TweetFollow Us on Twitter

March 96 - Print Hints: QuickDraw GX Breaks the Space Hack

Print Hints: QuickDraw GX Breaks the Space Hack

Dave Polaschek

Before QuickDraw GX, when an application that generated its own PostScript(TM) code wanted to make sure the printer could print a particular font, it could send one space character in the needed font. The LaserWriter driver would check the printer to see if the font was available, and if not, the driver would send the font to the printer so that it would be available to print the space character -- and any other characters in that font that the application-generated PostScript code might require. The reason for using a space was simple: you didn't want to mark the page just to get a font to the printer, and a space wouldn't mark it. This technique, first described in "The Perils of PostScript" back in develop Issue 1, became known as the "space hack."

Unfortunately, the space hack doesn't work with QuickDraw GX. This column describes a new way for applications that generate their own PostScript code to send fonts to the printer. The code to do this is provided on this issue's CD.

QUICKDRAW GX CHANGES THE PICTURE

QuickDraw GX has a really cool imaging model, supports all kinds of whizzy features, and to top it off, introduces the long-awaited new printing architecture. But it has one snag: after all the years you've spent getting your PostScript printing tuned just the way you like it, QuickDraw GX breaks the space hack.

The space hack depends on a font's entire character set being sent to the printer in response to the need for a single character (the space character). But QuickDraw GX sends only the needed characters in a font to a printer, because it's trying to conserve memory on the printer and also because sending less data means faster transmission of that data. This isn't such a big issue with Roman fonts, where there are only 256 characters at most, but in the case of two-byte fonts such as Chinese, Japanese, and Korean fonts, where there can be tens of thousands of characters and the font can be tens of megabytes in size, sending only the required characters makes a big difference in speed.

Incidentally, with QuickDraw GX you don't need a specialized printer to print two-byte fonts. It divides fonts with more than 256 characters into several smaller fonts with new encodings containing just the characters you need, so you can print characters from the font on any PostScript printer.

THE NEW WAY TO DOWNLOAD FONTS

So QuickDraw GX has lots of advantages over QuickDraw, but the space hack is broken. What's the poor programmer to do?

You can use a new font downloading method based on calling GXFlattenFont, a handy function introduced with QuickDraw GX, to convert the font to a form that's easily sent to the printer. GXFlattenFont is intended to convert any font present on your Macintosh into the output font format of your choice. (Conversion is limited by the capabilities of the scalers present, as explained in "QuickDraw GX Font Scalers.")

    QUICKDRAW GX FONT SCALERS

    The QuickDraw GX Open Font Architecture accepts drop-in font scalers. A font scaler is a bit of code that takes a font of a given type and converts it to bitmaps for display. It also converts fonts to outline format and can optionally convert a font to another font format. QuickDraw GX includes three default scalers:

    • the bitmap scaler, which is essentially the same as in QuickDraw
    • the TrueType GX scaler, which supports the TrueType GX format
    • the Type 1 scaler, which is part of Adobe(TM) Type Manager

    All of these default scalers are capable of generating bitmaps for screen display and PostScript fonts for printing. Only the TrueType GX scaler can generate downloadable TrueType fonts.

GXFlattenFont can produce Type 1 data that's ready to be sent to your PostScript printer with no problem.

Now let's turn to the code that replaces the old space hack. The rough idea is to call GXFlattenFont on a QuickDraw font reference and a set of characters (an encoding) that you need to print, and return the result in a form that's easy to send to the printer. For simplicity, if no encoding is present, we use the standard Macintosh encoding. Listing 1 shows a font-downloading routine, FontToPict, that uses this technique if QuickDraw GX is installed. (This is a somewhat simplified version; see the CD for the full code of FontToPict and its related utility functions.)

