EN 28632-1:1994

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Information technology - Computer graphics - Metafile for the storage and transfer of picture description information - Part 1: Functional specification (ISO/IEC 8632-1:1992)Informationstechnik - Graphische Datenverarbeitung - Datei für die Speicherung und die Übertragung von BildinformationTechnologies de l'information - Infographie - Métafichier de stockage et de transfert des informations de description d'Information technology - Computer graphics - Metafile for the storage and transfer of picture description information -35.140Computer graphicsICS:Ta slovenski standard je istoveten z:EN 28632-1:1994SIST EN 28632-1:1997en01-december-1997SIST EN 28632-1:1997SLOVENSKI
STANDARD
INTERNATIONAL STANDARD ISO/IEC 86324 Second edi tian 1992-l o-01 e-e-_- -pl_-----------Y -.------- .______-_ I ____ __ ___ ___________._-. -___ ____. _ -__._- - _._, _. _ ._-_ . . _--._ _-_-e.- -- --.c- - .--.--.-.-- _-- _ __---_- -_-. - .- -_ -. - ---- ----_ ---_ _ __. _-. Information technology - Computer graphics - Metafile for the storage and transfer of picture description information - Part 1: Functional speckfication Technologies de l’inforn7a tion - lnfogr-aphie --- AMaficl~ier de stockage et de tr&sfert des informations de description d’imges -- Pariie I: Description fonctionnelle Reference nutnber ISCMEC 8632-1:1992(E) SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) CONTENTS 1 Scope . . . . . . . 2 Normative references . . . 3 Definitions and abbreviations 3.1 Definitions . . . . 3.2 Abbreviations . . . 4 Concepts . . . . . . . 4.1 Introduction . . . . 4.2 Delimiter elements . . 4.3 Metafile descriptor elements 4.3.1 4.3.2 4.3.3 4.3.4 4.4 Picture 4.4.1 4.4.2 4.4.3 4.4.4 4.4.5 4.4.6 4.4.7 4.4.8 4.4.9 IdentifiLation Functional capab& Default metafile state . . . . . . . . . . . . Fonts and character sets descriptor elements . Scaling mode o . . Colour selection mode Specification modes . VDC extent . . . . CGM tailoring . . . Background colour Device viewport control Representations . . Definable attributes . 4.5 Control elements . 4.51 VDC space and rang; . 4.52 Clipping . . . . . . . . . . . . . . . . . e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.3 Save and restore primitive context 4.5.4 Compound clipping and shielding 4.5.5 Generalized text path . . . . 4.5.6 Mitre limit . . . . . . . 4.5.7 Transparent cell colour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . 0 . . . . . . . . . . . . . . . 1 2 4 4 9 10 10 10 11 12 12 L 16 16 21 21 21 21 22 22 24 24 25 25 25 25 25 27 27 30 30 30 0 ISO/IEC 1992 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopyin g and microfilm, without permission in writing from the publisher. lSO/IEC Copyright Office l Case postale 56 l CH-1211 Genkve 20 l Switzerland Printed in Switzerland 11 SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) 4.6 Graphical primitive elements . . . 4.6.1 Line elements . . . . . 4.6.2 Marker element . . . . 4.6.3 Text elements . m . . . 4.6.4 Filled-area elements . . . 4.6.5 Cell elements . . . 4.6.6 Circular arc elements . . . 4.6.7 Elliptical elements . . . . 4.6.8 Hyperbolic Arc Element . . 4.6.9 Parabolic arc element . . . 4.6.10 Spline curve elements . . . 4.6.11 Closed figures . . . . . 4.6.12 Symbol elements . . . . 4.7 Attribute elements . . . . . . 4.7.1 Line attributes . . . . . 4.7.2 Marker attributes . . . . 4.7.3 Text attributes . . . . . 4.7.4 Filled-area attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7.5 SDecification modes and transformation of aspects 4.7.6 C&our attributes . 4.7.7 Pick identifier . 4.7.8 Compound text path . 4.7.9 Symbol Attributes . 4.8 Escape elements . 4.9 External elements . 4.10 Segment elements . 4.10.1 Introduction . 4.10.2 Local and global segments . 4.10.3 Delimiting and naming segments . . 4.10.4 Segment attributes . 4.105 Copy segment and inheritance . 4.11 Metafile states . 4.12 Registration . 5 Abstract specification of elements . 5.1 Introduction . 5.2 Delimiter elements . 5.2.1 BEGIN METAFILE . 5.2.2 END METAFILE . 5.2.3 BEGIN PICTURE . 5.2.4 BEGINPICTURE BODY . 5.2.5 END PICTURE 5.2.6 BEGIN SEGMENT . 5.2.7 END SEGMENT . 5.2.8 BEGIN FIGURE . 5.2.9 END FIGURE . 5.2.10 BEGIN PROTECTION REGION’ . . . . 5.2.11 END PROTECTION REGION . 5.2.12 BEGIN COMPOUNDLINE . 5.2.13 END COMPOUND LINE 5.2.14 BEGIN COMPOUND TEXT PATH l . . 5.2.15 END COMPOUND TEXT PATH . . 5.2.16 BEGINTILE ARRAY . 