(-2.0, 0.5, 1.0));  // define the direction of the light beam


    //-----------------------------------------------------------------------
    // 2D - WIDGETS
    //-----------------------------------------------------------------------

    // create a 2D bitmap logo
    logo = new cBitmap();

    // add logo to the front plane
    camera->m_front_2Dscene.addChild(logo);

    // load a "chai3d" bitmap image file
    bool fileload;
    fileload = logo->m_image.loadFromFile(RESOURCE_PATH("resources/images/chai3d.bmp"));
    if (!fileload)
    {
        #if defined(_MSVC)
        fileload = logo->m_image.loadFromFile("../../../bin/resources/images/chai3d.bmp");
        #endif
    }

    // position the logo at the bottom left of the screen (pixel coordinates)
    logo->setPos(10, 10, 0);

    // scale the logo along its horizontal and vertical axis
    logo->setZoomHV(0.4, 0.4);

    // here we replace all black pixels (0,0,0) of the logo bitmap
    // with transparent black pixels (0, 0, 0, 0). This allows us to make
    // the background of the logo look transparent.
    logo->m_image.replace(
                          cColorb(0, 0, 0),      // original RGB color
                          cColorb(0, 0, 0, 0)    // new RGBA color
                          );

    // enable transparency
    logo->enableTransparency(true);


    //-----------------------------------------------------------------------
    // HAPTIC DEVICES / TOOLS
    //-----------------------------------------------------------------------

    // create a haptic device handler
    handler = new cHapticDeviceHandler();

    // get access to the first available haptic device
    cGenericHapticDevice* hapticDevice;
    handler->getDevice(hapticDevice, 0);

    // retrieve information about the current haptic device
    cHapticDeviceInfo info;
    if (hapticDevice)
    {
        info = hapticDevice->getSpecifications();
    }

    // create a 3D tool and add it to the world
    tool = new cGeneric3dofPointer(world);
    world->addChild(tool);

    // connect the haptic device to the tool
    tool->setHapticDevice(hapticDevice);

    // initialize tool by connecting to haptic device
    tool->start();

    // map the physical workspace of the haptic device to a larger virtual workspace.
    tool->setWorkspaceRadius(1.0);

    // define a radius for the tool
    tool->setRadius(0.01);

    // hide the device sphere. only show proxy.
    tool->m_deviceSphere->setShowEnabled(false);

    // set the physical radius of the proxy. for performance reasons, it is
    // sometimes useful to set this value to zero when dealing with
    // complex objects.
    proxyRadius = 0.01;
    tool->m_proxyPointForceModel->setProxyRadius(proxyRadius);

    // inform the proxy algorithm to only check front sides of triangles
    tool->m_proxyPointForceModel->m_collisionSettings.m_checkBothSidesOfTriangles = false;

    // enable if objects in the scene are going to rotate of translate
    // or possibly collide against the tool. If the environment
    // is entirely static, you can set this parameter to "false"
    tool->m_proxyPointForceModel->m_useDynamicProxy = true;

    // read the scale factor between the physical workspace of the haptic
    // device and the virtual workspace defined for the tool
    double workspaceScaleFactor = tool->getWorkspaceScaleFactor();

    // define a maximum stiffness that can be handled by the current
    // haptic device. The value is scaled to take into account the
    // workspace scale factor
    double stiffnessMax = info.m_maxForceStiffness / workspaceScaleFactor;


    //-----------------------------------------------------------------------
    // COMPOSE THE VIRTUAL SCENE
    //-----------------------------------------------------------------------

    // create a virtual mesh
    object = new cMesh(world);

    // add object to world
    world->addChild(object);

    // set the position of the object at the center of the world
    object->setPos(0.0, 0.0, 0.0);

    // load an object file
    fileload = object->loadFromFile(RESOURCE_PATH("resources/models/camera/camera.3ds"));
    if (!fileload)
    {
        #if defined(_MSVC)
        fileload = object->loadFromFile("../../../bin/resources/models/camera/camera.3ds");
        #endif
    }
    if (!fileload)
    {
        printf("Error - 3D Model failed to load correctly.\n");
        close();
        return (-1);
    }

    // compute a boundary box
    object->computeBoundaryBox(true);

