view src/stdlib/SDL_string.c @ 1643:51038e80ae59

More general fix for bug #189 The clipping is done at a higher level, and the low level functions are passed clipped rectangles. Drivers which don't support source clipping have not been changed, so the image will be squished instead of clipped, but at least they will no longer crash when the destination rect was out of bounds.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 17 Apr 2006 06:47:23 +0000
parents 845b1619c8f6
children 14717b52abc0
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* This file contains portable string manipulation functions for SDL */

#include "SDL_stdinc.h"


#define SDL_isupperhex(X)   (((X) >= 'A') && ((X) <= 'F'))
#define SDL_islowerhex(X)   (((X) >= 'a') && ((X) <= 'f'))

#if !defined(HAVE_SSCANF) || !defined(HAVE_STRTOL)
static size_t SDL_ScanLong(const char *text, int radix, long *valuep)
{
    const char *textstart = text;
    long value = 0;
    SDL_bool negative = SDL_FALSE;

    if ( *text == '-' ) {
        negative = SDL_TRUE;
        ++text;
    }
    if ( radix == 16 && SDL_strncmp(text, "0x", 2) == 0 ) {
        text += 2;
    }
    for ( ; ; ) {
        int v;
        if ( SDL_isdigit(*text) ) {
            v = *text - '0';
        } else if ( radix == 16 && SDL_isupperhex(*text) ) {
            v = 10 + (*text - 'A');
        } else if ( radix == 16 && SDL_islowerhex(*text) ) {
            v = 10 + (*text - 'a');
        } else {
            break;
        }
        value *= radix;
        value += v;
        ++text;
    }
    if ( valuep ) {
        if ( negative && value ) {
            *valuep = -value;
        } else {
            *valuep = value;
        }
    }
    return (text - textstart);
}
#endif

#if !defined(HAVE_SSCANF) || !defined(HAVE_STRTOUL) || !defined(HAVE_STRTOD)
static size_t SDL_ScanUnsignedLong(const char *text, int radix, unsigned long *valuep)
{
    const char *textstart = text;
    unsigned long value = 0;

    if ( radix == 16 && SDL_strncmp(text, "0x", 2) == 0 ) {
        text += 2;
    }
    for ( ; ; ) {
        int v;
        if ( SDL_isdigit(*text) ) {
            v = *text - '0';
        } else if ( radix == 16 && SDL_isupperhex(*text) ) {
            v = 10 + (*text - 'A');
        } else if ( radix == 16 && SDL_islowerhex(*text) ) {
            v = 10 + (*text - 'a');
        } else {
            break;
        }
        value *= radix;
        value += v;
        ++text;
    }
    if ( valuep ) {
        *valuep = value;
    }
    return (text - textstart);
}
#endif

#ifndef HAVE_SSCANF
static size_t SDL_ScanUintPtrT(const char *text, int radix, uintptr_t *valuep)
{
    const char *textstart = text;
    uintptr_t value = 0;

    if ( radix == 16 && SDL_strncmp(text, "0x", 2) == 0 ) {
        text += 2;
    }
    for ( ; ; ) {
        int v;
        if ( SDL_isdigit(*text) ) {
            v = *text - '0';
        } else if ( radix == 16 && SDL_isupperhex(*text) ) {
            v = 10 + (*text - 'A');
        } else if ( radix == 16 && SDL_islowerhex(*text) ) {
            v = 10 + (*text - 'a');
        } else {
            break;
        }
        value *= radix;
        value += v;
        ++text;
    }
    if ( valuep ) {
        *valuep = value;
    }
    return (text - textstart);
}
#endif