Listing 1. FontToPict

PicHandle FontToPict(short qdFont, short qdStyle)
{
   Rect         theRect = {0, 0, 1, 1};
   PicHandle      thePict = OpenPicture(&theRect);
   const   short   kPostScriptHandle = 192;

   // If QuickDraw GX is installed, use the new method.
   if (GXInstalled()) {
      Handle            piccommentHdl;
      unsigned   short   *myEncoding = nil;
      
      MakePSHandle(qdFont, qdStyle, myEncoding, &piccommentHdl);
      PicComment(kPostScriptHandle, GetHandleSize(piccommentHdl),
          piccommentHdl);
   } else {
     // If QuickDraw GX isn't installed, use the old method.
      Point   penPoint;

      // We would normally set the clip here, but since we're just
      // drawing a space there's no need.
      GetPen(&penPoint);             // Save the pen location.
      TextFont(qdFont);
      TextFace(qdStyle);
      DrawChar(' ');
      MoveTo(penPoint.h, penPoint.v);    // Restore the pen location.
   }
   ClosePicture();
   return (thePict);
)
FontToPict starts by checking to see if QuickDraw GX is installed. If not, it uses the old hack of printing a space; otherwise, it calls MakePSHandle (Listing 2), which calls the utility function ConvertQDFontToGXFont to convert the QuickDraw font reference into a QuickDraw GX font reference. MakePSHandle then checks to see if an encoding has been passed in; if not, it builds the standard Macintosh encoding. Next it calls FontToHandle, which is just a wrapper for GXFlattenFont. GXFlattenFont converts the specified font to the Type 1 format. Error-handling and cleanup code is last. Simplicity itself! The result, whether QuickDraw GX is present or not, is a PICT that you can send to the printer by calling DrawPicture once the printer port has been opened.

When calling MakePSHandle, you should specify an encoding array that contains the characters you intend to actually print. This prevents QuickDraw GX from sending the entire font to the printer and becomes very important when you make your application WorldScript aware. There's an #ifdef in the code on the CD that generates only the encoding array you need in order to use a portion of the font. As mentioned earlier, with Chinese, Japanese, and Korean fonts, sending only the characters you need can make the difference between sending a few kilobytes or many megabytes of data to the printer. If you don't use the entire font, remember to encode the characters that you want to draw, using the same encoding that you passed in to the MakePSHandle function.

Listing 2. MakePSHandle

OSErr MakePSHandle(short qdFont, char qdStyle,
    unsigned short *encodingArray, Handle *outputHandle)
{
   OSErr            status = noErr;
   gxFont            theFont;
   unsigned short   *myEncoding;
   Boolean         madeEncoding = false;

   // Convert to a QuickDraw GX font reference.
   theFont = ConvertQDFontToGXFont(qdFont, qdStyle);

   // If no encoding, create the standard Macintosh encoding.
   if (!encodingArray) {
      long   returnLength;

      myEncoding =
          (unsigned short *)NewPtrClear(256 * sizeof(short));
      returnLength = MakeMac8BitEncoding(theFont, myEncoding);
      if (returnLength != 256) {
         DebugStr("\pHmm. We didn't get a full encoding.");
         return (returnLength);      // Pass the error along.
      }
      madeEncoding = true;
   } else {
      myEncoding = encodingArray;
   }

   *outputHandle = FontToHandle(theFont, myEncoding);
   if (madeEncoding) DisposePtr((Ptr)myEncoding);

   status = MemError();
   if (status == noErr) {
      status = GXGetGraphicsError(nil);
      if (status != noErr) {
         DisposeHandle(*outputHandle);
         *outputHandle = nil;
      }
   }
   return (status);
}
You may want to have HandleSpoolProc (which is called by GXFlattenFont and included on the CD) spool directly to the printer via picture comments. This way you won't need memory available to hold the font data at the intermediate steps.

DOWNLOADING HAPPINESS

The new font downloading method takes a little more work but produces better results in your printer font handling. You can easily send needed fonts to the printer, either the whole font or only the characters you'll be using. As a side benefit, you get support for two-byte font systems without having to write custom code for handling the large fonts or, worse yet, having to depend on the fonts being installed on the printer in a specific manner. Even if you're not ready to add QuickDraw GX imaging to your application today, adding QuickDraw GX compatibility improves the printing experience for your customers.

