convert lvgl from submodule to a plain old directory

2 files changed, 879 insertions, 0 deletions

diff --git a/lib/lvgl b/lib/lvgl
deleted file mode 160000
-Subproject 0732400e7b564dd0e7dc4a924619d8e19c5b23a
diff --git a/lib/lvgl/src/misc/lv_printf.c b/lib/lvgl/src/misc/lv_printf.c
new file mode 100644
index 00000000..9077a7a1
--- /dev/null
+++ b/lib/lvgl/src/misc/lv_printf.c
@@ -0,0 +1,879 @@
+///////////////////////////////////////////////////////////////////////////////
+// \author (c) Marco Paland (info@paland.com)
+//             2014-2019, PALANDesign Hannover, Germany
+//
+// \license The MIT License (MIT)
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+// \brief Tiny printf, sprintf and (v)snprintf implementation, optimized for speed on
+//        embedded systems with a very limited resources. These routines are thread
+//        safe and reentrant!
+//        Use this instead of the bloated standard/newlib printf cause these use
+//        malloc for printf (and may not be thread safe).
+//
+///////////////////////////////////////////////////////////////////////////////
+
+/*Original repository: https://github.com/mpaland/printf*/
+
+#include "lv_printf.h"
+
+#if LV_SPRINTF_CUSTOM == 0
+
+#include <stdbool.h>
+
+#define PRINTF_DISABLE_SUPPORT_FLOAT    (!LV_SPRINTF_USE_FLOAT)
+
+// 'ntoa' conversion buffer size, this must be big enough to hold one converted
+// numeric number including padded zeros (dynamically created on stack)
+// default: 32 byte
+#ifndef PRINTF_NTOA_BUFFER_SIZE
+    #define PRINTF_NTOA_BUFFER_SIZE    32U
+#endif
+
+// 'ftoa' conversion buffer size, this must be big enough to hold one converted
+// float number including padded zeros (dynamically created on stack)
+// default: 32 byte
+#ifndef PRINTF_FTOA_BUFFER_SIZE
+    #define PRINTF_FTOA_BUFFER_SIZE    32U
+#endif
+
+// support for the floating point type (%f)
+// default: activated
+#if !PRINTF_DISABLE_SUPPORT_FLOAT
+    #define PRINTF_SUPPORT_FLOAT
+#endif
+
+// support for exponential floating point notation (%e/%g)
+// default: activated
+#ifndef PRINTF_DISABLE_SUPPORT_EXPONENTIAL
+    #define PRINTF_SUPPORT_EXPONENTIAL
+#endif
+
+// define the default floating point precision
+// default: 6 digits
+#ifndef PRINTF_DEFAULT_FLOAT_PRECISION
+    #define PRINTF_DEFAULT_FLOAT_PRECISION 6U
+#endif
+
+// define the largest float suitable to print with %f
+// default: 1e9
+#ifndef PRINTF_MAX_FLOAT
+    #define PRINTF_MAX_FLOAT 1e9
+#endif
+
+// support for the long long types (%llu or %p)
+// default: activated
+#ifndef PRINTF_DISABLE_SUPPORT_LONG_LONG
+    #define PRINTF_SUPPORT_LONG_LONG
+#endif
+
+// support for the ptrdiff_t type (%t)
+// ptrdiff_t is normally defined in <stddef.h> as long or long long type
+// default: activated
+#ifndef PRINTF_DISABLE_SUPPORT_PTRDIFF_T
+    #define PRINTF_SUPPORT_PTRDIFF_T
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+
+// internal flag definitions
+#define FLAGS_ZEROPAD   (1U <<  0U)
+#define FLAGS_LEFT      (1U <<  1U)
+#define FLAGS_PLUS      (1U <<  2U)
+#define FLAGS_SPACE     (1U <<  3U)
+#define FLAGS_HASH      (1U <<  4U)
+#define FLAGS_UPPERCASE (1U <<  5U)
+#define FLAGS_CHAR      (1U <<  6U)
+#define FLAGS_SHORT     (1U <<  7U)
+#define FLAGS_LONG      (1U <<  8U)
+#define FLAGS_LONG_LONG (1U <<  9U)
+#define FLAGS_PRECISION (1U << 10U)
+#define FLAGS_ADAPT_EXP (1U << 11U)
+
+// import float.h for DBL_MAX
+#if defined(PRINTF_SUPPORT_FLOAT)
+    #include <float.h>
+#endif
+
+// output function type
+typedef void (*out_fct_type)(char character, void * buffer, size_t idx, size_t maxlen);
+
+// wrapper (used as buffer) for output function type
+typedef struct {
+    void (*fct)(char character, void * arg);
+    void * arg;
+} out_fct_wrap_type;
+
+// internal buffer output
+static inline void _out_buffer(char character, void * buffer, size_t idx, size_t maxlen)
+{
+    if(idx < maxlen) {
+        ((char *)buffer)[idx] = character;
+    }
+}
+
+// internal null output
