TweetFollow Us on Twitter

Regions with CLR
Volume Number:2
Issue Number:2
Column Tag:Basic School

Basic Does Regions (with CLR!)

By Dave Kelly, General Dynamics Corp., MacTutor Editorial Board

Hello! This month we will explore the Macintosh Quickdraw routines with a trip into the world of regions. This may be a review for some of you that program in other languages such as Pascal or C as this subject has been covered quite well in past issues of MacTutor (See Vol. 1 No. 3 "Quickdraw does Regions" or Vol 1 No. 4 "Ports O' Call in Quickdraw"). Until recently it has been impossible to meaningfully talk about regions from MSBASIC. Wth the Clear Lake Research (CLR) Libraries available it is now possible to give BASIC equal time with the other languages when referring to Quickdraw. Quickdraw routines are called from BASIC in much the same method used in Pascal or other languages. In fact, we recommend that you review the Pascal columns referred to above as they have information which may pertain to any language, not just Pascal. The same is true for this column when discussing calls to Quickdraw or other routines used by all languages.

Fig. 1 Screen dump of our regions program

First a bit of a review for those that are not familiar with Quickdraw regions and associated calls. We have available to us via the CLR Libraries [Note: These libraries are available from the MacTutor mail order store for $50 for both the libraries and the speech routines. -Ed.], over 20 statements involving regions. These are found listed with their functions on page 14 of the CLR manual or you may refer to Chapter 4 of Macintosh™ Revealed, Volume One by Chernicoff and published by Hayden Press. Instead of going into a detailed study of Quickdraw I refer you to the previous issues of MacTutor mentioned above. (Back issues are available through the MacTutor Store).

A few things to remember when working with Quickdraw: The horizontal coordinates increase from left to right and the vertical coordinates increase from top to bottom. You may want to think of a region as an area on the screen with a set of points inside the region and a set of points outside. A point in the region cannot be both inside and outside the region. It should also be noted that a graphic point is located to the 'right' and 'below' its corresponding mathematical coordinate.

The Region/Clip Demo program (note: requires CLR Libraries) will set up a region and by using the GetClip and SetClip statements (CLR) we can specify the region which we want the text (or graphics) to be drawn to. In this way, only drawing that occurs within the region will show up on the screen. Any drawing outside the region will not show up. This could be useful when you want to draw in a particular part of the screen without disturbing the contents of another part of the screen. The demo program first opens up the appropriate library:

LIBRARY"ToolLib"

Remember to include the disk volume name if necessary. I would advise you to use the Statement Mover program to move the libraries that you use over to the BASIC program file so they will always follow the program no matter what disk you put it on.

Next we set up some of the array variables used by the program and associated library routines. If the variable is undeclared the libraries cannot work. Also be sure to dimension the arrays properly. For example, if the pattern%() array below were dimensioned to 0 instead of three, the routine SetRect would go ahead and try to store 4 variables, but would only be able to find one. The results could be unpredictable. Save your work before running your program in case there might be any misteaks (ha, ha). The SetRect command sets the left, top, right, and bottom coordinates of the array equal to the indicated values respectively.

DIM R%(3),OvalR%(3),fontinfo%(3),pattern%(3)
x1%=50:y1%=20:x2%=450:y2%=200
SetRect R%(0),x1%,y1%,x2%,y2%
SetRect pattern%(0),&HAA,&HAA,&HAA,&HAA
SetRect pattern%(0),&HAA,&HAA,&HAA,&HAA

The window is opened and the background is set to the background pattern defined in the pattern%() array. The screen is cleared so that the background pattern will be redrawn. The pattern%() array is cleared with SetRect and the background pattern cleared so that subsequent CLS statements will clear the screen to white. Note that the CLS command only clears within the clipping region. When a BASIC window is opened up the clipping region defaults to the window size.

WINDOW 1,"",(2,30)-(508,275),4
CALL BACKPAT (VARPTR(pattern%(0)))
CLS
SetRect pattern%(0),0,0,0,0
CALL BACKPAT(VARPTR(pattern%(0)))

Another CLR Library statement allows us to determine the size of the currently selected font. The program sets the TEXTSIZE to 9 and then calls the getfontinfo routine. The font info is returned in the array fontinfo%(). The variable fontinfo%(0) returns the ascent, fontinfo%(1) returns the descent, fontinfo%(2) returns the maximum character width, and fontinfo%(3) returns the vertical distance between the descent line and the ascent line below it. The program needed to know the total spacing for each line of text which is given by the sum of the ascent, descent, and the vertical distance between the descent line and the ascent line below it. Note that a call to getfontinfo would be useful for programs trying to determine the number of lines of text to print per page (or screen) when using various sizes and styles of fonts.

