CAAudioValueRange.cpp

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//==================================================================================================
//  Includes
//==================================================================================================

//  Self Include
#include "CAAudioValueRange.h"

//  Standard Library
#include <algorithm>

//==================================================================================================
//  CAAudioValueRange
//==================================================================================================

Float64 CAAudioValueRange::PickCommonSampleRate(const AudioValueRange& inRange)
{
    //  This routine will pick a "common" sample rate from the give range of rates or the maximum
    //  if no common rates can be found. It assumes that inRange contains a continuous range of
    //  sample rates.
    Float64 theAnswer = inRange.mMaximum;
    
    if(ContainsValue(inRange, 44100.0))
    {
        theAnswer = 44100.0;
    }
    else if(ContainsValue(inRange, 48000.0))
    {
        theAnswer = 48000.0;
    }
    else if(ContainsValue(inRange, 96000.0))
    {
        theAnswer = 96000.0;
    }
    else if(ContainsValue(inRange, 88200.0))
    {
        theAnswer = 88200.0;
    }
    else if(ContainsValue(inRange, 64000.0))
    {
        theAnswer = 64000.0;
    }
    else if(ContainsValue(inRange, 32000.0))
    {
        theAnswer = 32000.0;
    }
    else if(ContainsValue(inRange, 24000.0))
    {
        theAnswer = 24000.0;
    }
    else if(ContainsValue(inRange, 22050.0))
    {
        theAnswer = 22050.0;
    }
    else if(ContainsValue(inRange, 16000.0))
    {
        theAnswer = 16000.0;
    }
    else if(ContainsValue(inRange, 12000.0))
    {
        theAnswer = 12000.0;
    }
    else if(ContainsValue(inRange, 11025.0))
    {
        theAnswer = 11025.0;
    }
    else if(ContainsValue(inRange, 8000.0))
    {
        theAnswer = 8000.0;
    }
    
    return theAnswer;
}

bool    CAAudioValueRange::Intersection(const AudioValueRange& x, const AudioValueRange& y, AudioValueRange& outRange)
{
    bool isNonEmpty;
    if(!IsStrictlyLessThan(x, y) && !IsStrictlyGreaterThan(x, y))
    {
        outRange.mMinimum = std::max(x.mMinimum, y.mMinimum);
        outRange.mMaximum = std::min(x.mMaximum, y.mMaximum);
        isNonEmpty = true;
    }
    else
    {
        outRange.mMinimum = 0;
        outRange.mMaximum = 0;
        isNonEmpty = false;
    }
    return isNonEmpty;
}

bool    CAAudioValueRange::Union(const AudioValueRange& x, const AudioValueRange& y, AudioValueRange& outRange)
{
    bool isDisjoint;
    if(!IsStrictlyLessThan(x, y) && !IsStrictlyGreaterThan(x, y))
    {
        outRange.mMinimum = std::min(x.mMinimum, y.mMinimum);
        outRange.mMaximum = std::max(x.mMaximum, y.mMaximum);
        isDisjoint = false;
    }
    else
    {
        outRange.mMinimum = 0;
        outRange.mMaximum = 0;
        isDisjoint = true;
    }
    return isDisjoint;
}

void    CAAudioValueRange_ComputeUnion(const AudioValueRange& inRange, const CAAudioValueRangeList& inRangeList, CAAudioValueRangeList& outUnion)
{
    //  this method assumes that the ranges in inRangeList are disjoint and that they are sorted from low to high and
    outUnion.clear();
    
    //  start at the beginning of inRangeList
    CAAudioValueRangeList::const_iterator theIterator = inRangeList.begin();
    
    //  iterate through inRangeList and add all the ranges that are strictly less than inRange
    while((theIterator != inRangeList.end()) && CAAudioValueRange::IsStrictlyLessThan(*theIterator, inRange))
    {
        //  put this range in the union
        outUnion.push_back(*theIterator);
        
        //  go to the next one
        std::advance(theIterator, 1);
    }
    
    if(theIterator != inRangeList.end())
    {
        if(!CAAudioValueRange::IsStrictlyGreaterThan(*theIterator, inRange))
        {
            //  inRange intersects the range that theIterator points at, but might actually intersect several contiguous ranges
            
            //  initialize the starting point, noting that we can skip the current one since we already know it's in the intersection
            CAAudioValueRangeList::const_iterator theGreaterIterator = theIterator;
            std::advance(theGreaterIterator, 1);
            
            //  iterate until we find a range that is strictly greater than inRange
            while((theGreaterIterator != inRangeList.end()) && !CAAudioValueRange::IsStrictlyGreaterThan(*theGreaterIterator, inRange))
            {
                //  go to the next one
                std::advance(theGreaterIterator, 1);
            }
            
            //  theGreaterIterator now points at either one past the highest range in the intersection or the end of the vector
            //  Either way, we have to adjust it to point at the true highest range in the intersection
            std::advance(theGreaterIterator, -1);
            
            //  now theIterator points at the lowest range in the intersection and theGreaterIterator points at the highest
            //  so we can compute the coagulated range
            AudioValueRange theCoagulation;
            theCoagulation.mMinimum = std::min(theIterator->mMinimum, inRange.mMinimum);
            theCoagulation.mMaximum = std::max(theGreaterIterator->mMaximum, inRange.mMaximum);
            
            //  add the coagulation to the union
            outUnion.push_back(theCoagulation);
            
            //  adjust theIterator to point at the next range for processing
            theIterator = theGreaterIterator;
            std::advance(theIterator, 1);
        }
        else
        {
            //  the range theIterator points at is strictly greater than inRange, so insert inRange in front of it and we're done
            outUnion.push_back(inRange);
        }
            
        //  we need to now copy the remaining higher ranges in inRangeList into the union
        while(theIterator != inRangeList.end())
        {
            //  put this range in the union
            outUnion.push_back(*theIterator);
            
            //  go to the next one
            std::advance(theIterator, 1);
        }
    }
    else
    {
        //  inRange is larger than all of the ranges in inRangeList, so just add it onto the end of the union and we're done
        //  This is also the case if inRangeList is empty
        outUnion.push_back(inRange);
    }
}

void    CAAudioValueRange_ComputeIntersection(const AudioValueRange& inRange, const CAAudioValueRangeList& inRangeList, CAAudioValueRangeList& outIntersections)
{
    outIntersections.clear();
    //  iterate through the list and compute the intersections
    CAAudioValueRangeList::const_iterator theIterator = inRangeList.begin();
    while(theIterator != inRangeList.end())
    {
        //  figure out if the range intersects
        AudioValueRange theIntersection;
        if(CAAudioValueRange::Intersection(inRange, *theIterator, theIntersection))
        {
            //  it does, so add the intersection to the return list
            outIntersections.push_back(theIntersection);
        }
        
        //  go to the next one
        std::advance(theIterator, 1);
    }
}