include/cinder/Camera.h

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/*
 Copyright (c) 2010, The Barbarian Group
 All rights reserved.
 
 Portions of this code (C) Paul Houx
 All rights reserved.

 Redistribution and use in source and binary forms, with or without modification, are permitted provided that
 the following conditions are met:

    * Redistributions of source code must retain the above copyright notice, this list of conditions and
    the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
    the following disclaimer in the documentation and/or other materials provided with the distribution.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
*/

#pragma once

#include "cinder/Vector.h"
#include "cinder/Matrix.h"
#include "cinder/Quaternion.h"
#include "cinder/Ray.h"

namespace cinder {

// By default the camera is looking down -Z
class Camera {
  public:
    Camera() : mModelViewCached(false), mProjectionCached(false), mInverseModelViewCached( false ), mWorldUp( Vec3f::yAxis() ) {}
    virtual ~Camera() {}

    Vec3f       getEyePoint() const { return mEyePoint; }
    void        setEyePoint( const Vec3f &aEyePoint );
    
    float       getCenterOfInterest() const { return mCenterOfInterest; }
    void        setCenterOfInterest( float aCenterOfInterest ) { mCenterOfInterest = aCenterOfInterest; }
    
    Vec3f       getCenterOfInterestPoint() const { return mEyePoint + mViewDirection * mCenterOfInterest; }
    void        setCenterOfInterestPoint( const Vec3f &centerOfInterestPoint );
        
    Vec3f       getWorldUp() const { return mWorldUp; }
    void        setWorldUp( const Vec3f &aWorldUp );

    void        lookAt( const Vec3f &target );
    void        lookAt( const Vec3f &aEyePoint, const Vec3f &target );
    void        lookAt( const Vec3f &aEyePoint, const Vec3f &target, const Vec3f &aUp );
    Vec3f       getViewDirection() const { return mViewDirection; }
    void        setViewDirection( const Vec3f &aViewDirection );

    Quatf       getOrientation() const { return mOrientation; }
    void        setOrientation( const Quatf &aOrientation );

    float   getFov() const { return mFov; }
    void    setFov( float aFov ) { mFov = aFov;  mProjectionCached = false; }
    float   getAspectRatio() const { return mAspectRatio; }
    void    setAspectRatio( float aAspectRatio ) { mAspectRatio = aAspectRatio; mProjectionCached = false; }
    float   getNearClip() const { return mNearClip; }
    void    setNearClip( float aNearClip ) { mNearClip = aNearClip; mProjectionCached = false; }
    float   getFarClip() const { return mFarClip; }
    void    setFarClip( float aFarClip ) { mFarClip = aFarClip; mProjectionCached = false; }

    virtual void    getNearClipCoordinates( Vec3f *topLeft, Vec3f *topRight, Vec3f *bottomLeft, Vec3f *bottomRight ) const;
    virtual void    getFarClipCoordinates( Vec3f *topLeft, Vec3f *topRight, Vec3f *bottomLeft, Vec3f *bottomRight ) const;

    void    getFrustum( float *left, float *top, float *right, float *bottom, float *near, float *far ) const;
    virtual bool isPersp() const = 0;
    
    virtual const Matrix44f&    getProjectionMatrix() const { if( ! mProjectionCached ) calcProjection(); return mProjectionMatrix; }
    virtual const Matrix44f&    getModelViewMatrix() const { if( ! mModelViewCached ) calcModelView(); return mModelViewMatrix; }
    virtual const Matrix44f&    getInverseModelViewMatrix() const { if( ! mInverseModelViewCached ) calcInverseModelView(); return mInverseModelViewMatrix; }

    Ray     generateRay( float u, float v, float imagePlaneAspectRatio ) const;
    void    getBillboardVectors( Vec3f *right, Vec3f *up ) const;

    Vec2f worldToScreen( const Vec3f &worldCoord, float screenWidth, float screenHeight ) const;
    Vec3f worldToEye( const Vec3f &worldCoord ) { return getModelViewMatrix().transformPointAffine( worldCoord ); }
    float worldToEyeDepth( const Vec3f &worldCoord ) const { return getModelViewMatrix().m[2] * worldCoord.x + getModelViewMatrix().m[6] * worldCoord.y + getModelViewMatrix().m[10] * worldCoord.z + getModelViewMatrix().m[14]; }
    Vec3f worldToNdc( const Vec3f &worldCoord ) { Vec3f eye = getModelViewMatrix().transformPointAffine( worldCoord ); return getProjectionMatrix().transformPoint( eye ); }


    float   getScreenRadius( const class Sphere &sphere, float screenWidth, float screenHeight ) const;

  protected:
    Vec3f   mEyePoint;
    Vec3f   mViewDirection;
    Quatf   mOrientation;
    float   mCenterOfInterest;
    Vec3f   mWorldUp;

    float   mFov;
    float   mAspectRatio;
    float   mNearClip;      
    float   mFarClip;

    mutable Vec3f       mU; // Right vector
    mutable Vec3f       mV; // Readjust up-vector
    mutable Vec3f       mW; // Negative view direction

    mutable Matrix44f   mProjectionMatrix, mInverseProjectionMatrix;
    mutable bool        mProjectionCached;
    mutable Matrix44f   mModelViewMatrix;
    mutable bool        mModelViewCached;
    mutable Matrix44f   mInverseModelViewMatrix;
    mutable bool        mInverseModelViewCached;
    