CALL TEXTSIZE(9)
getfontinfo fontinfo%(0)
fh%=fontinfo%(0)+fontinfo%(1)

Next the region handle variables are defined and the clipping region represented by the screen is stored away so it may be restored again later. If the OldReg! handle were not saved in this way, the last clipping region would be used the next time printing to the window. To define a new region, execute a NewRgn command. This allocates space for the new region and the region is initialized to the empty region. GetClip sets the region with the handle indicated (in this case OldReg! is the handle) to the current clip region.

handle!=0
OldReg!=0
NewRgn OldReg!
getclip OldReg!

We now define the region which we want to use as our clipping region. First we initialize the region with NewRgn with handle! . Next we may define the contents of the region. A series of graphics statements will make up the region we wish to create. We open the region with OpenRgn and follow it with whatever graphics commands we desire such as FRAMEOVAL, FRAMERECT, LINE, and others. Note that arcs cannot form part of the region definition. The end of the definition is indicated with the CloseRgn handle! statement where handle! is the handle! of the region being defined. Next the clipping region is set to the region with handle! with the statement Setclip handle! . All points either printed or drawn outside the region will not be shown. Only those points inside the region may be seen when printing is done inside the region.

NewRgn handle!
OpenRgn
    FRAMEOVAL VARPTR(R%(0))
CloseRgn handle!
Setclip handle!

The next several statements of the program print text in the region which has been set as the clipping region. Note that CLR has provided us with the Drawtext text$ statement to drawtext much faster than with the BASIC PRINT statement. To use drawtext you must move the quickdraw pen to the desired pixel position and issue the drawtext statement. It is harder to use that the BASIC printing statements but the speed difference makes it worth using when speed counts.

There are other statements which may be used with regions. One region may be subtracted from another with DiffRgn or use XorRgn or UnionRgn to combine regions. These and other commands will be left for future MacTutor columns. The program uses the framergn command to draw a border around the edge of the region. The current pensize is used for the border line.

CALL PENSIZE (2,2)
framergn handle!

Now for a word of caution: If your program should crash for some reason before your region is disposed of, you should be prepared to manually type in the disposeRgn statement and appropriate handle or handles for the regions used. Remember to dispose of all regions before quiting your program as the space for the regions has been allocated and will not be returned unless the regions have been disposed of. Otherwise, you may find yourself wondering why you are running out of room on the heap. The statement is:

disposergn handle!

A few words on the CLR Libraries clipping statements: The CLR Libraries manual mentions a statement named ClipRect which is supposed to set the clipping region to a rectangle. The ClipRect routine is not included on my ToolLib file. No need to panic yet, however, because the same command can be reconstructed with a combination of region calls and clipping calls. One solution is to use the following sequence to do a ClipRect (set the clipping region to a rectangle):

DIM rect%(3)
handle!=0
SetRect rect%(0),x1%,y1%,x2%,y2%
NewRgn handle!
OpenRgn
    FRAMERECT ( VARPTR(Rect%(0))
CloseRgn handle!
Setclip handle!

You may also use SetRectRgn or RectRgn to set a region equal to a rectangle. The statement syntax is:

SetRectRgn hand!,left%,top%,right%,bottom%

The region with handle hand! is set equal to the rectangle with coordinates left%,top%,right%, and bottom%.

RectRgn hand!, rect%(0)

The region specified by the handle hand! is set equal to the rectangle rect%. A region is not created by this, but must have been previously defined with NewRgn.

You may use either of these two statements in place of the OpenRgn and CloseRgn sequence above as desired.

Use GetClip to set a region to the current clipping region and SetClip to set the clipping region to a different region. You may want to use SetClip to switch back and forth between different clipping regions.

Have any interesting programs you have created after experimenting with clipping regions? Feel free to share them with others by sending them in to MacTutor.