DAVE POLASCHEK recently relocated to California to join Apple's Developer Technical Support group. He's been told that supporting printing leads to hair loss and insanity. Dave previously lived in beautiful sunny Minnesota, and wonders if he'll get used to the harsh San Francisco Bay Area winters before he's bald and crazy, or if it's already too late.*

Thanks to Dan Lipton for providing the idea and core code illustrating the new font downloading method, and to Pete "Luke" Alexander, Dave Hersey, and Dan Lipton for reviewing this column.*

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Luminar 1.0.2 - Powerful, adaptive, conf...
Luminar is the new full-featured image editor that adapts to the way you edit photos. Over 300 essential tools to fix, edit, and enhance your photos with comfort. The future of photo editing is here... Read more
WhatRoute 2.0.10 - Geographically trace...
WhatRoute is designed to find the names of all the routers an IP packet passes through on its way from your Mac to a destination host. It also measures the round-trip time from your Mac to the router... Read more
Slack 2.3.3 - Collaborative communicatio...
Slack is a collaborative communication app that simplifies real-time messaging, archiving, and search for modern working teams. Version 2.3.3: Fixed window zoom jumping back-and-forth OS X 10.9... Read more
Lens Blur 1.4.3 - True out-of-focus boke...
Lens Blur transforms your existing photo into true SLR-quality out-of-focus bokeh effect! Everyone needs a gorgeous personalized background for a social profile, blog, Web/UI design, presentation, or... Read more
CleanMyMac 3.6.0 - $39.95
CleanMyMac makes space for the things you love. Sporting a range of ingenious new features, CleanMyMac lets you safely and intelligently scan and clean your entire system, delete large, unused files... Read more
DEVONthink Pro 2.9.8 - Knowledge base, i...
DEVONthink Pro is your essential assistant for today's world, where almost everything is digital. From shopping receipts to important research papers, your life often fills your hard drive in the... Read more
MacFamilyTree 8.1 - Create and explore y...
MacFamilyTree gives genealogy a facelift: modern, interactive, convenient and fast. Explore your family tree and your family history in a way generations of chroniclers before you would have loved.... Read more
HoudahSpot 4.2.7 - Advanced file-search...
HoudahSpot is a powerful file search tool. Use HoudahSpot to locate hard-to-find files and keep frequently used files within reach. HoudahSpot will immediately feel familiar. It works just the way... Read more
TunnelBear 3.0.7 - Subscription-based pr...
TunnelBear is a subscription-based virtual private network (VPN) service and companion app, enabling you to browse the internet privately and securely. Features Browse privately - Secure your data... Read more
Garmin Express 4.5.0.0 - Manage your Gar...
Garmin Express is your essential tool for managing your Garmin devices. Update maps, golf courses and device software. You can even register your device. Update maps Update software Register your... Read more

Latest Forum Discussions

See All

Amateur Surgeon 4 Guide: Become the worl...
It's time to wield your trusty pizza cutter again, as Amateur Surgeon has returned with a whole fresh set of challenges (and some old, familiar ones, too). Starting anew isn't easy, especially when all you have at your disposal is a lighter, the... | Read more »
Le Parker: Sous Chef Extraordinaire (Ga...
Le Parker: Sous Chef Extraordinaire 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Telltale Games really is working on a Gu...
Telltale Games' next episodic adventure is indeed Guardians of the Galaxy. A document tied to the voice actors strike suggested that the project was in the work, but now we have direct confirmation following an announcement at the Game Awards that... | Read more »
Amateur Surgeon returns to iOS and Andro...
Amateur Surgeon and its two sequels disappeared from the App Store some time and it was sad days for all. But now, just in time for the holidays, the Adult Swim favorite makes its joyous return in the shape of Amateur Surgeon 4, a remake with... | Read more »
The best board games on mobile
Sometimes you need to ditch all of the high speed, high action games in favor of something a little more traditional. If you don't feel like parting ways from your mobile device, though, there are still plenty of ways to get that old-school fix.... | Read more »
The best Facebook Messenger Instant Game...
Facebook's new Instant Games is now here, meaning you can play games with your friends directly via Facebook. It's a fun new way to connect with friends, of course, but it's also proving to be a solid gaming experience in its own right, with a... | Read more »
You can now play game's on Facebook...
Facebook launched its new Instant Games platform in an exciting new attempt to engage its user base. As a result, you can now play a number of different games directly through Facebook Messenger. All of these games run with HTML5, meaning you play... | Read more »
Apollo Justice Ace Attorney (Games)
Apollo Justice Ace Attorney 1.00.00 Device: iOS Universal Category: Games Price: $.99, Version: 1.00.00 (iTunes) Description: Court Is Back In Session Star as rookie defense attorney, Apollo Justice, as he visits crime scenes,... | Read more »
KORG iWAVESTATION (Music)
KORG iWAVESTATION 1.0 Device: iOS Universal Category: Music Price: $19.99, Version: 1.0 (iTunes) Description: A revolutionary new world of sound.The Wave Sequence Synthesizer for iPad - KORG iWAVESTATION | Read more »
Don't Grind Guide: Tips for becomin...
Don’t Grind is a surprising, derpy little one touch game with fun hand-drawn graphics. The goal is simple -- get the high score without being chopped to bits. That can be tough when you’re not used to the game, and that’s compounded by the fact... | Read more »