    mutable float       mFrustumLeft, mFrustumRight, mFrustumTop, mFrustumBottom;

    inline void     calcMatrices() const;

    virtual void    calcModelView() const;
    virtual void    calcInverseModelView() const;
    virtual void    calcProjection() const = 0;
};

class CameraPersp : public Camera {
  public:
    CameraPersp();
    CameraPersp( int pixelWidth, int pixelHeight, float fov ); // constructs screen-aligned camera
    CameraPersp( int pixelWidth, int pixelHeight, float fov, float nearPlane, float farPlane ); // constructs screen-aligned camera
    
    void    setPerspective( float horizFovDegrees, float aspectRatio, float nearPlane, float farPlane );
    
    void    getLensShift( float *horizontal, float *vertical ) const { *horizontal = mLensShift.x; *vertical = mLensShift.y; }
    Vec2f   getLensShift() const { return Vec2f( mLensShift.x, mLensShift.y ); }
    void    setLensShift( float horizontal, float vertical );
    void    setLensShift( const Vec2f &shift ) { setLensShift( shift.x, shift.y ); }
    float   getLensShiftHorizontal() const { return mLensShift.x; }
    void    setLensShiftHorizontal( float horizontal ) { setLensShift( horizontal, mLensShift.y ); }
    float   getLensShiftVertical() const { return mLensShift.y; }
    void    setLensShiftVertical( float vertical ) { setLensShift( mLensShift.x, vertical ); }
    
    virtual bool    isPersp() const { return true; }

    CameraPersp getFrameSphere( const class Sphere &worldSpaceSphere, int maxIterations = 20 ) const;

  protected:
    Vec2f   mLensShift;

    virtual void    calcProjection() const;
};

class CameraOrtho : public Camera {
  public:
    CameraOrtho();
    CameraOrtho( float left, float right, float bottom, float top, float nearPlane, float farPlane );

    void setOrtho( float left, float right, float bottom, float top, float nearPlane, float farPlane );

    virtual bool    isPersp() const { return false; }
    
  protected:
    virtual void    calcProjection() const;
};

class CameraStereo : public CameraPersp {
  public:
    CameraStereo() 
        : mConvergence(1.0f), mEyeSeparation(0.05f), mIsStereo(false), mIsLeft(true) {}
    CameraStereo( int pixelWidth, int pixelHeight, float fov )
        : CameraPersp( pixelWidth, pixelHeight, fov ), 
        mConvergence(1.0f), mEyeSeparation(0.05f), mIsStereo(false), mIsLeft(true) {} // constructs screen-aligned camera
    CameraStereo( int pixelWidth, int pixelHeight, float fov, float nearPlane, float farPlane )
        : CameraPersp( pixelWidth, pixelHeight, fov, nearPlane, farPlane ), 
        mConvergence(1.0f), mEyeSeparation(0.05f), mIsStereo(false), mIsLeft(true) {} // constructs screen-aligned camera

    float           getConvergence() const { return mConvergence; }
    void            setConvergence( float distance, bool adjustEyeSeparation=false ) { 
        mConvergence = distance; mProjectionCached = false;

        if(adjustEyeSeparation) 
            mEyeSeparation = mConvergence / 30.0f;
    }
    float           getEyeSeparation() const { return mEyeSeparation; }
    void            setEyeSeparation( float distance ) { mEyeSeparation = distance; mModelViewCached = false; mProjectionCached = false; }
    Vec3f           getEyePointShifted() const;
    
    void            enableStereoLeft() { mIsStereo = true; mIsLeft = true; }
    bool            isStereoLeftEnabled() const { return mIsStereo && mIsLeft; }
    void            enableStereoRight() { mIsStereo = true; mIsLeft = false; }
    bool            isStereoRightEnabled() const { return mIsStereo && !mIsLeft; }
    void            disableStereo() { mIsStereo = false; }
    bool            isStereoEnabled() const { return mIsStereo; }

    virtual void    getNearClipCoordinates( Vec3f *topLeft, Vec3f *topRight, Vec3f *bottomLeft, Vec3f *bottomRight ) const;
    virtual void    getFarClipCoordinates( Vec3f *topLeft, Vec3f *topRight, Vec3f *bottomLeft, Vec3f *bottomRight ) const;
    
    virtual const Matrix44f&    getProjectionMatrix() const;
    virtual const Matrix44f&    getModelViewMatrix() const;
    virtual const Matrix44f&    getInverseModelViewMatrix() const;

  protected:
    mutable Matrix44f   mProjectionMatrixLeft, mInverseProjectionMatrixLeft;
    mutable Matrix44f   mProjectionMatrixRight, mInverseProjectionMatrixRight;
    mutable Matrix44f   mModelViewMatrixLeft, mInverseModelViewMatrixLeft;
    mutable Matrix44f   mModelViewMatrixRight, mInverseModelViewMatrixRight;

    virtual void    calcModelView() const;
    virtual void    calcInverseModelView() const;
    virtual void    calcProjection() const;
  private:
    bool            mIsStereo;
    bool            mIsLeft;

    float           mConvergence;
    float           mEyeSeparation;
};

} // namespace cinder