Precalculating atan2

void trig_precomp() {  int ix, iy;  for(ix = -800; ix < 800; ix++)  for(iy = -600; iy < 600; iy++) {    arctans[ix + 800][iy + 600] = int(atan2(ix, iy) * (180/M_PI));  }  for(ix = 0; ix < 360; ix++) {    coses[ix] = cos(ix / RADDEG);    sins[ix] = sin(ix / RADDEG);  }}int atan2_lt(int fromx, int fromy, int tox, int toy) {  return arctans[(tox-fromx) + 800][(toy-fromy) + 600];}