UT/UT_FloatArray.h

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * Produced by:
 *      Cristin Barghiel
 *      Side Effects Software Inc.
 *      123 Front Street West, Suite 1401
 *      Toronto, Ontario
 *      Canada   M5J 2M2
 *      416-504-9876
 *
 * NAME:        Utility Library (C++)
 *
 * COMMENTS:
 *      This is a class that is used by UT_FloatArray to do all the work...
 *
 */

#ifndef __UT_FloatArray_h__
#define __UT_FloatArray_h__

#include "UT_API.h"
#include <stdlib.h>
#include <SYS/SYS_Types.h>
#include "UT_Assert.h"
#include "UT_ArrayHelp.h"

UT_API extern void UTsetCompareFloatsTolerance( float tol );
UT_API extern int UTcompareFloats(const float *a, const float *b);

class UT_API UT_FloatArray {
public:
    typedef int (*Comparator)(const float *, const float *);

    UT_FloatArray(const UT_FloatArray &a);
    UT_FloatArray(unsigned int sz, unsigned int count)
    {
        arr = (sz) ? (float *)calloc(sizeof(float), sz) : 0;
        if (sz         < count) count = sz;
        nbrEntries = count;
        arrSize = sz;
    }
    explicit UT_FloatArray(unsigned int sz = 0) : arrSize(sz), nbrEntries(0)
    {
        arr = (sz) ? (float *)calloc(sizeof(float), sz) : 0;
    }
    ~UT_FloatArray(void);

    void swap( UT_FloatArray &other );

    // Append an element to the current entries and return its index in the
    // array, or insert the element at a specified position; if necessary,
    // insert() grows the array to accommodate the element. The insert
    // methods use the assignment operator '=' to place the Thing into the
    // right spot; be aware that '=' works differently on objects and pointers.
    // The test for duplicates uses the logical equal operator '=='; as with
    // '=', the behaviour of the equality operator on pointers versus objects
    // is not the same.
    // Use the subscript operators instead of insert() if you are appending
    // to the array, or if  you don't mind overwriting the element already 
    // inserted at the given index.
    unsigned int        append(void)            { return insert(nbrEntries); }
    unsigned int        append(float t);
    unsigned int        insert(unsigned index);
    unsigned int        insert(float t, unsigned index);

    // Assuming the array is sorted, it inserts item t maintaining the sorted
    // state of the array. It returns the index of the inserted item.
    unsigned int        sortedInsert(float t, Comparator compare );
    unsigned int        uniqueSortedInsert(float t, Comparator compare );

    // Assuming the array is already a heap, it inserts item t maintaining
    // the heap. It returns the index of the inserted item.
    unsigned int        heapPush(float t, Comparator compare );
    // Assuming the array is already a heap, extracts the top (maximum)
    // element from the heap and returns it.
    float               heapPop(Comparator compare);
    // Assuming the array is already a heap, return the top (maximum)
    // element.
    float               heapMax() const
                        {
                             UT_ASSERT_P(nbrEntries > 0);
                             return arr[0];
                        }

    // Takes another float array and concatenate it onto my end
    unsigned int        concat(const UT_FloatArray &a);

    // Insert an element "count" times at the given index. Return the index.
    unsigned  int       multipleInsert(unsigned int index, unsigned int count);

    // An alias for unique element insertion at a certain index. Also used by
    // the other insertion methods.
    unsigned int         insertAt(float t, unsigned int index);

    // Remove one element from the array given the element itself or its 
    // position in the list, and fill the gap by shifting the elements down
    // by one position. Both methods return the index if successful, 
    // If dupliCheck is 1, both methods search for all objects that match t or 
    // arr[index] respectively.
    int         findAndRemove(float t);
    int         removeIndex(unsigned int index)
                {
                    return (index < nbrEntries) ? removeAt(index) : -1;
                }

    // Move howMany objects starting at index srcIndex to destIndex;
    // Method returns 0 if OK, -1 if overflow.
    int                 shift(unsigned int srcIdx,
                              unsigned int destIdx,
                              unsigned int howMany);

    // Cyclically shifts the entire array by howMany
    void                cycle(int howMany);

    // Quickly set the array to a single value
    void                constant(float v=0);

    // Search for t in one of two ways: linearly using the '==' operator, or
    // binary using the function specified in the parameter list respectively.
    // find() returns the index of the matching element or (int)-1.
    // Parameter s indicates the index the search should start at.
    int          find(float t, unsigned int s = 0) const;
    int          find(float t, Comparator compare) const;

    void                reverse();

