Camera.cpp

#include "Camera.h"

// class based on www.gametutorials.com - see license.txt

Camera::Camera(){
  init();
}

void Camera::init(){
  position = CVector3(0.0f, 10.0f, -20.0f);
  view = CVector3(0.0f, 10.0f, -19.0f);
  upVector = CVector3(0.0f, 1.0f, 0.0f); 
}

Camera::~Camera(){
}

void Camera::rotateView(float angle, float x, float y, float z){
  CVector3 direction = getDirectionNormalized();

  // mouse/touch look sensitivity
  angle *= Engine::sensitivity;

  const float cosTheta = cosf(angle);
  const float sinTheta = sinf(angle);

  CVector3 newView;

  newView.x  = (cosTheta + (1 - cosTheta) * x * x)       * direction.x;
  newView.x += ((1 - cosTheta) * x * y - z * sinTheta)   * direction.y;
  newView.x += ((1 - cosTheta) * x * z + y * sinTheta)   * direction.z;

  newView.y  = ((1 - cosTheta) * x * y + z * sinTheta)   * direction.x;
  newView.y += (cosTheta + (1 - cosTheta) * y * y)       * direction.y;
  newView.y += ((1 - cosTheta) * y * z - x * sinTheta)   * direction.z;

  newView.z  = ((1 - cosTheta) * x * z - y * sinTheta)   * direction.x;
  newView.z += ((1 - cosTheta) * y * z + x * sinTheta)   * direction.y;
  newView.z += (cosTheta + (1 - cosTheta) * z * z)       * direction.z;

  view = position + newView;
}

void Camera::strafeCamera(float speed){   
  speed *= -1.0f; // invert

  position.x += strafe.x * speed;
  position.z += strafe.z * speed;

  view.x += strafe.x * speed;
  view.z += strafe.z * speed;
}

void Camera::moveCamera(float speed){
  CVector3 direction = getDirectionNormalized();

  position += direction * speed;
  view += direction * speed;
}

void Camera::applyKeyboardMovements(){
  const float speedUp = 30.0f;
  float speed = speedUp * Engine::frameInterval;

  if(speed < 0.0f)
    speed = -speed;

//#ifdef ANDROID
  if(Engine::buttonPressed != CVector2(-666.6f, -666.6f)){
    Engine::upKey = false;
    Engine::downKey = false; 
    Engine::leftKey = false; 
    Engine::rightKey = false;
    Engine::jumpKey = false;
    Engine::crouchKey = false;    

    CVector2 translatedButtonPressed = CVector2(Engine::buttonPressed.x - ((float)Engine::fontSize * 1.32f), Engine::screenHeightGL - Engine::buttonPressed.y - ((float)Engine::fontSize * (4.0f / 8.0f)));

    CVector2 distanceToLeftButton = Engine::buttonLeftCenter - translatedButtonPressed;
    float distanceLeft = distanceToLeftButton.magnitude();

    const float radiusForButton = 125.0f;
    if(distanceLeft < radiusForButton && distanceLeft > 1.0f){
      distanceToLeftButton.normalize();

      int maxComponent = distanceToLeftButton.maxComponentAbs();
      if(maxComponent == CVector2::X_COMPONENT){
        if(distanceToLeftButton.x > 0.0f){
          Engine::rightKey = true; // swapped left/right on purpose!
        } else {
          Engine::leftKey = true;           
        }
      } else {
        if(distanceToLeftButton.y > 0.0f){
          Engine::downKey = true; 
        } else {
          Engine::upKey = true;
        }
      }
    }

    // Handle right button field for mouse view
    CVector2 distanceToRightButton = Engine::buttonRightCenter - translatedButtonPressed;
    float distanceRight = distanceToRightButton.magnitude();
    if(distanceRight < radiusForButton){
      float angleY = 0.0f;                
      float angleZ = 0.0f;                       
      static float currentRotX = 0.0f;

      // mouse look
      CVector2 mouseMotion = CVector2(-distanceToRightButton.x, distanceToRightButton.y);
      angleY = (float)( (-mouseMotion.x)  / 3500.0f);       
      angleZ = (float)( (-mouseMotion.y)  / 3500.0f);     

      CVector3 viewMinusPosition = view - position;

      float dotProduct = upVector.dotProduct(&viewMinusPosition);

      currentRotX -= angleZ; 

      if(currentRotX > 1.0f)
        currentRotX = 1.0f;
      else if(currentRotX < -1.0f)
        currentRotX = -1.0f;

      if(dotProduct > 0.95f){					
        viewMinusPosition.x += 0.05f;
        viewMinusPosition.y -= 0.1f;
        viewMinusPosition.normalize();
        dotProduct = upVector.dotProduct(&viewMinusPosition);
      }

      if(dotProduct < -0.95f){
        viewMinusPosition.x += 0.05f;
        viewMinusPosition.y += 0.1f;
        viewMinusPosition.normalize();
        dotProduct = upVector.dotProduct(&viewMinusPosition);
      }

      CVector3 axis;
      axis = axis.cross(viewMinusPosition, upVector);
      axis.normalize();

      rotateView(angleZ, axis.x, axis.y, axis.z);
      rotateView(angleY, 0, 1, 0);
    }
  }
//#endif
 
  if(Engine::crouchKey){
    position.y -= speed;
    view.y -= speed;
  }
  if(Engine::jumpKey){
    position.y += speed;
    view.y += speed;
  }

  if(Engine::upKey){
    moveCamera(speed);
  }

  if(Engine::downKey){
    moveCamera(-speed);             
  }

  if(Engine::leftKey){
    strafeCamera(-speed);
  }

  if(Engine::rightKey){
  strafeCamera(speed);
  }
}

void Camera::update() {
  strafe = strafe.cross(view - position, upVector);
  strafe.normalize();

  applyKeyboardMovements();
}

CVector3 Camera::getDirectionNormalized(){
  CVector3 dir = view - position;
  if(dir.magnitude() < 0.01f) {
    cerr << "Camera direction is too small..." << endl;
  }
  dir.normalize();

  return dir;
}