ISO/IEC INTERNATIONAL STANDARD 9637-2 First edition 1992-12-01 Information technology Computer graphics --- Interfacing techniques for dialogues with graphical devices (CGl) - Data stream binding Part 2: Binary encoding Technologies de I'information - Infographie - Interfaces pour I'infographie -- Interface du flux de données CGl- Partie 2: Codage binaire Reference number ISO/IEC 9637-2:1992(E) IS0/IEC 9637-2:1992 (E) CONTENTS Page Foreword iv Introduction v 1 Scope 1 2 Normative References 2 3 Definitions 4 4 Overall structure 5 4.1 General form of the data stream 5 4.2 General structure of the Binary Encoding 5 4.3 Encoding functions 7 4.3.1 General structure of the representation header 7 4.3.2 Basic short-form representation header 8 4.3.3 Basic long-form representation header 8 4.3.4 Extended-form representation header 10 4.4 Encoding parameter data 12 4.5 Encoding function response data 12 4.5.1 Structure of response representations 13 5 Binary Encoding primitive data forms 14 5.1 Signed Integer 14 5.1.1 Signed Integer at 8-bit precision 15 5.1.2 Signed Integer at 16-bit precision 15 5.1.3 Signed Integer at : 24-bit precision 15 5.1.4 Signed Integer at 32-bit precision 15 5.2 Unsigned Integer 16 5.2.1 Unsigned Integer at 8-bit precision 16 5.2.2 Unsigned Integer at 16-bit precision 16 5.2.3 Unsigned Integer at 24-bit precision 16 5.2.4 Unsigned Integer at 32-bit I precision 16 5.3 Octet 17 5.4 Fixed Point Real 17 5.4.1 Fixed Point Real at 32-bit 1 precision 17 5.4.2 Fixed Point Real at 64-bit precision 17 5.4.3 Values of Fixed Point Real 18 5.5 Floating Point Real 18 ISO/IEC1992 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without per- mission in writing from the publisher. ISO/IEC Copyright Office· Case Postale 56· CH-1211 Geneve 20· Switzerland Printed in Switzerland ii @1SO/ 1EC IS0/IEC 9637-2:1992 (E) 6 Representation of abstract parameter data types 19 6.1 Special Binary Encoding rules 24 6.1.1 Encoding the precision functions 24 6.1.1.1 Binary Encoding precision functions 25 6.1.2 Encoding strings, fixed strings, and data records 28 6.1.2.1 Encoding data record contents 29 6.1.2.2 String parameters and character sets 30 6.1.3 Encoding <input class> input functions 31 6.1.4 INHERITANCE FILTER enumerated values 31 6.1.5 Encoding point lists 33 6.1.6 Encoding transformation matrix components 34 6.1.7 Encoding local colour precision 34 6.1.7.1 Encoding CELL ARRAY and PATTERN TABLE local colour precision 35 6.1.7.2 Encoding PIXEL ARRAY local colour precision 6.1.8 Colour specifier lists . 36 6.1.8.1 Encoding colour specifier lists 37 6.1.8.2 Encoding lists of input colour values and local 37 colour precision 38 6.1.9 EnCoding PATTERN TABLE and INOUIRE PATTERN colour specifiers. 38 Representation of each function and response 39 7.i Opcode assignments 39 7.1.1 Class code assignments 39 7.1.2 Function id code assignments 41 8 Defaults 62 Classification and designation 63 9.1 Conformance 63 A Algorithms and rules for class code assignment 64 B Encoding examples 66 iii