Snake-Game-Project/objPosArrayList.cpp at main · xu826Jamin/Snake-Game-Project · GitHub

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#include "objPosArrayList.h"

objPosArrayList::objPosArrayList()
{
    aList = new objPos[ARRAY_MAX_CAP];
    listSize = 0;
    arrayCapacity = ARRAY_MAX_CAP;
}

objPosArrayList::~objPosArrayList()
{
    delete[] aList;
}

int objPosArrayList::getSize() const
{
    return listSize;
}

void objPosArrayList::insertHead(objPos thisPos)
{
    if(listSize == arrayCapacity)
    {
        return;
    }

    // shift right to make room at 0
    for(int i = listSize; i > 0; i--)
    {
        aList[i] = aList[i-1];
    }
    aList[0] = thisPos;
    listSize++;
}

void objPosArrayList::insertTail(objPos thisPos)
{
    if(listSize == arrayCapacity)
    {
        return;
    }
    aList[listSize] = thisPos;
    listSize++;
}

void objPosArrayList::removeHead()
{
    if(listSize == 0)
    {
        return;
    }

    // shift left, this overwrites 0
    for(int i = 0; i < listSize - 1; i++)
    {
        aList[i] = aList[i+1];
    }
    listSize--;
}

void objPosArrayList::removeTail()
{
    if(listSize == 0)
    {
        return;
    }
    listSize--;
}

objPos objPosArrayList::getHeadElement() const
{
    return aList[0];
}

objPos objPosArrayList::getTailElement() const
{
    return aList[listSize - 1];
}

objPos objPosArrayList::getElement(int index) const
{
    if(index < 0 || index >= listSize)
    {
        return aList[0];  // this is a silent callback to head. CALLER BEWARE
    }
    return aList[index];
}