    // Sort the array using a comparison function that you must provide. t1 and
    // t2 are pointers to Thing.
    void                sort(Comparator compare);
    void                sortAscending();

    // Partitions the array into values greater than or less than
    // the Nth element, returns the resulting partition number.
    // idx == 0 will get the minimum value, idx == entries()-1 the
    // maximum value.  This does modify this array!
    float               selectNthLargest(int idx);

    // Resize the array, ie. grow it or shrink it. If copyFlag is 1, the 
    // function copies the data after reallocating space for the array.
    void                resize(unsigned int sz, unsigned short copyFlag=1);
    void                resizeIfNeeded(uint sz, bool copyFlag=true)
                        {
                            if (sz > capacity())
                                resize(sz, copyFlag);
                        }

    // Query the allocated length of the array or the number of elements
    // in the array: capacity() >= entries().
    uint        capacity(void) const    { return arrSize;       }
    int64       getMemoryUsage() const  { return capacity()*sizeof(float); }
    uint        entries(void) const     { return nbrEntries;    }
    bool        isEmpty(void) const     { return nbrEntries==0; }

    // Set the number of entries. Normally, you should not have to use it.
    void        entries(unsigned int ne)        { nbrEntries = ne; }

    // Assign array a to this array by copying each of a's Things with the
    // '=' operator.
    UT_FloatArray       &operator=(const UT_FloatArray &a);

    // Compare two array and return 1 if they are equal and 0 otherwise.
    // Two Things are checked against each other using operator '==' or
    // compare() respectively. Arrays of different size but equal number of
    // entries are checked for member-wise equality.
    // t1 and t2 must point to Things.
    int                 operator==(const UT_FloatArray &a) const;
    int                 isEqual(const UT_FloatArray &a, Comparator compare
                               ) const;
     
    // Subscript operators. operator() does NOT do any bound checking, while
    // the non-const operator[] grows the array to accommodate the given index.
    float               &operator()(unsigned int i)
                         {
                             UT_ASSERT_P(i < nbrEntries);
                             return arr[i];
                         }
    float                operator()(unsigned int i) const
                         {
                             UT_ASSERT_P(i < nbrEntries);
                             return arr[i];
                         }
    float               &operator[](unsigned int i)
                         {
                            if (i >= arrSize   ) resize(bumpAlloc(i+1));
                            if (i >= nbrEntries) nbrEntries = i+1;
                            return arr[i];
                         }
    float                operator[](unsigned int i) const
                         {
                            UT_ASSERT_P(i < nbrEntries);
                            return (i < nbrEntries) ? arr[i] : 0; 
                         }
    float               &last()
                         {
                             UT_ASSERT_P(nbrEntries);
                             return arr[nbrEntries-1];
                         }
    float                last() const
                         {
                             return nbrEntries ? arr[nbrEntries-1] : 0;
                         }

    void         copyMemory(const UT_FloatArray &from)  { *this = from; }

    // Apply a user-defined function to each element of the array 
    // as int as the function returns zero. If applyFct returns
    // 1, apply() stops traversing the list and returns the current
    // index; otherwise, apply() returns the number of entries.
    unsigned int        apply(int (*applyFct)(float &t, void *d), void *d);

    const float *getRawArray(void) const        { return arr;      }
    float       *array(void)                    { return arr;      }
    void         setCapacity(unsigned int sz)   { arrSize    = sz; }

    // This method allows you to swap in a new raw float array, which must be
    // the same size as arrSize. Use caution with this method.
    float       *aliasArray(float *newdata)
                 { float *data = arr; arr = newdata; return data; }

    // Returns the sum of the entries in the array.
    float        sum() const
                 {
                     float  s = 0.0f;
                     for (int i = 0; i < entries(); i++)
                         s += arr[i];
                     return s;
                 }
    
    void         display() const;
private:
    // Pointer to a list of elements of type Thing:
    float               *arr;

    // The number of elements we have allocated space for versus the actual
    // number of entries in the array:
    unsigned int         arrSize;
    unsigned int         nbrEntries;

    // The guts of the remove() methods.
    int                 removeAt(unsigned int index);
    // The guts of the popHeap() method.
    void                heapify(unsigned int index, Comparator compare);

    friend class        UT_FloatMatrix;
};

#endif

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