TweetFollow Us on Twitter

4D Graphics
Volume Number:7
Issue Number:2
Column Tag:Database Corner

Related Info: Quickdraw

4th Dimension Graphics

By Haven C. Sweet, Orlando, FL

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

Graphics Output in Fourth Dimension.

Haven Sweet is a Professor of Biology at the University of Central Florida. He has been interested in using the Macintosh for a variety of educational purposes, and has tried to incorporate the computer into an academic laboratory setting. He has developed several classroom exercises using 4th Dimension.

Introduction

Although Fourth Dimension (4D) is not a programming language, I prefer to use it for most of my projects since it vastly simplifies programming and managing complex data. However, I recently discovered a very unfortunate limitation of Fourth Dimension; it is unable to draw on the screen using tool box calls.

The Problem

After creating a large data base of organisms with 4D, I added calculations for a cluster analysis to elucidate their possible relationships. When I wanted to present the final results in a dendrogram (Figure 1), I discovered there was no simple mechanism for drawing on the screen or printing text at variable locations.

Figure 1. A sample clustering output, showing the similarity of four different records in the data base. The figure was drawn on an output layout which only contained the buttons.

I would have to write the entire graphics routine in Pascal, compile it as an external procedure, and create external areas within my program. Not being proficient with MPW, I was hesitant to attempt writing anything which would require debugging by switching from MPW to Ext. Mover to 4D to MPW etc. Hoping version 2 would provide direct toolbox routines such as MoveTo(xStart,yStart), LineTo(xEnd,yEnd) and Writeln(Message), I found that Acius had no such plans.

The Solution

Facing the tedium of learning MPW and Pascal, I hit upon a much simpler solution; I created four external units which provide equivalent procedures for moving the pen, drawing a line, writing text at any location on the screen, and defining both pen and text characteristics. Then, using a blank layout screen, I wrote the graphics routines in the layout procedure and invoked these procedures. Although the graphics output is quite slow, it is more than adequate for the occasional presentation of simple data.

The “pseudo toolbox” routines can be as short or long as needed, but each must be compiled separately and given a name different from the toolbox routine. While I toyed with putting a “4D” before the name of every toolbox call, I decided to combine several I need into a single procedure. So, when text must appear at variable locations on the screen, instead of using MoveTo(xStart;yStart); Writeln(message), the new procedure is WriteAt(xStart;yStart;Message). Likewise, when a line must be drawn, instead of using MoveTo and LineTo, they were combined into DrawLine(xStart;yStart;xEnd;yEnd) which defines the start and end of the line. To alter the text or pen’s characteristics, I adopted the syntax used in ZBasic to produce Pen(xSize;ySize;visible;PenMode) and Text(font;point size;mode). Because variables are used, the procedures can use data either stored in the database or generated from it to draw appropriate lines.

These procedures were written in Pascal and compiled as units which can be moved using 4D External Mover into either the resource of a 4D program or the Proc.Ext. The units are quite small, taking under 600 bytes for all four routines. Once installed, the procedures can be called from within the program in the same manner as any global procedure.

The Output Screen

The next problem was to provide a blank screen on which the results could be written, as well as to find the best way to call the function. My solution was to create a dummy data file with all the drawing done in the output layout procedure. However, there must be exactly one record in the file; if the file is empty, the layout screen never appears, while if there are more than one record in the selection, the drawing procedure is executed for each record. Although it is possible to create a set with only one record in it, it is simpler to create a file named “Blank” which contains only one field, “Dummy”. Then, with the User mode, add one record to the file. An empty layout screen must be created for each different graphics screen.

The layout forms in the file “Blank” should have the three markers Header, Detail, and Break positioned at the very top of the page. If no buttons are to appear in the form, the Footer should also should be placed at the top; otherwise, it should be just far enough down to accomidate the buttons (Figure 2).

Figure 2. The appearance of the layout screen on which the drawing or text placement will be done. Note that the markers for Header, Detail and Break are all at the top of the page.

