TweetFollow Us on Twitter

Video
Volume Number:3
Issue Number:5
Column Tag:Assembly Language Lab

Video Independence

By Dan Weston, Macintosh Author

Working With Big Screens

The big screens are here. You've seen them at MacExpo in Boston and elsewhere. Micrographix, E-machine, Radius; the names will soon be more familiar. And now the Macintosh II and custom third party video boards and monitors will soon dominate the Macintosh world. Will your applications run on the big screens?

If you've already been testing your programs on the Lisa/XL, then you probably already know how to work with other screen sizes. But most of us are poking along with a single Mac and we don't get a chance to play with the other members of the Macintosh family.

It's really easy to make sure that your programs will take advantage of the big screens. This short article shows how find out how big the current screen is and how to grow and move your windows so that they can use the whole screen.

How Big is the Screen?

The first thing to do is check the Quickdraw globals for the screenbits.bounds rectangle which gives the bounding rectangle for the whole screen. Quickdraw and the window manager use this rectangle, so you might as well do it too.

GetScreenSize is a short assembly language subroutine that takes a pointer to a rectangle variable and fills it in with the coordinates of screenbits.bounds.

; GetScreenSize.ASM
; This module finds out the size of the screen
; currently installed on your Mac
; It fills in a VAR rectangle with the coordinates 
; of screenbits.bounds

INCLUDE QuickEqu.D

XDEF    GetScreenSize

; Procedure GetScreenSize(VAR r:rect)
GetScreenSize:

r  SET  8 ;offset to rectangle parameter
parambytesSET  4 ; bytes for parameter 
 
LINK    A6,#0    ; no locals 
MOVE.L  r(A6),A1 ; get dest rect
MOVE.L  GrafGlobals(A5),A0; get QD globals
LEAscreenBits+bounds(A0),A0 
 
MOVE.L  (A0)+,(A1)+; move the first part
MOVE.L  (A0)+,(A1)+; move the rest
 
UNLK    A6; get rid of stack frame
MOVE.L  (SP)+,A0 ; return address
ADDA.W  #parambytes,SP    ; strip parameter
JMP(A0) ; return

GetScreenSize uses register A5 to get the pointer to the Quickdraw globals and then offsets into the globals to get at screenbits.bounds. Then it copies the coordinates into the VAR rectangle. If you are using a high level language, then you can probably use an expression like

tempRect := screenbits.bounds;

Dragging a Window all Over Town

Once you have the screen dimensions (top and left of screenbits.bounds are always 0,0) you can use them to guide window dragging and growing. For instance, DragWindow takes a rectangle parameter that delimits the boundaries in which the window may be dragged. A good strategy is to inset our copy of screenbits.bounds by about 20 pixels so that at least part of the window will remain on the screen at all times. Figure 1 shows just how far we can drag a window within the inset screen rectangle. The code for doing this is shown below.

figure 1: DragWindow limits

;-------- DoDrag -------------
DoDrag
; The click was in the drag bar of the window.  Drag it.

; xProcedureGetScreenSize(VAR r:Rect)
PEAtRect(A5); global scratch rect
JSRGetScreenSize
 
;Procedure  InsetRect(VAR r:Rect;dh,dv:INTEGER)
PEAtRect(A5); the rect
MOVE.W  #20,-(SP); dh
MOVE.W  #20,-(SP); dv
_InsetRect

; DragWindow (theWindow:WindowPtr; startPt: Point;             
 boundsRect: Rect);
MOVE.L  WWindow(A5),-(SP) ; Pass window 
MOVE.L  Point(A5),-(SP) ; mouse coordinates
PEAtRect(A5); and boundaries
_DragWindow ; Drag Window 
BRA     NextEvent; Go get next event

Growing As Big as You Can

Another use for the screen boundaries is to govern GrowWindow so that your windows can get as big as the biggest screen. GrowWindow takes a rectangle parameter; the top and left coordinates specify the smallest vertical and horizontal measurements the window can have. I choose 70 for each of these so that even the smallest window will have complete scoll bars, including a thumb, as shown in figure 2.