    // get dimensions of object
    double size = cSub(object->getBoundaryMax(), object->getBoundaryMin()).length();

    // resize object to screen
    if (size > 0)
    {
        object->scale( 2.0 * tool->getWorkspaceRadius() / size);
    }

    // compute collision detection algorithm
    object->createAABBCollisionDetector(1.01 * proxyRadius, true, false);

    // define a default stiffness for the object
    object->setStiffness(stiffnessMax, true);

    // define some haptic friction properties
    object->setFriction(0.1, 0.2, true);


    //-----------------------------------------------------------------------
    // OPEN GL - WINDOW DISPLAY
    //-----------------------------------------------------------------------

    // initialize GLUT
    glutInit(&argc, argv);

    // retrieve the resolution of the computer display and estimate the position
    // of the GLUT window so that it is located at the center of the screen
    int screenW = glutGet(GLUT_SCREEN_WIDTH);
    int screenH = glutGet(GLUT_SCREEN_HEIGHT);
    int windowPosX = (screenW - WINDOW_SIZE_W) / 2;
    int windowPosY = (screenH - WINDOW_SIZE_H) / 2;

    // initialize the OpenGL GLUT window
    glutInitWindowPosition(windowPosX, windowPosY);
    glutInitWindowSize(WINDOW_SIZE_W, WINDOW_SIZE_H);
    glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
    glutCreateWindow(argv[0]);
    glutDisplayFunc(updateGraphics);
    glutKeyboardFunc(keySelect);
    glutReshapeFunc(resizeWindow);
    glutSetWindowTitle("CHAI 3D");

    // create a mouse menu (right button)
    glutCreateMenu(menuSelect);
    glutAddMenuEntry("full screen", OPTION_FULLSCREEN);
    glutAddMenuEntry("window display", OPTION_WINDOWDISPLAY);
    glutAttachMenu(GLUT_RIGHT_BUTTON);


    //-----------------------------------------------------------------------
    // START SIMULATION
    //-----------------------------------------------------------------------

    // simulation in now running
    simulationRunning = true;

    // create a thread which starts the main haptics rendering loop
    cThread* hapticsThread = new cThread();
    hapticsThread->set(updateHaptics, CHAI_THREAD_PRIORITY_HAPTICS);

    // start the main graphics rendering loop
    glutMainLoop();

    // close everything
    close();

    // exit
    return (0);
}

//---------------------------------------------------------------------------

void resizeWindow(int w, int h)
{
    // update the size of the viewport
    displayW = w;
    displayH = h;
    glViewport(0, 0, displayW, displayH);
}

//---------------------------------------------------------------------------

void keySelect(unsigned char key, int x, int y)
{
    // escape key
    if ((key == 27) || (key == 'x'))
    {
        // close everything
        close();

        // exit application
        exit(0);
    }

    // option 1:
    if (key == '1')
    {
        bool useTexture = object->getUseTexture();
        object->setUseTexture(!useTexture);
    }

    // option 2:
    if (key == '2')
    {
        bool useWireMode = object->getWireMode();
        object->setWireMode(!useWireMode, true);
    }

    // option 3:
    if (key == '3')
    {
        cColorf tmpColor = cColorf(1.0, 0.0, 0.0);
        object->setCollisionDetectorProperties(collisionTreeDisplayLevel, tmpColor, true);
        bool showCollisionTree = object->getShowCollisionTree();
        object->setShowCollisionTree(!showCollisionTree, true);
    }

    // option -:
    if (key == '-')
    {
        collisionTreeDisplayLevel--;
        if (collisionTreeDisplayLevel < 0) { collisionTreeDisplayLevel = 0; }
        cColorf tmpColor = cColorf(1.0, 0.0, 0.0);
        object->setCollisionDetectorProperties(collisionTreeDisplayLevel, tmpColor, true);
        object->setShowCollisionTree(true, true);
    }

    // option +:
    if (key == '+')
    {
        collisionTreeDisplayLevel++;
        cColorf tmpColor = cColorf(1.0, 0.0, 0.0);
        object->setCollisionDetectorProperties(collisionTreeDisplayLevel, tmpColor, true);
        object->setShowCollisionTree(true, true);
    }
}