#ifdef SDL_HAS_64BIT_TYPE
#if !defined(HAVE_SSCANF) || !defined(HAVE_STRTOLL)
static size_t SDL_ScanLongLong(const char *text, int radix, Sint64 *valuep)
{
    const char *textstart = text;
    Sint64 value = 0;
    SDL_bool negative = SDL_FALSE;

    if ( *text == '-' ) {
        negative = SDL_TRUE;
        ++text;
    }
    if ( radix == 16 && SDL_strncmp(text, "0x", 2) == 0 ) {
        text += 2;
    }
    for ( ; ; ) {
        int v;
        if ( SDL_isdigit(*text) ) {
            v = *text - '0';
        } else if ( radix == 16 && SDL_isupperhex(*text) ) {
            v = 10 + (*text - 'A');
        } else if ( radix == 16 && SDL_islowerhex(*text) ) {
            v = 10 + (*text - 'a');
        } else {
            break;
        }
        value *= radix;
        value += v;
        ++text;
    }
    if ( valuep ) {
        if ( negative && value ) {
            *valuep = -value;
        } else {
            *valuep = value;
        }
    }
    return (text - textstart);
}
#endif

#if !defined(HAVE_SSCANF) || !defined(HAVE_STRTOULL)
static size_t SDL_ScanUnsignedLongLong(const char *text, int radix, Uint64 *valuep)
{
    const char *textstart = text;
    Uint64 value = 0;

    if ( radix == 16 && SDL_strncmp(text, "0x", 2) == 0 ) {
        text += 2;
    }
    for ( ; ; ) {
        int v;
        if ( SDL_isdigit(*text) ) {
            v = *text - '0';
        } else if ( radix == 16 && SDL_isupperhex(*text) ) {
            v = 10 + (*text - 'A');
        } else if ( radix == 16 && SDL_islowerhex(*text) ) {
            v = 10 + (*text - 'a');
        } else {
            break;
        }
        value *= radix;
        value += v;
        ++text;
    }
    if ( valuep ) {
        *valuep = value;
    }
    return (text - textstart);
}
#endif
#endif /* SDL_HAS_64BIT_TYPE */

#if !defined(HAVE_SSCANF) || !defined(HAVE_STRTOD)
static size_t SDL_ScanFloat(const char *text, double *valuep)
{
    const char *textstart = text;
    unsigned long lvalue = 0;
    double value = 0.0;
    SDL_bool negative = SDL_FALSE;

    if ( *text == '-' ) {
        negative = SDL_TRUE;
        ++text;
    }
    text += SDL_ScanUnsignedLong(text, 10, &lvalue);
    value += lvalue;
    if ( *text == '.' ) {
        int mult = 10;
        ++text;
        while ( SDL_isdigit(*text) ) {
            lvalue = *text - '0';
            value += (double)lvalue / mult;
            mult *= 10;
            ++text;
        }
    }
    if ( valuep ) {
        if ( negative && value ) {
            *valuep = -value;
        } else {
            *valuep = value;
        }
    }
    return (text - textstart);
}
#endif

#ifndef SDL_memset
void *SDL_memset(void *dst, int c, size_t len)
{
    size_t left = (len % 4);
    if ( len >= 4 ) {
        Uint32 value = 0;
        Uint32 *dstp = (Uint32 *)dst;
        int i;
        for (i = 0; i < 4; ++i) {
            value <<= 8;
            value |= c;
        }
        len /= 4;
        while ( len-- ) {
            *dstp++ = value;
        }
    }
    if ( left > 0 ) {
        Uint8 value = (Uint8)c;
        Uint8 *dstp = (Uint8 *)dst;
	switch(left) {
	case 3:
            *dstp++ = value;
	case 2:
            *dstp++ = value;
	case 1:
            *dstp++ = value;
        }
    }
    return dst;
}
#endif

#ifndef SDL_memcpy
void *SDL_memcpy(void *dst, const void *src, size_t len)
{
    char *srcp = (char *)src;
    char *dstp = (char *)dst;
    while ( len-- ) {
        *dstp++ = *srcp++;
    }
    return dst;
}
#endif