Figure 2: GrowWindow limits

The bottom and right coordinates of the growrect parameter to GrowWindow specify the maximum vertical and horizontal dimensions the window can have. The bottom coordinate of screenbits.bounds, minus about 15 pixels, is good for the maximum height. The maximum width should be wider than the screen, however, to allow for stretching windows partially off the sides of the screen, as many people learned to do with MacWrite. I chose the largest positive integer, $7FFF, for my maximum width. Beware of using negative numbers for this parameter.

Interestingly enough, even though MacWrite will let you make a window much wider than the screen, it seems to have the original Mac screen height hard-coded into its grow routine. E-Machines includes a nice ROM patch with its big screen that lets you hold down the option key while growing a window to override the limits that the underlying program may be trying to impose on window size. The code fragment to grow a window on an arbitrary screen is shown below.

;-----------------  DoGrow  ------------------------
DoGrow:

; first include scroll bar and grow region in update region
BSRInvalidScroll
 
; here is where we actually grow the window
; xProcedureGetScreenSize(VAR r:Rect)
PEAtRect(A5); global scratch rect
JSRGetScreenSize
 
ADD.W #70,tRect+top(A5)   ; 70 pixels high
ADD.W #70,tRect+left(A5)  ; 70 pixels wide
SUB.W #15,tRect+bottom(A5); not too tall
MOVE.W  #$7FFF,tRect+right(A5);extra-wide OK
 
;FUNCTION GrowWindow(theWindow:WindowPtr;startPt:Point;
;   sizeRect:Rect):LONGINT
CLR.L -(SP) ; space for result
MOVE.L  WWindow(A5),-(SP) ; theWindow
MOVE.L  Point(A5),-(SP) ; startPt
PEAtRect(A5); sizeRect
_GrowWindow
MOVE.W  (SP)+,D1 ; new vertical dimension
MOVE.W  (SP)+,D0 ; new horizontal dimension
 
; now draw it to the new size

True Confessions

It is really so easy to check the screen size that there is no excuse for not doing it. I am sorry to say that I make the mistake of using hard-coded screen sizes in some of my example programs in The Complete Book of Macintosh Assembly Langauge Programming, Vol I. We all live and learn, I guess. I am preparing a list of other things that could have been better in the book. Some suggestions have already come from readers. I encourage you to send me your comments so that I can keep the material up-to-date through articles like this or maybe with mailings to readers. [Dan Weston's two book series, The Complete Book of Macintosh Assembly Language Programming, Vol. 1 & 2, is a classic and one of the best of all Mac programming books. We recommend it highly. Write to Dan care of MacTutor and we will forward any comments to him. His books are published by Scott Foresman & Co. and available at B. Dalton bookstores. -Ed]

Big Screens Have Big Prices

Anthony J. Oresteen

Batavia, IL

In recent months there have been numerous large screen monitors introduced for the Macintosh. These include the Radius, Big Picture, MegaScreen II, ect. One thing in common with these products is the big price. They all cost about $2000! Similar screens are available for the IBM PC world at half the price, around $999 for screen, PC card and support software. The Wyse WY-700 at 1200 x 800 is one that comes to mind. Somehow I smell a snake here. What are Macintosh buyers getting for the extra $1000? Perhaps we can learn a lesson from "hard disk" history. I'm waiting for the price drop!

