1*11471Sralph /* emptyrow.c 4.1 83/03/09 */ 2*11471Sralph /* 3*11471Sralph * emptyrow: returns true if row r of m is all zeros. 4*11471Sralph * 5*11471Sralph * Note that we assume the garbage at the end of the 6*11471Sralph * row is all zeros. 7*11471Sralph */ 8*11471Sralph 9*11471Sralph #include "bit.h" 10*11471Sralph 11*11471Sralph emptyrow(m, rows, cols, r) 12*11471Sralph bitmat m; 13*11471Sralph int rows, cols, r; 14*11471Sralph { 15*11471Sralph char *top, *bot; 16*11471Sralph 17*11471Sralph bot = &m[r*((cols+7)>>3)]; 18*11471Sralph top = bot + ((cols-1) >> 3); 19*11471Sralph while (bot <= top) 20*11471Sralph if (*bot++) 21*11471Sralph return(0); 22*11471Sralph return (1); 23*11471Sralph } 24