+static inline void _out_null(char character, void * buffer, size_t idx, size_t maxlen)
+{
+    LV_UNUSED(character);
+    LV_UNUSED(buffer);
+    LV_UNUSED(idx);
+    LV_UNUSED(maxlen);
+}
+
+// internal secure strlen
+// \return The length of the string (excluding the terminating 0) limited by 'maxsize'
+static inline unsigned int _strnlen_s(const char * str, size_t maxsize)
+{
+    const char * s;
+    for(s = str; *s && maxsize--; ++s);
+    return (unsigned int)(s - str);
+}
+
+// internal test if char is a digit (0-9)
+// \return true if char is a digit
+static inline bool _is_digit(char ch)
+{
+    return (ch >= '0') && (ch <= '9');
+}
+
+// internal ASCII string to unsigned int conversion
+static unsigned int _atoi(const char ** str)
+{
+    unsigned int i = 0U;
+    while(_is_digit(**str)) {
+        i = i * 10U + (unsigned int)(*((*str)++) - '0');
+    }
+    return i;
+}
+
+// output the specified string in reverse, taking care of any zero-padding
+static size_t _out_rev(out_fct_type out, char * buffer, size_t idx, size_t maxlen, const char * buf, size_t len,
+                       unsigned int width, unsigned int flags)
+{
+    const size_t start_idx = idx;
+
+    // pad spaces up to given width
+    if(!(flags & FLAGS_LEFT) && !(flags & FLAGS_ZEROPAD)) {
+        size_t i;
+        for(i = len; i < width; i++) {
+            out(' ', buffer, idx++, maxlen);
+        }
+    }
+
+    // reverse string
+    while(len) {
+        out(buf[--len], buffer, idx++, maxlen);
+    }
+
+    // append pad spaces up to given width
+    if(flags & FLAGS_LEFT) {
+        while(idx - start_idx < width) {
+            out(' ', buffer, idx++, maxlen);
+        }
+    }
+
+    return idx;
+}
+
+// internal itoa format
+static size_t _ntoa_format(out_fct_type out, char * buffer, size_t idx, size_t maxlen, char * buf, size_t len,
+                           bool negative, unsigned int base, unsigned int prec, unsigned int width, unsigned int flags)
+{
+    // pad leading zeros
+    if(!(flags & FLAGS_LEFT)) {
+        if(width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
+            width--;
+        }
+        while((len < prec) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
+            buf[len++] = '0';
+        }
+        while((flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
+            buf[len++] = '0';
+        }
+    }
+
+    // handle hash
+    if(flags & FLAGS_HASH) {
+        if(!(flags & FLAGS_PRECISION) && len && ((len == prec) || (len == width))) {
+            len--;
+            if(len && (base == 16U)) {
+                len--;
+            }
+        }
+        if((base == 16U) && !(flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
+            buf[len++] = 'x';
+        }
+        else if((base == 16U) && (flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
+            buf[len++] = 'X';
+        }
+        else if((base == 2U) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
+            buf[len++] = 'b';
+        }
+        if(len < PRINTF_NTOA_BUFFER_SIZE) {
+            buf[len++] = '0';
+        }
+    }
+
+    if(len < PRINTF_NTOA_BUFFER_SIZE) {
+        if(negative) {
+            buf[len++] = '-';
+        }
+        else if(flags & FLAGS_PLUS) {
+            buf[len++] = '+';  // ignore the space if the '+' exists
+        }
+        else if(flags & FLAGS_SPACE) {
+            buf[len++] = ' ';
+        }
+    }
+
+    return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
+}
+
+// internal itoa for 'long' type
+static size_t _ntoa_long(out_fct_type out, char * buffer, size_t idx, size_t maxlen, unsigned long value, bool negative,
+                         unsigned long base, unsigned int prec, unsigned int width, unsigned int flags)
+{
+    char buf[PRINTF_NTOA_BUFFER_SIZE];
+    size_t len = 0U;
+
+    // no hash for 0 values
+    if(!value) {
+        flags &= ~FLAGS_HASH;
+    }
+
+    // write if precision != 0 and value is != 0