#ifndef SDL_revcpy
void *SDL_revcpy(void *dst, const void *src, size_t len)
{
    char *srcp = (char *)src;
    char *dstp = (char *)dst;
    srcp += len;
    dstp += len;
    while ( len-- ) {
        *dstp-- = *srcp--;
    }
    return dst;
}
#endif

#ifndef SDL_memcmp
int SDL_memcmp(const void *s1, const void *s2, size_t len)
{
    char *s1p = (char *)s1;
    char *s2p = (char *)s2;
    while ( len-- ) {
        if ( *s1p != *s2p ) {
            return (*s1p - *s2p);
    }
    ++s1p;
    ++s2p;
    }
    return 0;
}
#endif

#ifndef HAVE_STRLEN
size_t SDL_strlen(const char *string)
{
    size_t len = 0;
    while ( *string++ ) {
        ++len;
    }
    return len;
}
#endif

#ifndef HAVE_STRLCPY
size_t SDL_strlcpy(char *dst, const char *src, size_t maxlen)
{
    size_t srclen = SDL_strlen(src);
    if ( maxlen > 0 ) {
        size_t len = SDL_min(srclen, maxlen-1);
        SDL_memcpy(dst, src, len);
        dst[len] = '\0';
    }
    return srclen;
}
#endif

#ifndef HAVE_STRLCAT
size_t SDL_strlcat(char *dst, const char *src, size_t maxlen)
{
    size_t dstlen = SDL_strlen(dst);
    size_t srclen = SDL_strlen(src);
    if ( dstlen < maxlen ) {
        SDL_strlcpy(dst+dstlen, src, maxlen-dstlen);
    }
    return dstlen+srclen;
}
#endif

#ifndef HAVE_STRDUP
char *SDL_strdup(const char *string)
{
    size_t len = SDL_strlen(string)+1;
    char *newstr = SDL_malloc(len);
    if ( newstr ) {
        SDL_strlcpy(newstr, string, len);
    }
    return newstr;
}
#endif

#ifndef HAVE__STRREV
char *SDL_strrev(char *string)
{
    size_t len = SDL_strlen(string);
    char *a = &string[0];
    char *b = &string[len-1];
    len /= 2;
    while ( len-- ) {
        char c = *a;
        *a++ = *b;
        *b-- = c;
    }
    return string;
}
#endif

#ifndef HAVE__STRUPR
char *SDL_strupr(char *string)
{
    char *bufp = string;
    while ( *bufp ) {
        *bufp = SDL_toupper(*bufp);
	++bufp;
    }
    return string;
}
#endif

#ifndef HAVE__STRLWR
char *SDL_strlwr(char *string)
{
    char *bufp = string;
    while ( *bufp ) {
        *bufp = SDL_tolower(*bufp);
	++bufp;
    }
    return string;
}
#endif

#ifndef HAVE_STRCHR
char *SDL_strchr(const char *string, int c)
{
    while ( *string ) {
        if ( *string == c ) {
            return (char *)string;
        }
	++string;
    }
    return NULL;
}
#endif

#ifndef HAVE_STRRCHR
char *SDL_strrchr(const char *string, int c)
{
    const char *bufp = string + SDL_strlen(string) - 1;
    while ( bufp >= string ) {
        if ( *bufp == c ) {
            return (char *)bufp;
        }
	--bufp;
    }
    return NULL;
}
#endif

#ifndef HAVE_STRSTR
char *SDL_strstr(const char *haystack, const char *needle)
{
    size_t length = SDL_strlen(needle);
    while ( *haystack ) {
        if ( SDL_strncmp(haystack, needle, length) == 0 ) {
            return (char *)haystack;
        }
	++haystack;
    }
    return NULL;
}
#endif

#if !defined(HAVE__LTOA)  || !defined(HAVE__I64TOA) || \
    !defined(HAVE__ULTOA) || !defined(HAVE__UI64TOA)
static const char ntoa_table[] = {
    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
    'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
    'U', 'V', 'W', 'X', 'Y', 'Z'
};
#endif /* ntoa() conversion table */

