LANGUAGE REFERENCE third edition

1 Addison-Wesley Publishing Company Reading, Massachusetts Menlo Park, California New York Don Mills, OntarioHarlow, England Amsterdam Bonn sydney Singapore Tokyo Madrid San Juan Paris Seoul Milan Mexico City TaipeiAdobe Systems IncorporatedPostScript LANGUAGE REFERENCE third edition Library of Congress Cataloging-in-Publication Data postscript LANGUAGE REFERENCE manual / Adobe Systems Incorporated. 3rd ed. p. bibliographical references and 0-201-37922-81. postscript (Computer program LANGUAGE ) I. Adobe P67 '3 dc2198-55489 CIP 1985 1999 Adobe Systems Incorporated. All rights : All information contained herein is the property of Adobe Systems part of this publication (whether in hardcopy or electronic form) may be reproducedor transmitted, in any form or by any means, electronic, mechanical, photocopying,recording, or otherwise, without the prior written consent of the is a registered trademark of Adobe Systems Incorporated.

2 All instances of thename postscript in the text are references to the postscript LANGUAGE as defined by AdobeSystems Incorporated unless otherwise stated. The name postscript also is used as a prod-uct trademark for Adobe Systems implementation of the postscript LANGUAGE as otherwise stated, any mention of a postscript printer, postscript software, orsimilar item refers to a product that contains postscript technology created or licensed byAdobe Systems Incorporated, not to one that purports to be merely , Adobe Illustrator, Adobe Type Manager, Chameleon, Display postscript , Frame-Maker, Minion, Myriad, Photoshop, postscript , postscript 3, and the postscript logo aretrademarks of Adobe Systems Incorporated.

3 LocalTalk, QuickDraw, and TrueType aretrademarks and Mac OS is a registered trademark of Apple Computer, Inc. Helvetica andTimes are registered trademarks of Linotype-Hell AG and/or its subsidiaries. Times NewRoman is a trademark of The Monotype Corporation registered in the Patent andTrademark Office and may be registered in certain other jurisdictions. Unicode is a regis-tered trademark of Unicode, Inc. PANTONE is a registered trademark and Hexachrome isa trademark of Pantone, Inc. Windows is a registered trademark of Microsoft other trademarks are the property of their respective publication and the information herein are furnished AS IS, are subject to changewithout notice, and should not be construed as a commitment by Adobe Systems Incorpo-rated.

4 Adobe Systems Incorporated assumes no responsibility or liability for any errors orinaccuracies, makes no warranty of any kind (express, implied, or statutory) with respectto this publication, and expressly disclaims any and all warranties of merchantability, fit-ness for particular purposes, and noninfringement of third -party 0-201-37922-81 2 3 4 5 6 7 8 9 CRS 03 02 01 00 99 First printing February 1999 iii Contents Preface xiii Chapter 1: Introduction This of the postscript 3 and Trademarks9 Chapter 2: Basic Ideas Output Description the postscript Language15 Chapter 3: LANGUAGE Types and of Basic Input and Name Files Encoding Details156 Chapter 4: Graphics Systems and Transformations182 Contents iv Spaces Chapter 5: Fonts and Use of Metric ID 3 Base Font Derivation and Fonts364 Chapter 6: Device Control Page Device Device Dictionary455 Chapter 7: Rendering Color to Device among Device Color Conversion Details501 Chapter 8: Operators Details524 Appendix A: LanguageLevel Feature Summary 3 2 Contents v Appendix B: Implementation Limits Memory Use742 Appendix C.

5 Interpreter Parameters of User and System User and System of User and System Parameters760 Appendix D: Compatibility Strategies LanguageLevel to Provide Emulations769 Appendix E: Character Sets and Encoding Vectors Latin Character Encoding Encoding Encoding Character Encoding Encoding Character Encoding Vector794 Appendix F: System Name Encodings 795 Appendix G: Operator Usage Guidelines 801 Bibliography 811 INDEX 817 vii Figures How the postscript interpreter and an application interact16 Mapping with the Decode array112 Homogeneous number array161 Binary object sequence164 The two squares produced by Example Effects of coordinate transformations188 Nonzero winding number rule195 Even-odd rule196 Color specification212 Color rendering213 Component transformations in the CIEB asedABC color space222 Component transformations in the CIEB asedA color space229 CIEB asedDEFG pre-extension to the CIEB asedABC color space232 Output from Example Output from Example Starting a new

