DXFTOOLS
COPYRIGHT 1992
DENNIS W. WEBB

DXFTOOLS consists of two Turbo Pascal units designed to allow program to read
and write DXF files. DXF (Drawing Exchange Format) is used by AutoCAD and
other CAD programs as an ASCII representation of the drawing file.

DXFTOOLS provides allows the programmer to read and write many 2-D entities.
By registering your copy, you will receive DXFTOOLS PLUS which as additional
2_D procedures as well as 3-D.

On this disk:

README.DOC => This file

INVOICE.DOC => Registration form. Type PRINT INVOICE.DOC from your DOS
prompt, with your printer on line, for a hard copy.

MANUAL.DOC => Users Manual. Type PRINT MANUAL.DOC from your DOS prompt,
with your printer on line, for a hard copy.

DXFREAD.TPU => Turbo Pascal unit to read .DXF files.

DXFWRITE.TPU => Turbo Pascal unit to write .DXF files.

EXAMPLE1.PAS => Source for example using DXFWRITE.

EXAMPLE2.PAS => Source for example using DXFREAD.

DXFTOOLS
COPYRIGHT 1992
DENNIS W. WEBB

DXFTOOLS consists of two Turbo Pascal units designed to allow program to read
and write DXF files. DXF (Drawing Exchange Format) is used by AutoCAD and
other CAD programs as an ASCII representation of the drawing file.

DXFTOOLS provides allows the programmer to read and write many 2-D entities.
By registering your copy, you will receive DXFTOOLS PLUS which as additional
2_D procedures as well as 3-D.

On this disk:

README.DOC => This file

INVOICE.DOC => Registration form. Type PRINT INVOICE.DOC from your DOS
prompt, with your printer on line, for a hard copy.

MANUAL.DOC => Users Manual. Type PRINT MANUAL.DOC from your DOS prompt,
with your printer on line, for a hard copy.

DXFREAD.TPU => Turbo Pascal unit to read .DXF files.

DXFWRITE.TPU => Turbo Pascal unit to write .DXF files.

EXAMPLE1.PAS => Source for example using DXFWRITE.

EXAMPLE2.PAS => Source for example using DXFREAD.







DXFTOOLS 1.0

Copyright (c) 1992 Dennis W. Webb


DXFTOOLS is a shareware product. You may feel free to make copies of these
utilities and pass them on to friends for their evaluation. If you make use
of this software you are expected to pay a registration fee of $50 to:

Dennis W. Webb
1801 Edna Dr.
Vicksburg, MS 39180

Checks are accepted. Purchase Orders are accepted from most companies,
schools, and government agencies.

Your registration fee entitles you to use this software on a single computer
and to make as many copies of this software as you wish for backup purposes.
Site licenses are available, call (601)636-7202.

DXFTOOLS is a complete product containing the functions and procedures
required to read or write the DXF code for most 2D entities. Upon receipt of
your registration fee you will be upgraded to DXFTOOLS PLUS which includes
TEXT, and BLOCK support, 3D entities, and additional 2D entities not included
with DXFTOOLS. You will also receive a printed manual for DXFTOOLS PLUS, and
notice of future upgrades.

I will be able to offer telephone support of this product evenings and
weekends. You may call me in the evening between 5:00 and 9:00 CST. If I am
not home, leave a message and I will return your call.

INVOICE

Remit to: From

Dennis W. Webb _________________________________
1801 Edna Dr. _________________________________
Vicksburg, MS 39180 _________________________________
(601)636-7202 _________________________________

Contact Individual:

_________________________________
_________________________________



Qyt Unit Price Total

____ DXFTOOLS PLUS 1.0 $50.00




I use ____5 1/4" ____ 3 1/2" disks

For your convenience units compiled with earlier version of Turbo Pascal are
available at no additional charge.

____ Turbo Pascal 4.0

____ Turbo Pascal 5.0
INTRODUCTION

In order for AutoCAD to exchange drawing files with other Computer-Aided
Design/Drafting (CAD) packages, the "Drawing Interchange" file format (DXF)
was developed. DXF files are standard ASCII text files. They contain an
ASCII representation of the same information in the drawing database (.dwg
file). AutoCAD has the ability to read and write DXF files through the DXFIN
and DXFOUT commands. In order to assist in the development of applications
utilizing these DXF files, the DXF TOOLBOX has been developed.

The DXF TOOLBOX for Turbo Pascal consists of two Turbo Pascal units (.TPU
files). Each of these two units is a library of the necessary procedures and
functions to output to and input from DXF files. This manual assumes that
you have a working knowledge of Turbo Pascal, the ability to link Turbo
Pascal units with the USES command, and a basic understanding of AutoCAD.

