// ==========================================================

// Utility functions

//

// Design and implementation by

// - Floris van den Berg (flvdberg@wxs.nl)

// - Hervé Drolon <drolon@infonie.fr>

// - Ryan Rubley (ryan@lostreality.org)

//

// This file is part of FreeImage 3

//

// COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY

// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES

// THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE

// OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED

// CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT

// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY

// SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL

// PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER

// THIS DISCLAIMER.

//

// Use at your own risk!

// ==========================================================



#ifndef UTILITIES_H

#define UTILITIES_H



// ==========================================================

//   Standard includes used by the library

// ==========================================================



#include <math.h>

#include <stdlib.h> 

#include <memory.h>

#include <stdio.h>

#include <string.h>

#include <stdarg.h>

#include <ctype.h>



#include <string>

#include <list>

#include <map>

#include <set>

#include <vector>

#include <stack>

#include <sstream>



// ==========================================================

//   Bitmap palette and pixels alignment

// ==========================================================



#define FIBITMAP_ALIGNMENT	16	// We will use a 16 bytes alignment boundary



// Memory allocation on a specified alignment boundary

// defined in BitmapAccess.cpp



void* FreeImage_Aligned_Malloc(size_t amount, size_t alignment);

void FreeImage_Aligned_Free(void* mem);



// ==========================================================

//   File I/O structs

// ==========================================================



// these structs are for file I/O and should not be confused with similar

// structs in FreeImage.h which are for in-memory bitmap handling



#ifdef WIN32

#pragma pack(push, 1)

#else

#pragma pack(1)

#endif // WIN32



typedef struct tagFILE_RGBA {

  unsigned char r,g,b,a;

} FILE_RGBA;



typedef struct tagFILE_BGRA {

  unsigned char b,g,r,a;

} FILE_BGRA;



typedef struct tagFILE_RGB {

  unsigned char r,g,b;

} FILE_RGB;



typedef struct tagFILE_BGR {

  unsigned char b,g,r;

} FILE_BGR;



#ifdef WIN32

#pragma pack(pop)

#else

#pragma pack()

#endif // WIN32



// ==========================================================

//   Utility functions

// ==========================================================



#ifndef WIN32

inline char*

i2a(unsigned i, char *a, unsigned r) {

	if (i/r > 0) a = i2a(i/r,a,r);

	*a = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"[i%r];

	return a+1;

}



/** 

 Transforms integer i into an ascii string and stores the result in a; 

 string is encoded in the base indicated by r.

 @param i Number to be converted

 @param a String result

 @param r Base of value; must be in the range 2 - 36

 @return Returns a

*/

inline char *

_itoa(int i, char *a, int r) {

	r = ((r < 2) || (r > 36)) ? 10 : r;

	if(i < 0) {

		*a = '-';

		*i2a(-i, a+1, r) = 0;

	}

	else *i2a(i, a, r) = 0;

	return a;

}



#endif // !WIN32



inline unsigned char

HINIBBLE (unsigned char byte) {

	return byte & 0xF0;

}



inline unsigned char

LOWNIBBLE (unsigned char byte) {

	return byte & 0x0F;

}



inline int

CalculateUsedBits(int bits) {

	int bit_count = 0;

	unsigned bit = 1;



	for (unsigned i = 0; i < 32; i++) {

		if ((bits & bit) == bit) {

			bit_count++;

		}



		bit <<= 1;

	}



	return bit_count;

}



inline int

CalculateLine(int width, int bitdepth) {

	return ((width * bitdepth) + 7) / 8;

}



inline int

CalculatePitch(int line) {

	return line + 3 & ~3;

}



inline int

CalculateUsedPaletteEntries(int bit_count) {

	if ((bit_count >= 1) && (bit_count <= 8))

		return 1 << bit_count;



	return 0;

}



inline unsigned char *

CalculateScanLine(unsigned char *bits, unsigned pitch, int scanline) {

	return (bits + (pitch * scanline));

}



inline void

ReplaceExtension(char *result, const char *filename, const char *extension) {

	for (int i = strlen(filename) - 1; i > 0; --i) {

		if (filename[i] == '.') {

			memcpy(result, filename, i);

			result[i] = '.';

			memcpy(result + i + 1, extension, strlen(extension) + 1);

			return;

		}

	}



	memcpy(result, filename, strlen(filename));

	result[strlen(filename)] = '.';

	memcpy(result + strlen(filename) + 1, extension, strlen(extension) + 1);

}



// ==========================================================

//   Big Endian / Little Endian utility functions

// ==========================================================



inline void

SwapShort(unsigned short *sp) {

	unsigned char *cp = (unsigned char *)sp, t = cp[0]; cp[0] = cp[1]; cp[1] = t;

}



inline void

SwapLong(unsigned long *lp) {

	unsigned char *cp = (unsigned char *)lp, t = cp[0]; cp[0] = cp[3]; cp[3] = t;

	t = cp[1]; cp[1] = cp[2]; cp[2] = t;

}



// ==========================================================

//   Greyscale conversion

// ==========================================================



#define GREY(r, g, b) (BYTE)(((WORD)r * 77 + (WORD)g * 150 + (WORD)b * 29) >> 8)	// .299R + .587G + .114B

/*

#define GREY(r, g, b) (BYTE)(((WORD)r * 169 + (WORD)g * 256 + (WORD)b * 87) >> 9)	// .33R + 0.5G + .17B

*/



// ==========================================================

//   Template utility functions

// ==========================================================



/// Max function

template <class T> T MAX(T a, T b) {

	return (a > b) ? a: b;

}



/// Min function

template <class T> T MIN(T a, T b) {

	return (a < b) ? a: b;

}



/// INPLACESWAP adopted from codeguru.com 

template <class T> void INPLACESWAP(T& a, T& b) {

	a ^= b; b ^= a; a ^= b;

}



/** This procedure computes minimum min and maximum max

 of n numbers using only (3n/2) - 2 comparisons.

 min = L[i1] and max = L[i2].

 ref: Aho A.V., Hopcroft J.E., Ullman J.D., 

 The design and analysis of computer algorithms, 

 Addison-Wesley, Reading, 1974.

*/

template <class T> void 

MAXMIN(const T* L, long n, T& max, T& min) {

	long i1, i2, i, j;

	T x1, x2;

	long k1, k2;



	i1 = 0; i2 = 0; min = L[0]; max = L[0]; j = 0;

	if((n % 2) != 0)  j = 1;

	for(i = j; i < n; i+= 2) {

		k1 = i; k2 = i+1;

		x1 = L[k1]; x2 = L[k2];

		if(x1 > x2)	{

			k1 = k2;  k2 = i;

			x1 = x2;  x2 = L[k2];

		}

		if(x1 < min) {

			min = x1;  i1 = k1;

		}

		if(x2 > max) {

			max = x2;  i2 = k2;

		}

	}

}



#endif // UTILITIES_H