+    if(!(flags & FLAGS_PRECISION) || value) {
+        do {
+            const char digit = (char)(value % base);
+            buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10;
+            value /= base;
+        } while(value && (len < PRINTF_NTOA_BUFFER_SIZE));
+    }
+
+    return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags);
+}
+
+// internal itoa for 'long long' type
+#if defined(PRINTF_SUPPORT_LONG_LONG)
+static size_t _ntoa_long_long(out_fct_type out, char * buffer, size_t idx, size_t maxlen, unsigned long long value,
+                              bool negative, unsigned long long base, unsigned int prec, unsigned int width, unsigned int flags)
+{
+    char buf[PRINTF_NTOA_BUFFER_SIZE];
+    size_t len = 0U;
+
+    // no hash for 0 values
+    if(!value) {
+        flags &= ~FLAGS_HASH;
+    }
+
+    // write if precision != 0 and value is != 0
+    if(!(flags & FLAGS_PRECISION) || value) {
+        do {
+            const char digit = (char)(value % base);
+            buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10;
+            value /= base;
+        } while(value && (len < PRINTF_NTOA_BUFFER_SIZE));
+    }
+
+    return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags);
+}
+#endif  // PRINTF_SUPPORT_LONG_LONG
+
+#if defined(PRINTF_SUPPORT_FLOAT)
+
+#if defined(PRINTF_SUPPORT_EXPONENTIAL)
+// forward declaration so that _ftoa can switch to exp notation for values > PRINTF_MAX_FLOAT
+static size_t _etoa(out_fct_type out, char * buffer, size_t idx, size_t maxlen, double value, unsigned int prec,
+                    unsigned int width, unsigned int flags);
+#endif
+
+// internal ftoa for fixed decimal floating point
+static size_t _ftoa(out_fct_type out, char * buffer, size_t idx, size_t maxlen, double value, unsigned int prec,
+                    unsigned int width, unsigned int flags)
+{
+    char buf[PRINTF_FTOA_BUFFER_SIZE];
+    size_t len  = 0U;
+    double diff = 0.0;
+
+    // powers of 10
+    static const double pow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 };
+
+    // test for special values
+    if(value != value)
+        return _out_rev(out, buffer, idx, maxlen, "nan", 3, width, flags);
+    if(value < -DBL_MAX)
+        return _out_rev(out, buffer, idx, maxlen, "fni-", 4, width, flags);
+    if(value > DBL_MAX)
+        return _out_rev(out, buffer, idx, maxlen, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4U : 3U, width,
+                        flags);
+
+    // test for very large values
+    // standard printf behavior is to print EVERY whole number digit -- which could be 100s of characters overflowing your buffers == bad
+    if((value > PRINTF_MAX_FLOAT) || (value < -PRINTF_MAX_FLOAT)) {
+#if defined(PRINTF_SUPPORT_EXPONENTIAL)
+        return _etoa(out, buffer, idx, maxlen, value, prec, width, flags);
+#else
+        return 0U;
+#endif
+    }
+
+    // test for negative
+    bool negative = false;
+    if(value < 0) {
+        negative = true;
+        value = 0 - value;
+    }
+
+    // set default precision, if not set explicitly
+    if(!(flags & FLAGS_PRECISION)) {
+        prec = PRINTF_DEFAULT_FLOAT_PRECISION;
+    }
+    // limit precision to 9, cause a prec >= 10 can lead to overflow errors
+    while((len < PRINTF_FTOA_BUFFER_SIZE) && (prec > 9U)) {
+        buf[len++] = '0';
+        prec--;
+    }
+
+    int whole = (int)value;
+    double tmp = (value - whole) * pow10[prec];
+    unsigned long frac = (unsigned long)tmp;
+    diff = tmp - frac;
+
+    if(diff > 0.5) {
+        ++frac;
+        // handle rollover, e.g. case 0.99 with prec 1 is 1.0
+        if(frac >= pow10[prec]) {
+            frac = 0;
+            ++whole;
+        }
+    }
+    else if(diff < 0.5) {
+    }
+    else if((frac == 0U) || (frac & 1U)) {
+        // if halfway, round up if odd OR if last digit is 0
+        ++frac;
+    }
+
+    if(prec == 0U) {
+        diff = value - (double)whole;
