#include "common.h"
#include "Camera.h"



namespace CHCDemo 
{


Camera::Camera() 
{
	mWidth = 100;
	mHeight = 100;
	mFovy = 90.0f * M_PI/180.0f;
}


Camera::Camera(int width, int height, float fieldOfView) 
{
	mWidth = width;
	mHeight = height;
	
	mFovy = fieldOfView * M_PI/180.0f;
}


void Camera::Precompute() 
{
	mDirection.Normalize();

	Vector3 side = CrossProd(Vector3(0,1,0), mDirection);
	mUp = Normalize(CrossProd(side, mDirection));
	mRight = Normalize(CrossProd(mDirection, mUp));

	float k = tan(mFovy/2);
	mUp *= k;
	mRight *= k*mWidth/mHeight;
}


void Camera::SetPosition(const Vector3 &pos) 
{
	mPosition = pos;
	Precompute();
}


void Camera::SetDirection(const Vector3 &dir) 
{
	mDirection = dir;
	Precompute();
}


void Camera::LookInBox(const AxisAlignedBox3 &box)
{
	mDirection = Vector3(0,0,1);
	mPosition = box.Center();

	Precompute();
}


void Camera::LookAtBox(const AxisAlignedBox3 &box)
{
	mDirection = box.Max() - box.Min();
	mPosition = box.Min() - mDirection;

	Precompute();
}

}