52.17 END TILE ARRAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 33 35 36 36 38 41 41 42 42 46 48 54 55 58 59 61 85 87 88 90 90 91 93 93 93 93 94 95 95 96 101 112 115 115 119 119 119 119 120 121 121 121 122 122 122 123 123 123 124 1’4 L 124 125 . . . 111 SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) 5.3 Metafile descriptor elements . . . 5.3.1 5.3.2 5.3.3 5.3.4 5.3.5 5.3.6 5.3.7 5.3.8 5.3.9 5.3.10 5.3.11 5.3.12 5.3.13 5.3.14 5.3.15 5.3.16 5.3.17 5.3.18 5.3.19 5.3.20 5.3.21 5.3.22 5.3.23 5.4 Picture 5.4.1 5.4.2 5.4.3 5.4.4 5.4.5 5.4.6 5.4.7 5.4.8 5.4.9 5.4.10 5.4.11 5.4.12 5.4.13 5.4.14 5.4.15 5.4.16 5.4.17 5.4.18 5.4.19 METAFILE VERSION METAFILE DESCRIPTIbN l VDCTYPE . . . . . . INTEGER PRECISION . . REAL PRECISION . . . INDEXPRECISION . . . COLOUR PRECISION COLOUR INDEX PRECISION MAXIMUM COLOUR INDEX COLOUR VALUE EXTENT METAFILE ELEMENT LIST METAFILE DEFAULTS REPLACEMENT FONT LIST . . . . . . . . . CHARACTER SET LIST CHARACTER CODING A&ObN& NAMEPRECISION . . . . MAXIMUM VDC EXTENT . . SEGMENT PRIORITY EXTENT COLOUR MODEL . . COLOUR CALIBRAT;ON . . FONTPROPERTIES . . . . GLYPH MAPPING . . SYMBOL LIBRARY I& . . descriptor elements . . . . SCALINGMODE . . . . . COLOUR SELECTION MODE LINE WIDTH SPECIFICATION MODE MARKER SIZE SPECIFICATION MODE EDGE WIDTH SPECIFICATION MODE VDC EXTENT . . . . . . . . . BACKGROUNDCOLOUR . . . . . DEVICEVIEWPORT . . . . . . DEVICE VIEWPORT SPECIFICATION MODE DEVICE VIEWPORTMAPPING . . . . . LINE REPRESENTATION . . . . . . . MARKERREPRESENT-ATION . . . . . TEXT REPRESENTATION . . . . . . . FILL REPRESENTATION . . . . . . . EDGE REPRESENTATION . . . . . . . INTERIOR STYLE SPECIFICATION MODE . LINE AND EDGE TYPE DEFINITION . . . HATCH STYLE DEFINITION . . . . GEOMETRIC PATTERN DEFINIT;ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Control elements . . . . . . 5.5.1 vDc INTEGER ‘PREC&I;)N’ . . . . . . 5.5.2 VDC REAL PRECISION . . . . . . . 5.5.3 AUXILIARY COLOUR . . . . . . . . 5.5.4 TRANSPARENCY . . . . . . . . . 5.5.5 CLIP RECTANGLE . . . . . . . . . 5.5.6 CLIP INDICATOR LINE CLIPPING MODE . . . . . . . . 5.5.7 . . . . 5.5.8 MARKER CLIPPING MODE’ . . . . : : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 . 127 . 127 . 127 . 128 . 128 . 128 . 128 . 129 . 129 . 129 . 130 . 131 . 132 . 132 . 133 . 134 . 134 . 134 . 135 . 135 . 137 . 141 . 142 . 143 . 143 . 143 . 144 . 144 . 145 . 145 . 146 . 146 . 147 . 147 . 148 . 148 . 149 . 150 . 150 . 151 . 151 . 152 . 153 . 155 . 155 . 155 . 155 . 156 . 157 . 157 . 157 . 158 iv SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) 5.5.9 EDGE CLIPPINGMODE . . . . 5.5.10 NEW REGION . . . . . . . . 5.5.11 SAVE PRIMITIVE CONTEXT . . . 5.5.12 RESTORE PRIMITIVE CONTEXT . 5.5.13 PROTECTION REGION INDICATOR 5.5.14 GENERALIZED TEXT PATH MODE 5.5.15 MITRE LIMIT . . . . . . . . 5.5.16 TRANSPARENT CELL COLOUR . . 5.6 Graphical primitive elements . . . . . . 5.6.1 POLYLINE . . . . . . . . . 5.6.2 DISJOINT POLYLINE . . . . . 5.6.3 POLYMARKER . . . . . . . 5.6.4 TEXT . . . . . . 5.6.5 RESTRI&ED TEXT . . . . . . 5.6.6 APPENDTEXT . . . . . . . 5.6.7 POLYGON . . . . . . . . . 5.6.8 POLYGON SET . . . . . . . 5.6.9 CELL ARRAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6.10 GENERALIZED DRAWING PRIMITIVE (GDP) 5.6.11 RECTANGLE . 5.6.12 CIRCLE . 5.6.13 CIRCULAR ARC 3 POINT . 5.6.14 CIRCULAR ARC 3 POINT CLOSE . . 5.6.15 CIRCULAR ARC CENTRE . 5.6.16 CIRCULAR ARC CENTRE CLOSE . . 5.6.17 ELLIPSE 5.6.18 ELLIPTICAL’ARC’ . 5.6.19 ELLIPTICAL ARC CL&E . . 5.6.20 CIRCULAR ARC CENTRE REVERSED . 5.6.2 1 CONNECTING EDGE . 5.6.22 HYPERBOLIC ARC . 5.6.23 PARABOLIC ARC 5.6.24 NON-UNIFORM B-SPLIl?k l . 5.6.25 NON-UNIFORM RATIONAL B-bPLIl& l 5.6.26 POLYBEZIER . 5.6.27 POLYSYMBOL . 5.6.28 BITONAL TILE . 5.6.29 TILE . 5.7 Attribute elements . 5.7.1 LINE BUNDLE INDEX . 5.7.2 LINE TYPE . 5.7.3 LINE WIDTH . 5.7.4 LINE COLOUR 5.7.5 MARKERBUNDLEINDEX’ . . 5.7.6 MARKER TYPE . 5.7.7 MARKER SIZE 5.7.8 MARKER COLOUI; . 5.7.9 TEXT BUNDLE INDEk . 5.7.10 TEXTFONT INDEX . 5.7.11 TEXT PRECISION . 5.7.12 CHARACTER EXPANSION FA;CT~R’ . 5.7.13 CHARACTER SPACING . 5.7.14 TEXT COLOUR . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 . 158 . 159 . 160 . 160 . 161 . 161 . 161 . 163 . 163 . 163 . 163 . 164 . 165 . 166 . 167 . 168 . 171 . 173 . 173 . 174 . 174 . 175 . 177 . 177 . 178 . 179 . 180 . 181 . 181 . 182 . 182 . 183 . 183 . 184 . 185 . 185 . 187 . 190 . 190 . 190 . 191 . 192 . 192 . 192 . 193 . 194 . 194 . 195 . 195 . 196 . 196 . 