+        if((!(diff < 0.5) || (diff > 0.5)) && (whole & 1)) {
+            // exactly 0.5 and ODD, then round up
+            // 1.5 -> 2, but 2.5 -> 2
+            ++whole;
+        }
+    }
+    else {
+        unsigned int count = prec;
+        // now do fractional part, as an unsigned number
+        while(len < PRINTF_FTOA_BUFFER_SIZE) {
+            --count;
+            buf[len++] = (char)(48U + (frac % 10U));
+            if(!(frac /= 10U)) {
+                break;
+            }
+        }
+        // add extra 0s
+        while((len < PRINTF_FTOA_BUFFER_SIZE) && (count-- > 0U)) {
+            buf[len++] = '0';
+        }
+        if(len < PRINTF_FTOA_BUFFER_SIZE) {
+            // add decimal
+            buf[len++] = '.';
+        }
+    }
+
+    // do whole part, number is reversed
+    while(len < PRINTF_FTOA_BUFFER_SIZE) {
+        buf[len++] = (char)(48 + (whole % 10));
+        if(!(whole /= 10)) {
+            break;
+        }
+    }
+
+    // pad leading zeros
+    if(!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD)) {
+        if(width && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
+            width--;
+        }
+        while((len < width) && (len < PRINTF_FTOA_BUFFER_SIZE)) {
+            buf[len++] = '0';
+        }
+    }
+
+    if(len < PRINTF_FTOA_BUFFER_SIZE) {
+        if(negative) {
+            buf[len++] = '-';
+        }
+        else if(flags & FLAGS_PLUS) {
+            buf[len++] = '+';  // ignore the space if the '+' exists
+        }
+        else if(flags & FLAGS_SPACE) {
+            buf[len++] = ' ';
+        }
+    }
+
+    return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
+}
+
+#if defined(PRINTF_SUPPORT_EXPONENTIAL)
+// internal ftoa variant for exponential floating-point type, contributed by Martijn Jasperse <m.jasperse@gmail.com>
+static size_t _etoa(out_fct_type out, char * buffer, size_t idx, size_t maxlen, double value, unsigned int prec,
+                    unsigned int width, unsigned int flags)
+{
+    // check for NaN and special values
+    if((value != value) || (value > DBL_MAX) || (value < -DBL_MAX)) {
+        return _ftoa(out, buffer, idx, maxlen, value, prec, width, flags);
+    }
+
+    // determine the sign
+    const bool negative = value < 0;
+    if(negative) {
+        value = -value;
+    }
+
+    // default precision
+    if(!(flags & FLAGS_PRECISION)) {
+        prec = PRINTF_DEFAULT_FLOAT_PRECISION;
+    }
+
+    // determine the decimal exponent
+    // based on the algorithm by David Gay (https://www.ampl.com/netlib/fp/dtoa.c)
+    union {
+        uint64_t U;
+        double   F;
+    } conv;
+
+    conv.F = value;
+    int exp2 = (int)((conv.U >> 52U) & 0x07FFU) - 1023;           // effectively log2
+    conv.U = (conv.U & ((1ULL << 52U) - 1U)) | (1023ULL << 52U);  // drop the exponent so conv.F is now in [1,2)
+    // now approximate log10 from the log2 integer part and an expansion of ln around 1.5
+    int expval = (int)(0.1760912590558 + exp2 * 0.301029995663981 + (conv.F - 1.5) * 0.289529654602168);
+    // now we want to compute 10^expval but we want to be sure it won't overflow
+    exp2 = (int)(expval * 3.321928094887362 + 0.5);
+    const double z  = expval * 2.302585092994046 - exp2 * 0.6931471805599453;
+    const double z2 = z * z;
+    conv.U = (uint64_t)(exp2 + 1023) << 52U;
+    // compute exp(z) using continued fractions, see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex
+    conv.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14)))));
+    // correct for rounding errors
+    if(value < conv.F) {
+        expval--;
+        conv.F /= 10;
+    }
+
+    // the exponent format is "%+03d" and largest value is "307", so set aside 4-5 characters
+    unsigned int minwidth = ((expval < 100) && (expval > -100)) ? 4U : 5U;
+
+    // in "%g" mode, "prec" is the number of *significant figures* not decimals
+    if(flags & FLAGS_ADAPT_EXP) {
+        // do we want to fall-back to "%f" mode?
