
GLE2000   Version GLE2000b

Description   
  GLE (Graphics Language Editor) is a graphics package for producing publication quality precision diagrams and graphs, originally written by Chris Pugmire, (Department of Scientific and Industrial Research,New Zealand.) and subsequent updated by Axel Rhode (University of Keil) and Stephen Mundt (University of Dusseldorf.). All of these systems were written for Unix or MSDOS operating systems. GLE is a vector based drawing system, its primary input being a list of drawing instructions 
  ( e.g. amove 3,4  2.5
         aline 5.9 1.5
         circle 3.0       etc.)

  GLE2000 is an adaptation of GLE for operation under Windows95/98, and N.T.4 prepared by Derek Ingram. (Gonville & Caius College, Cambridge U.K.) It places more emphasis on screen drawing operations using the mouse and new features have been added (24 bit colour, extended mathematical functions, polar plots etc.) A prime objective was to upgrade GLE to match developments in graphics displays and printers. GLE2000 can now produce high quality coloured graphics for screen display, printing, Web pages etc. 

Installation
   The files in this zip archive should be extracted into a new empty folder, suggested name GLE2000. The zip extraction program should be set to use the path information in this archive to restore the original directory structure. This will install the following files in the root directory  of folder GLE2000:

 GLE2000.exe       - the main .exe file
 GLE2000.hlp       - The program manual in Windows Help format
 GLE2000coms.hlp   - A summary of program commands in Help format
 GLE2000err.hlp    - Notes on error messages
 GLE2000cnvrt.hlp  - Notes on conversion from older versions of GLE. 

 GLE2000.GID       - Auxilliary help system files.
 GLE2000CNVRT.GID  
 GLE2000ERR.GID
 GLE2000Coms.GID

and will also create four sub-folders:

 Docs  
  Contains the following text files describing various azpects of GLE2000
  AngularAxes.txt  	Arrows.txt  		Bezier.txt
  Colours.txt 		Comcodes.txt  		Coords.txt
  Data Input.txt  	FillPatterns.txt  	GraphCoords.txt
  IF Statements.txt  	Source Index.txt  	Licence.txt
  LogValues.txt  	Procedures Index.txt  	Source Index.txt

 Examples
  Contains an extensive set of example GLE programs which cover most of the features of GLE2000. These can be used as a Tutorial.

 Help
  Contains the Help Files in .rtf format and the auxilliary project files used by Microsoft Help Workshop. These can be used to modify the Help system.

 Source
  Contains the source listings  for recompiling GLE2000 using the Delphi-2 Development system. The main files are:
  GLE2000.dpr  - The main project file
  GLE2000.res  - The project resource file
  GLE2000D.pas - Pascal listing for the Display Unit 
  GLE2000D.dfm - Listing for the Display window.
  GLE2000E.pas, GLE2000E,dfm  Ditto for the Edit window
  GLE2000F.pas, GLE2000F.dfm  ditto for the Fills drop-down window
  GLE2000G.pas  Source listing for the Graphs Unit (no window for this)
  GLE2000P.pas, GLE2000P.dfm.  Listings for the print drop-down window
  GLE2000T.pas  Source listings for the Tools Unit
  GLE2000W.pas, GLE2000W.dfm Listings for the drop down window control panel
  Pointers1.Res  Data file for a custom mouse pointer.

None of these sub folders are essential, but the Examples folder 
is useful during the initial stages of learning how to use GLE.

System Requirements
  A standard P.C. with 133 Mhz. Pentium processor or better. 
32 Mbytes memory or better. A standard graphics card, preferably 
offerering 24 bit colour at 800x600 or better. (As supplied GLE2000 is set for a 1024x768 display) For hard copy output, an inkjet printer (300 d.p.i or better) is needed. To align source listing values with screen dimensions and printer hard copy dimensions the parameters pixelspercm and dotspercm must be reset to match your system characteristics, See example SetScale.GLE

  GLE2000 has been tested on various P.C. machines using  Windows95 and N.T.4. It is almost certainly O.K. under Windows 98 and probably O.K. under Windows 2000. Hard copy output has been checked on H.P Deskjet and Cannon BJC240 printers.