197 V SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) 5.7.15 5.7.16 5.7.17 5.7.18 5.7.19 5.7.20 5.7.21 5.7.22 5.7.23 5.7.24 5.7.25 5.7.26 5.7.27 5.7.28 5.7.29 5.7.30 5.7.31 5.7.32 5.7.33 5.7.34 5.7.35 5.7.36 5.7.37 5.7.38 5.7.39 5.7.40 5.7.41 5.742 5.7.43 5.7.44 5.7.45 5.7.46 5.7.47 5.7.48 5.7.49 5.7.50 5.7.5 1 CHARACTERHEIGHT . . . . . . CHARACTERORIENTATION . . . TEXT PATH TEXT ALIGNMENT . . . . . . . CHARACTER SET INDEX . . . . . ALTERNATE CHARACTER’SE;. IND’EX’ FILLBUNDLEINDEX . . . INTERIORSTYLE . . . . FILLCOLOUR . . . . . HATCHINDEX . . . . . PATTERN INDEX . . . EDGEBUNDLEINDEX . . . EDGETYPE . . . . . . EDGE WIDTH . . . . . . EDGECOLOUR . . . . . EDGE VISIBILITY . . FILLREFERENCEPOiNi’ . . PATTERNTABLE . . . . PATTERNSIZE . . . . . COLOURTABLE . . . . . ASPECT SOURCEFLAGS . . PICKIDENTIFIER . . . . LINE CAP . . . . . . . LINE JOIN . . . . . . . LINE TYPE CONTINUATION . LINE TYPE INITIAL OFFSET . TEXTSCORETYPE . . . . RESTRICTEDTEXTTYPE . . INTERPOLATED INTERIOR . EDGE CAP . . . . . . . EDGE JOIN EDGE TYPE CONTINUATION l EDGE TYPE INITIAL OFFSET SYMBOL LIBRARY INDEX . SYMBOLCOLOUR . . . . SYMBOL SIZE . . SYMBOL 0RIENTAT;ON . . 5.8 Escape elements . . . . . . . . 5.8.1 ESCAPE . . . . . . . 5.9 External elements . . . . . . . 5.9.1 MESSAGE . . . . . 5.9.2 APPLICATION DATA. . . . 5.10 Segment elements 5.10.1 COPY SEGMENi’ . . . . . . . . 5.10.2 INHERITANCE FILTER . . 5.10.3 CLIP INHERITANCE 5.10.4 SEGMENT TRANSFORMATION 5.10.5 SEGMENT HIGHLIGHTING 5.10.6 SEGMENT DISPLAY PRIORITY 5.10.7 SEGMENT PICK PRIORITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Metafile defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 . 198 . 199 . 199 . 200 . 200 . 201 . 201 . 202 . 202 . 203 . 204 . 204 . 205 . 205 . 206 . 206 . 207 . 207 . 208 . 209 . 210 . 210 . 211 . 211 . 212 . 212 . 213 . 214 . 215 . 216 . 216 . 217 . 217 . 218 . 218 . 219 . 220 . 220 . 221 . 221 . 221 . 222 . 222 . 222 . 224 . 224 . 224 . 225 . 225 . . . . . . . 227 vi SIST EN 28632-1:1997

7 Conformance 7.1 Forms of co~formark . 7.2 Functional conformance of meta& . . 7.3 Full conformance of metafiles . 7.4 Conformance of other encodings . A Formal grammar of the functional specification of version 1 metafiles A. 1 Introduction . A.2 Notation used A.3 Detailed grammar’ . . . . A.3.1 Metafile struc&re . A.3.2 Metafile descriptor elements . . . A.3.3 Picture descriptor elements . A.3.4 Control elements . . . . A.3.5 Graphical elements . A.3.6 Attribute elements . . A.3.7 Escape elements . A.3.8 External elements . A.4 Terminal symbols . B Formal Grammar of the functional specification of version 2 metafiles B.l Introduction . B.2 Notation used B .3 Detailed grammar’ . . l . B.3.1 Metafile struck-e . B .3.2 Metafile descriptor elemenk . . B.3.3 Picture descriptor elements . B.3.4 Control elements . . B .3.5 Graphical elements . B.3.6 Attribute elements . B.3.7 Closed figure element . B .3.8 Escape elements . B.3.9 External elements . B .3.10 Segment elements . B.4 Terminal symbols . C Formal grammar of the functional specification of version 3 metafiles C.1 Introduction . C.2 Definitions C.2.1 Notatidn &ed . C.2.2 Structured Data Records: . . . C.3 Detailed Grammar . C.3.1 Metafile structure . C.3.2 Metafile descriptor elements . C.3.3 Picture descriptor elements . C.3.4 Control elements . C.3.5 Graphical elements . C.3.6 Attribute elements . C.3.7 Escape elements . C.3.8 External elements . C.3.9 I Segment elements . C.4 Terminal symbols . D Guidelines for metafile generators and interpreters . . . . . . D. 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ISO/IEC 8632-l: 1992 (E) . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . l . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . 232 232 232 232 232 233 233 233 233 233 234 236 236 237 240 243 243 244 248 248 248 248 248 249 252 254 255 257 261 261 262 262 264 272 272 272 272 272 273 273 278 281 285 286 289 294 294 294 297 307 307 vii SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) D.2 Errors and degeneracies . . . . . . . . D.2.1 Syntax errors . . . . . . . . . D.2.2 Geometrically degenerate primitives . . D.2.3 Mathematical singularities and ambiguities D.3 General guidelines . D.3.1 Indexes . D.3.2 Colour model . D.3.3 Order of metafile descriptor elements D.3.4 Unsatisfied references . . . D.4 Guidelines for element classes . . D.4.1 Delimiter elements . D.4.2 Metafile descriptor elemenk . D.4.3 Picture descriptor elements . D.4.4 Control elements . . . . D.4.5 Graphical primitive elements D.4.6 Attribute elements . . . . D.4.7 Escape elements . . . . D.4.8 External elements . . . . D.4.9 Segment elements . . . . E Guidelines for private encodings . . . F Reference models . