#include "Camera.h"
#include "GameEngine.h"
#include "Utils.h"
#include <cmath>

Camera::Camera()
{
}

Camera::Camera(const Camera& orig)
{
}

Camera::~Camera()
{
}

void Camera::storePosition()
{
    oldCamera.set(camera);
}

void Camera::storeAngles()
{
    oldLengthAngle = lengthAngle;
    oldWidthAngle = widthAngle;
}

void Camera::setPosition(float x, float y, float z)
{
    camera.set(x, y, z);
}

void Camera::setAngles(float length, float width)
{
    lengthAngle = length;
    widthAngle = width;
}

void Camera::updateView(float lag)
{
    // -------------------------------------------------------------------------
    // calculate vectors for the view matrix
    // -------------------------------------------------------------------------
    
    // front
    front.setAngles(interpolate(lag, oldLengthAngle, lengthAngle), interpolate(lag, oldWidthAngle, widthAngle));

    // back
    back.setInverse(front);

    // right
    right.set(front);
    right.cross(0.0f, 1.0f, 0.0f);
    right.normalize();
    
    // left
    left.setInverse(right);
    
    // up
    up.set(front);
    up.cross(left);
    up.normalize();
    
    interCamera.set(oldCamera);
    interCamera.addMul(camera, lag);
    interCamera.addMul(oldCamera, -lag);
    
    view.set(0, 0, right.getX());
    view.set(0, 1, right.getY());
    view.set(0, 2, right.getZ());
    view.set(0, 3, right.dotInverse(interCamera));
    
    view.set(1, 0, up.getX());
    view.set(1, 1, up.getY());
    view.set(1, 2, up.getZ());
    view.set(1, 3, up.dotInverse(interCamera));
    
    view.set(2, 0, back.getX());
    view.set(2, 1, back.getY());
    view.set(2, 2, back.getZ());
    view.set(2, 3, back.dotInverse(interCamera));
    
    view.set(3, 0, 0.0f);
    view.set(3, 1, 0.0f);
    view.set(3, 0, 0.0f);
    view.set(3, 3, 1.0f);
   
    // -------------------------------------------------------------------------
    // calculate vectors for movement
    // -------------------------------------------------------------------------
    
    // front
    front.setY(0.0f);
    front.normalize();

    // back
    back.setInverse(front);

    // right
    right.set(front);
    right.cross(0.0f, 1.0f, 0.0f);
    right.normalize();
    
    // left
    left.setInverse(right);

    // up
    up.set(0.0f, 1.0f, 0.0f);
    
    // down
    down.setInverse(up);
    
    GameEngine::updateView(view);
}

const Vector3D& Camera::getFront()
{
    return front;
}

const Vector3D& Camera::getBack()
{
    return back;
}

const Vector3D& Camera::getRight()
{
    return right;
}

const Vector3D& Camera::getLeft()
{
    return left;
}

const Vector3D& Camera::getUp()
{
    return up;
}

const Vector3D& Camera::getDown()
{
    return down;
}