src/main/common/encoding.c

   1 #include "encoding.h"
   2
   3 /**
   4  * Cast the in-memory representation of the given float directly to an int.
   5  *
   6  * This is useful for printing the hex representation of a float number (which is considerably cheaper
   7  * than a full decimal float formatter, in both code size and output length).
   8  */
   9 uint32_t castFloatBytesToInt(float f)
  10 {
  11     union floatConvert_t {
  12         float f;
  13         uint32_t u;
  14     } floatConvert;
  15
  16     floatConvert.f = f;
  17
  18     return floatConvert.u;
  19 }
  20
  21 /**
  22  * ZigZag encoding maps all values of a signed integer into those of an unsigned integer in such
  23  * a way that numbers of small absolute value correspond to small integers in the result.
  24  *
  25  * (Compared to just casting a signed to an unsigned which creates huge resulting numbers for
  26  * small negative integers).
  27  */
  28 uint32_t zigzagEncode(int32_t value)
  29 {
  30     return (uint32_t)((value << 1) ^ (value >> 31));
  31 }