polycode-engine/Core/Contents/Source/PolyQuaternionCurve.cpp

/*
 Copyright (C) 2011 by Ivan Safrin
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
*/

#include "PolyQuaternionCurve.h"
#include "PolyBezierCurve.h"
#include "PolyLogger.h"

using namespace Polycode;

QuaternionCurve::QuaternionCurve(BezierCurve *wCurve, BezierCurve *xCurve, BezierCurve *yCurve, BezierCurve *zCurve) {
	generatePointsFromCurves(wCurve, xCurve, yCurve, zCurve);
}

QuaternionCurve::~QuaternionCurve() {

}

void QuaternionCurve::generatePointsFromCurves(BezierCurve *wCurve, BezierCurve *xCurve, BezierCurve *yCurve, BezierCurve *zCurve) {
	for(int i=0; i < wCurve->getNumControlPoints(); i++) {
		/*
		Quaternion newQuat(wCurve->getControlPoint(i)->p2.y,
							xCurve->getControlPoint(i)->p2.y,
							yCurve->getControlPoint(i)->p2.y,
							zCurve->getControlPoint(i)->p2.y);

		points.push_back(newQuat);
		recalcTangents();
		*/
		Quaternion quat1(wCurve->getControlPoint(i)->p1.y,
							xCurve->getControlPoint(i)->p1.y,
							yCurve->getControlPoint(i)->p1.y,
							zCurve->getControlPoint(i)->p1.y);

		Quaternion quat2(wCurve->getControlPoint(i)->p2.y,
							xCurve->getControlPoint(i)->p2.y,
							yCurve->getControlPoint(i)->p2.y,
							zCurve->getControlPoint(i)->p2.y);

		Quaternion quat3(wCurve->getControlPoint(i)->p3.y,
							xCurve->getControlPoint(i)->p3.y,
							yCurve->getControlPoint(i)->p3.y,
							zCurve->getControlPoint(i)->p3.y);

		
		QuatTriple newTriple;
		newTriple.q1 = quat1;
		newTriple.q2 = quat2;
		newTriple.q3 = quat3;		
		tPoints.push_back(newTriple);
	}
}

    Quaternion QuaternionCurve::interpolate(Number t, bool useShortestPath)
    {
        // Work out which segment this is in
        Number fSeg = t * (tPoints.size() - 1);
        unsigned int segIdx = (unsigned int)fSeg;
        // Apportion t 
        t = fSeg - segIdx;

        return interpolate(segIdx, t, useShortestPath);

    }
    //---------------------------------------------------------------------
    Quaternion QuaternionCurve::interpolate(unsigned int fromIndex, Number t,
		bool useShortestPath)
    {
        // Bounds check
        assert (fromIndex >= 0 && fromIndex < tPoints.size() &&
            "fromIndex out of bounds");

        if ((fromIndex + 1) == tPoints.size() && tPoints[fromIndex].q2 != tPoints[0].q2)
        {
			Logger::log("size\n");
            // Duff request, cannot blend to nothing
            // Just return source
            return points[fromIndex];

        }
        // Fast special cases
        if (t == 0.0f)
        {
            return tPoints[fromIndex].q2;
        }
        else if(t == 1.0f)
        {
            return tPoints[fromIndex + 1].q2;
        }
		
        Quaternion &p = tPoints[fromIndex].q2;
        Quaternion &q = tPoints[fromIndex+1].q2;
        Quaternion &a = tPoints[fromIndex].q3;
        Quaternion &b = tPoints[fromIndex+1].q1;		
		
		if ((fromIndex + 1) == tPoints.size() && tPoints[fromIndex].q2 == tPoints[0].q2) {
			q = tPoints[1].q2;
			b = tPoints[1].q1;					
		} 

        // NB interpolate to nearest rotation
        return Quaternion::Squad(t, p, a, b, q, useShortestPath);

    }

void QuaternionCurve::recalcTangents()
{
        unsigned int i, numPoints;
        bool isClosed;

        numPoints = (unsigned int)points.size();

        if (numPoints < 2) {
            return;
        }

        tangents.resize(numPoints);

        if (points[0] == points[numPoints-1])
        {
            isClosed = true;
        }
        else
        {
            isClosed = false;
        }

        Quaternion invp, part1, part2, preExp;
        for(i = 0; i < numPoints; ++i)
        {
            Quaternion &p = points[i];
            invp = p.Inverse();

            if (i ==0)
            {
                // special case start
                part1 = (invp * points[i+1]).Log();
                if (isClosed)
                {
                    // Use numPoints-2 since numPoints-1 == end == start == this one
                    part2 = (invp * points[numPoints-2]).Log();
                }
                else
                {
                    part2 = (invp * p).Log();
                }
            }
            else if (i == numPoints-1)
            {
                // special case end
                if (isClosed)
                {
                    // Wrap to [1] (not [0], this is the same as end == this one)
                    part1 = (invp * points[1]).Log();
                }
                else
                {
                    part1 = (invp * p).Log();
                }
                part2 = (invp * points[i-1]).Log();
            }
            else
            {
                part1 = (invp * points[i+1]).Log();
                part2 = (invp * points[i-1]).Log();
            }

            preExp =(part1 + part2)  * -0.25 ;
            tangents[i] = p * preExp.Exp();
            
        }



    }