Although other line positions may work (including using the default positioning of the lines), having them at the top is more reliable since unusual things may occur with some positions. For example, if Break or Header are below the window’s margin, nothing will be drawn; if the Detail line is below the window, then the image is drawn and immediately erased; if space remains between the Header and Detail, clicking on the area permits the user to double click the region and jump to the data input mode. Thus, since the user may resize the window, it is safest to prevent anomalies by placing the lines at the top.

The Procedures’ Syntax

The drawing procedures should only be executed in the BEFORE phase, and should use the following formats:

Pen([xSize] [; [YSize]; [Visible]; [Pen Mode]] )

XSize is the horizontal width of the line in pixels.

YSize is the vertical width of the line in pixels. If omitted or set to zero, the xSize value is used for ySize.

Visible is set to one if the line is to be seen or zero if it is invisible.

Pen Mode uses the following;

0 or 8 Pattern COPY

1 or 9 Pattern OR

2 or 10 Pattern XOR

3 or 11 Pattern BIC

4 or 12 Not pattern COPY

5 or 13 Not pattern OR

6 or 14 Not pattern XOR

7 or 15 Not Pattern BIC

All values are optional. A call to Pen with no parameters resets the normal pen (1 by 1 pixel, visible in the copy mode). Partial parameters may also be used. For example, Pen(3;3;1;8) would produce the same effect as Pen(3) or Pen(3;3)-- that is, a visible pen, 3 by 3 pixels in the copy mode. Although ZBasic also includes the possibility of altering the pen pattern, I did not include it in these routines.

Text( [Font] [; [Point size] ; [Face] ; [Mode]] )

Font codes include;

0 System font

1 Application font

2 New York 20 Times

3 Geneva 21 Helvetica

4 Monaco 22 Courier

5 Venice 23 Symbol

11 Cairo 24 Taliesin

Point size can range from 1 through 127

Face codes are; Mode uses the following;

0 Plain 0 or 8 Pattern COPY

1 Bold 1 or 9 Pattern OR

2 Italic 3 or 11 Pattern BIC

4 Underlined 2 or 10 Pattern XOR

8 Outlined 4 or 12 Not pattern COPY

16 Shadow 5 or 13 Not pattern OR

32 Condensed 6 or 14 Not pattern XOR

64 Extended 7 or 15 Not Pattern BIC

Combinations would be the sum of each face; i.e., bold italic text would have a code of 3.

All values are optional; if omitted, the result is 12 point, plain system font in the copy mode. Both Text(22;10;3;0) and Text(22;10;3) define text as 10 point Courier, italic and bold, which is in the COPY mode.

DrawLine( xStart; yStart; xEnd; yEnd)

This procedure draws a line, with the characteristics defined in the Pen procedure, which begins at a point xStart, yStart, and extends to the point xEnd, yEnd. For example DrawLine(1;1;200;1) would draw a line across the top of the screen.

WriteAt( xStart; yStart; Message)

This procedure writes any text stored in Message beginning at a point xStart, yStart. For example, WriteAt(10;YPos;”The results follow”) would print the text 10 pixels from the left edge and YPos pixels from the top.

Example

The following procedures are designed to draw a line on the screen and to place text near its origin. In this example, the coordinates of the line are entered by the user in a dialog box, but they could have been derived from data in the file.

‘ global procedure Draw a line
DEFAULT FILE([Blank])
ALL RECORDS([Blank]) ‘ this file has one record
 ‘ ask for characteristics of line and text
DIALOG(“Dialog box”)
If (OK=1)|(b1=1)
     INPUT LAYOUT(“Blank-line”)
     OUTPUT LAYOUT(“Blank-line”)
     DISPLAY SELECTION(*)
End if 
‘Layout procedure Blank-line
If (Before)
  visible:=1
  PenMode:=8   ‘Pattern copy  
 ‘ pen size entered by user
  Pen (xSize;Ysize;visible;PenMode)
 ‘ start and end positions entered by user
  DrawLine (h1;v1;h2;v2)
 ‘ Face entered by user
  Text (0;12;Face;0) ‘ font,point size,style,mode
  WriteAt ((h1+20);(v1+20);”This is where the line begins.”)
End if 

The Units

The Pascal versions of the four procedures are followed by one annoted example of the MPW commands needed to compile each into a unit. This method of directly creating units was devised by Jud Spencer of After Hours Software, and was distributed by Acius as Technical Note #150, March, 1989.

