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

Firefox 58.0 - Fast, safe Web browser.
Firefox offers a fast, safe Web browsing experience. Browse quickly, securely, and effortlessly. With its industry-leading features, Firefox is the choice of Web development professionals and casual... Read more
macOS High Sierra 10.13.3 - The latest O...
macOS High Sierra introduces new core technologies that improve the most important functions of your Mac. From rearchitecting how it stores your data to improving the efficiency of video streaming to... Read more
Apple iOS 11.2.5 - The latest version of...
iOS 11 sets a new standard for what is already the world’s most advanced mobile operating system. It makes iPhone better than before. It makes iPad more capable than ever. And now it opens up both to... Read more
Adobe Audition CC 2018 11.0.1 - Professi...
Audition CC 2018 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous Audition customer). Adobe Audition CC 2018 empowers you to create and... Read more
Adobe After Effects CC 2018 15.0.1 - Cre...
After Effects CC 2018 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous After Effects customer). The new, more connected After Effects CC... Read more
Adobe Premiere Pro CC 2018 12.0.1 - Digi...
Premiere Pro CC 2018 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous Premiere Pro customer). Adobe Premiere Pro CC 2018 lets you edit... Read more
Adobe Photoshop CC 2018 19.1 - Professio...
Photoshop CC 2018 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous Photoshop customer). Adobe Photoshop CC 2018, the industry standard... Read more
Spotify 1.0.69.336. - Stream music, crea...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
rekordbox 5.1.1.0001 - Professional DJ m...
rekordbox is the best way of preparing and managing your tracks, be it at home, in the studio, or even on the plane! It allows you to import music from other music-management software using the... Read more
Mactracker 7.7.1 - Database of all Mac m...
Mactracker provides detailed information on every Mac computer ever made, including items such as processor speed, memory, optical drives, graphic cards, supported OS X versions, and expansion... Read more

Latest Forum Discussions

See All

Jydge hints, tips, and tricks - Everythi...
Just released on iOS, Jydge is a prequel to Neon Chrome and is set in the same universe. Not just that, but the games play in pretty similar ways with them both being twin stick shooters full of surprises. As you might expect from a 10tons game,... | Read more »
World of Warships Blitz: A guide to tact...
Ahoy mates! It's time to set out on the high seas for some PvP battles, and ... sorry, actually, World of Warships Blitz has nothing to do with pirates. Let's start over. [Read more] | Read more »
Around the Empire: What have you missed...
Around this time every week we're going to have a look at the comings and goings on the other sites in Steel Media's pocket-gaming empire. We'll round up the very best content you might have missed, so you're always going to be up to date with the... | Read more »
Everything about Hero Academy 2: Part 4...
In this part of our Hero Academy 2 guide, we're going to have a look at some of the tactics you're going to need to learn if you want to rise up the ranks. We're going to start off slow, then get more advanced in the next section. [Read more] | Read more »
All the best games on sale for iPhone an...
Another week has flown by. Sometimes it feels like the only truly unstoppable thing is time. Time will make dust of us all. But before it does, we should probably play as many awesome mobile videogames as we can. Am I right, or am I right? [Read... | Read more »
The 7 best games that came out for iPhon...
Well, it's that time of the week. You know what I mean. You know exactly what I mean. It's the time of the week when we take a look at the best games that have landed on the App Store over the past seven days. And there are some real doozies here... | Read more »
Popular MMO Strategy game Lords Mobile i...
Delve into the crowded halls of the Play Store and you’ll find mobile fantasy strategy MMOs-a-plenty. One that’s kicking off the new year in style however is IGG’s Lords Mobile, which has beaten out the fierce competition to receive Google Play’s... | Read more »
Blocky Racing is a funky and fresh new k...
Blocky Racing has zoomed onto the App Store and Google Play this week, bringing with it plenty of classic kart racing shenanigans that will take you straight back to your childhood. If you’ve found yourself hooked on games like Mario Kart or Crash... | Read more »
Cytus II (Games)
Cytus II 1.0.1 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0.1 (iTunes) Description: "Cytus II" is a music rhythm game created by Rayark Games. It's our fourth rhythm game title, following the footsteps of three... | Read more »
JYDGE (Games)
JYDGE 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: Build your JYDGE. Enter Edenbyrg. Get out alive. JYDGE is a lawful but awful roguehate top-down shooter where you get to build your... | Read more »

