RadioLibSmol/src/protocols/Print/ITA2String.cpp
2024-05-11 20:33:39 +01:00

116 lines
3 KiB
C++

#include "ITA2String.h"
#include <string.h>
ITA2String::ITA2String(char c) {
asciiLen = 1;
#if !RADIOLIB_STATIC_ONLY
strAscii = new char[1];
#endif
strAscii[0] = c;
ita2Len = 0;
}
ITA2String::ITA2String(const char* str) {
asciiLen = strlen(str);
#if !RADIOLIB_STATIC_ONLY
strAscii = new char[asciiLen + 1];
#endif
strcpy(strAscii, str);
ita2Len = 0;
}
ITA2String::~ITA2String() {
#if !RADIOLIB_STATIC_ONLY
delete[] strAscii;
#endif
}
size_t ITA2String::length() {
// length returned by this method is different than the length of ASCII-encoded strAscii
// ITA2-encoded string length varies based on how many number and characters the string contains
if(ita2Len == 0) {
// ITA2 length wasn't calculated yet, call byteArr() to calculate it
byteArr();
}
return(ita2Len);
}
uint8_t* ITA2String::byteArr() {
// create temporary array 2x the string length (figures may be 3 bytes)
#if RADIOLIB_STATIC_ONLY
uint8_t temp[RADIOLIB_STATIC_ARRAY_SIZE*2 + 1];
#else
uint8_t* temp = new uint8_t[asciiLen*2 + 1];
#endif
// ensure the minimum possible array size is always initialized
temp[0] = 0;
size_t arrayLen = 0;
bool flagFigure = false;
for(size_t i = 0; i < asciiLen; i++) {
uint16_t code = getBits(strAscii[i]);
uint8_t shift = (code >> 5) & 0b11111;
uint8_t character = code & 0b11111;
// check if the code is letter or figure
if(shift == RADIOLIB_ITA2_FIGS) {
// check if this is the first figure in sequence
if(!flagFigure) {
flagFigure = true;
temp[arrayLen++] = RADIOLIB_ITA2_FIGS;
}
// add the character code
temp[arrayLen++] = character & 0b11111;
// check the following character (skip for message end)
if(i < (asciiLen - 1)) {
uint16_t nextCode = getBits(strAscii[i+1]);
uint8_t nextShift = (nextCode >> 5) & 0b11111;
if(nextShift == RADIOLIB_ITA2_LTRS) {
// next character is a letter, terminate figure shift
temp[arrayLen++] = RADIOLIB_ITA2_LTRS;
flagFigure = false;
}
} else {
// reached the end of the message, terminate figure shift
temp[arrayLen++] = RADIOLIB_ITA2_LTRS;
flagFigure = false;
}
} else {
temp[arrayLen++] = character & 0b11111;
}
}
// save ITA2 string length
ita2Len = arrayLen;
uint8_t* arr = new uint8_t[arrayLen];
memcpy(arr, temp, arrayLen);
#if !RADIOLIB_STATIC_ONLY
delete[] temp;
#endif
return(arr);
}
uint16_t ITA2String::getBits(char c) {
// search ITA2 table
uint16_t code = 0x0000;
for(uint8_t i = 0; i < RADIOLIB_ITA2_LENGTH; i++) {
if(RADIOLIB_NONVOLATILE_READ_BYTE(&ITA2Table[i][0]) == c) {
// character is in letter shift
code = (RADIOLIB_ITA2_LTRS << 5) | i;
break;
} else if(RADIOLIB_NONVOLATILE_READ_BYTE(&ITA2Table[i][1]) == c) {
// character is in figures shift
code = (RADIOLIB_ITA2_FIGS << 5) | i;
break;
}
}
return(code);
}