Unit Pen;
INTERFACE
 USES 
 Memtypes,Quickdraw,OSIntf,Toolintf,packintf;
 Procedure  PenSet(var Xsize,Ysize,visible, Mode: Integer);
IMPLEMENTATION
Procedure PenSet(var Xsize,Ysize,visible, Mode: Integer);
 begin
 PenNormal;
 if (Xsize>0) then
 {its OK}
 else
 Xsize:=1;
 if (Ysize>0) then
 {its OK}
 else
 Ysize:=Xsize;
 PenSize(Xsize,Ysize);
 if (visible=0) then
 HidePen
 else
 ShowPen;
 if (Mode>=0) and (Mode<8) then
 Mode:=Mode+8; {correct if wrong mode range used}
 if (Mode>7) and (Mode<16) then
 PenMode(Mode);
 end;
END.
____________________________________________
Unit DrawLine;
INTERFACE
 USES 
 Memtypes,Quickdraw,OSIntf,Toolintf,packintf;
 
 Procedure DrawALine(var h1,v1,h2,v2: Integer);
 
IMPLEMENTATION
 Procedure DrawALine(var h1,v1,h2,v2: Integer);
 begin
 MoveTo(h1,v1);
 LineTo(h2,v2);
 end;
END.
____________________________________________
Unit Text;
INTERFACE
 USES 
  Memtypes,Quickdraw,OSIntf,Toolintf,packintf;
 Procedure TextSet(var font,point,StyleNum,mode: Integer);
IMPLEMENTATION
 Procedure TextSet(var font,point,StyleNum,mode: Integer);
 begin
 if (font>0) then
 TextFont(font)
 else
 TextFont(0);
 if (point>0) and (point<128) then
 TextSize(point)
 else
 TextSize(12);
 if (mode>7) and (mode<16) then
 mode:=mode-8; {correct if wrong mode range used}
 if (mode>=0) and (mode<8) then
 TextMode(mode) 
 else
 TextMode(0);
 if (StyleNum>0) and (StyleNum<128) then
 TextFace(Style(StyleNum))
 else
 TextFace([]);
 end; {procedure}
END.
____________________________________________
Unit WriteAt;
INTERFACE
 USES 
 Memtypes,Quickdraw,OSIntf,Toolintf,packintf;
 Procedure WriteItAt(var h1,v1:Integer;var s: Str255);   IMPLEMENTATION
 Procedure WriteItAt(var h1,v1:Integer;var s: Str255);
 begin
 MoveTo(h1,v1);
 DrawString(s);
 end;
END.

Workshop Commands

MPW worksheet commands for the WriteAt procedure are described below. Set the correct directory, then replace or correct all the items noted below as each different unit is compiled and linked.

Pascal WriteAt.p
#      Fix ^     Use unit’s name
Link -w -p WriteAt.p.o 
#             Fix ^    Use unit’s name
“{Libraries}”Runtime.o 
“{Libraries}”Interface.o 
“{PLibraries}”PasLib.o 
-m WRITEITAT 
#    Fix ^    use ALL CAPS with the procedure’s name (not the Unit’s)
-rt 4DEX=16114 
#Fix ^ be sure 4D is name of 4th Dimension, or change it here
-sg Main2 
-sn “Main2=WriteAt(&I;&I;&S)” 
#      Fix ^         Fix ^  with proper variable list, where I=integer, 
S=String
-o Proc.Ext(WriteAt)
#          Fix ^      with proper unit name

Conclusions

Although some labor is required to initially write and compile the graphics external procedures, it only needs to be done once. After being installed in the Proc.Ext, a 4th Dimension database can access the procedures with minimal effort. Unfortunately, describing the process makes it sound much more difficult than it actually is.