Price Scanner via MacPrices.net

Parallels Toolbox 1.3 for Mac Offers 25 Singl...
Parallels has launched Parallels Toolbox 1.3 for Mac, an upgrade that adds five new utilities to the stand-alone application which was released in August and is available exclusively online at http... Read more
OWC Mercury Elite Pro Dual mini Ultra-Portabl...
OWC has introduced the new OWC Mercury Elite Pro Dual mini, a powerful yet ultra-portable dual-drive RAID solution. The new Mercury Elite Pro Dual mini packs phenomenal performance into a small... Read more
Clearance 13-inch Retina MacBook Pros availab...
B&H Photo has clearance 2015 13″ Retina Apple MacBook Pros available for up to $200 off original MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $... Read more
Roundup of 2016 13-inch 2.0GHz MacBook Pro sa...
B&H has the non-Touch Bar 13″ MacBook Pros in stock today for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (MLL42LL/A): $1449 $... Read more
New 13-inch 2.0GHz Space Gray MacBook Pro in...
Adorama has the new 13″ 2.0GHz Space Gray MacBook Pro (non-Touch Bar, MLL42LL/A) in stock for $1499 including a free 3-year AppleCare Protection Plan. Shipping is free, and Adorama charges sales tax... Read more
Finnair Adopts iOS Enterprise iPad Apps from...
Finnair and IBM have announced a first-of-its-kind agreement to utilize iOS enterprise apps from IBM to support the airline’s overall digital transformation. Finnair is focused on Asia-Europe traffic... Read more
Tech21 Launches Evo Go iPhone 7 Case Availabl...
Tech21 has announced the launch of the Evo Go case for Apple iPhone 7 and iPhone 7 Plus, exclusively at T-Mobile. Available online and at participating T-Mobile stores nationwide, Evo Go cases start... Read more
Apple Turns (RED) with More Ways to Join the...
In recognition of World AIDS Day, Apple is offering more ways than ever for customers to join (RED) in its mission to create an AIDS-free generation. Apple is the worlds largest corporate contributor... Read more
Deals on new 15-inch Touch Bar MacBook Pros,...
B&H Photo has new 2016 Apple 15″ Touch Bar MacBook Pro models in stock today with some available for $50 off MSRP, each including free shipping plus NY sales tax only: - 15″ 2.7GHz Touch Bar... Read more
12-inch Retina MacBooks on sale for up to $10...
12-inch Retina MacBooks remain on sale at B&H Photo with models available for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only. B&H will also include a free copy... Read more

Jobs Board

*Apple* Retail - Multiple Positions- White P...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Automotive Detailer - *Apple* Used Autos -...
We are currently conductinginterviews and will be accepting applications for a part-time detailer. Apple Used Autos is a great place to work andstart a career. We Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
US- *Apple* Store Leader Program - Apple (Un...
…Summary Learn and grow as you explore the art of leadership at the Apple Store. You'll master our retail business inside and out through training, hands-on Read more
*Apple* & PC Desktop Support Technician...
Apple & PC Desktop Support Technician job in Dallas TX Introduction: We have immediate job openings for several Desktop Support Technicians with one of our most Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.