//---------------------------------------------------------------------------

void menuSelect(int value)
{
    switch (value)
    {
        // enable full screen display
        case OPTION_FULLSCREEN:
            glutFullScreen();
            break;

        // reshape window to original size
        case OPTION_WINDOWDISPLAY:
            glutReshapeWindow(WINDOW_SIZE_W, WINDOW_SIZE_H);
            break;
    }
}

//---------------------------------------------------------------------------

void close(void)
{
    // stop the simulation
    simulationRunning = false;

    // wait for graphics and haptics loops to terminate
    while (!simulationFinished) { cSleepMs(100); }

    // close haptic device
    tool->stop();
}

//---------------------------------------------------------------------------

void updateGraphics(void)
{
    // render world
    camera->renderView(displayW, displayH);

    // Swap buffers
    glutSwapBuffers();

    // check for any OpenGL errors
    GLenum err;
    err = glGetError();
    if (err != GL_NO_ERROR) printf("Error:  %s\n", gluErrorString(err));

    // inform the GLUT window to call updateGraphics again (next frame)
    if (simulationRunning)
    {
        glutPostRedisplay();
    }
}

//---------------------------------------------------------------------------

void updateHaptics(void)
{
    // reset clock
    simClock.reset();

    // main haptic simulation loop
    while(simulationRunning)
    {
        // compute global reference frames for each object
        world->computeGlobalPositions(true);

        // update position and orientation of tool
        tool->updatePose();

        // compute interaction forces
        tool->computeInteractionForces();

        // send forces to device
        tool->applyForces();

        // retrieve and update the force that is applied on each object

        // stop the simulation clock
        simClock.stop();

        // read the time increment in seconds
        double timeInterval = simClock.getCurrentTimeSeconds();

        // restart the simulation clock
        simClock.reset();
        simClock.start();

        // temp variable to compute rotational acceleration
        cVector3d rotAcc(0,0,0);

        // check if tool is touching an object
        cGenericObject* objectContact = tool->m_proxyPointForceModel->m_contactPoint0->m_object;
        if (objectContact != NULL)
        {
            // retrieve the root of the object mesh
            cGenericObject* obj = objectContact->getSuperParent();

            // get position of cursor in global coordinates
            cVector3d toolPos = tool->m_deviceGlobalPos;

            // get position of object in global coordinates
            cVector3d objectPos = obj->getGlobalPos();

            // compute a vector from the center of mass of the object (point of rotation) to the tool
            cVector3d vObjectCMToTool = cSub(toolPos, objectPos);

            // compute acceleration based on the interaction forces
            // between the tool and the object
            if (vObjectCMToTool.length() > 0.0)
            {
                // get the last force applied to the cursor in global coordinates
                // we negate the result to obtain the opposite force that is applied on the
                // object
                cVector3d toolForce = cNegate(tool->m_lastComputedGlobalForce);

                // compute effective force to take into account the fact the object
                // can only rotate around a its center mass and not translate
                cVector3d effectiveForce = toolForce - cProject(toolForce, vObjectCMToTool);

                // compute the resulting torque
                cVector3d torque = cMul(vObjectCMToTool.length(), cCross( cNormalize(vObjectCMToTool), effectiveForce));

                // update rotational acceleration
                const double OBJECT_INERTIA = 0.4;
                rotAcc = (1.0 / OBJECT_INERTIA) * torque;
            }
        }

        // update rotational velocity
        rotVel.add(timeInterval * rotAcc);

        // set a threshold on the rotational velocity term
        const double ROT_VEL_MAX = 10.0;
        double velMag = rotVel.length();
        if (velMag > ROT_VEL_MAX)
        {
            rotVel.mul(ROT_VEL_MAX / velMag);
        }

        // add some damping too
        const double DAMPING_GAIN = 0.1;
        rotVel.mul(1.0 - DAMPING_GAIN * timeInterval);

        // if user switch is pressed, set velocity to zero
        if (tool->getUserSwitch(0) == 1)
        {
            rotVel.zero();
        }

        // compute the next rotation configuration of the object
        if (rotVel.length() > CHAI_SMALL)
        {
            object->rotate(cNormalize(rotVel), timeInterval * rotVel.length());
        }
    }

    // exit haptics thread
    simulationFinished = true;
}

//---------------------------------------------------------------------------