 
AAPL
$101.32
Apple Inc.
+0.74
MSFT
$45.15
Microsoft Corpora
-0.07
GOOG
$582.56
Google Inc.
-0.81

MacTech Search:
Community Search:

Software Updates via MacUpdate

Garmin Express 3.2.17.0 - Manage your Ga...
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
Audio Hijack Pro 2.11.1 - Record and enh...
Audio Hijack Pro drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio with Audio Hijack... Read more
calibre 2.0.0 - Complete e-library manag...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital... Read more
Apple iMovie 10.0.5 - Edit personal vide...
With an all-new design, Apple iMovie lets you enjoy your videos like never before. Browse your clips more easily, instantly share your favorite moments, and create beautiful HD movies and Hollywood-... Read more
Apple Keynote 6.2.2 - Apple's prese...
Apple Keynote makes it simple to create and deliver beautiful presentations. Powerful tools and dazzling effects bring your ideas to life. You can work seamlessly between Mac and iOS devices. And... Read more
Apple Numbers 3.2.2 - Apple's sprea...
With Apple Numbers, sophisticated spreadsheets are just the start. The whole sheet is your canvas. Just add dramatic interactive charts, tables, and images that paint a revealing picture of your data... Read more
OpenOffice 4.1.1 - Free and open-source...
OpenOffice.org is both an Open Source product and a project. The product is a multi-platform office productivity suite. It includes the key desktop applications, such as a word processor,... Read more
Pages 5.2.2 - Apple's word processo...
Apple Pages is a powerful word processor that gives you everything you need to create documents that look beautiful. And read beautifully. It lets you work seamlessly between Mac and iOS devices. And... Read more
Quicken 2015 2.0.1 - Complete personal f...
The new Quicken 2015 helps you manage all your personal finances in one place, so you can see where you're spending and where you can save. Quicken automatically categorizes your financial... Read more
CleanMyMac 2.2.7 - Delete files that was...
CleanMyMac makes space for the things you love. Sporting a range of ingenious new features, CleanMyMac 2 lets you safely and intelligently scan and clean your entire system, delete large, unused... Read more

Latest Forum Discussions

See All

Trolls vs Vikings Update Adds Over One H...
Trolls vs Vikings Update Adds Over One Hundred Levels, Reduces Item Cost, and More Posted by Ellis Spice on August 22nd, 2014 [ permalink ] | Read more »
SNK Celebrates the 20th Anniversary of T...
SNK Celebrates the 20th Anniversary of The King of Fighters With a Big Sale Posted by Ellis Spice on August 22nd, 2014 [ permalink ] | Read more »
It Came From Canada: Star Wars: Commande...
With a brand new Star Wars trilogy on the horizon, prepare yourselves for Disney and George Lucas’s space fantasy throwback to be more omnipresent than ever before. So it should come as no surprise that new adventures in that galaxy far, far away... | Read more »
Swing Copters Review
Swing Copters Review By Jordan Minor on August 22nd, 2014 Our Rating: :: DIE TRYINGUniversal App - Designed for iPhone and iPad The creator of Flappy Bird is back with a vengeance.   | Read more »
Beam Me an Update Scotty – Star Trek Tre...
Beam Me an Update Scotty – Star Trek Trexels Receives its Biggest Update Yet Posted by Jessica Fisher on August 22nd, 2014 [ permalink ] | Read more »
The Outcast Review
The Outcast Review By Nadia Oxford on August 22nd, 2014 Our Rating: :: HANDS OFF. WAY OFF.Universal App - Designed for iPhone and iPad It’s easy to see what The Outcast is trying for, but its execution needs a lot of work.   | Read more »
HeroCraft Unveils New iOS Game, Marble D...
HeroCraft Unveils New iOS Game, Marble Duel Posted by Jessica Fisher on August 22nd, 2014 [ permalink ] HeroCraft is developing a new chain popper game called Marble Duel, wh | Read more »
Brain+ Review
Brain+ Review By Nadia Oxford on August 22nd, 2014 Our Rating: :: DIM BULBUniversal App - Designed for iPhone and iPad Brain+ is just another entry in an over-saturated brain-training marketplace – and not a particularly fun entry... | Read more »
The Witcher Battle Arena – New Gameplay...
The Witcher Battle Arena – New Gameplay Trailer Revealed Posted by Jessica Fisher on August 22nd, 2014 [ permalink ] Based in the Witcher universe, | Read more »
Max Gentlemen Review
Max Gentlemen Review By Jennifer Allen on August 22nd, 2014 Our Rating: :: OUTSTAYING ITS WELCOMEiPhone App - Designed for the iPhone, compatible with the iPad Max Gentlemen seems pretty quirky initially but that appeal wears thin... | Read more »

