Gynvael’s mission 006 [en]

This time a mission from an English stream. As usual we have to discover a hidden message. This time we got this.

Now I must admit I had a lot of luck here. Being after technical studies with a lot of maths, that looked just like some vectors. So the first thought was to draw them as if they were points.

Since it’s too much work by hand, I’ve written a piece of terrible c code to do it for me (warning – no error checking):

#include <stdio.h>
#include <string.h>

int main(int argc, char** argv) {

    unsigned char buf[25*25];
    memset(buf, 0xff, 25*25);

    FILE* f = fopen(argv[1], "r");
    int x,y;
    while(fscanf(f, "[%d, %d]\n", &x, &y) == 2) {
        buf[25*y + x] = 0x0;

    f = fopen("", "w");
    fwrite(buf, 1, 25*25, f);

    return 0;

When compiled with gcc main.c -o mission006 and run like ./mission006, this will produce a raw bitmap with 8 bits/pixel. The 25*25 comes from a quick inspection of the file – values are exclusively between 0 and 24.
Then I opened it in GIMP, set mode to grey scale and size to 25×25 and saw…

At which point I grabbed my phone and scanned it. Turns out it encodes:

Mirrored QR? Seriously?!
One thing though. If you know the QR well or if you’re like me and you used the opportunity to do some reading, you’ll notice soon enough that this image is actually flipped horizontally. (Well you could also get a hint from the solution if you’re smarter than me…). It seems that my scanner doesn’t care but to be completely correct one should just flip it in GIMP or change line 12 of the code to say

buf[25*y + 24-x] = 0x0;

instead. Then you’ll get this: