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#ifndef __FTCharToGlyphIndexMap__
#define __FTCharToGlyphIndexMap__
#include <stdlib.h>
#include "FTGL.h"
/**
* Provides a non-STL alternative to the STL map<unsigned long, unsigned long>
* which maps character codes to glyph indices inside FTCharmap.
*
* Implementation:
* - NumberOfBuckets buckets are considered.
* - Each bucket has BucketSize entries.
* - When the glyph index for the character code C has to be stored, the
* bucket this character belongs to is found using 'C div BucketSize'.
* If this bucket has not been allocated yet, do it now.
* The entry in the bucked is found using 'C mod BucketSize'.
* If it is set to IndexNotFound, then the glyph entry has not been set.
* - Try to mimic the calls made to the STL map API.
*
* Caveats:
* - The glyph index is now a signed long instead of unsigned long, so
* the special value IndexNotFound (= -1) can be used to specify that the
* glyph index has not been stored yet.
*/
class FTGL_EXPORT FTCharToGlyphIndexMap
{
public:
typedef unsigned long CharacterCode;
typedef signed long GlyphIndex;
enum
{
NumberOfBuckets = 256,
BucketSize = 256,
IndexNotFound = -1
};
FTCharToGlyphIndexMap()
{
this->Indices = 0;
}
virtual ~FTCharToGlyphIndexMap()
{
if( this->Indices)
{
// Free all buckets
this->clear();
// Free main structure
delete [] this->Indices;
this->Indices = 0;
}
}
void clear()
{
if(this->Indices)
{
for( int i = 0; i < FTCharToGlyphIndexMap::NumberOfBuckets; i++)
{
if( this->Indices[i])
{
delete [] this->Indices[i];
this->Indices[i] = 0;
}
}
}
}
const GlyphIndex find( CharacterCode c)
{
if( !this->Indices)
{
return 0;
}
// Find position of char code in buckets
div_t pos = div( c, FTCharToGlyphIndexMap::BucketSize);
if( !this->Indices[pos.quot])
{
return 0;
}
const FTCharToGlyphIndexMap::GlyphIndex *ptr = &this->Indices[pos.quot][pos.rem];
if( *ptr == FTCharToGlyphIndexMap::IndexNotFound)
{
return 0;
}
return *ptr;
}
void insert( CharacterCode c, GlyphIndex g)
{
if( !this->Indices)
{
this->Indices = new GlyphIndex* [FTCharToGlyphIndexMap::NumberOfBuckets];
for( int i = 0; i < FTCharToGlyphIndexMap::NumberOfBuckets; i++)
{
this->Indices[i] = 0;
}
}
// Find position of char code in buckets
div_t pos = div(c, FTCharToGlyphIndexMap::BucketSize);
// Allocate bucket if does not exist yet
if( !this->Indices[pos.quot])
{
this->Indices[pos.quot] = new GlyphIndex [FTCharToGlyphIndexMap::BucketSize];
for( int i = 0; i < FTCharToGlyphIndexMap::BucketSize; i++)
{
this->Indices[pos.quot][i] = FTCharToGlyphIndexMap::IndexNotFound;
}
}
this->Indices[pos.quot][pos.rem] = g;
}
private:
GlyphIndex** Indices;
};
#endif // __FTCharToGlyphIndexMap__