#ifndef _XJV3D_VIEWER_
#define _XJV3D_VIEWER_

#include "ViewExport.h"
#include "XJObjectManager/XJObjectManager.h"
#include <osgViewer/Viewer>
#include <osg/Matrixd>

namespace OSGView
{

	//屏幕上的长方形
	class ViewRect
	{
	public:

		ViewRect()
		{
			x = 0;
			y = 1;
			width = height = 1;
		}

		ViewRect(int l, int b, int r, int t)
		{
			x = l;
			y = b;
			width = abs(r - l);
			height = abs(t - b);
		}

		~ViewRect(){}

		bool IsInsideRect(int pX, int pY)
		{
			if(pX > x && pX < x+width &&
				pY > y && pY < y+height)
				return true;
			else
				return false;
		}

	public:
		int x, y;
		int width, height;
	};


	class XJOSGVIEWEXPORT XJV3D_Viewer : public osgViewer::Viewer
	{
	public:
		XJV3D_Viewer(void);
		~XJV3D_Viewer(void);

		/** check to see if the new frame is required, called by run(..) when FrameScheme is set to ON_DEMAND.*/
		virtual bool checkNeedToDoFrame();

		//! Converts the projected point into a point
		//! in the reference frame of the view corresponding
		//! to the intersection with the projection plane
		//! of the eye/view point vector.
		void  Convert(int x, int y, osg::Vec3& pnt) const;

		//convert pt from world to window
		void projecObjectIntoWindowXY(osg::Vec3 pnt, int& x, int& y);

		/** Calculate, via glUnProject, the object coordinates of a window x,y
		when projected onto the near planes.*/
		void projectWindowXYIntoObject(int x, int y, osg::Vec3& pnt) const;

		/** Calculate, via glUnProject, the object coordinates of a window x,y
		when projected onto the near and far planes.
		Note, current implementation requires that SceneView::draw() has been previously called
		for projectWindowIntoObject to produce valid values.  As per OpenGL
		windows coordinates are calculated relative to the bottom left of the window.*/
		bool projectWindowXYIntoObject(int x, int y, osg::Vec3d& near_point, osg::Vec3d& far_point, bool yInverse = true);

		/** Calculate, via glUnProject, the object coordinates of a window x,y
		when projected onto the near planes.*/
		void projectWindowIntoObject(const osg::Vec3& windowPt, osg::Vec3& pnt) const;

		//将坐标从窗口坐标系转化到归一化设备坐标系（NDC）
		void projectWindowXYIntoProjection(int x, int y, osg::Vec3& projPnt) const;

		/** Calculate, via glUnProject, the object coordinates of a window x,y
		when projected onto the near planes.*/
		void projectWindowXYIntoViewPoint(int x, int y, osg::Vec3& viewPortPt) const;

		/** Calculate, via glUnProject, the object coordinates of a window x,y
		when projected onto the near planes.*/
		void ProjectViewpointIntoObject(const osg::Vec3& viewpoint, osg::Vec3& worldpt) const;

		/** Calculate, via glUnProject, the object coordinates of a window x,y
		when projected onto the near planes.*/
		osg::Vec3 GetCameraNormal();  

		//get the viewport position and size
		void GetViewRect(ViewRect& rect);

		/** Get the const view matrix. */
		const osg::Matrixd& getViewMatrix() const { return _camera->getViewMatrix(); }

		/** Get the view matrix. */
		osg::Matrixd& getViewMatrix() { return _camera->getViewMatrix(); }

		/** Get to the position and orientation of a modelview matrix, using the same convention as gluLookAt. */
		void getViewMatrixAsLookAt(osg::Vec3& eye,osg::Vec3& center,osg::Vec3& up,float lookDistance=1.0f) const;

		/** Get the projection matrix.*/
		osg::Matrixd& getProjectionMatrix() { return _camera->getProjectionMatrix(); }

		/** Get the  const projection matrix.*/
		const osg::Matrixd& getProjectionMatrix() const { return _camera->getProjectionMatrix(); }

		/** Get the orthographic settings of the orthographic projection matrix. 
		* Returns false if matrix is not an orthographic matrix, where parameter values are undefined.*/
		bool getProjectionMatrixAsOrtho(double& left, double& right,
			double& bottom, double& top,
			double& zNear, double& zFar) const;

		/** Get the frustum setting of a perspective projection matrix.
		* Returns false if matrix is not a perspective matrix, where parameter values are undefined.*/
		bool getProjectionMatrixAsFrustum(double& left, double& right,
			double& bottom, double& top,
			double& zNear, double& zFar) const;

		/** Get the frustum setting of a symmetric perspective projection matrix.
		* Returns false if matrix is not a perspective matrix, where parameter values are undefined. 
		* Note, if matrix is not a symmetric perspective matrix then the shear will be lost.
		* Asymmetric matrices occur when stereo, power walls, caves and reality center display are used.
		* In these configurations one should use the 'getProjectionMatrixAsFrustum' method instead.*/
		bool getProjectionMatrixAsPerspective(double& fovy,double& aspectRatio,
			double& zNear, double& zFar) const;

		//get the near plane and far plane from eye
		bool getNearAndFarPlaneDistance(double& nearDis, double& farDis);

		//pan camera to cur window postion
		void panCamera(const osg::Vec2 curpos);

		//获取投影矩阵中的宽高比
		float getProjectionAspectRatio();

		//scale Project Window(used for box zoom)
		void ScaleProjectWindow(const float scale);

		const osg::Matrix computeMVPWInverse() const;

		const osg::Matrix computeMVPW() const;

		const osg::Matrix computePW() const;

		/** Get the viewport. */
		osg::Viewport* getViewport() { return (_camera->getViewport()!=0) ? _camera->getViewport() : 0; }

		/** Get the const viewport. */
		const osg::Viewport* getViewport() const { return (_camera->getViewport()!=0) ? _camera->getViewport() : 0; }

		//坐标的转化
		static Point3D Vec3ToPoint3D(const osg::Vec3& value);
		static osg::Vec3 Point3DToVec3(const Point3D& value);
	};

}  //end namespace

#endif