The conversion of a group to fragments is controlled with
void PixelZoom ( float 
, float 
) ;
Let 
be the current raster position
(section 2.12).
(If the current raster position is invalid,
then DrawPixels is ignored.)
If a particular group (index or components) is the nth in a row
and belongs to the mth row,
consider the region in window coordinates bounded by the rectangle with
corners
(either 
or 
may be negative).
Any fragments whose centers lie inside of this rectangle (or on its bottom
or left boundaries) are produced in correspondence with this particular group
of elements.
A fragment arising from a group consisting of color data
takes on the color index or color components of the group;
the depth and texture coordinates are taken from the current raster
position's associated data.
A fragment arising from a depth component takes the component's depth
value;
the color and texture coordinates are given by those associated
with the current raster position.
In both cases texture coordinates s, t, and r are
replaced with 
, 
, and 
, respectively. If q is less then
or equal to zero, the results are undefined.
Groups arising from DrawPixels with a format of STENCIL_INDEX are treated specially and are described in section 4.3.1.