#ifndef HAVE__LTOA
char *SDL_ltoa(long value, char *string, int radix)
{
    char *bufp = string;

    if ( value < 0 ) {
        *bufp++ = '-';
        value = -value;
    }
    if ( value ) {
        while ( value > 0 ) {
            *bufp++ = ntoa_table[value % radix];
            value /= radix;
        }
    } else {
        *bufp++ = '0';
    }
    *bufp = '\0';

    /* The numbers went into the string backwards. :) */
    if ( *string == '-' ) {
        SDL_strrev(string+1);
    } else {
        SDL_strrev(string);
    }

    return string;
}
#endif

#ifndef HAVE__ULTOA
char *SDL_ultoa(unsigned long value, char *string, int radix)
{
    char *bufp = string;

    if ( value ) {
        while ( value > 0 ) {
            *bufp++ = ntoa_table[value % radix];
            value /= radix;
        }
    } else {
        *bufp++ = '0';
    }
    *bufp = '\0';

    /* The numbers went into the string backwards. :) */
    SDL_strrev(string);

    return string;
}
#endif

#ifndef HAVE_STRTOL
long SDL_strtol(const char *string, char **endp, int base)
{
    size_t len;
    long value;

    len = SDL_ScanLong(string, base ? base : 10, &value);
    if ( endp ) {
        *endp = (char *)string + len;
    }
    return value;
}
#endif

#ifndef HAVE_STRTOUL
unsigned long SDL_strtoul(const char *string, char **endp, int base)
{
    size_t len;
    unsigned long value;

    len = SDL_ScanUnsignedLong(string, base ? base : 10, &value);
    if ( endp ) {
        *endp = (char *)string + len;
    }
    return value;
}
#endif

#ifdef SDL_HAS_64BIT_TYPE

#ifndef HAVE__I64TOA
char *SDL_lltoa(Sint64 value, char *string, int radix)
{
    char *bufp = string;

    if ( value < 0 ) {
        *bufp++ = '-';
        value = -value;
    }
    if ( value ) {
        while ( value > 0 ) {
            *bufp++ = ntoa_table[value % radix];
            value /= radix;
        }
    } else {
        *bufp++ = '0';
    }
    *bufp = '\0';

    /* The numbers went into the string backwards. :) */
    if ( *string == '-' ) {
        SDL_strrev(string+1);
    } else {
        SDL_strrev(string);
    }

    return string;
}
#endif

#ifndef HAVE__UI64TOA
char *SDL_ulltoa(Uint64 value, char *string, int radix)
{
    char *bufp = string;

    if ( value ) {
        while ( value > 0 ) {
            *bufp++ = ntoa_table[value % radix];
            value /= radix;
        }
    } else {
        *bufp++ = '0';
    }
    *bufp = '\0';

    /* The numbers went into the string backwards. :) */
    SDL_strrev(string);

    return string;
}
#endif

#ifndef HAVE_STRTOLL
Sint64 SDL_strtoll(const char *string, char **endp, int base)
{
    size_t len;
    Sint64 value;

    len = SDL_ScanLongLong(string, base ? base : 10, &value);
    if ( endp ) {
        *endp = (char *)string + len;
    }
    return value;
}
#endif

#ifndef HAVE_STRTOULL
Uint64 SDL_strtoull(const char *string, char **endp, int base)
{
    size_t len;
    Uint64 value;

    len = SDL_ScanUnsignedLongLong(string, base ? base : 10, &value);
    if ( endp ) {
        *endp = (char *)string + len;
    }
    return value;
}
#endif

#endif /* SDL_HAS_64BIT_TYPE */

#ifndef HAVE_STRTOD
double SDL_strtod(const char *string, char **endp)
{
    size_t len;
    double value;

    len = SDL_ScanFloat(string, &value);
    if ( endp ) {
        *endp = (char *)string + len;
    }
    return value;
}
#endif

