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PostScript Operator Reference

General

This section provides comprehensive documentation for PostScript operators implemented or relevant to the Postsvg library. Operators are organized by functional category.

Operator Categories

Path Construction Operators

Operators for building geometric paths:

• newpath - Initialize empty path

• moveto - Begin new subpath at point

• rmoveto - Begin new subpath at relative point

• lineto - Append straight line segment

• rlineto - Append relative straight line segment

• curveto - Append cubic Bézier curve

• rcurveto - Append relative cubic Bézier curve

• arc - Append circular arc (counterclockwise)

• arcn - Append circular arc (clockwise)

• arct - Append circular arc tangent to two lines

• closepath - Close current subpath

Painting Operators

Operators for rendering paths:

• stroke - Stroke current path

• fill - Fill current path (non-zero winding rule)

• eofill - Fill current path (even-odd rule)

• clip - Establish clipping path (non-zero winding rule)

• eoclip - Establish clipping path (even-odd rule)

• flattenpath - Flatten curves to line segments

• strokepath - Convert stroke to filled path

Graphics State Operators

Operators for managing graphics state:

• gsave - Save current graphics state

• grestore - Restore saved graphics state

• setlinewidth - Set line width for stroking

• setlinecap - Set line cap style

• setlinejoin - Set line join style

• setmiterlimit - Set miter limit for joins

• setdash - Set dash pattern for lines

• setrgbcolor - Set RGB color

• setgray - Set grayscale color

• setcmykcolor - Set CMYK color

• currentlinewidth - Get current line width

• currentrgbcolor - Get current RGB color

Transformation Operators

Operators for coordinate system transformations:

• translate - Translate origin

• scale - Scale coordinate system

• rotate - Rotate coordinate system

• concat - Concatenate matrix to CTM

• matrix - Create identity matrix

• currentmatrix - Get current transformation matrix

• setmatrix - Set transformation matrix

• identmatrix - Create identity matrix

• defaultmatrix - Get default matrix

• transform - Transform point by matrix

• itransform - Inverse transform point

Stack Manipulation Operators

Operators for working with the operand stack:

• dup - Duplicate top stack element

• pop - Remove top stack element

• exch - Exchange top two elements

• roll - Roll stack elements

• copy - Copy stack elements

• clear - Clear entire stack

• count - Count stack elements

• index - Access stack element by index

• mark - Push mark on stack

• cleartomark - Clear stack to mark

• counttomark - Count elements to mark

Arithmetic Operators

Mathematical operators:

• add - Addition

• sub - Subtraction

• mul - Multiplication

• div - Division (real result)

• idiv - Integer division

• mod - Modulo (remainder)

• abs - Absolute value

• neg - Negation

• sqrt - Square root

• sin - Sine

• cos - Cosine

• atan - Arctangent

• exp - Exponential

• ln - Natural logarithm

• log - Base-10 logarithm

• floor - Round down

• ceiling - Round up

• round - Round to nearest

• truncate - Remove fractional part

Control Flow Operators

Operators for program flow control:

• if - Conditional execution

• ifelse - Conditional branch

• for - Counted loop

• repeat - Simple loop

• loop - Infinite loop

• exit - Exit loop

• forall - Iterate over array/dictionary

• exec - Execute object

• stopped - Execute with error handling

• stop - Terminate stopped context

Dictionary Operators

Operators for dictionary management:

• dict - Create dictionary

• begin - Push dictionary on dictionary stack

• end - Pop dictionary from dictionary stack

• def - Define key-value pair

• load - Get value for key

• store - Store value for key

• get - Get dictionary entry

• put - Put dictionary entry

• known - Test if key exists

• undef - Remove definition

• where - Find dictionary containing key

• currentdict - Get current dictionary

• countdictstack - Count dictionary stack depth

Operator Summary Table

Operator	Category	Description
newpath	Path Construction	Initialize empty current path
moveto	Path Construction	Begin new subpath at (x, y)
lineto	Path Construction	Append line to (x, y)
curveto	Path Construction	Append Bézier curve
closepath	Path Construction	Close current subpath
arc	Path Construction	Append counterclockwise circular arc
stroke	Painting	Stroke current path
fill	Painting	Fill current path
clip	Painting	Set clipping path
gsave	Graphics State	Save graphics state
grestore	Graphics State	Restore graphics state
setlinewidth	Graphics State	Set line width
setrgbcolor	Graphics State	Set RGB color
setgray	Graphics State	Set grayscale value
translate	Transformations	Translate coordinate system
scale	Transformations	Scale coordinate system
rotate	Transformations	Rotate coordinate system
dup	Stack Manipulation	Duplicate top element
pop	Stack Manipulation	Remove top element
exch	Stack Manipulation	Exchange top two elements
add	Arithmetic	Add two numbers
mul	Arithmetic	Multiply two numbers
div	Arithmetic	Divide two numbers
if	Control Flow	Conditional execution
for	Control Flow	Counted loop
def	Dictionary	Define variable

Implementation Status in Postsvg

The Postsvg library currently implements the following operators:

Fully implemented

• Path construction: newpath, moveto, lineto, curveto, closepath

• Painting: stroke, fill

• Graphics state: gsave, grestore, setlinewidth, setrgbcolor, setgray

• Transformations: translate, scale, rotate

• Stack manipulation: Basic stack operations

• Arithmetic: Basic math operations

Partially implemented

• Path construction: arc, arcn (basic support)

• Control flow: Limited support for procedures

Not yet implemented

• Text operators: show, findfont, setfont

• Image operators: image, imagemask

• Pattern operators: makepattern, setpattern

• Advanced clipping: Full clipping path support

• Advanced graphics state: setlinecap, setlinejoin, setdash

See Also

• Language Fundamentals

• Graphics Model

• Implementation Notes

• Back to PostScript Quick Reference