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G Conversions between the CIEXYZ reference corour space and metafile colour spaces Gl G’2 . G3 . G4 . G5 . Introduction . . . . . . . . . . . . . . . . . . . Definitions . . . . . . . . . . . . . . . . . . . CIELUV . . . . . . . . . . . . . . . . . . . . G.3.1 Conversion from the CIEXYZ reference colour space to CIELUV G.3.2 Conversion from CIELUV to the CIEXYZ reference colour space CIELAB . . . . . . . . . . . . . . . . . . . . G.4.1 Conversion from the CIEXYZ reference colour space to CIELAB G.4.2 Conversion from CIELAB to the CIEXYZ reference colour space RGB . G.5.1 Conversion frbm*the CIEXYZ*re fk,,,,‘,olour sphce.to kGi . . . G6 G-7 . G8 . G.5.2 Conversion from RGB to the CIEXYZ reference colour space . . RGB-related . . . . . . . . . . . . . . . . . . . CMYK . G.7.1 Converkon fromC&YK to the &EXYZ refere’nce copout &a& . G.7.2 CMYK Calibration data . . . . . . . . . . . . . Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . l l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 308 308 309 309 309 309 312 312 312 312 312 312 313 313 316 318 318 318 320 321 325 325 325 325 325 326 327 327 328 329 329 330 331 331 331 331 332 . . . Vlll SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) Foreword IS0 (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of IS0 or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. IS0 and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non- governmental, in liaison with IS0 and IEC, also take part in the work. In the field of information technology, IS0 and IEC have established a joint technical committee, ISO/IEC JTC 1, Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. International Standard ISO/IEC 8632-l was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology. This second edition cancels and replaces the first edition (IS0 863291:1987), which has been technically revised. ISO/IEC 8632 consists of the following parts, under the general title Information technology - Comyutel graphics - IMetafile for the storage and transfer of picture description information : Part I : Functional specification Part 2: Character encoding Part 3: Binary encoding Fart 4: Clear text encoding Annexes A, B, and C form an integral part of this part of ISO/IEC 8632. Annexes D, E, F and G are for information only ix SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) Introduction 0.1 Purpose The Computer Graphics Metafile provides a file format suitable for the storage and retrieval of picture information. The file format consists of a set of elements that can be used to describe pictures in a way that is compatible between systems of different architectures and devices of differing capabilities and design. This picture description includes the capability for describing static pictures. Static pictures are those where elements which may lead to dynamic effects (for example those leading to regeneration) are prohi- bited within the picture body. 0.2 Reasons for this International Standard The main reasons for producing a stand ard corn puter graphics metafile are a> b) to allow picture information to be stored in an organized way on a graphical software system; to facilitate transfer of picture information between different graphical software systems; c> to enable picture information to be transferred between graphical devices; d) to enable picture information to be transferred between different computer graphics installations. 0.3 Design requirements To reach these objectives, a number of design principles were adopted: a> The metafile should provide a suitable set of elements for the transfer of a wide range of pictorial information. b) The metafile should address the more usual and essential features found on graphical devices directly and should provide access to less common facilities via an escape mechanism. C) The design of the metafile should not preclude extension of ISO/IEC 8632 at a later stage to cover facilities beyond those included in this version of the Standard. It should also not preclude further extensions to support future standards. d) The metafile should be usable from GKS (Graphical Kernel System - IS0 7942) with both metafile input and metafile output functions. It should include the capability to support IS0 7942 (GKS) static picture capture. X SIST EN 28632-1:1997

