Setaspect

setaspect <viewingrange> <yxaspect> is used to set the field of view in both dimensions in the original BUILD renderer. <viewingrange> is the tangent of half of the horizontal FOV, multiplied by 65536. (Default value: 65536, corresponding to a FOV of 90 degrees).
<yxaspect> is the Y to X ratio multiplied by 65536. In the editor, its default value is (65536*ydim*8)/(xdim*5). Note that <yxaspect> also affects rotatesprite.