source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/Camera.h @ 3147

#ifndef __CAMERA_H
#define __CAMERA_H

#include "Vector3.h"
#include "AxisAlignedBox3.h"
#include "Plane3.h"


namespace CHCDemoEngine 
{

class Matrix4x4;
class Polyhedron;


/** Class representing a frustum.
*/
class Frustum
{
        friend class Camera;

public:

        enum {LEFT_PLANE, RIGHT_PLANE, BOTTOM_PLANE, TOP_PLANE, NEAR_PLANE, FAR_PLANE};

        Frustum() {};

        Frustum(const Matrix4x4 &trafo);

        /** Resizes the current frustum so that it fully encloses the given polyhedron
        */
        void EnclosePolyhedron(const Polyhedron &polyhedron);

        void ExtractTransformation(Matrix4x4 &m) const;


        /// the 6 clip planes
        Plane3 mClipPlanes[6];
};


/** Classs representing a camera.
*/
class Camera
{
public:
        /** Default constructor.
        */
        Camera();
        /** Sets the current camera position.
        */
        void SetPosition(const Vector3 &pos);
        /** See set.
        */
        inline Vector3 GetPosition() const { return mPosition; }
        /** Returns view direction.
        */
        Vector3 GetDirection() const;
        /** Returns up vector.
        */
        Vector3 GetUpVector() const;
        /** Returns right vector.
        */
        Vector3 GetRightVector() const;

        Vector3 GetBaseDirection() const;
        Vector3 GetBaseUpVector() const;
        Vector3 GetBaseRightVector() const;
        /** Sets up viewing matrices in for opengl rendering
        */
        void SetupCameraView();
        /** Returns the current projection matrix.
        */
        void GetProjectionMatrix(Matrix4x4 &mat) const;
        /** Returns the current model view matrix.
        */
        void GetModelViewMatrix(Matrix4x4 &mat) const;
        /** Returns the view orientation (the model view matrix without the translation)
        */
        void GetViewOrientationMatrix(Matrix4x4 &mat) const;
        /** Returns the near plane.
        */
        inline float GetNear() const { return mNear; }
        /** Returns the far plane.
        */
        inline float GetFar() const { return mFar; }
        /** Sets the near plane
        */
        void SetNear(float nearDist);
        /** Sets the far plane.
        */
        void SetFar(float farDist);
        /** Set yaw (rotation around vertical axis.
        */
        void Yaw(float angle);
        /** Set pitch.
        */
        void Pitch(float angle);
        /** Returns pitch.
        */
        float GetPitch() const { return mPitch; }
        /** Returns yaw.
        */
        float GetYaw() const { return mYaw; }
        /** Resets pitch and yaw.
        */
        void ResetPitchAndYaw() { mPitch = 0; mYaw = 0; }
        /** Sets the view direction.
        */
        void SetDirection(const Vector3 &direction);
        /** Sets up projection matrix in OpenGl.
        */
        void SetupProjection();
        /** Sets up view + projection matrix in OpenGl.
        */
        void SetupViewProjection();
        /** Calculates a frustum from the projection and the modelview matrix.
        */
        void CalcFrustum(Frustum &frustum);

protected:

        virtual void UpdateProjectionMatrix() = 0;

        void Precompute(const Vector3 &direction);

        void CalculateFromPitchAndYaw();


        ////////////////
        //-- members

        float mNear;
        float mFar;
        
        Matrix4x4 mBaseOrientation;
        Matrix4x4 mViewOrientation;

        Matrix4x4 mProjection;

        float mPitch;
        float mYaw;

        Vector3 mPosition;
};


/** Classs representing a perspective camera.
*/
class PerspectiveCamera: public Camera
{
        friend class ShadowMap;

public:
        /** Default constructor.
        */
        PerspectiveCamera();
        /** Camera taking the image width and height and the field of view.
        */
        PerspectiveCamera(float aspect, float fieldOfView = 90.f);
        /** Returns the field of view.
        */
        inline float GetFov() const { return mFOVy; }
        /** Returns the aspect ratio.
        */
        inline float GetAspect() const { return mAspect; }
        /** Computes the extremal points of this frustum.
                If farthestVisibleDistance is nearer than the far plane, 
                it is used to define the far plane instead.
        */
        void ComputePoints(Vector3 &ftl, Vector3 &ftr, Vector3 &fbl, Vector3 &fbr,
                               Vector3 &ntl, Vector3 &ntr, Vector3 &nbl, Vector3 &nbr,
                                           float farthestVisibleDistance = 1e25f) const;
        /** Returns frustum as polyhedron. 
        */
        Polyhedron *ComputeFrustum(float farthestVisibleDistance = 1e25f) const;


protected:
        /** Calculates the current projection matrix.
        */
        virtual void UpdateProjectionMatrix();

        void ComputePointsInternal(Vector3 &ftl, Vector3 &ftr, Vector3 &fbl, Vector3 &fbr,
                                                           Vector3 &ntl, Vector3 &ntr, Vector3 &nbl, Vector3 &nbr,
                                                           const Vector3 &view, const Vector3 &right, const Vector3 &up,
                                                           const Vector3 &pos,
                                                           float farthestVisibleDistance = 1e25f) const;

        ////////////////
        //-- members

        float mFOVy;
        float mAspect;
};

/** Classs representing an orthographics camera.
*/
class OrthoCamera: public Camera
{
        friend class ShadowMap;

public:
        /** Default constructor.
        */
        OrthoCamera();
        /** Camera taking the frustum left, right, bottom, top.
        */
        OrthoCamera(float l, float r, float b, float t);

        /** Camera taking the frustum left, right, bottom, top, near, far.
        */
        OrthoCamera(float l, float r, float b, float t, float n, float f);


protected:
        /** Calculates the current projection matrix.
        */
        virtual void UpdateProjectionMatrix();


        //////////
        //-- members

        float mLeft;
        float mRight;
        float mBottom;
        float mTop;
};
}
#endif