ISO/IEC 8632-1: 1992 (E) Design requirements Introduction e) ISO/IEC 8632 should address the needs of different applications that have conflicting require- ments for size of metafile, speed of generation and interpretation, readability, editability and ease of transfer through different transport mechanisms. 0.4 Design criteria The requirements of 0.3 were used to formulate the following criteria which were used to decide between different design possibilities. a> b) c) d) e> f) s) h) . J) k) Completeness: In any area of ISO/IEC 8632, the functionality specified by ISO/IEC 8632 should be complete in itself. Conciseness: Redundant elements or parameters should be avoided. Consistency: Contradictory elements should be avoided. Extensibility: The ability to add new elements and generality to ISO/IEC 8632 should not be pre- cluded. Fidelity: The minimal results and characteristics of elements should be well defined. Implementability: An element should be able to be supported efficiently on most host systems and/or graphics hardware. Orthogonality: The elements of the metafile should be independent of each other, or any depen- dencies should be structured and well defined. Predictability: ISO/IEC 8632 should be such that the recommended or proper use of standard ele- ments guarantees the results of using a particular element. Standard practice: Only those elements that reflect existing practice, that are necessary to support existing practice, or that are necessary to support proposed standards should be standardized. Usefulness: Functions should be powerful enough to perform useful tasks. Well-structured: The assumptions that elements make about each other should be minimized. An element should have a well-defined interface and a simply stated unconditional purpose. Mul- tipurpose elements and side effects should be avoided. 0.5 Access to a metafile The metafile has been designed so that, although its main usage is anticipated as being with completely sequential access, non-sequential access is also possible. Once the basic environment of the metafile has been established, individual pictures may be accessible if the medium, the encoding and the implementation support this form of access. 0.6 Generation and interpretation of metafiles The specific mechanisms of metafile generation and interpretation are not described by ISO/IEC 8632, although it does describe the intended result of such interpretation. The basic set of metafile elements includes a capability for the addition of application-dependent data, which do not have graphical meaning and for which no intended interpretation results are described. 0.7 Distinction between formal specification and encodings The functionality provided by the metafile is separated from the specification of any particular encoding format. ISO/IEC 8632 provides for both standard and private encodings of the elements described in this xi SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) Introduction Distinction between formal specification and encodings part of ISO/IEC 8632. Guidelines for private encodings are specified in annex E ; these guidelines do not form part of ISO/IEC 8632. Three standard encodings are specified in parts 2, 3 and 4 of ISO/IEC 8632. Each of the standardized encodings is capable of representing the full functionality described in this part of ISO/IEC 8632. Transla- tion between the standardized encodings is possible without loss of picture information, although subse- quent translation back into the original encoding may not result in precisely the same data stream, due to different quantizations of precisions in the different encodings. The character encoding specified in ISO/IEC 8632-2 is intended to provide an encoding of minimum size. It conforms to the rules for code extension specified in IS0 2022 in the category of complete code system. It is particularly suitable for transfer through networks that cannot support binary transfers. The binary encoding specified in ISO/IEC 8632-3 provides an encoding that requires least effort to generate and interpret on many systems. The clear text encoding specified in ISO/IEC 8632-4 provides an encoding that can be created, viewed and edited with standard text editors. It is therefore also suitable for transfer through networks that support only transfer of text files. 