#include "stdafx.h"
#include "IResourceFactory.h"
#include "PerspectiveCamera.h"


PerspectiveCamera::PerspectiveCamera(IEngine& argEngine)
	: BaseCamera(argEngine)
	, m_Fov(90.0f)
{
}

PerspectiveCamera::~PerspectiveCamera()
{
	m_Engine.get_ResourceFactory().DeletePerspectiveCamera(*const_cast<PerspectiveCamera*>(this), true);
}


void PerspectiveCamera::set_Fov(float argFov)
{
	m_Fov = argFov;
	m_IsDirty = true;
}


void PerspectiveCamera::Update(bool argForceUpdate)
{
	BaseCamera::Update(argForceUpdate);

	D3DXMATRIXA16 projectionMatrix;
	D3DXMATRIXA16 viewMatrix;

	D3DXVECTOR3 worldPos = this->get_WorldPosition();
	D3DXVECTOR3 worldDirection = this->get_WorldDirection();
	D3DXVECTOR3 worldUpDirection = this->get_WorldUpDirection();

	::D3DXMatrixPerspectiveFovLH(&projectionMatrix, static_cast<float>(D3DXToRadian(m_Fov)), m_AspectRatio, m_NearClip, m_FarClip);
	::D3DXMatrixLookAtLH(&viewMatrix, &worldPos, &(worldPos + worldDirection), &worldUpDirection);

	m_ProjectionMatrix = projectionMatrix;
	m_ViewMatrix = viewMatrix;

	// generate view frustum
	D3DXMATRIXA16 viewProjection = viewMatrix * projectionMatrix;

	// Left plane
	m_Frustum.Plane[0].a = viewProjection._14 + viewProjection._11;
	m_Frustum.Plane[0].b = viewProjection._24 + viewProjection._21;
	m_Frustum.Plane[0].c = viewProjection._34 + viewProjection._31;
	m_Frustum.Plane[0].d = viewProjection._44 + viewProjection._41;

	// Right plane
	m_Frustum.Plane[1].a = viewProjection._14 - viewProjection._11;  
	m_Frustum.Plane[1].b = viewProjection._24 - viewProjection._21;
	m_Frustum.Plane[1].c = viewProjection._34 - viewProjection._31;
	m_Frustum.Plane[1].d = viewProjection._44 - viewProjection._41;

	// Top plane
	m_Frustum.Plane[2].a = viewProjection._14 - viewProjection._12;  
	m_Frustum.Plane[2].b = viewProjection._24 - viewProjection._22;
	m_Frustum.Plane[2].c = viewProjection._34 - viewProjection._32;
	m_Frustum.Plane[2].d = viewProjection._44 - viewProjection._42;

	// Bottom plane
	m_Frustum.Plane[3].a = viewProjection._14 + viewProjection._12;  
	m_Frustum.Plane[3].b = viewProjection._24 + viewProjection._22;
	m_Frustum.Plane[3].c = viewProjection._34 + viewProjection._32;
	m_Frustum.Plane[3].d = viewProjection._44 + viewProjection._42;

	// Near plane
	m_Frustum.Plane[4].a = viewProjection._13;  
	m_Frustum.Plane[4].b = viewProjection._23;
	m_Frustum.Plane[4].c = viewProjection._33;
	m_Frustum.Plane[4].d = viewProjection._43;

	// Far plane
	m_Frustum.Plane[5].a = viewProjection._14 - viewProjection._13;  
	m_Frustum.Plane[5].b = viewProjection._24 - viewProjection._23;
	m_Frustum.Plane[5].c = viewProjection._34 - viewProjection._33;
	m_Frustum.Plane[5].d = viewProjection._44 - viewProjection._43;
}