The first unit DXFWRITE.TPU is a library of procedures and functions allowing
your Turbo Pascal program to create and wire output to a DXF file. This
feature is extremely powerful for any program that requires graphical output.
By creating a DXF file, you can load graphical results directly into AutoCAD,
use AutoCAD to edit the figure, and produce a hard copy via any of AutoCAD's
supported output devices. Or, you could use AutoCAD to create a slide show
of your graphics. As a programmer, you no longer need to concern yourself
with device drivers for video cards, plotters, and printer plotters.

The second unit DXFREAD.TPU is the library of procedures and functions that
allows your program to read information stored in a drawing created in
AutoCAD. You can read the location, size, and orientation of AutoCAD
entities. This can be used to calculate a bill of materials for house plans,
calculate volume, or any number of engineering or architectural applications.

These units have been developed for pc-compatibles using the MS-DOS operating
systems. They were compiled with Turbo Pascal versions 6.0. For those still
using Turbo Pascal versions 4 and 5, the units compatible with those versions
are available at no additional charge if requested on the registration form.

We warrant that the software will function as described in this documentation
for a period of 30 days from receipt. If you encounter a bug or deficiency,
a problem report will be required for us to fix the problem. If you properly
notify us of such a software problem within the warranty period, we will
update the defective software at no cost. Failing that we will refund the
full purchase price of the software upon receipt of the original program
diskette and documentation in undamaged condition. We also warranty the
original program diskette and documentation for a period of 30 days from
receipt.

We do not assume any liability for the use of the DXF TOOLBOX beyond the
original purchase price of the software. In no event will we be liable for
additional damages included lost profits, lost data, or any other damages out
of the use or inability to use DXF TOOLBOX.

No royalties are required for any programs using the procedures and functions
contained within DXF TOOLBOX provided that the fact that DXF TOOLBOX was used
is contained in the program documentation.DXFWRITE

The unit DXFWRITE contains the procedures required to open and initialize a
DXF output file, write the DXF code for 2D and 3D entities, and close the
file. Entities supported include lines, circles, points, arcs, polylines,
meshes, and text.

Note concerning DXF2D_entity. These procedures will write the DXF text to
draw entity at the default elevation and thickness of 0. If the programmer
wishes to draw entities in two dimensions, but in a plane other than z=0, the
global variable dxfelev may be set to the desired elevation. Likewise, the
global variable dxfthick may be set to a thickness other than 0. You do not
need to initialize these variables to 0.

To input your DXF file into AutoCAD, use AutoCAD's DXFIN command from the
AutoCAD command line, and enter the name of the file you created in your
Turbo Pascal program. Your program's output will become part of an AutoCAD
drawing.

An example using DXFWRITE, EXAMPLE1.PAS is included with the shareware
version of this program.

-----------------------------------------------------------------------------

PROCEDURE INIT_DXFFILE(filename : string);

Purpose
Assigns Filename to a TEXT variable, opens the file, and writes the DXF
initialization records to the file. This procedure must be called before any
of the other DXF procedures are used. You can only have one DXF file open at
time. Therefore you must call the procedure CLOSE_DXFFILE before initializing
a second DXF file in your program.

WARNING! INIT_DXFFILE will not check to make sure that the DXF output file
does not already exist. Any existing filenames passed to INIT_DXFFILE will
be overwritten. It is up to the user to make certain that this does not
happen, unless filename is intended to be overwritten.

-----------------------------------------------------------------------------

PROCEDURE CLOSE_DXFFILE;

Purpose
Writes the closing records to the DXF file opened in the previous
INIT_DXFFILE procedure and closes the file.
DXF2D_POINT

Declaration
PROCEDURE DXF2D_POINT(x,y:real;layer:string);

Definition of variables
x,y => coordinates for point.
layer => AutoCAD layer for point.

Purpose
Writes the DXF code to place a point at x,y in the assigned layer. The point
will be drawn at the default thickness and elevation. The default thickness
and elevation are both 0 unless the global variables dxfelev and dxfthick are
changed.

Example
Draw two points x=1 and y=2 in layer "POINTS". Draw the second point at an
elevation of 5.

var
x,y : real;
filename:string[12];
layer : string[30];

begin
x:=1;
y:=2;
filename:='output.dxf';
layer:='POINTS';
INIT_DXFFILE(filename);
DXF2D_POINT(x,y,layer);
dxfelev:=5.0; {Change the default elevation to 5.0}
DXF2D_POINT(x,y,layer);
CLOSE_DXFFILE;
end;
PROCEDURE DXF2D_LINE(x1,y1,x2,y2 real;layer:string);

Definition of variables
x1,y1 => coordinates for beginning of line.
x2,y2 => coordinates for ending of line.
layer => AutoCAD layer for line.

