® Multiple Master Font ®®Programs for the Macintosh Adobe Developer Support Technical Note #5087 14 February 1992 Adobe Systems Incorporated Adobe Developer Technologies 345 Park Avenue San Jose, CA 95110 http://partners.adobe.com/ PN LPS5087 Copyright 1992 by Adobe Systems Incorporated. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written consent of the publisher. Any software referred to herein is furnished under license and may only be used or copied in accordance with the terms of such license. PostScript is a registered trademark of Adobe Systems Incorporated. All instances of the name PostScript in the text are references to the PostScript language as defined by Adobe Systems Incorporated unless otherwise stated. The name PostScript also is used as a product trademark for Adobe Systems’ implementation of the PostScript language interpreter. Any references to a “PostScript printer,” a “PostScript file,” or a “PostScript driver” refer to printers, files, and driver programs (respectively) which are written in or support the PostScript language. The sentences in this book that use “PostScript language” as an adjective phrase are so constructed to reinforce that the name refers to the standard language definition as set forth by Adobe Systems Incorporated. PostScript, the PostScript logo, Adobe, the Adobe logo, Adobe Type Manager, ATM, and Myriad are trademarks of Adobe Systems Incorporated which may be registered in certain jurisdictions. Apple, LaserWriter, and Macintosh are registered trademarks of Apple Computer, Inc. Other brand or product names are the trademarks or registered trademarks of their respective holders. This publication and the information herein is furnished AS IS, is subject to change without notice, and should not be construed as a commitment by Adobe Systems Incorporated. Adobe Systems Incorporated assumes no responsibility or liability for any errors or inaccuracies, makes no warranty of any kind (express, implied or statutory) with respect to this publication, and expressly disclaims any and all warranties of merchantability, fitness for particular purposes and noninfringement of third party rights. Contents Multiple Master Font Programs for the Macintosh 5 1 Introduction 5 2 Multiple Master Font Programs for the Macintosh 5 3 The BLND Resource 6 BLND Resource Header Table 6 Axis Information Table 7 Master Design Name Table 9 The Style Table 9 Primary Font Table 10 Primary Font Name table 11 4 The Macintosh FOND Resource: Style Mapping Table 12 5 Multiple Master Naming Conventions 14 Appendix A: Primary Font Axis Labels 15 Appendix B: Style Abbreviations 17 Index 19 iii iv Contents (14 Feb 92) Multiple Master Font Programs for the Macintosh 1 Introduction The Adobe™ Technical Specification, “Adobe Type 1 Font Format: Multiple Master Extensions.” describes the device-independent format for multiple master font programs, which is the format used by PostScript™ printers. This document describes how to adapt those font programs for use on the Macin- tosh®. It contains information on changes in the FOND resource, the newly defined BLND resource, and information on font naming conventions. A knowledge of Macintosh font data structures is assumed. For more informa- tion on this subject refer to the following: • Inside Macintosh, Volume 4; Addison Wesley, 1986 • Apple® LaserWriter® Reference, Addison Wesley, 1988 •“Macintosh FOND Resources,” Adobe Technical Note #0091 For information on multiple master font programs, see Adobe Technical Specification: “Multiple Master Extensions to the Adobe Type 1 Font For- mat.” 2 Multiple Master Font Programs for the Macintosh The current Macintosh font data structure must be extended in two ways to support multiple master typefaces: there must be a BLND resource (described in section 3) for each multiple master font program, and the Style Mapping table in the FOND resource must be adapted to include new entries. The BLND resource is used by Adobe Type Manager™ (ATM™) software to access information needed to create, display, and manage multiple master typefaces in the Macintosh environment. Multiple master typefaces are represented as Type 1 font programs. The out- line information for all master designs is represented as a single CharStrings dictionary in the multiple master font program. Each multiple master font program has one FOND resource for each master design it contains so that information, like kerning data, can be represented for each design. 