0.8 Relationship to other International Standards ISO/IEC 8632 draws extensively for its model of a graphics system on GKS (Graphical Kernel System - IS0 7942). In addition, ISO/IEC 8632 specifies a metafile that may be used as a static picture-capture metafile by GKS. This part of ISO/IEC 8632 uses font concepts and the font architecture defined in ISO/IEC 9541-1 for defining CGM references to fonts and font resources. The font properties of ISO/IEC 9541-1 are adopted, where appropriate, to define CGM mechanisms to provide information useful for font substitution between parties interchanging Metafiles. This part of ISO/IEC 8632 includes the minimum font description subset defined in ISO/IEC 9541-2. Clause 3 contains a number of glossary definitions that are taken from, and are identical to, those found in ISO/IEC 9541- 1. This part of ISO/IEC 8632 also defines access to extended families of glyph based on the principles and procedures of ISO/IEC 10036. This part of ISO/IEC 8632 uses a calorimetrically precise reference colour space to allow for interchange of precise colour specifications. It uses concepts defined in ISO/IEC 8613/Amd.2 which are based on CIE publications. ISO/IEC 8613/Amd.2 provides tutorial material on relevant definitions and colour concepts, which is useful for understanding the material in this Standard but is not incorporated into this Standard in that amount of detail. The character encoding specified in ISO/IEC 8632-2 conforms to the code extension techniques of IS0 2022. The binary encoding specified in ISO/IEC 8632-3 employs the mechanism for representing floating point numbers specified in ANSI/IEEE 754-1986. For certain elements, the CGM defines value ranges of parameters as being reserved for registration. The meanings of these values will be defined using the established procedures (see 4.12) of the IS0 Interna- tional Registration Authority for Graphical Items. These procedures do not apply to values and value ranges defined as being reserved for private use; these values and ranges are not standardized. There is a very close relationship between many of the elements in IS0 8632 and a subset of the functions in the CGI * (Computer Graphics Interface - ISO/IEC 9636). x11 SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) Versions Introduction 0.9 Versions ISO/IEC 8632 defines several versions of the Computer Graphics Metafile. A version is defined by a for- mal grammar and additional specifications contained in clauses 4, 5, and 6. Clause 7 contains conformance criteria defined by version. These versions are currently defined: Version 1 (one); Version 2 (two); and Version 3 (three). NOTES 1 A valid Version 2 metafile is also a valid Version 3 metafile. A valid Version 1 metafile is also a valid Version 2 metafile. 2 Version 1 metafiles are as defined by the original CGM standard, which was designated IS0 8632:1987. Version 2 metafrles are as defined by the first amendment to the CGM standard, which was designated IS0 8632:1987/Amd.1:1990. Version 3 metafiles are as defined by an amendment to Version 2 of the CGM standard. This amendment was originally designated ISO/IEC 8632: 1987/Amd.3: 1991, but was never published as an amend- ment. Instead all documents were consolidated to produce this revision of IS0 8632; Versions 1, 2, and 3 are all defined by this revision. 3 Many of the figures in this International Standard were produced using ISO/IEC 8632 standard Version 1 metafiles, as defined herein. . . . x111 SIST EN 28632-1:1997

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INTERNATIONAL STANDARD ISO/IEC 8632-l : 1992 (E) Information technology - Computer graphics - Metafile for the storage and transfer of picture description information - Part 1 : Functional specification 1 Scope ISO/IEC 8632 provides a file format suitable for the storage and retrieval of picture description information. The file format consists of an ordered set of elements that can be used to describe pictures in a way that is compatible between systems of different architectures and devices of differing capabilities and design. This picture description includes the capability for describing static images. The elements specified provide for the representation of a wide range of pictures on a wide range of graphi- cal devices. The elements are split into groups that delimit major structures (metafiles and pictures), that specify the representations used within the metafile, that control the display of the picture, that perform basic drawing actions, that control the attributes of the basic drawing