+        if((value >= 1e-4) && (value < 1e6)) {
+            if((int)prec > expval) {
+                prec = (unsigned)((int)prec - expval - 1);
+            }
+            else {
+                prec = 0;
+            }
+            flags |= FLAGS_PRECISION;   // make sure _ftoa respects precision
+            // no characters in exponent
+            minwidth = 0U;
+            expval   = 0;
+        }
+        else {
+            // we use one sigfig for the whole part
+            if((prec > 0) && (flags & FLAGS_PRECISION)) {
+                --prec;
+            }
+        }
+    }
+
+    // will everything fit?
+    unsigned int fwidth = width;
+    if(width > minwidth) {
+        // we didn't fall-back so subtract the characters required for the exponent
+        fwidth -= minwidth;
+    }
+    else {
+        // not enough characters, so go back to default sizing
+        fwidth = 0U;
+    }
+    if((flags & FLAGS_LEFT) && minwidth) {
+        // if we're padding on the right, DON'T pad the floating part
+        fwidth = 0U;
+    }
+
+    // rescale the float value
+    if(expval) {
+        value /= conv.F;
+    }
+
+    // output the floating part
+    const size_t start_idx = idx;
+    idx = _ftoa(out, buffer, idx, maxlen, negative ? -value : value, prec, fwidth, flags & ~FLAGS_ADAPT_EXP);
+
+    // output the exponent part
+    if(minwidth) {
+        // output the exponential symbol
+        out((flags & FLAGS_UPPERCASE) ? 'E' : 'e', buffer, idx++, maxlen);
+        // output the exponent value
+        idx = _ntoa_long(out, buffer, idx, maxlen, (expval < 0) ? -expval : expval, expval < 0, 10, 0, minwidth - 1,
+                         FLAGS_ZEROPAD | FLAGS_PLUS);
+        // might need to right-pad spaces
+        if(flags & FLAGS_LEFT) {
+            while(idx - start_idx < width) out(' ', buffer, idx++, maxlen);
+        }
+    }
+    return idx;
+}
+#endif  // PRINTF_SUPPORT_EXPONENTIAL
+#endif  // PRINTF_SUPPORT_FLOAT
+
+// internal vsnprintf
+static int _vsnprintf(out_fct_type out, char * buffer, const size_t maxlen, const char * format, va_list va)
+{
+    unsigned int flags, width, precision, n;
+    size_t idx = 0U;
+
+    if(!buffer) {
+        // use null output function
+        out = _out_null;
+    }
+
+    while(*format) {
+        // format specifier?  %[flags][width][.precision][length]
+        if(*format != '%') {
+            // no
+            out(*format, buffer, idx++, maxlen);
+            format++;
+            continue;
+        }
+        else {
+            // yes, evaluate it
+            format++;
+        }
+
+        // evaluate flags
+        flags = 0U;
+        do {
+            switch(*format) {
+                case '0':
+                    flags |= FLAGS_ZEROPAD;
+                    format++;
+                    n = 1U;
+                    break;
+                case '-':
+                    flags |= FLAGS_LEFT;
+                    format++;
+                    n = 1U;
+                    break;
+                case '+':
+                    flags |= FLAGS_PLUS;
+                    format++;
+                    n = 1U;
+                    break;
+                case ' ':
+                    flags |= FLAGS_SPACE;
+                    format++;
+                    n = 1U;
+                    break;
+                case '#':
+                    flags |= FLAGS_HASH;
+                    format++;
+                    n = 1U;
+                    break;
+                default :
+                    n = 0U;
+                    break;
+            }
+        } while(n);
+
+        // evaluate width field
+        width = 0U;
+        if(_is_digit(*format)) {
+            width = _atoi(&format);
+        }
+        else if(*format == '*') {
+            const int w = va_arg(va, int);
+            if(w < 0) {
+                flags |= FLAGS_LEFT;    // reverse padding
+                width = (unsigned int) - w;
+            }
+            else {
+                width = (unsigned int)w;
+            }
+            format++;
+        }
+
+        // evaluate precision field
+        precision = 0U;
+        if(*format == '.') {
+            flags |= FLAGS_PRECISION;
+            format++;
+            if(_is_digit(*format)) {
+                precision = _atoi(&format);
+            }
+            else if(*format == '*') {
+                const int prec = (int)va_arg(va, int);
+                precision = prec > 0 ? (unsigned int)prec : 0U;
+                format++;
+            }
+        }
+
+        // evaluate length field
+        switch(*format) {
+            case 'l' :
+                flags |= FLAGS_LONG;
+                format++;
+                if(*format == 'l') {