[The impact of the Mac II will make alternate screen technologies more acceptable, driving up demand and competition, which will drive down the price. -Ed]

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Monosnap 3.5.9 - Versatile screenshot ut...
Monosnap lets you capture screenshots, share files, and record video and .gifs. Features Capture Capture full screen, just part of the screen, or a selected window Make your crop area pixel... Read more
Tweetbot 3 for Twitter 3.3.1 - Popular T...
Tweetbot is a full-featured OS X Twitter client with a lot of personality. Whether it's the meticulously-crafted interface, sounds and animation, or features like multiple timelines and column views... Read more
Tunnelblick 3.8.0 - GUI for OpenVPN.
Tunnelblick is a free, open source graphic user interface for OpenVPN on OS X. It provides easy control of OpenVPN client and/or server connections. It comes as a ready-to-use application with all... Read more
Bookends 13.2.5 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more
Quicken 2019 5.11.2 - Complete personal...
Quicken makes managing your money easier than ever. Whether paying bills, upgrading from Windows, enjoying more reliable downloads, or getting expert product help, Quicken's new and improved features... Read more
Bookends 13.2.5 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more
Quicken 2019 5.11.2 - Complete personal...
Quicken makes managing your money easier than ever. Whether paying bills, upgrading from Windows, enjoying more reliable downloads, or getting expert product help, Quicken's new and improved features... Read more
Dashlane 6.1927.0 - Password manager and...
Dashlane is an award-winning service that revolutionizes the online experience by replacing the drudgery of everyday transactional processes with convenient, automated simplicity - in other words,... Read more
Capo 3.7.4 - Slow down and learn to play...
Capo lets you slow down your favorite songs so you can hear the notes and learn how they are played. With Capo, you can quickly tab out your songs atop a highly-detailed OpenCL-powered spectrogram... Read more
BetterTouchTool 3.153 - Customize multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom)... Read more

Latest Forum Discussions

See All

Void Tyrant guide - Tips and tricks for...
Void Tyrant continues to get a lot of play in these parts. Probably because the game is just so deep and varied. The next stop on our guide series for Void Tyrant is class-specific guides. First up is the Knight, as it’s the first class anyone has... | Read more »
Summon beasts and battle evil in epic re...
Imagine a tale of conlict between factions of good and evil, where rogueish heroes summon beasts to aid them in them in warfare and courageously battle dragons over fields of scorched earth and brimstone - that's exactly the essence of epic fantasy... | Read more »
Upcoming visual novel Arranged shines a...
If you’re in the market for a new type of visual novel designed to inform and make you think deeply about its subject matter, then Arranged by Kabuk Games could be exactly what you’re looking for. It’s a wholly unique take on marital traditions in... | Read more »
TEPPEN guide - The three best decks in T...
TEPPEN’s unique take on the collectible card game genre is exciting. It’s just over a week old, but that isn’t stopping lots of folks from speculating about the long-term viability of the game, as well as changes and additions that will happen over... | Read more »
Intergalactic puzzler Silly Memory serve...
Recently released matching puzzler Silly Memory is helping its fans with their intergalactic journeys this month with some very special offers on in-app purchases. In case you missed it, Silly Memory is the debut title of French based indie... | Read more »
TEPPEN guide - Tips and tricks for new p...
TEPPEN is a wild game that nobody asked for, but I’m sure glad it exists. Who would’ve thought that a CCG featuring Capcom characters could be so cool and weird? In case you’re not completely sure what TEPPEN is, make sure to check out our review... | Read more »
Dr. Mario World guide - Other games that...
We now live in a post-Dr. Mario World world, and I gotta say, things don’t feel too different. Nintendo continues to squirt out bad games on phones, causing all but the most stalwart fans of mobile games to question why they even bother... | Read more »
Strategy RPG Brown Dust introduces its b...
Epic turn-based RPG Brown Dust is set to turn 500 days old next week, and to celebrate, Neowiz has just unveiled its biggest and most exciting update yet, offering a host of new rewards, increased gacha rates, and a brand new feature that will... | Read more »
Dr. Mario World is yet another disappoin...
As soon as I booted up Dr. Mario World, I knew I wasn’t going to have fun with it. Nintendo’s record on phones thus far has been pretty spotty, with things trending downward as of late. [Read more] | Read more »
Retro Space Shooter P.3 is now available...
Shoot-em-ups tend to be a dime a dozen on the App Store, but every so often you come across one gem that aims to shake up the genre in a unique way. Developer Devjgame’s P.3 is the latest game seeking to do so this, working as a love letter to the... | Read more »