Price Scanner via MacPrices.net

Updated Mac Price Trackers
We’ve updated our Mac Price Trackers with the latest information on prices, bundles, and availability on systems from Apple’s authorized internet/catalog resellers: - 15″ MacBook Pros - 13″ MacBook... Read more
Leftover 15-inch 2.0GHz Retina MacBook Pros a...
B&H Photo has leftover previous-generation 15″ 2.0GHz Retina MacBook Pros now available for $1599 including free shipping plus NY sales tax only. Their price is $400 off original MSRP. B&H... Read more
Pro.Calendar – New Productivity App for iPad...
Austin, Texas based mobile business and productivity app developer LightArrow, Inc. has announced Pro.Calendar, a powerful and intuitive calendar app with eight versatile calendar options including... Read more
SanDisk Ultra II SSD — Supercharge Your Syste...
SanDisk Corporation has announced the new SanDisk Ultra II SSD with enhanced SSD Dashboard. The new drive is designed to deliver a cost-effective and easy upgrade solution for PC owners looking to... Read more
Samsung and Barnes & Noble Introduce New...
Samsung Electronics America and NOOK Media, a subsidiary of Barnes & Noble, Inc. have announced the introduction of the new Samsung Galaxy Tab 4 NOOK, a 7-inch tablet combining Samsung’s leading... Read more
21-inch iMacs on sale for up to $150 off MSRP
B&H Photo has 21″ iMacs on sale for up to $150 off MSRP including free shipping plus NY sales tax only. B&H will also include a free copy of Parallels Desktop software: - 21″ 2.7GHz iMac: $... Read more
27-inch 3.2GHz iMac on sale for $1698, save $...
Abt has the 27″ 3.2GHz iMac on sale for $1698 including free shipping. Their price is $101 off MSRP. Read more
Mac Backup Guru 2.0 Drive Backup/Cloneing Uti...
Mac Backup Guru developer MacDaddy has released Mac Backup Guru 2.0, offering new and enhanced advanced features, such as bootable backups, synchronised volumes and folders, and a Snapshot mode that... Read more
Operate GE’s New Free-Standing KItchen Range...
Think you accidentally left the oven on? Switch it off while on the go. The new free-standing Profile™ Series gas and electric ranges are GE’s second cooking appliances, following their wall oven, to... Read more
Parallels Announces Parallels Desktop 10 for...
The no. 1-selling software for running Windows applications on a Mac becomes an even easier choice for millions of consumers and IT professionals worldwide with the launch of the most powerful... Read more

Jobs Board

Position Opening at *Apple* - Apple (United...
…customers purchase our products, you're the one who helps them get more out of their new Apple technology. Your day in the Apple Store is filled with a range of Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** As businesses discover the power of Apple computers and mobile devices, it's your job - as a Solutions Engineer - to show them how to introduce these Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** At the Apple Store, you connect business professionals and entrepreneurs with the tools they need in order to put Apple solutions to work in their Read more
Project Manager / Business Analyst, WW *Appl...
…a senior project manager / business analyst to work within our Worldwide Apple Fulfillment Operations and the Business Process Re-engineering team. This role will work Read more
*Apple* Retail - Multiple Positions (US) - A...
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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.