looper/base85.cpp

#include "base85.h"
using std::vector;
// Functions modified from Dear ImGui and renamed to avoid collisions.
static unsigned int DecodeBase85Byte(char c) {
    return c >= '\\' ? c-36 : c-35;
}
vector<unsigned char> DecodeBase85(const char *src) {
    vector<unsigned char> dst_vec;
    dst_vec.resize(((strlen(src) + 4) / 5) * 4);
    unsigned char *dst = dst_vec.data();
    size_t dst_size = 0;
    while (*src)
    {
        unsigned int tmp = DecodeBase85Byte(src[0]) + 85 * (DecodeBase85Byte(src[1]) + 85 * (DecodeBase85Byte(src[2]) + 85 * (DecodeBase85Byte(src[3]) + 85 * DecodeBase85Byte(src[4]))));
        dst[0] = ((tmp >> 0) & 0xFF); dst[1] = ((tmp >> 8) & 0xFF); dst[2] = ((tmp >> 16) & 0xFF); dst[3] = ((tmp >> 24) & 0xFF);   // We can't assume little-endianness.
        src += 5;
        dst += 4;
        dst_size += 4;
    }
    dst_vec.resize(dst_size);
    return dst_vec;
}