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image.c
42 lines (37 loc) · 851 Bytes
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image.c
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#include "lib.h"
#define CHRS "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"
void
image(uint8_t *start, uint8_t *end)
{
uint32_t lo, hi_octet;
uint8_t *p;
int n, r;
if (start == end) return;
n = 0;
while (start + 5 < end) {
hi_octet = *start++;
lo = 0;
for (int i = 0; i < 4; i++)
lo = lo << 8 | *start++;
writechar(CHRS[hi_octet >> 3]);
writechar(CHRS[(hi_octet & 7) << 2 | lo >> 30]);
for (int i = 6; i > 0;)
writechar(CHRS[(lo >> (5*--i)) & 0x1f]);
if (++n % 10 == 0)
writechar('\n');
}
p = start;
hi_octet = *p++;
lo = 0;
while (p < end)
lo = lo << 8 | *p++;
r = start + 5 - p;
lo <<= 8*r;
writechar(CHRS[hi_octet >> 3]);
writechar(CHRS[(hi_octet & 7) << 2 | lo >> 30]);
for (int i = 6; i > 8*r/5;)
writechar(CHRS[(lo >> (5*--i)) & 0x1f]);
for (int i = 0; i < 8*r/5; i++)
writechar('=');
writechar('\n');
}