+                    flags |= FLAGS_LONG_LONG;
+                    format++;
+                }
+                break;
+            case 'h' :
+                flags |= FLAGS_SHORT;
+                format++;
+                if(*format == 'h') {
+                    flags |= FLAGS_CHAR;
+                    format++;
+                }
+                break;
+#if defined(PRINTF_SUPPORT_PTRDIFF_T)
+            case 't' :
+                flags |= (sizeof(ptrdiff_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
+                format++;
+                break;
+#endif
+            case 'j' :
+                flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
+                format++;
+                break;
+            case 'z' :
+                flags |= (sizeof(size_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
+                format++;
+                break;
+            default :
+                break;
+        }
+
+        // evaluate specifier
+        switch(*format) {
+            case 'd' :
+            case 'i' :
+            case 'u' :
+            case 'x' :
+            case 'X' :
+            case 'p' :
+            case 'P' :
+            case 'o' :
+            case 'b' : {
+                    // set the base
+                    unsigned int base;
+                    if(*format == 'x' || *format == 'X') {
+                        base = 16U;
+                    }
+                    else if(*format == 'p' || *format == 'P') {
+                        base = 16U;
+                        flags |= FLAGS_HASH;   // always hash for pointer format
+#if defined(PRINTF_SUPPORT_LONG_LONG)
+                        if(sizeof(uintptr_t) == sizeof(long long))
+                            flags |= FLAGS_LONG_LONG;
+                        else
+#endif
+                            flags |= FLAGS_LONG;
+
+                        if(*(format + 1) == 'V')
+                            format++;
+                    }
+                    else if(*format == 'o') {
+                        base =  8U;
+                    }
+                    else if(*format == 'b') {
+                        base =  2U;
+                    }
+                    else {
+                        base = 10U;
+                        flags &= ~FLAGS_HASH;   // no hash for dec format
+                    }
+                    // uppercase
+                    if(*format == 'X' || *format == 'P') {
+                        flags |= FLAGS_UPPERCASE;
+                    }
+
+                    // no plus or space flag for u, x, X, o, b
+                    if((*format != 'i') && (*format != 'd')) {
+                        flags &= ~(FLAGS_PLUS | FLAGS_SPACE);
+                    }
+
+                    // ignore '0' flag when precision is given
+                    if(flags & FLAGS_PRECISION) {
+                        flags &= ~FLAGS_ZEROPAD;
+                    }
+
+                    // convert the integer
+                    if((*format == 'i') || (*format == 'd')) {
+                        // signed
+                        if(flags & FLAGS_LONG_LONG) {
+#if defined(PRINTF_SUPPORT_LONG_LONG)
+                            const long long value = va_arg(va, long long);
+                            idx = _ntoa_long_long(out, buffer, idx, maxlen, (unsigned long long)(value > 0 ? value : 0 - value), value < 0, base,
+                                                  precision, width, flags);
+#endif
+                        }
+                        else if(flags & FLAGS_LONG) {
+                            const long value = va_arg(va, long);
+                            idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)(value > 0 ? value : 0 - value), value < 0, base, precision,
+                                             width, flags);
+                        }
+                        else {
+                            const int value = (flags & FLAGS_CHAR) ? (char)va_arg(va, int) : (flags & FLAGS_SHORT) ? (short int)va_arg(va,
+                                                                                                                                       int) : va_arg(va, int);
+                            idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned int)(value > 0 ? value : 0 - value), value < 0, base, precision,
+                                             width, flags);
+                        }
+                    }
+                    else if(*format == 'V') {
+                        lv_vaformat_t * vaf = va_arg(va, lv_vaformat_t *);
+                        va_list copy;
+
+                        va_copy(copy, *vaf->va);
+                        idx += _vsnprintf(out, buffer + idx, maxlen - idx, vaf->fmt, copy);