Purpose
Writes the DXF code to draw a line from x1,y1 to x2,y2 in the appropriate
layer. The line will be drawn at the default thickness and elevation. The
default thickness and elevation are both 0 unless the global variables
dxfelev and dxfthick are changed.

Example
Draw a line at coordinate 1,2 to coordinate 11,21 in layer "LINES". Draw a
second line from 4,5 to 8,6 with a thickness of 1.5. Place the second line a
layer called "THICK-LINES".


var
x1,y1,x2,y2 : real;

begin
x1:=1;
y1:=2;
x2:=11;
y2:=21;
INIT_DXFFILE('outfile.dxf');
DXF2D_LINE(x1,y1,x2,y2,'LINES');
dxfthick:=1.5; {Change the default thickness to 1.5}
x1:=4;
y1:=5;
x2:=8;
y2:=6;
DXF2D_LINE(x1,y1,x2,y2,'THICK-LINES');
CLOSE_DXFFILE;
end;
PROCEDURE DXF2D_ARC(x,y,radius,start_ang,end_ang:real;layer:string);

Definition of variables
x,y => coordinates for center of arc.
radius => length of radius.
start_ang => starting angle of arc.
end_ang => ending angle of arc.
layer => AutoCAD layer for arc.

Purpose
Writes the appropriate DXF text to draw an arc of a given radius from center
point x,y in the appropriate layer. The arc will begin at start_angle and
terminate at end_angle. Angles should be in agreement with the angle format
selected via the AutoCAD UNITS command. The arc will be drawn at the default
thickness and elevation. The default thickness and elevation are both 0
unless the global variables dxfelev and dxfthick are changed.

Example
Draw an angle of radius 2 from 45 to 90 degrees at location 5,6 in layer
"ARC".

var
x,y,rad,ang1,ang2 : real;
layer : string[30];

begin
x:=5;
y:=6;
rad:=2;
ang1:=45;
ang2:=90;
layer:='ARC';
INIT_DXFFILE('outfile.dxf');
DXF2D_ARC(x,y,rad,ang1,ang2,layer);
CLOSE_DXFFILE;
end;

PROCEDURE DXF2D_CIRCLE(x,y,radius:real;layer:string);

Definition of variables
x,y => coordinates for center point of the circle.
radius => length of radius.
layer => AutoCAD layer for circle.

Purpose
Writes the DXF code to draw a circle of a given radius from center point x,y
in the appropriate layer. The circle will be drawn at the default thickness
and elevation. The default thickness and elevation are both 0 unless the
global variables dxfelev and dxfthick are changed.

Example
Draw a circle of radius 8 at location 4,2 in layer "CIRCLES" with an
elevation of 6.12. The circles's thickness is 0.

var
x,y,rad : real;
layer : string[30];
begin
x:=4;
y:=2;
rad:=8;
layer:='CIRCLES';
dxfelev:=6.12;
INIT_DXFFILE('outfile.dxf');
DXF2D_CIRCLE(x,y,rad,layer);
CLOSE_DXFFILE;
end;

-----------------------------------------------------------------------------
2D-POLYLINES

Drawing polylines is accomplished by calling three different
procedures. The first BEGIN_2DPLINE is called to initialize the
polyline, it is called once per polyline. The second DXF2D_PLINE
is called for each vertex to be included in the polyline. The
last END_PLINE is called to close the polyline, it is called once
per polyline.

-----------------------------------------------------------------------------

PROCEDURE BEGIN_2DPLINE(layer:string;closed:boolean);

Definition of variables
layer => AutoCAD layer for polyline.
closed => TRUE if polyline is closed, FALSE if open.
PROCEDURE DXF2D_PLINE(x,y,w1,w2:real)

Definition of variables
x,y => coordinates for vertex of polyline.
layer => AutoCAD layer for polyline.
w1 => beginning width for polyline.
w2 => ending width for polyline.

-----------------------------------------------------------------------------

PROCEDURE END_PLINE;

Definition of variables
No variables are required for this procedure.

Example
Draw an open polyline representing the function Y=X2 from X=1 to X=10 in
layer Function. For this example all widths, the thickness, and elevation
are 0.

var
x,y,begin_width,end_width : real;
closed:boolean;
layer : string[30];
I:integer;

begin
layer:='Function';
closed:=FALSE;
thick:=0.0;
elev:=0.0;
begin_width:=0.0;
end_width:=0.0;
INIT_DXFFILE('outfile.dxf');
begin2d_pline(layer,closed);
for I:=1 to 10 do
begin
x:=I;
y:=I*I;
dxf2d_pline(x,y,begin_width,end_width);
end;
end_pline;
close_dxfile;
end;
DXFREAD

The unit DXFREAD contains the procedures required to open DXF file for input,
read the DXF code for layer names, block names, and entities. Entities
supported include lines, circles, points, arcs, polylines, meshes, and text.