Price Scanner via MacPrices.net

Apple has clearance 2018 13″ MacBook Airs now...
Apple has Certified Refurbished 2018 13″ MacBook Airs available starting at only $849. Each MacBook features a new outer case, comes with a standard Apple one-year warranty, and is shipped free. The... Read more
Save $400 on the 8-Core iMac Pro today at Ama...
Amazon has the base 8-core iMac Pro on sale today for $4599 including free shipping. Their price is $400 off Apple’s MSRP, and it’s the currently lowest price available for an iMac Pro. For the... Read more
Flash sale! New 11″ 1TB WiFi iPad Pros for th...
Amazon has the 11″ 1TB WiFi iPad Pro on sale today for only $1199.99 including free shipping. Their price is $350 off Apple’s MSRP for this model, and it’s the lowest price ever for a 1TB 11″ iPad... Read more
Weekend Deal: 2018 13″ MacBook Airs starting...
B&H Photo has clearance 2018 13″ MacBook Airs available starting at only $999 with all models now available for $200 off Apple’s original MSRP. Overnight shipping, or expedited shipping, is free... Read more
Apple has clearance 10.5″ iPad Pros available...
Apple has Certified Refurbished 2017 10.5″ iPad Pros available starting at $469. An Apple one-year warranty is included with each iPad, outer shells are new, and shipping is free: – 64GB 10″ iPad Pro... Read more
Apple restocks refurbished iPad mini 4 models...
Apple has restocked Certified Refurbished 32GB iPad mini 4 WiFi models for $229 shipped. That’s $70 off original MSRP for the iPad mini 4. Space Gray, Silver, and Gold colors are available. Read more
Apple, Yet Again, Is Missing An Ultraportable...
EDITORIAL: 07.19.19 Prior to the decision made by Apple earlier this month to retire the thin and light MacBook model with a 12-inch retina display, the Cupertino, California-based company offered,... Read more
Verizon is offering a 50% discount on iPhone...
Verizon is offering 50% discounts on Apple iPhone 8 and iPhone 8 Plus models though July 24th, plus save 50% on activation fees. New line required. The fine print: “New device payment & new... Read more
Get a new 21″ iMac for under $1000 today at t...
B&H Photo has new 21″ Apple iMacs on sale for up to $100 off MSRP with models available starting at $999. These are the same iMacs offered by Apple in their retail and online stores. Shipping is... Read more
Clearance 2017 15″ 2.8GHz Touch Bar MacBook P...
Apple has Certified Refurbished 2017 15″ 2.8GHz Space Gray Touch Bar MacBook Pros available for $1809. Apple’s refurbished price is currently the lowest available for a 15″ MacBook Pro. An standard... Read more

Jobs Board

Best Buy *Apple* Computing Master - Best Bu...
**711346BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Store Associates **Location Number:** 001095-Chesterfield-Store **Job Description:** Read more
Best Buy *Apple* Computing Master - Best Bu...
**704899BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Location Number:** 000135-Pleasant Hill-Store **Job Description:** **What does Read more
Best Buy *Apple* Computing Master - Best Bu...
**707083BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Location Number:** 000045-Rockford-Store **Job Description:** **What does a Read more
Geek Squad *Apple* Master Consultation Agen...
**702908BR** **Job Title:** Geek Squad Apple Master Consultation Agent **Job Category:** Services/Installation/Repair **Location Number:** 000360-Williston-Store Read more
Best Buy *Apple* Computing Master - Best Bu...
**711023BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Location Number:** 000012-St Cloud-Store **Job Description:** **What does a Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.