+                        va_end(copy);
+                    }
+                    else {
+                        // unsigned
+                        if(flags & FLAGS_LONG_LONG) {
+#if defined(PRINTF_SUPPORT_LONG_LONG)
+                            idx = _ntoa_long_long(out, buffer, idx, maxlen, va_arg(va, unsigned long long), false, base, precision, width, flags);
+#endif
+                        }
+                        else if(flags & FLAGS_LONG) {
+                            idx = _ntoa_long(out, buffer, idx, maxlen, va_arg(va, unsigned long), false, base, precision, width, flags);
+                        }
+                        else {
+                            const unsigned int value = (flags & FLAGS_CHAR) ? (unsigned char)va_arg(va,
+                                                                                                    unsigned int) : (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(va, unsigned int) : va_arg(va, unsigned int);
+                            idx = _ntoa_long(out, buffer, idx, maxlen, value, false, base, precision, width, flags);
+                        }
+                    }
+                    format++;
+                    break;
+                }
+#if defined(PRINTF_SUPPORT_FLOAT)
+            case 'f' :
+            case 'F' :
+                if(*format == 'F') flags |= FLAGS_UPPERCASE;
+                idx = _ftoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
+                format++;
+                break;
+#if defined(PRINTF_SUPPORT_EXPONENTIAL)
+            case 'e':
+            case 'E':
+            case 'g':
+            case 'G':
+                if((*format == 'g') || (*format == 'G')) flags |= FLAGS_ADAPT_EXP;
+                if((*format == 'E') || (*format == 'G')) flags |= FLAGS_UPPERCASE;
+                idx = _etoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
+                format++;
+                break;
+#endif  // PRINTF_SUPPORT_EXPONENTIAL
+#endif  // PRINTF_SUPPORT_FLOAT
+            case 'c' : {
+                    unsigned int l = 1U;
+                    // pre padding
+                    if(!(flags & FLAGS_LEFT)) {
+                        while(l++ < width) {
+                            out(' ', buffer, idx++, maxlen);
+                        }
+                    }
+                    // char output
+                    out((char)va_arg(va, int), buffer, idx++, maxlen);
+                    // post padding
+                    if(flags & FLAGS_LEFT) {
+                        while(l++ < width) {
+                            out(' ', buffer, idx++, maxlen);
+                        }
+                    }
+                    format++;
+                    break;
+                }
+
+            case 's' : {
+                    const char * p = va_arg(va, char *);
+                    unsigned int l = _strnlen_s(p, precision ? precision : (size_t) -1);
+                    // pre padding
+                    if(flags & FLAGS_PRECISION) {
+                        l = (l < precision ? l : precision);
+                    }
+                    if(!(flags & FLAGS_LEFT)) {
+                        while(l++ < width) {
+                            out(' ', buffer, idx++, maxlen);
+                        }
+                    }
+                    // string output
+                    while((*p != 0) && (!(flags & FLAGS_PRECISION) || precision--)) {
+                        out(*(p++), buffer, idx++, maxlen);
+                    }
+                    // post padding
+                    if(flags & FLAGS_LEFT) {
+                        while(l++ < width) {
+                            out(' ', buffer, idx++, maxlen);
+                        }
+                    }
+                    format++;
+                    break;
+                }
+
+            case '%' :
+                out('%', buffer, idx++, maxlen);
+                format++;
+                break;
+
+            default :
+                out(*format, buffer, idx++, maxlen);
+                format++;
+                break;
+        }
+    }
+
+    // termination
+    out((char)0, buffer, idx < maxlen ? idx : maxlen - 1U, maxlen);
+
+    // return written chars without terminating \0
+    return (int)idx;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+int lv_snprintf(char * buffer, size_t count, const char * format, ...)
+{
+    va_list va;
+    va_start(va, format);
+    const int ret = _vsnprintf(_out_buffer, buffer, count, format, va);
+    va_end(va);
+    return ret;
+}
+
+int lv_vsnprintf(char * buffer, size_t count, const char * format, va_list va)
+{
+    return _vsnprintf(_out_buffer, buffer, count, format, va);
+}
+
+#endif /*LV_SPRINTF_CUSTOM*/