%!PS-Adobe-3.0
% gs -dBATCH -dNOPAUSE -sDEVICE=png16m -sOutputFile="x.png" linear.ps && open x.png
<< /PageSize [500 300] >> setpagedevice
50 50 translate
newpath
0 0 moveto
0 200 lineto
300 200 lineto
300 0 lineto
0 0 lineto
closepath
gsave
clip
% shading dict
<<
/ShadingType 2 % 2-axial, 3-radial
/ColorSpace /DeviceRGB
/Coords [ 0 0 300 300 ] % [x0 y0 x1 y1]
/Function <<
/FunctionType 2 % 2-exponential interpolation
/Domain [ 0.0 1.0 ]
/C0 [ 1 0 0 ] % start color
/C1 [ 0 0 1 ] % end color
/N 1 % exponent, 1 = linear interpolation
>>
>>
shfill
grestore
showpage