actions and that provide access to non-standard device capabilities. The Metafile is defined in such a way that, in addition to sequential access to the whole metafile, random access to individual pictures is well-defined; whether this is available in any system that uses ISO/IEC 8632 depends on the medium, the encoding and the implementation. In addition to a functional specification, three standard encodings of the metafile syntax are specified. These encodings address the needs of applications that require minimum metafile size, minimum effort to generate and interpret, and maximum flexibility for a human reader or editor of the metafile. This part of ISO/IEC 8632 describes the format using an abstract syntax. The remaining three parts of IS0 8632 specify three standardized encodings that conform to this syntax: ISO/IEC 8632-2 specifies a charac- ter encoding that conforms to the rules for code extension specified in IS0 2022 in the category of complete coding system; ISO/IEC 8632-3 specifies a binary encoding; ISO/IEC 8632-4 specifies a clear text encod- ing. SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO/IEC 8632. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO/IEC 8632 are encouraged to investi- gate the possibility of applying the most recent editions of the standards listed below. Members of IEC and IS0 maintain registers of currently valid International Standards. ISOIIEC 646: 1991, Information technology - IS0 7-bit coded character set for information interchange. IS0 2022: 1986, Information processing - IS0 7-bit and 8-bit coded character sets - Code extension techniques. IS0 2375: 1985, Data processing - Procedure for registration of escape sequences. IS0 7942~1985, information processing systems - Computer graphics - Graphical Kernel System (GKS) functional description. ISOIIEC 8613: 1989lAmdS:-I>, Information processing systems - Text and ofice systems - Ofice document architecture (ODA) and interchange format - Amendment 1: Tiled raster graphics. ISO/IEC 8613:1989/Amd.2:-11, Information processing systems - Text and ofice systems - Ofice document architecture (ODA) and interchange format - Amendment 2: Colour. ISO/IEC 9541- 1: 199 1, Information technology - Font information interchange - Part 1: Architecture. ISOAEC 9541-2: 199 1, Information technology - Font information interchange - Part 2: Interchange format. ISO/IEC 9636- 1: 199 1, Information technology - Computer graphics - Inter$acing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 1: Overview, profiles, and conformance. ISOIIEC 9636-2: 1991, Information technology - Computer graphics - Intetiacing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 2: Control. ISO/IEC 9636-3: 1991, Information technology - Computer graphics - Interfacing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 3: Output. ISOAEC 9636-4: 199 1, Information technology - Computer graphics - Interjiacing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 4: Segments. ISO/IEC TR 9973: 1988, Information processing - Computer graphics - Procedures for registration of . graphical items. ISO/IEC 10036:-l), Information technology - Font information interchange - Procedure for registration of glyph and glyph collection identifiers. 1) To be published. 2 SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) Normative references CCITT Recommendation T.4 (1988), Standardization of group 3 facsimile apparatus for document transmission. CCITT Recommendation T.6 (1988), Standardization of group 4 facsimile apparatus for document transmission. CIE Publication 15.2, Calorimetry, 1986 (2nd edition). CIE Publication SOO2, Calorimetric Observers, 1986 (1st edition). SIST EN 28632-1:1997

ISO/IEC 8632-1: 1992 (E) 3 Definitions and abbreviations 3.1 Definitions For the purposes of ISOAEC 8632 the following definitions apply. NOTE - As far as possible, commonly accepted graphics terminology is used. 3.1-l anisotropic mapping: A mapping in which the scale factors applied along each axis are not equal. This is often used in reference to the mapping from VDC to distance units on the physical display surface. With anisotropic mapping, the angle between any pair of non-parallel line segments can change; circles cease to be circles and become ellipses after such a transformation. See “isotropic mapping”. 3.1.2 aspect ratio: The ratio of the width to the height of a rectangular area, such as a window or viewport. For example, an aspect ratio of 2.0 indicates an area twice as wide as it is high. 3.1.3 aspect source flag (ASF): Indicator as to whether a particular attribute selection is to be individual or bundled. 