Progam Status    Freeware

Distribution Status  May be freely distributed and used in other programs
provided that the source is acknowledged, no charge is made for GLE2000 and source listings of any software which includes all or parts of  GLE2000 are provided as part of the published material, (See file GLE2000.hlp for a formal licence statement.)

General Description
  A major feature of all GLE packages, including GLE2000, is the depth of control offered to the user. For example, when setting up a graph, features down to the length and colour of axis sub-ticks can be set, text, graphs and graphics may all be included in a diagram. In Gle2000 extensions to cover current high definition graphics displays have been included. Loop structures (For .. Next, Repeat .. Until  and While .. EndWhile) can be used for repeated drawing of graphics objects. Subroutines can be used. High level mathematical functions including Bessel functions, Error functions and Fresnel integrals are included. Both Cartesian and polar graphs can be set up. Although GLE is primarily a vector based system limited support for bitmap graphics is also included.

 A very extensive set of error traps has been included which should detect most errors in inputs to GLE2000.
 
Operation
 To run GLE2000 either double-click GLE2000.exe or drag a short-cut out of that file on to the desktop and use it.

 On opening, GLE2000 displays an input window with a menu bar above it.
The help option on this gives access to the four help files which will tell you all you need to know about GLE2000. The main help file is GLE2000.hlp, GLE2000coms,hlp gives a quick reference to commands, 
GLE2000err,hlp gives information on error messages and GLE2000cnvrt,hlp 
covers conversion of diagrams prepared under earlier versions of GLE to GLE2000.  It may be necessary to tell the program where these help 
files are located when it is first run. (You will be prompted by a 
message for this.)

 For a quick start use the File menu option to open an examples file 
and run it by clicking the buttons DRAW and GRAPH in turn.

 At an early stage you should adjust the PixelsPerCm parameter to 
match the characteristics of your display. The example program 
SetScale.GLE may assist in this. Also, set the DotsPerCm parameter 
to match the characteristics of your printer.

Prior Versions
 A first beta version (GLE99) appeared about a year ago and was made available informally on a small scale. Since this beta was issued the following features have been added:

          High quality printed output.
          Output and input of .bmp files
          Clipboard operations
          String Functions.
          Subroutines.
          Local variables.
          Time and date functions
          Zoom feature for the Graphics window.
          Line drawing using polar co-ordinates
          Bar Charts
          Polar Graphs

There are no known bugs apart from:

(1) Some difficulties with the twidth() and theight() functions, 
which can give unexpected results. (See examples files StringProc1.GLE 
and Stringproc2.GLE)
 
(2) A fault in the background colours of fill patterns 1 to 7 which 
has only occurred on a system using a Diamond Viper 550 graphics card. 
Hence this may be due to a bug in the graphics card driver.
 
(3) A limitation in the Windows Screen drivers may cause the system to 
crash if very large zoom factors are used. This appears to be due to the use of 16 bit operations in the Windows 95 A.P.I. It may not appear in NT4 or Win2000 (Not yet checked,)
 
(4) When opening a new GLE file the graphics window may not, initially, 
resize correctly. Key the Draw button again - it should set the correct 
size on the second attempt. (The cause of this is known, but I've not 
yet decided the best way of dealing with it!}  
 
No doubt other bugs are lurking somewhere!

Apart from this the package seems to be fairly robust - at least for me. However, since I am familiar with the structure of the program I probably instinctively avoid some undesirable operations. These might not be apparent to other users.
 
The most recent version of GLE2000 will be found on my home page 
 http://www.cai.cam.ac.uk/people/dgi  (downloads only). If you want to know who you are dealing with look at:  http://www2.eng.cam.ac.uk/~dmh/gcc/fellows.htm

I hope that this is now a fairly complete and robust adaption of GLE 
to the Windows environment.

      Derek Ingram  (dgi1@cus.cam.ac.uk)
      Friday  30th May 2000

  