'Region/Clip Demo
'by Dave Kelly
'MacTutor ©1986

LIBRARY"ToolLib"
DIM R%(3),OvalR%(3),fontinfo%(3),pattern%(3)
x1%=50:y1%=20:x2%=450:y2%=200
SetRect R%(0),x1%,y1%,x2%,y2%
SetRect pattern%(0),&HAA,&HAA,&HAA,&HAA
WINDOW 1,"",(2,30)-(508,275),4
CALL BACKPAT (VARPTR(pattern%(0)))
CLS
SetRect pattern%(0),0,0,0,0
CALL BACKPAT(VARPTR(pattern%(0)))
CALL TEXTSIZE(9)
getfontinfo fontinfo%(0)
fh%=fontinfo%(0)+fontinfo%(1)
handle!=0
OldReg!=0
NewRgn OldReg!
getclip OldReg!
NewRgn handle!
OpenRgn
    FRAMEOVAL VARPTR(R%(0))
CloseRgn handle!
Setclip handle!
CALL MOVETO(x1%,y1%)
FOR i=1 TO 18
    CALL MOVETO (x1%,y1%+i*fh%)
    FOR j=1 TO 6
        drawtext "Read Mac Tutor!  "
    NEXT j
NEXT i
CALL PENSIZE (2,2)
framergn handle!
disposergn handle!
dh%=50:dy%=25
x1%=x1%+dh%:y1%=y1%+dy%
x2%=x2%-dh%:y2%=y2%-dy%
SetRect R%(0),x1%,y1%,x2%,y2%

NewRgn handle!
OpenRgn
    FRAMEOVAL VARPTR(R%(0))
CloseRgn handle!

Setclip handle!
CLS
CALL MOVETO(x1%,y1%)
FOR i=1 TO 18
    CALL MOVETO (x1%,y1%+i*fh%)
    FOR j= 1 TO 6
        drawtext "It's Grrrreat!  "
    NEXT j
NEXT i
framergn handle!
disposergn handle!
Setclip OldReg!
disposergn OldReg!
LIBRARY CLOSE
END
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Sublime Text 3126 - Sophisticated text e...
Sublime Text is a sophisticated text editor for code, markup, and prose. You'll love the slick user interface, extraordinary features, and amazing performance. Features Goto Anything. Use Goto... Read more
1Password 6.3.3 - Powerful password mana...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more
WhatsApp 0.2.1880 - Desktop client for W...
WhatsApp is the desktop client for WhatsApp Messenger, a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for... Read more
NeoFinder 6.9.3 - Catalog your external...
NeoFinder (formerly CDFinder) rapidly organizes your data, either on external or internal disks, or any other volumes. It catalogs all your data, so you stay in control of your data archive or disk... Read more
Amadeus Pro 2.3.1 - Multitrack sound rec...
Amadeus Pro lets you use your Mac computer for any audio-related task, such as live audio recording, digitizing tapes and records, converting between a variety of sound formats, etc. Thanks to its... Read more
Yasu 4.0.0 β - System maintenance app; p...
Yasu was created with System Administrators who service large groups of workstations in mind, Yasu (Yet Another System Utility) was made to do a specific group of maintenance tasks quickly within a... Read more
Hazel 4.0.6 - Create rules for organizin...
Hazel is your personal housekeeper, organizing and cleaning folders based on rules you define. Hazel can also manage your trash and uninstall your applications. Organize your files using a familiar... Read more
EtreCheck 3.0.5 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
Skype 7.37.0.178 - Voice-over-internet p...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more
Yasu 4.0.0 β - System maintenance app; p...
Yasu was created with System Administrators who service large groups of workstations in mind, Yasu (Yet Another System Utility) was made to do a specific group of maintenance tasks quickly within a... Read more

