MGrabParticlesQ CoordinateList.l,NumPoints.l,Buffer.l ; Grab lots of points from X.q,Y.q table, to buffer mem

Does the same as MGrabParticles except that the list data are pairs of X.q,Y.q.
In this respect, a .q quick are longwords each, causing two longwords to be
needed for each pixel. The top 16 bits of each component will be used as integer
coordinates, and the lower 16 bits are the decimal part which this command will
ignore.