#ifndef HAVE_STRCMP
int SDL_strcmp(const char *str1, const char *str2)
{
    while (*str1 && *str2) {
        if ( *str1 != *str2 )
            break;
        ++str1;
        ++str2;
    }
    return (int)((unsigned char)*str1 - (unsigned char)*str2);
}
#endif

#ifndef HAVE_STRNCMP
int SDL_strncmp(const char *str1, const char *str2, size_t maxlen)
{
    while ( *str1 && *str2 && maxlen ) {
        if ( *str1 != *str2 )
            break;
        ++str1;
        ++str2;
        --maxlen;
    }
    if ( ! maxlen ) {
        return 0;
    }
    return (int)((unsigned char)*str1 - (unsigned char)*str2);
}
#endif

#if !defined(HAVE_STRCASECMP) && !defined(HAVE__STRICMP)
int SDL_strcasecmp(const char *str1, const char *str2)
{
    char a = 0;
    char b = 0;
    while ( *str1 && *str2 ) {
        a = SDL_tolower(*str1);
        b = SDL_tolower(*str2);
        if ( a != b )
            break;
        ++str1;
        ++str2;
    }
    return (int)((unsigned char)a - (unsigned char)b);
}
#endif

#if !defined(HAVE_STRNCASECMP) && !defined(HAVE__STRNICMP)
int SDL_strncasecmp(const char *str1, const char *str2, size_t maxlen)
{
    char a = 0;
    char b = 0;
    while ( *str1 && *str2 && maxlen ) {
        a = SDL_tolower(*str1);
        b = SDL_tolower(*str2);
        if ( a != b )
            break;
        ++str1;
        ++str2;
        --maxlen;
    }
    return (int)((unsigned char)a - (unsigned char)b);
}
#endif

#ifndef HAVE_SSCANF
int SDL_sscanf(const char *text, const char *fmt, ...)
{
    va_list ap;
    int retval = 0;

    va_start(ap, fmt);
    while ( *fmt ) {
        if ( *fmt == ' ' ) {
            while ( SDL_isspace(*text) ) {
                ++text;
            }
            ++fmt;
            continue;
        }
        if ( *fmt == '%' ) {
            SDL_bool done = SDL_FALSE;
            long count = 0;
            int radix = 10;
            enum {
                DO_SHORT,
                DO_INT,
                DO_LONG,
                DO_LONGLONG
            } inttype = DO_INT;
            SDL_bool suppress = SDL_FALSE;

            ++fmt;
            if ( *fmt == '%' ) {
                if ( *text == '%' ) {
                    ++text;
                    ++fmt;
                    continue;
                }
                break;
            }
            if ( *fmt == '*' ) {
                suppress = SDL_TRUE;
                ++fmt;
            }
            fmt += SDL_ScanLong(fmt, 10, &count);

            if ( *fmt == 'c' ) {
                if ( ! count ) {
                    count = 1;
                }
                if ( suppress ) {
                    while ( count-- ) {
                        ++text;
                    }
                } else {
                    char *valuep = va_arg(ap, char*);
                    while ( count-- ) {
                        *valuep++ = *text++;
                    }
                    ++retval;
                }
                continue;
            }

