assimp/code/StringComparison.h

/*
Open Asset Import Library (ASSIMP)
----------------------------------------------------------------------

Copyright (c) 2006-2010, ASSIMP Development Team
All rights reserved.

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  following disclaimer.

* Redistributions in binary form must reproduce the above
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  written permission of the ASSIMP Development Team.

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*/

/** @file Definition of platform independent string workers:

   ASSIMP_itoa10
   ASSIMP_stricmp
   ASSIMP_strincmp

   These functions are not consistently available on all platforms,
   or the provided implementations behave too differently.
*/
#ifndef INCLUDED_AI_STRING_WORKERS_H
#define INCLUDED_AI_STRING_WORKERS_H

namespace Assimp	{

// -------------------------------------------------------------------------------
/** @brief itoa with a fixed base 10
 * 'itoa' is not consistently available on all platforms so it is quite useful
 * to have a small replacement function here. No need to use a full sprintf()
 * if we just want to print a number ...
 * @param out Output buffer
 * @param max Maximum number of characters to be written, including '\0'
 * @param number Number to be written
 * @return Number of bytes written. Including the terminal zero.
 */
inline unsigned int ASSIMP_itoa10( char* out, unsigned int max, int32_t number)
{
	ai_assert(NULL != out);

	static const char lookup[] = {'0','1','2','3','4','5','6','7','8','9'};

	// write the unary minus to indicate we have a negative number
	unsigned int written = 1u;
	if (number < 0 && written < max)
	{
		*out++ = '-';
		++written;
	}

	// We begin with the largest number that is not zero. 
	int32_t cur = 1000000000; // 2147483648
	bool mustPrint = false;
	while (cur > 0 && written <= max)
	{
		unsigned int digit = number / cur;
		if (digit > 0 || mustPrint || 1 == cur)
		{
			// print all future zero's from now
			mustPrint = true;	
			*out++ = lookup[digit];

			++written;
			number -= digit*cur;
		}
		cur /= 10;
	}

	// append a terminal zero
	*out++ = '\0';
	return written;
}

// -------------------------------------------------------------------------------
/** @brief itoa with a fixed base 10 (Secure template overload)
 *  The compiler should choose this function if he is able to determine the
 *  size of the array automatically.
 */
template <unsigned int length>
inline unsigned int ASSIMP_itoa10( char(& out)[length], int32_t number)
{
	return ASSIMP_itoa10(out,length,number);
}

// -------------------------------------------------------------------------------
/** @brief Helper function to do platform independent string comparison.
 *
 *  This is required since stricmp() is not consistently available on
 *  all platforms. Some platforms use the '_' prefix, others don't even
 *  have such a function. 
 *
 *  @param s1 First input string
 *  @param s2 Second input string
 *  @return 0 if the given strings are identical
 */
inline int ASSIMP_stricmp(const char *s1, const char *s2)
{
	ai_assert(NULL != s1 && NULL != s2);

#if (defined _MSC_VER)

	return ::_stricmp(s1,s2);

#elif defined( __GNUC__ )

	return ::strcasecmp(s1,s2);

#else
	register char c1, c2;
	do 
	{
		c1 = tolower(*s1++);
		c2 = tolower(*s2++);
	} 
	while ( c1 && (c1 == c2) );

	return c1 - c2;
#endif
}

// -------------------------------------------------------------------------------
/** @brief Case independent comparison of two std::strings
 *
 *  @param a First  string
 *  @param b Second string
 *  @return 0 if a == b
 */
inline int ASSIMP_stricmp(const std::string& a, const std::string& b)
{
	register int i = (int)b.length()-(int)a.length();
	return (i ? i : ASSIMP_stricmp(a.c_str(),b.c_str()));
}

// -------------------------------------------------------------------------------
/** @brief Helper function to do platform independent string comparison.
 *
 *  This is required since strincmp() is not consistently available on
 *  all platforms. Some platforms use the '_' prefix, others don't even
 *  have such a function. 
 *
 *  @param s1 First input string
 *  @param s2 Second input string
 *  @param n Macimum number of characters to compare
 *  @return 0 if the given strings are identical
 */
inline int ASSIMP_strincmp(const char *s1, const char *s2, unsigned int n)
{
	ai_assert(NULL != s1 && NULL != s2);
	if (!n)return 0;

#if (defined _MSC_VER)

	return ::_strnicmp(s1,s2,n);

#elif defined( __GNUC__ )

	return ::strncasecmp(s1,s2, n);

#else
	register char c1, c2;
	unsigned int p = 0;
	do 
	{
		if (p++ >= n)return 0;
		c1 = tolower(*s1++);
		c2 = tolower(*s2++);
	} 
	while ( c1 && (c1 == c2) );

	return c1 - c2;
#endif
}


// -------------------------------------------------------------------------------
/** @brief Evaluates an integer power
 *
 * todo: move somewhere where it fits better in than here 
 */
inline unsigned int integer_pow (unsigned int base, unsigned int power)
{
	unsigned int res = 1;
	for (unsigned int i = 0; i < power;++i)
		res *= base;

	return res;
}
} // end of namespace

#endif // !  AI_STRINGCOMPARISON_H_INC