Function drawFinderPattern

Libraries/QRCode/src/qrcode.c:284–296

Draws a 9*9 finder pattern including the border separator, with the center module at (x, y).

// Draws a 9*9 finder pattern including the border separator, with the center module at (x, y).
static void drawFinderPattern(BitBucket *modules, BitBucket *isFunction, uint8_t x, uint8_t y) {
    uint8_t size = modules->bitOffsetOrWidth;

    for (int8_t i = -4; i <= 4; i++) {
        for (int8_t j = -4; j <= 4; j++) {
            uint8_t dist = max(abs(i), abs(j));  // Chebyshev/infinity norm
            int16_t xx = x + j, yy = y + i;
            if (0 <= xx && xx < size && 0 <= yy && yy < size) {
                setFunctionModule(modules, isFunction, xx, yy, dist != 2 && dist != 4);
            }
        }
    }
}

// Draws a 5*5 alignment pattern, with the center module at (x, y).
static void drawAlignmentPattern(BitBucket *modules, BitBucket *isFunction, uint8_t x, uint8_t y) {