            while ( SDL_isspace(*text) ) {
                ++text;
            }

            /* FIXME: implement more of the format specifiers */
            while (!done) {
                switch(*fmt) {
                    case '*':
                        suppress = SDL_TRUE;
                        break;
                    case 'h':
                        if ( inttype > DO_SHORT ) {
                            ++inttype;
                        }
                        break;
                    case 'l':
                        if ( inttype < DO_LONGLONG ) {
                            ++inttype;
                        }
                        break;
                    case 'I':
                        if ( SDL_strncmp(fmt, "I64", 3) == 0 ) {
                            fmt += 2;
                            inttype = DO_LONGLONG;
                        }
                        break;
                    case 'i':
                        {
                            int index = 0;
                            if ( text[index] == '-' ) {
                                ++index;
                            }
                            if ( text[index] == '0' ) {
                                if ( SDL_tolower(text[index+1]) == 'x' ) {
                                    radix = 16;
                                } else {
                                    radix = 8;
                                }
                            }
                        }
                        /* Fall through to %d handling */
                    case 'd':
#ifdef SDL_HAS_64BIT_TYPE
                        if ( inttype == DO_LONGLONG ) {
                            Sint64 value;
                            text += SDL_ScanLongLong(text, radix, &value);
                            if ( ! suppress ) {
                                Sint64 *valuep = va_arg(ap, Sint64*);
                                *valuep = value;
                                ++retval;
                            }
                        }
                        else
#endif /* SDL_HAS_64BIT_TYPE */
                        {
                            long value;
                            text += SDL_ScanLong(text, radix, &value);
                            if ( ! suppress ) {
                                switch (inttype) {
                                    case DO_SHORT:
                                        { short* valuep = va_arg(ap, short*);
                                            *valuep = (short)value;
                                        }
                                        break;
                                    case DO_INT:
                                        { int* valuep = va_arg(ap, int*);
                                            *valuep = (int)value;
                                        }
                                        break;
                                    case DO_LONG:
                                        { long* valuep = va_arg(ap, long*);
                                            *valuep = value;
                                        }
                                        break;
                                    case DO_LONGLONG:
                                        /* Handled above */
                                        break;
                                }
                                ++retval;
                            }
                        }
                        done = SDL_TRUE;
                        break;
                    case 'o':
                        if ( radix == 10 ) {
                            radix = 8;
                        }
                        /* Fall through to unsigned handling */
                    case 'x':
                    case 'X':
                        if ( radix == 10 ) {
                            radix = 16;
                        }
                        /* Fall through to unsigned handling */
                    case 'u':
#ifdef SDL_HAS_64BIT_TYPE
                        if ( inttype == DO_LONGLONG ) {
                            Uint64 value;
                            text += SDL_ScanUnsignedLongLong(text, radix, &value);
                            if ( ! suppress ) {
                                Uint64 *valuep = va_arg(ap, Uint64*);
                                *valuep = value;
                                ++retval;
                            }
                        }
                        else
#endif /* SDL_HAS_64BIT_TYPE */
                        {
                            unsigned long value;
                            text += SDL_ScanUnsignedLong(text, radix, &value);
                            if ( ! suppress ) {
                                switch (inttype) {
                                    case DO_SHORT:
                                        { short* valuep = va_arg(ap, short*);
                                            *valuep = (short)value;
                                        }
                                        break;
                                    case DO_INT:
                                        { int* valuep = va_arg(ap, int*);
                                            *valuep = (int)value;
                                        }
                                        break;
                                    case DO_LONG:
                                        { long* valuep = va_arg(ap, long*);
                                            *valuep = value;
                                        }
                                        break;
                                    case DO_LONGLONG:
                                        /* Handled above */
                                        break;
                                }
                                ++retval;
                            }
                        }
                        done = SDL_TRUE;
                        break;
                    case 'p':
                        {
                            uintptr_t value;
                            text += SDL_ScanUintPtrT(text, 16, &value);
                            if ( ! suppress ) {
                                void** valuep = va_arg(ap, void**);
                                *valuep = (void*)value;
                                ++retval;
                            }
                        }
                        done = SDL_TRUE;
                        break;
                    case 'f':
                        {
                            double value;
                            text += SDL_ScanFloat(text, &value);
                            if ( ! suppress ) {
                                float* valuep = va_arg(ap, float*);
                                *valuep = (float)value;
                                ++retval;
                            }
                        }
                        done = SDL_TRUE;
                        break;
                    case 's':
                        if ( suppress ) {
                            while ( !SDL_isspace(*text) ) {
                                ++text;
                                if ( count ) {
                                    if ( --count == 0 ) {
                                        break;
                                    }
                                }
                            }
                        } else {
                            char *valuep = va_arg(ap, char*);
                            while ( !SDL_isspace(*text) ) {
                                *valuep++ = *text++;
                                if ( count ) {
                                    if ( --count == 0 ) {
                                        break;
                                    }
                                }
                            }
                            *valuep = '\0';
                            ++retval;
                        }
                        done = SDL_TRUE;
                        break;
                    default:
                        done = SDL_TRUE;
                        break;
                }
                ++fmt;
            }
            continue;
        }
        if ( *text == *fmt ) {
            ++text;
            ++fmt;
            continue;
        }
        /* Text didn't match format specifier */
        break;
    }
    va_end(ap);

