MATRIX_X_HEADER
(void) memcpy(*p, &bmp[MATRIX_X_HEADER],
(void) memcpy(*p, &bmp[MATRIX_X_HEADER],
#define SIZEOF_X_UNIT(M) (((M)->x + MATRIX_X_HEADER) * sizeof (bmp_t))
#define MATRIX_X_UNIT(M, N) &(M)->m[(N) * ((M)->x + MATRIX_X_HEADER)]
(BMP)[(PRI) + MATRIX_X_HEADER] |= (0x1 << (SND))
(BMP)[(PRI) + MATRIX_X_HEADER] &= ~(0x1 << (SND))
((BMP)[(PRI) + MATRIX_X_HEADER] & (0x1 << (SEC)))