#include "XCamera.h"
namespace XGeomLib
{
	/*
	將眼睛信息轉化成視圖矩陣。
	*/
	void XCamera::XEye::ToMatirx(XMatrix& matView)
	{
		XM_LookAt(matView,m_EyePos,m_EyeTarget,m_Up);
		return ;
	}
	XCamera::XEye::XEye():
	m_EyePos(0,0,0),m_EyeTarget(0,0,-1),m_Up(0,1,0)
	{
	}

	/**
	從一個Camera對象構造出兩個矩陣。
	一個投影矩陣，
	一個視圖矩陣，
	*/
	void XCamera::ToMatrix(XMatrix& matView,XMatrix& matProject)
	{
		/*構造視圖矩陣*/
		m_Eye.ToMatirx(matView);

		/*
		注意，這是個投影矩陣。可能有好幾種投影方式。
		平行投影和透視投影在本庫中被支持
		*/
		if(m_ProjectType == PT_PROJECT)
		{
			XM_Perspective(matProject,m_fFov,m_fAspect,m_fNear,m_fFar);
		}
		else if(m_ProjectType == PT_ORTHO)
		{
			XM_Ortho3D(matProject,m_fNear,m_fFar,m_ViewRect.m_top,m_ViewRect.m_bottom,m_ViewRect.m_left,m_ViewRect.m_right);
		}
		else
		{
			matProject.LoadIdentity();
		}
		return ;

	}

	/**
	從攝影機里構造出一個視圖矩陣
	*/

	void XCamera::ToViewMatrix(XMatrix& matView)
	{
		m_Eye.ToMatirx(matView);
	}

	/**
	從一個攝影機里構造出一個投影矩陣出來
	*/
	void XCamera::ToProjectMatrix(XMatrix& matProject)
	{

		/*
		注意，這是個投影矩陣。可能有好幾種投影方式。
		平行投影和透視投影在本庫中被支持
		*/
		if(m_ProjectType == PT_PROJECT)
		{
			XM_Perspective(matProject,m_fFov,m_fAspect,m_fNear,m_fFar);
		}
		else if(m_ProjectType == PT_ORTHO)
		{
			XM_Ortho3D(matProject,m_fNear,m_fFar,m_ViewRect.m_top,m_ViewRect.m_bottom,m_ViewRect.m_left,m_ViewRect.m_right);
		}
		else
		{
			matProject.LoadIdentity();
		}
		return ;

	}

	/*****************************************************************
	攝影機的俯仰和旋轉函數
	*****************************************************************/
	void XCamera::Yaw(float angle)
	{
             XVector vDir  = m_Eye.m_EyeTarget - m_Eye.m_EyePos;
             XVector newDir;
             float len = vDir.len();

             vDir.normalize();
             XMatrix matRot ;
             XM_Rotate(matRot,m_Eye.m_Up,angle);
             XMatrix_Mul(vDir,matRot,newDir);

             newDir = newDir * len;
	     m_Eye.m_EyeTarget = m_Eye.m_EyePos + newDir;

	}
	void XCamera::Pitch(float angle)
	{
		XVector vDir  = m_Eye.m_EyeTarget - m_Eye.m_EyePos;
		float len = vDir.len();
		vDir.normalize();
		XVector vLeft = vDir.cp(m_Eye.m_Up);

		XVector newDir;
		XVector newUp;

		XMatrix matRot;
		XM_Rotate(matRot,vLeft,angle);

		XMatrix_Mul(vDir,matRot,newDir);
		XMatrix_Mul(m_Eye.m_Up,matRot,newUp);
		m_Eye.m_Up = newUp;
                newDir = newDir * len;
		m_Eye.m_EyeTarget = m_Eye.m_EyePos + newDir;
	}

	void XCamera::Roll(float angle)
	{
		XVector vDir  = m_Eye.m_EyeTarget - m_Eye.m_EyePos;
		vDir.normalize();
		XVector vLeft = vDir.cp(m_Eye.m_Up);

		XVector newUp;

		XMatrix matRot;
		XM_Rotate(matRot,vDir,angle);

		XMatrix_Mul(m_Eye.m_Up,matRot,newUp);
		m_Eye.m_Up = newUp;
	}

	void XCamera::Circle(float angle)
	{
             XVector vDir  = m_Eye.m_EyeTarget - m_Eye.m_EyePos;
             XVector newDir;
             float len = vDir.len();

             vDir.normalize();
             XMatrix matRot ;
             XM_Rotate(matRot,m_Eye.m_Up,angle);
             XMatrix_Mul(vDir,matRot,newDir);

             newDir = newDir * len;
	     m_Eye.m_EyePos = m_Eye.m_EyeTarget - newDir;
	}


	/*****************************************************************
	攝影機的位置改變。函數。
	*****************************************************************/
	void XCamera::Toward(float dist)
	{
		XVector vDir = m_Eye.m_EyeTarget - m_Eye.m_EyePos;
		vDir.normalize();
		vDir *= dist;

		m_Eye.m_EyePos.x += vDir.x;
		m_Eye.m_EyePos.y += vDir.y;
		m_Eye.m_EyePos.z += vDir.z;

		m_Eye.m_EyeTarget.x += vDir.x;
		m_Eye.m_EyeTarget.y += vDir.y;
		m_Eye.m_EyeTarget.z += vDir.z;

	}
	void XCamera::UpDown(float dist)
	{
		XVector vDir = m_Eye.m_Up;
		vDir *= dist;

		m_Eye.m_EyePos.x += vDir.x;
		m_Eye.m_EyePos.y += vDir.y;
		m_Eye.m_EyePos.z += vDir.z;

		m_Eye.m_EyeTarget.x += vDir.x;
		m_Eye.m_EyeTarget.y += vDir.y;
		m_Eye.m_EyeTarget.z += vDir.z;
	}
	void XCamera::Shift(float  dist)
	{

		//向右移動為正
		XVector vDir  = m_Eye.m_EyeTarget - m_Eye.m_EyePos;
		XVector vLeft = vDir.cp(m_Eye.m_Up);
		vLeft.normalize();
		vLeft *= dist;

		m_Eye.m_EyePos.x += vLeft.x;
		m_Eye.m_EyePos.y += vLeft.y;
		m_Eye.m_EyePos.z += vLeft.z;

		m_Eye.m_EyeTarget.x += vLeft.x;
		m_Eye.m_EyeTarget.y += vLeft.y;
		m_Eye.m_EyeTarget.z += vLeft.z;	
	}


};