    return retval;
}
#endif

#ifndef HAVE_SNPRINTF
int SDL_snprintf(char *text, size_t maxlen, const char *fmt, ...)
{
    va_list ap;
    int retval;

    va_start(ap, fmt);
    retval = SDL_vsnprintf(text, maxlen, fmt, ap);
    va_end(ap);

    return retval;
}
#endif

#ifndef HAVE_VSNPRINTF
static size_t SDL_PrintLong(char *text, long value, int radix, size_t maxlen)
{
    char num[130];
    size_t size;

    SDL_ltoa(value, num, radix);
    size = SDL_strlen(num);
    if ( size > maxlen ) {
        size = maxlen;
    }
    SDL_strlcpy(text, num, size);

    return size;
}
static size_t SDL_PrintUnsignedLong(char *text, unsigned long value, int radix, size_t maxlen)
{
    char num[130];
    size_t size;

    SDL_ultoa(value, num, radix);
    size = SDL_strlen(num);
    if ( size > maxlen ) {
        size = maxlen;
    }
    SDL_strlcpy(text, num, size);

    return size;
}
#ifdef SDL_HAS_64BIT_TYPE
static size_t SDL_PrintLongLong(char *text, Sint64 value, int radix, size_t maxlen)
{
    char num[130];
    size_t size;

    SDL_lltoa(value, num, radix);
    size = SDL_strlen(num);
    if ( size > maxlen ) {
        size = maxlen;
    }
    SDL_strlcpy(text, num, size);

    return size;
}
static size_t SDL_PrintUnsignedLongLong(char *text, Uint64 value, int radix, size_t maxlen)
{
    char num[130];
    size_t size;

    SDL_ulltoa(value, num, radix);
    size = SDL_strlen(num);
    if ( size > maxlen ) {
        size = maxlen;
    }
    SDL_strlcpy(text, num, size);

    return size;
}
#endif /* SDL_HAS_64BIT_TYPE */
static size_t SDL_PrintFloat(char *text, double arg, size_t maxlen)
{
    char *textstart = text;
    if ( arg ) {
        /* This isn't especially accurate, but hey, it's easy. :) */
        const double precision = 0.00000001;
        size_t len;
        unsigned long value;

        if ( arg < 0 ) {
            *text++ = '-';
            --maxlen;
            arg = -arg;
        }
        value = (unsigned long)arg;
        len = SDL_PrintUnsignedLong(text, value, 10, maxlen);
        text += len;
        maxlen -= len;
        arg -= value;
        if ( arg > precision && maxlen ) {
            int mult = 10;
            *text++ = '.';
            while ( (arg > precision) && maxlen ) {
                value = (unsigned long)(arg * mult);
                len = SDL_PrintUnsignedLong(text, value, 10, maxlen);
                text += len;
                maxlen -= len;
                arg -= (double)value / mult;
                mult *= 10;
            }
        }
    } else {
        *text++ = '0';
    }
    return (text - textstart);
}
static size_t SDL_PrintString(char *text, const char *string, size_t maxlen)
{
    char *textstart = text;
    while ( *string && maxlen-- ) {
        *text++ = *string++;
    }
    return (text - textstart);
}
int SDL_vsnprintf(char *text, size_t maxlen, const char *fmt, va_list ap)
{
    char *textstart = text;
    if ( maxlen <= 0 ) {
        return 0;
    }
    --maxlen; /* For the trailing '\0' */
    while ( *fmt && maxlen ) {
        if ( *fmt == '%' ) {
            SDL_bool done = SDL_FALSE;
            size_t len = 0;
            SDL_bool do_lowercase = SDL_FALSE;
            int radix = 10;
            enum {
                DO_INT,
                DO_LONG,
                DO_LONGLONG
            } inttype = DO_INT;

