/* TODO: make it not as dog slow as this */
for (dx = dxmin, sx = sxmin; dx < dxmax; ++dx, ++sx)
for (dy = dymin, sy = symin; dy < dymax; ++dy, ++sy)
/* TODO: make it not as dog slow as this */
for (dx = dxmin, sx = sxmin; dx < dxmax; ++dx, ++sx)
for (dy = dymin, sy = symin; dy < dymax; ++dy, ++sy)