Price Scanner via MacPrices.net

Where to buy 13″ Apple MacBook Pros for up to...
B&H Photo has 13″ MacBook Pros on sale for $100 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13-inch 2.3GHz/128GB Space Gray MacBook Pro (MPXQ2LL/A... Read more
Apple Refurbished 2017 iMacs available starti...
Apple has a full line of Certified Refurbished iMacs available for up to $350 off original MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are available: – 27... Read more
Apple offers clearance 2016 13-inch MacBook A...
Apple has Certified Refurbished 2016 13″ MacBook Airs available starting at $809. An Apple one-year warranty is included with each MacBook, and shipping is free: – 13″ 1.6GHz/8GB/128GB MacBook Air: $... Read more
Clearance Apple refurbished iMacs available s...
Apple has previous-generation Certified Refurbished 2015 21″ & 27″ iMacs available starting at $849. Apple’s one-year warranty is standard, and shipping is free. The following models are... Read more
How to save $150-$420 on the purchase of a 20...
B&H Photo has 15″ MacBook Pros on sale for up to $200 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 15″ 2.8GHz Touch Bar MacBook Pro Space Gray (... Read more
How to save $100-$180 on the purchase of a 20...
B&H Photo has 13″ MacBook Airs on sale for $50-$120 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13″ 1.8GHz/128GB MacBook Air (MQD32LL/A): $899, $... Read more
Save on Beats: $30-$80 off headphones, earpho...
Walmart has Beats by Dr. Dre on sale on their online store for $30-$80 off MSRP, depending on the item: – Powerbeats3 Wireless Earphones: $134, save $65 – BeatsX Earphones: $109, save $40 – Beats... Read more
Deals on clearance 15″ Apple MacBook Pros wit...
B&H Photo has clearance 2016 15″ MacBook Pros available for up to $800 off original MSRP. Shipping is free, and B&H charges NY & NJ sales tax only: – 15″ 2.7GHz Touch Bar MacBook Pro... Read more
Apple restocked Certified Refurbished 13″ Mac...
Apple has restocked a full line of Certified Refurbished 2017 13″ MacBook Airs starting at $849. An Apple one-year warranty is included with each MacBook, and shipping is free: – 13″ 1.8GHz/8GB/128GB... Read more
How to find the lowest prices on 2017 Apple M...
Apple has Certified Refurbished 13″ and 15″ 2017 MacBook Pros available for $200 to $420 off the cost of new models. Apple’s refurbished prices are the lowest available for each model from any... Read more

Jobs Board

*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
Product Manager- *Apple* News - Apple (Unit...
# Product Manager- Apple News Job Number: 52399385 Santa Clara Valley, California, United States Posted: 19-Jan-2018 Weekly Hours: 40.00 **Job Summary** The Apple Read more
*Apple* Solutions Consultant - Apple (United...
# Apple Solutions Consultant Job Number: 113384559 Brandon, Florida, United States Posted: 10-Jan-2018 Weekly Hours: 40.00 **Job Summary** Are you passionate about Read more
Security Engineering Coordinator, *Apple* R...
# Security Engineering Coordinator, Apple Retail Job Number: 113237456 Santa Clara Valley, California, United States Posted: 18-Jan-2018 Weekly Hours: 40.00 **Job Read more
*Apple* Data Center Site Selection and Strat...
# Apple Data Center Site Selection and Strategy Research Analyst Job Number: 83708609 Santa Clara Valley, California, United States Posted: 18-Jan-2018 Weekly Hours: Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.