            ++fmt;
            /* FIXME: implement more of the format specifiers */
            while (!done) {
                switch(*fmt) {
                    case '%':
                        *text = '%';
                        len = 1;
                        done = SDL_TRUE;
                        break;
                    case 'c':
                        /* char is promoted to int when passed through (...) */
                        *text = (char)va_arg(ap, int);
                        len = 1;
                        done = SDL_TRUE;
                        break;
                    case 'h':
                        /* short is promoted to int when passed through (...) */
                        break;
                    case 'l':
                        if ( inttype < DO_LONGLONG ) {
                            ++inttype;
                        }
                        break;
                    case 'I':
                        if ( SDL_strncmp(fmt, "I64", 3) == 0 ) {
                            fmt += 2;
                            inttype = DO_LONGLONG;
                        }
                        break;
                    case 'i':
                    case 'd':
                        switch (inttype) {
                            case DO_INT:
                                len = SDL_PrintLong(text, (long)va_arg(ap, int), radix, maxlen);
                                break;
                            case DO_LONG:
                                len = SDL_PrintLong(text, va_arg(ap, long), radix, maxlen);
                                break;
                            case DO_LONGLONG:
#ifdef SDL_HAS_64BIT_TYPE
                                len = SDL_PrintLongLong(text, va_arg(ap, Sint64), radix, maxlen);
#else
                                len = SDL_PrintLong(text, va_arg(ap, long), radix, maxlen);
#endif
                                break;
                        }
                        done = SDL_TRUE;
                        break;
                    case 'p':
                    case 'x':
                        do_lowercase = SDL_TRUE;
                        /* Fall through to 'X' handling */
                    case 'X':
                        if ( radix == 10 ) {
                            radix = 16;
                        }
                        if ( *fmt == 'p' ) {
                            inttype = DO_LONG;
                        }
                        /* Fall through to unsigned handling */
                    case 'o':
                        if ( radix == 10 ) {
                            radix = 8;
                        }
                        /* Fall through to unsigned handling */
                    case 'u':
                        switch (inttype) {
                            case DO_INT:
                                len = SDL_PrintUnsignedLong(text, (unsigned long)va_arg(ap, unsigned int), radix, maxlen);
                                break;
                            case DO_LONG:
                                len = SDL_PrintUnsignedLong(text, va_arg(ap, unsigned long), radix, maxlen);
                                break;
                            case DO_LONGLONG:
#ifdef SDL_HAS_64BIT_TYPE
                                len = SDL_PrintUnsignedLongLong(text, va_arg(ap, Uint64), radix, maxlen);
#else
                                len = SDL_PrintUnsignedLong(text, va_arg(ap, unsigned long), radix, maxlen);
#endif
                                break;
                        }
                        if ( do_lowercase ) {
                            SDL_strlwr(text);
                        }
                        done = SDL_TRUE;
                        break;
                    case 'f':
                        len = SDL_PrintFloat(text, va_arg(ap, double), maxlen);
                        done = SDL_TRUE;
                        break;
                    case 's':
                        len = SDL_PrintString(text, va_arg(ap, char*), maxlen);
                        done = SDL_TRUE;
                        break;
                    default:
                        done = SDL_TRUE;
                        break;
                }
                ++fmt;
            }
            text += len;
            maxlen -= len;
        } else {
            *text++ = *fmt++;
            --maxlen;
        }
    }
    *text = '\0';

    return (text - textstart);
}
#endif