ref: af36a8b50ad95196fdc21deac251919cd7bbd18a
dir: /sys/src/cmd/postscript/psfiles/forms.ps/
%
% Procedures that let you print any number of pages on each sheet of paper. It's
% far from perfect and won't handle everything (eg. it's not recursive), but should
% be good enough for now. Assumes the default page coordinate system has been set
% up before setupforms is called. lastpage makes certain the last page is printed,
% and should be called immediately after the %%Trailer comment.
%
% Three lines of code needed for page image clipping have been commented out for
% now. It works, but can really slow things down on some versions of PostScript.
% Uncomment them if you want to clip pages.
%
/setupforms {
/formsperpage exch def
/currentform 0 def
/slop 5 def
/min {2 copy gt {exch} if pop} def
%
% Save the current environment so the real showpage can be restored when we're all
% done. Occasionally helps when a banner page is included with the job.
%
/saveobj save def
%
% Number of rows and columns we'll need - may exchange them later.
%
/columns formsperpage sqrt ceiling cvi def
/rows formsperpage columns div ceiling cvi def
%
% Slop leaves a little room around the edge so page images can be outlined and have
% the borders show up. Distance is in default coordinates, so we need to figure out
% how it maps into user coordinates.
%
6 array defaultmatrix
6 array currentmatrix
6 array invertmatrix
6 array concatmatrix
/tempmatrix exch def
0 slop tempmatrix dtransform dup mul exch dup mul add sqrt
/slop exch def
%
% Determine how big the image area is, using the clipping path bounding box minus
% a little and leave the coordinates of the lower left corner of the clipping path
% on the stack. Also temporarily set the size of each page (ie. formheight and
% formwidth) from the clipping path - just in case old software uses this stuff.
% Only works for coordinate systems that have been rotated by a multiple of 90
% degrees.
%
newpath clippath pathbbox
2 index sub dup /formheight exch def slop 2 mul sub /pageheight exch def
2 index sub dup /formwidth exch def slop 2 mul sub /pagewidth exch def
%
% New translators all store the size of each page in default coordinates in the
% pagebbox array and it can be different than the size determined by the clipping
% path. If we can find pagebbox use it to set the real dimensions of each page.
% Leaves the coordinates of the lower left corner on the stack, (either from
% pagebbox or clippath) so four numbers are there when we're done.
%
userdict /gotpagebbox known userdict /pagebbox known and {
newpath
pagebbox 0 get pagebbox 1 get tempmatrix transform moveto
pagebbox 0 get pagebbox 3 get tempmatrix transform lineto
pagebbox 2 get pagebbox 3 get tempmatrix transform lineto
pagebbox 2 get pagebbox 1 get tempmatrix transform lineto
closepath pathbbox
2 index sub /formheight exch def
2 index sub /formwidth exch def
} {2 copy} ifelse
%
% Top two numbers are the displacement from the job's origin to the lower left
% corner of each page image when we finish setting up the new coordinate system.
%
/ycorner exch def
/xcorner exch def
%
% The two numbers left on the stack are the coordinates of the lower left corner
% of the clipping path. Go there and then up a bit so page images can be outlined.
%
translate
slop slop translate
%
% If the page is wider than high we may be able to do better if we exchange rows
% and columns. Won't make a difference in the current orientation or if rows and
% columns are the same.
%
pagewidth pageheight gt {
rows columns /rows exch def /columns exch def
} if
%
% Find the orientation and scaling that makes things as large as possible. More
% than what's really needed. First calculation essentially finds the minimum of
% 1/rows and 1/columns.
%
pagewidth formwidth columns mul div pageheight formheight rows mul div min
pageheight formwidth columns mul div pagewidth formheight rows mul div min
2 copy lt {
rotation 1 eq {
landscape {
0 pageheight translate
-90 rotate
}{
pagewidth 0 translate
90 rotate
} ifelse
}{
landscape {
pagewidth 0 translate
90 rotate
}{
0 pageheight translate
-90 rotate
} ifelse
} ifelse
pagewidth pageheight /pagewidth exch def /pageheight exch def
exch
} if
%
% Second number from the top is the best choice. Scale so everything will fit on
% the current page, go back to the original origin, and then get ready for the
% first page - which goes in the upper left corner.
%
pop dup dup scale
xcorner neg ycorner neg translate
0 rows 1 sub formheight mul translate
%
% Try to center everything on the page - scaling we used is on top of the stack.
%
dup pagewidth exch div formwidth columns mul sub 2 div
exch pageheight exch div formheight rows mul sub 2 div translate
%
% Redefine showpage.
%
/!PreForms~showpage~ /showpage load def % save current showpage
/showpage {
saveobj restore
% initclip
formsperpage 1 gt {
gsave .1 setlinewidth outlineform stroke grestore
} if
formwidth 0 translate
/currentform currentform 1 add def
currentform columns mod 0 eq {
columns formwidth mul neg formheight neg translate
} if
currentform formsperpage mod 0 eq {
gsave !PreForms~showpage~ grestore
currentform columns mod formwidth mul neg
formsperpage columns idiv formheight mul translate
/currentform 0 def
} if
% outlineform clip newpath
/saveobj save def
} bind def
/outlineform {
newpath
xcorner ycorner moveto
formwidth 0 rlineto
0 formheight rlineto
formwidth neg 0 rlineto
closepath
} bind def
/lastpage {
formsperpage 1 gt {
currentform 0 ne {
/saveobj save def
0 1 formsperpage currentform sub formsperpage mod {
pop showpage
} for
saveobj restore
} if
saveobj restore
saveobj restore
} if
} def
%
% Clip the first page image and save the environment we just set up, including
% the redefined showpage.
%
% outlineform clip
newpath
/saveobj save def
} def