3.1.4 aspects of primitives: Ways in which the appearance of a primitive can vary. Some aspects are con- trolled directly by primitive attributes; some are controlled indirectly through a bundle table. 3.1.5 attribute elements: Metafile elements that describe the appearance of graphical elements. 3.1.6 boundary: The mathematical locus that defines, in abstract VDC space, the limits of a region to be filled (for fill primitives and closed figures). The visual appearance of interior style ‘hollow’ consists of a depiction of the boundary obtained after clipping has been taken into account. 3.1.7 brightness: Attribute of a visual sensation according to which an area appears to emit more or less light. 3.1.8 bundle: Set of attributes associated with one of the following graphical element types: line, marker, text, and filled area. 3.1.9 bundle index: An index into a bundle table for a particular output primitive. 3.1.10 bundle table: An indexed table containing a set of attributes for each index. 3.1.11 character set: The set of displayable symbols mapped to individual characters in a TEXT, APPEND TEXT, or RESTRICTED TEXT string. This corresponds to the “G-set” defined in IS0 2022. A character set is independent of the font or typeface; examples of character sets are: ASCII (X3.4), German and Kata- kana. 3.1.12 chroma: Colourfulness (chromaticncss) of an area judged in proportion to the brightness of a simi- larly illuminated area that appears white or highly transmitting. 3.1.13 chromaticity: Ratio of each of a set of three tristimulus values to their sum. (As the sum of the three chromaticity coordinates equals 1, two of them are sufficient to define a chromaticity.) 3.1.14 CIELAB colour space: A CIE recommended, approximately uniform, colour space with rectangular coordinates L* , a *, and b * . L* is the approximate correlate of lightness, a* and b* are used to calculate approximate correlates of hue and chroma. CIELAB uses the tristimulus ratios X/X,, Y /Yn, Z/Z, instead of chromaticity coordinates as in CIELUV. X,, Y,, , Zn are the values of X, Y,Z for the appropriate chosen reference white. The reduced perceptual significance of a given difference in chromaticity as the colour becomes darker is incorporated by using the tristimulus ratios. 3.1.15 CIELUV colour space: A CIE recommended, approximately uniform, colour space with rectangular coordinates L* , u *, and v * . L* is the approximate correlate of lightness, u* and v* are used to calculate approximate correlates of hue and chroma. The colour stimulus is described by Y,u’sv’ and the the reference white by Y,, uR’, v,‘. A given difference in chromaticity is reduced in magnitude by the factor L* as the 4 SIST EN 28632-1:1997

ISO/IEC 8632-l: 1992 (E) Definitions and abbreviations Definitions colour becomes darker. 3.1.16 CIE tristimulus values: Amounts of the three reference colour stimuli, in a given trichromatic sys- tem, required to match the colour of the stimulus considered. 3.1.17 CIE uniform colour spaces: Two CIE recommended, approximately uniform colour spaces, CIELAB and CIELUV, are allowed in the CGM. These colour spaces are non-linear transformations of the CIE 1931 XYZ tristimulus space, into the approximate perceptual correlates of lightness, hue, and chroma. CIELAB and CIELUV closely approximate uniform colour spaces over small distances, and they each pro- vide an approximately uniform measure of perceived colour differences. Both colour spaces allow for the perceptual effect that a given difference in chromaticity represents a smaller and smaller colour difference as the lightness is reduced. 3.1.18 clip indicator: Indicator as to whether metafile graphical elements are to be clipped at the limits of CLIP RECTANGLE. 3.1.19 clipping mode: A generic term referring to one of Line Clipping, Marker Clipping or Edge Clip- ping Modes. An object clipping may be either ‘locus’, ‘shape’ or ‘locus then shape’. 3.1.20 clip rectangle: A rectangle defined in VDC space which is used as a clipping boundary when the metafile graphical elements are to be clipped. 3.1.21 clipping: Removing parts of displ.ay elements that lie outside a given boundary. 3.1.22 closed figure: A compound primitive that behaves as a fill primitive of more general shape. I
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