How to get past Vulture Island's tr...
Vulture Island is a colorful and quirky mish-mash of platforming and puzzles. It’s creative and fresh, but sometimes the game can throw a curveball at you, leaving you stuck as to how you should progress. These tips will help you explore smoothly... | Read more »
The new Clash of Kings is just for Weste...
If you’ve played the original Clash of Kings, you’ll probably recognise the city building, alliance forging and strategic battles in Clash of Kings: The West. What sets this version apart is that it’s tailor made for a Western audience and the... | Read more »
Frost - Survival card game (Games)
Frost - Survival card game 1.12.1 Device: iOS Universal Category: Games Price: $3.99, Version: 1.12.1 (iTunes) Description: *Warning: the game will work on iPhone 5C and above and iPad Pro / 4. Other devices are not supported* | Read more »
How to build and care for your team in D...
Before you hit the trail and become a dog sledding legend, there’s actually a fair bit of prep work to be done. In Dog Sled Saga, you’re not only racing, you’re also building and caring for a team of furry friends. There’s a lot to consider—... | Read more »
How to win every race in Dog Sled Saga
If I had to guess, I’d say Dog Sled Saga is the most adorable racing game on the App Store right now. It’s a dog sled racing sim full of adorable, loyal puppies. Just look at those fluffy little tails wagging. Behind that cute, pixelated facade is... | Read more »
Let the war games commence in Gunship Ba...
Buzz Lightyear famously said, “This isn’t flying, this is falling – with style!” In the case of Gunship Battle: Second War, though, this really is flying - with style! The flight simulator app from Joycity puts you in control of 20 faithfully... | Read more »
How to get a high score in Fired Up
Fired Up is Noodlecake Games’ high score chasing, firefighting adventure. You take control of a wayward firefighter who propels himself up the side of a highrise with blasts of water. Sound silly? It is. It’s also pretty difficult. You can’t... | Read more »
NBA 2K17 (Games)
NBA 2K17 1.0 Device: iOS iPhone Category: Games Price: $7.99, Version: 1.0 (iTunes) Description: Following the record-breaking launch of NBA 2K16, the NBA 2K franchise continues to stake its claim as the most authentic sports video... | Read more »
Dog Sled Saga (Games)
Dog Sled Saga 1.0.1 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0.1 (iTunes) Description: A game by Dan + Lisa As a rookie musher, foster a dogsledding team whose skills will grow if they're treated right. Week by... | Read more »
60 Seconds! Atomic Adventure (Games)
60 Seconds! Atomic Adventure 1.2 Device: iOS Universal Category: Games Price: $2.99, Version: 1.2 (iTunes) Description: 60 Seconds! is a dark comedy atomic adventure of scavenge and survival. Collect supplies and rescue your family... | Read more »

Price Scanner via MacPrices.net

21-inch iMacs on sale for up to $120 off MSRP
B&H Photo has 21″ iMacs on sale for up to $120 off MSRP including free shipping plus NY sales tax only: - 21″ 3.1GHz iMac 4K: $1379 $120 off MSRP - 21″ 2.8GHz iMac: $1199.99 $100 off MSRP - 21″ 1... Read more
13-inch 2.7GHz/256GB Retina MacBook Pro on sa...
Amazon.com has the 13″ 2.7GHz/256GB Retina Apple MacBook Pro on sale for $151 off MSRP including free shipping: - 13″ 2.7GHz/256GB Retina MacBook Pro (sku MF840LL/A): $1348 $151 off MSRP Read more
Apple TVs on sale for up to $50 off MSRP
Best Buy has 32GB and 64GB Apple TVs on sale for $40-$50 off MSRP on their online store. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-store... Read more
Apple refurbished 13-inch Retina MacBook Pros...
Apple has Certified Refurbished 13″ Retina MacBook Pros available for up to $270 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 13″ 2.7GHz... Read more
Duplicate Sweeper Free On Mac App Store For O...
To celebrate the launch of Apple’s latest macOS Sierra, Stafford, United Kingdom based Wide Angle Software has announced that its duplicate file finder software, Duplicate Sweeper, is now available... Read more
13-inch Retina MacBook Pros on sale for up to...
B&H Photo has 13″ Retina Apple MacBook Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1174.99 $125 off MSRP - 13... Read more
Evidence Surfaces Pointing To New A10X Chip F...
Citing a job description for a Project Lead position at Apple’s Austin, Texas engineering labs, Motley Fool’s Ashraf Eassa deduces that development is progressing well on Apple’s next-generation in-... Read more
Check Print’R for macOS Allows Anyone to Easi...
Delaware-based Match Software has announced the release and immediate availability of Check Print’R 3.21, an important update to their easy-to-use check printing application for macOS. Check Print’R... Read more
Apple refurbished 11-inch MacBook Airs availa...
Apple has Certified Refurbished 11″ MacBook Airs (the latest models), available for up to $170 off the cost of new models. An Apple one-year warranty is included with each MacBook, and shipping is... Read more
Apple refurbished 15-inch Retina MacBook Pros...
Apple has Certified Refurbished 2015 15″ Retina MacBook Pros available for up to $380 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2... Read more

Jobs Board

Sr. *Apple* Mac Engineer - Net2Source Inc....
…staffing, training and technology. We have following position open with our client. Sr. Apple Mac Engineer6+ Months CTH Start date : 19th Sept Travelling Job If Read more
*Apple* Retail - Multiple Positions-Norfolk,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Restaurant Manager (Neighborhood Captain) - A...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
Lead *Apple* Solutions Consultant - Apple (...
# Lead Apple Solutions Consultant Job Number: 51829230 Detroit, Michigan, United States Posted: Sep. 19, 2016 Weekly Hours: 40.00 **Job Summary** The Lead ASC is an 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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.