header.ps

%!PS-Adobe-2.0
%%DocumentFonts: Times-Roman
%%Creator: AXIOM
%%CreationDate: today
%%Pages: 1
%%processing (hard) limit: 250 pts or 500 values for the operand stack.
%%EndComments

%------------------------------- prologue -------------------------------%
%-------------------------- support procedures --------------------------%

%--------- first create user dictionary with 100 entries max ------------%
%          (number can be changed to accomodate definitions)             %

100	dict	begin		%% using 100 entries in top level dictionary

/FontHeight     12 def

/inch
        {       72 mul }
        def

% yVal and hVal are necessary because the Xwindow display origin
% is at the upper left corner, while the postscript display
% origin is at the lower left hand corner.

/yVal		%% get Y value -- make upper left corner origin
        {       maxY exch sub  }	%% maxY is viewWindow height
        def

/hVal		%% get H value -- used for displaying title text
        {       maxH sub abs }	%% maxH is viewWindow height+titleWindow height
        def

% loads in the font

/loadFont
        {       /Times-Roman findfont FontHeight scalefont setfont }
        def

% draws a rectangle with input operand: 
%		height
%		width
% notice that this function does not "draw" or ink the rectangle.
/drawRect
	{	1 index 1 add 0 rlineto		%% draw first side
                0 exch 1 add neg rlineto	%% draw second side
                1 add neg 0 rlineto		%% draw third side
                closepath }			%% draw fourth side
        def

% create a rectangle with input operand in the view window: 
%		y
%		x
%		height
%		width
% notice that this function does not "draw" or ink the rectangle.
/rectangle
        {       yVal moveto			%% set currentpoint for line
		drawRect }			%% draws the rectangle
        def

% These are global variables that every draw procedure uses
% THe operand should be as follows:
%		viewWindow width
%		viewWindow height
%		title height
/setDim
        {       /maxX exch def			%% width of display
                /maxY exch def			%% height of display
		/titleH exch def		%% height of title
		/maxH maxY titleH add def	%% height of display + title
        } def

%-------------------------- major procedures --------------------------%

/title		%% draws a rectangle around the title of picture
	{	gsave
		newpath
		moveto				%% lower left of title
                titleH 1 add 0 exch rlineto	%% draw first side
                1 add 0 rlineto			%% draw second side
                1 add neg 0 exch rlineto
		begin installGC stroke end	%% draw third side
		grestore }
	def

/drawFrame      %% draw display frame
        {	gsave
                newpath
                maxX maxY 0 0 rectangle
		begin installGC stroke end
                grestore }
        def

% updates the foreground color of existing graphics-context dictionary:
%		foreground color
%		dictionary name
/setForeground
	{	/FGcolor exch put }
	def

% updates the background color of existing graphics-context dictionary:
%		background color
%		dictionary name
/setBackground
	{	/BGcolor exch put }
	def

% updates the line width, line style, cap style, join style of
% existing graphics-context dictionary:
%		dictionary name
%		join style
%		cap style
%		line width
/setLineAttributes
	{	begin
		/JoinStyle exch def
		/CapStyle  exch def
		/LineWidth exch def
		end }
	def

% creates a graphics context dictionary with the following information:
%		/dictionary name
%		foreground color
%		background color
%		line width
%		cap style
%		join style
% this creates different graphical contexts for different drawing functions.
/makeDict
	{	5 dict 2 copy def begin	pop %% with dict name on top of stack
		/FGcolor   exch def	%% define drawing attributes
		/BGcolor   exch def	%% not heavily used
		/LineWidth exch def
		/CapStyle  exch def
		/JoinStyle exch def
		end }
	def

% makes the current dictionary attributes effective
% this function takes the values in the current dictionary to set the context
% these are the values currently being used: foreground, cap, join, and width
/installGC
	{
		FGcolor currentgray ne
		{FGcolor setgray} if		%% foreground color
		CapStyle currentlinecap ne
		{CapStyle setlinecap} if	%% cap style
		JoinStyle currentlinejoin ne
		{JoinStyle setlinejoin} if	%% join style
		LineWidth currentlinewidth ne
		{LineWidth setlinewidth} if }	%% line width
	def