5 3 The BLND Resource The BLND resource is stored as a resource in the PostScript language font file with an ID number of 501 and a Resource Type of BLND. It consists of data that is subdivided into a BLND Resource Header table, followed by an Axis Information table, a Master Design Name table, a Style table, a Primary Font table, and a Primary Font Name table. All strings in the BLND resource are Pascal strings where the first byte is the character count and are padded to even boundaries. Figure 1 BLND Resource Header table Bytes 2 Version number 2 Flags 2 Number of Axes 2 Number of master designs 2 Language ID 2 Index to "Regular" Primary font 2 Number of offsets 4 Offset to 1st axis information . 4 Offset to nth axis information 4 Offset to master FOND names 4 Offset to style table 4 Offset to list of primary fonts 4 Offset to list of primary font names 3.1 BLND Resource Header Table The first section of the BLND resource is the BLND Resource table, which contains the following entries: Version Number Currently ‘2’. Flags Reserved for future use. Number of Axes The number of axes defined in the multiple master font program. Language ID Currently uses a value of 0 for fonts with English lan- guage label strings. 6 Multiple Master Font Programs for the Macintosh (14 Feb 92) Index to “Regular” Primary font Index into the Primary Font table for the font consid- ered to be the regular, normal, or roman design for the font family. Indices start with 1. Primary fonts are those which correspond to standard styles of a typeface fam- ily, such as light, regular, bold, and so on, and which are generally included in the font package for backward compatibility. Number of offsets Total number of offsets which follow. Offset to 1st axis information Number of bytes from beginning of resource table to Axis Information table. Offset to FOND names Number of bytes from beginning of resource table to the FOND name table. Offset to Style tableNumber of bytes from beginning of resource table to the Style table. Offset to list of primary fonts Number of bytes from beginning of resource table to the Primary Font table. Offset to list of primary font names Number of bytes from the beginning of the Primary Font Names table. 3.2 Axis Information Table The Axis Information table follows the BLND Resource Header table and is shown in Figure 2. There is one table entry for each axis in the multiple master font program. Figure 2 Axis Information table Bytes 2 Flag 2 Min Range 2 Max Range Each entry: Axis Type <string> string size Long label <string> +1+ possible padding Short label <string> 2 Number of pairs (to follow) 2 + 4 Design coord0 Normalized value0 2 + 4 . 2 + 4 Design coordn-1 Normalized valuen-1 3 The BLND Resource 7 The Axis Information table contains the following entries: Flag If bit 0 is set to 1, axis mapping information follows the short label name. This information is required if the axis is piecewise linear as the result of non-linearity introduced by the values in the BlendDesignMap array in the font. Other bits are zero and are reserved for future use. Min Range The minimum design coordinate for the current axis. For example, if an axis has a range from 215 to 830, the value for Min Range would be 215. Max Range The maximum design coordinate for the current axis; for example, 830 for the above example. Axis Type Axis type, for example, Weight. This label should be constant for all languages, and should use one of the reserved keywords listed in the Appendix. It is intended primarily to allow applications to determine the axis type. Developers of new axis types should register new labels with Adobe Systems by contacting the Adobe Developers Association. Long Label The full name for the axis type, for example, Weight, or Optical Size. This label may be language-dependent, and is for use in user interface dialogue. Short Label Condensed axis label for use in font names. Example: wt for Weight, wd for Width, or op for Optical Size. This entry may contain leading and trailing spaces. This label may be language-dependent, and is for use in user interface dialogue. Number of Pairs Specifies the number of coordinate/value pairs which follow. Design Coordinate/Normalized Value pairs These pairs map the design coordinates of an axis to the normalized coordinates in the Blend number space. The normalized value is stored as a 16.16 fixed point num- ber. For example, in a font whose weight values range from 215 to 830, the pairs [215, 0] and [830, 1] would map the design coordinates for a minimum weight of 215 to the Blend coordinate of 0, and the maximum weight of 830 to the Blend coordinate of 1. An entry such as [215, 0] [450, .5] [830, 1] would make the mapping piecewise linear with a median blend coordinate of .5 equivalent to 450 in design space coordinates. 8 Multiple Master Font Programs for the Macintosh (14 Feb 92) 3.3 Master Design Name Table The Master Design Name table follows the Axis Information table and con- tains the FOND name of each master design as shown in Figure 3.