6 Triangle in a free-form Gouraud-shaded triangle mesh272 Connecting triangles in a free-form Gouraud-shaded triangle mesh272 Varying the value of the edge flag to create different shapes273 Lattice-form triangular meshes275 Coordinate mapping from a unit square to a four-sided Coons patch277 Painted area and boundary of a Coons patch279 Color values and edge flags in Coons patch meshes281 Edge connections in a Coons patch mesh282 Control points in a tensor-product mesh284 Typical sampled image288 Image data organization and processing293 Source image coordinate system294 Mapping the source image295 Contents viii Results of Example Glyphs painted in 50% gray318 Glyph outlines treated as a path319 Graphics clipped by a glyph path320 Encoding scheme for Type 1 fonts329 Glyph metrics331 Relationship between two sets of metrics333 Output from Example Composite font mapping example359 CID-keyed font basics367 Type 0 CIDFont character processing372 Trapping example440 Sliding trap452 Various halftoning effects486 Halftone cell with a nonzero angle493 Angled halftone cell divided into two squares493 Halftone cell and two squares tiled across device space494 Tiling of device space in a type 16 halftone dictionary497 Rasterization without stroke adjustment504 arc

7 Operator530 arc operator example531 arcn operator example532 arct operator533 arct operator example533 curveto operator565 imagemask example609 setflat operator669 Line cap parameter shapes673 Line join parameter shapes674 Miter length676 ix Tables Control characters for the interactive executive21 White-space characters27 Types of objects34 Standard local dictionaries65 Standard global dictionaries66 Access strings79 Standard filters85 Regular resources91 Resources whose instances are implicit91 Resources used in defining new resource categories92 Standard procedure sets in LanguageLevel 396 Entries in a category implementation dictionary101 Entries common to all function dictionaries108 Additional entries specific to a type 0 function dictionary109 Additional entries specific to a type 2 function dictionary113 Additional entries specific to a type 3 function dictionary114 Entries in the $error dictionary116 Entries in an LZWE ncode or LZWD ecode parameter dictionary133 Typical LZW encoding sequence135 Entries in a FlateEncode or FlateDecode parameter dictionary138 Predictor-related entries in an LZW or Flate filter parameter dictionary141 Entries in a CCITTFaxEncode or CCITTFaxDecode parameter dictionary144 Entries in a DCTE ncode

8 Parameter dictionary148 Entries in a SubFileDecode parameter dictionary (LanguageLevel 3)152 Entries in a ReusableStreamDecode parameter dictionary155 Binary token interpretation158 representation in header for a homogeneous number type, length, and value parameters of the graphics parameters of the graphics codes for encoded user in a type 1 form in a CIEB asedABC color space in a CIEB asedA color space entries specific to a CIEB asedDEF color space entries specific to a CIEB asedDEFG color space in a type 1 pattern in a type 2 pattern common to all shading entries specific to a type 1 shading entries specific to a type 2 shading entries specific to a type 3 shading entries specific to a type 4 shading entries specific to a type 5 shading entries specific to a type 6 shading values in a Coons patch values in a tensor-product patch in a type 1 image Decode in a

9 Type 3 image in an image data in a mask in a type 4 image common to all font entries common to all base entries specific to Type 1 in a FontInfo entries specific to Type 3 entries specific to Type 42 entries specific to Type 0 mapping in a CIDS ystemInfo and FontType common to all CIDFont entries specific to Type 0 CIDFont in a dictionary in replacing Subrs in the Private dictionary of an FDArray entry specific to Type 1 CIDFont entries specific to Type 2 CIDFont in a CMap of page device device parameters related to media device parameters related to roll-fed device parameters related to page image device parameters related to page device parameters related to color device parameters related to device initialization and page device parameter related to recovery in the Policies in a Type 1001 trapping details in a colorant details in a colorant in a trapping parameter of normal trapping in a ColorantZoneDetails in an output device in a type 1 CIE-based color rendering of halftone in a type 1 halftone in a type 3 halftone in a type 6 halftone in a type 10 halftone in a type 16 halftone in a proprietary halftone and result 3 operators defined in procedure resource resource page device and interpreter memory limits in

10 LanguageLevel summary802xiiiPrefaceIN THE 1980S, ADOBE DEVISED a powerful graphics imaging model that overtime has formed the basis for the Adobe postscript technologies. These technolo-gies a combination of the postscript LANGUAGE and postscript LANGUAGE basedgraphics and text-formatting applications, drivers, and imaging systems haveforever changed