For the most part, the same procedures are used for reading 2D and 3D
entities. This is because the programmer may not know which to expect. For
2D entities, the Z coordinates will be returned as 0.

In order to create the DXF file, enter DXFOUT from the AutoCAD command line.
Enter a new filename, or take the default. DXFREAD will use the file you
created (which contains all information concering the drawing) as your
programs input file.

An example using DXFWRITE, EXAMPLE2.PAS is included with the shareware
version of this program.

-----------------------------------------------------------------------------

PROCEDURE OPEN_DXF(filename:string);

Definition of variables
filename => DXF file to be used for input.

Purpose
Opens a DXF file for input and initializes certain variables required by
DXFREAD. ASSIGN_DXF must be called before any other procedures in the
DXFREAD unit.

-----------------------------------------------------------------------------

PROCEDURE CLOSE_DXF;

Definition of variables
No variables are required for this procedure.

Purpose
Closes the DXF file previously opened for input with the
OPEN_DXF procedure.

FUNCTION GET_LAYER:string;

Definition of variables
No parameters are passed to this function.

Purpose
Returns all layer names used in the drawing that the DXF file was generated
from. The layer names will be returned in the order that they were created
in the drawing. When no more layer names are listed in the DXF file,
GET_LAYER will return a null string ('').

Example
Read all of the layer names in a DXF file into an array.

PROGRAM TEST_DXFREAD;

USES DXFREAD;

const
maxlayers = 50;

var
layer : array [1..maxlayers] of string;
i,
numlayers : integer;
filename : string;

BEGIN
writeln('Enter name of input DXF file .');
readln(filename);
OPEN_DXF(filename);
numlayers:=0;
repeat;
numlayers:=numlayers+1;
layer[numlayers]:=GET_LAYER;
until layer[numlayers]='';
numlayers:=numlayers-1;
for i:=1 to numlayers do writeln(layer[i]);
CLOSE_DXF;
end.


PROCEDURE GET_ENT(var entid:byte;var enttype,layer:string);

Definition of variables
entid => value is determined by type of entity. This is useful if you use
the Pascal CASE statement to control program branching. The value of entid
will be one of the following:

0 => No more entities in DXF file.
1 => Point.
2 => Line.
3 => 3DLine.
4 => Arc.
5 => Circle.
6 => Trace.
7 => Solid.
8 => 3DFace.
9 => Polyline or Mesh.
10 => Vertex.
11 => Seqend.

enttype => name of entity. Such as line, circle, etc.
layer => layer that the entity resides in.

Purpose
Returns the names and layers of all entities in drawing that the DXF file was
generated from. The entities will be returned in the order that they were
drawn. Enttype will be one of the following type of entities: POINT, LINE,
3DLINE, ARC, CIRCLE, TRACE, SOLID, 3DFACE, PLINE, or VERTEX. After all
entities have been returned, GET_ENT will return a null string ('') for both
enttype, and layer.

Example
List all the entities and their layers in a DXF file on the screen.

PROGRAM TEST_DXFREAD;

USES DXFREAD;

var
entid:byte;
entname,layer : string;
filename : string;

BEGIN
writeln('Enter name of input DXF file .');
readln(filename);
OPEN_DXF(filename);
repeat;
GET_ENT(entid,entname,layer);
WRITELN('ENTID=',entid,' ENTITY=',entname,' LAYER=',layer);
until entname='';
CLOSE_DXF;
end.
PROCEDURE GET_POINT(var x,y,z,elev,thick:real);

Definition of variables
x,y,z => coordinates for point.
elev => elevation of point.
thick => thickness of point.

Example
List the properties of all POINTS in a DXF file that were drawn in the layer
"MYPOINTS".

PROGRAM TEST_DXFREAD;

USES DXFREAD;

var
entid:byte;
entname,layer,matchlayer : string;
x,y,z,elev,thick:real;
filename : string;

BEGIN
matchlayer:='MYPOINTS';
writeln('Enter name of input DXF file .');
readln(filename);
OPEN_DXF(filename);
repeat;
GET_ENT(entid,entname,layer);
if (entid=1) and (layer=matchlayer) then
begin
GET_POINT(x,y,z,elev,thick);
writeln('Point is ',x,',',y,',',z);
writeln('The elevation is ',elev,' and the thickness is',thick);
end;
until entid=0;
CLOSE_DXF;
end.

PROCEDURE GET_LINE(var x1,y1,z1,x2,y2,z2,elev,thick:real);

Definition of variables
x1,y1,z1 => coordinates for starting point of line.
x2,y2,z2 => coordinates for ending point of line.
elev => elevation of line.
thick => thickness of line.

Example

List the properties of all LINES in a DXF file regardless of their layer.

PROGRAM TEST_DXFREAD;

USES DXFREAD;

var
entid:byte;
entname,layer : string;
x1,y1,z1,x2,y2,z2,elev,thick:real;
filename : string;

BEGIN
writeln('Enter name of input DXF file .');
readln(filename);
OPEN_DXF(filename);
repeat;
GET_ENT(entid,entname,layer);
if (entid=2) then
begin
GET_LINE(x1,y1,z1,x2,y2,z2,elev,thick);
writeln('The line is from',x1,',',y1,',',z1,' to',x2,',',y2,',',z2);
writeln('The line was created in layer ',layer);
writeln('The elevation is ',elev,' and the thickness is ',thick);
end;
until entid=0;
CLOSE_DXF;
end.

PROCEDURE GET_ARC(var x,y,z,rad,ang1,ang2,elev,thick:real);

Definition of variables
x,y,z => coordinate for the center point of the arc.
rad => Radius of the arc.
ang1 => starting angle of the arc.
ang2 => ending angle of the arc.
elev => elevation of arc.
thick => thickness of arc.

Example
List the center point, radius, and layer of all arcs in a DXF file.

PROGRAM TEST_DXFREAD;

USES DXFREAD;

var
entid:byte;
entname,layer : string;
x,y,z,rad,ang1,ang2,elev,thick:real;
filename : string;

BEGIN
writeln('Enter name of input DXF file .');
readln(filename);
OPEN_DXF(filename);
repeat;
GET_ENT(entid,entname,layer);
if (entid=4) then
begin
GET_ARC(x,y,z,rad,ang1,ang2,elev,thick);
writeln('The center point of the arc is ',x,',',y,',',z);
writeln('It was created in layer ',layer,' and has a radius of ',rad);
end;
until entid=0;
CLOSE_DXF;
end.


PROCEDURE GET_CIRCLE(var x,y,z,rad,elev,thick:real);

Definition of variables
x,y,z => coordinate for the center point of the circle.
rad => Radius of the circle
elev => elevation of circle
thick => thickness of circle.

Example
List the properties of all CIRCLES in a DXF file regardless of the layer.

PROGRAM TEST_DXFREAD;

USES DXFREAD;

var
entid:byte;
entname,layer : string;
x,y,z,rad,elev,thick:real;
filename : string;

BEGIN
writeln('Enter name of input DXF file .');
readln(filename);
OPEN_DXF(filename);
repeat;
GET_ENT(entid,entname,layer);
if (entid=5) then
begin
GET_CIRCLE(x,y,z,rad,elev,thick);
writeln('The center point of the circle is',x,',',y,',',z);
writeln('It was created in layer ',layer,' and has a radius of ',rad);
writeln('The elevation is ',elev,' and the thickness is ',thick);
end;
until entid=0;
CLOSE_DXF;
end.

PROCEDURE GET_PLINE(var mesh,mclosed,nclosed:boolean;
var m,n:integer; var
begin_width,end_width,elev,thick:real);


Definition of variables
mesh => returns TRUE if PLINE is a 3D polyline mesh.
mclosed => returns TRUE if a polyline is closed,
or if a 3D mesh is closed in the m direction
nclosed => returns TRUE if a 3D mesh is closed in the n direction
m => the number of vertices in the m direction of a 3D mesh.
n => the number of vertices in the n direction of a 3D mesh.
begin_width => beginning width of polyline.
end_width => ending width of polyline.
elev => elevation of polyline.
thick => thickness of polyline.

Example
Example will be shown with the procedure GET_VERTEX.

-----------------------------------------------------------------------------

GET_VERTEX

PROCEDURE GET_VERTEX(var x,y,z,begin_width,end_width,elev,thick:real);

Definition of variables
x,y,z => coordinates for the vertex.
begin_width => beginning of polyline segment.
end_width => ending width of polyline segment.
elev => elevation of vertex.
thick => thickness of vertex.

Example
List the vertex points of all polylines in a DXF file.
PROGRAM TEST_DXFREAD;

USES DXFREAD;

var
entid:byte;
entname,layer : string;
x,y,z,begin_width,end_width,elev,thick : real;
mesh,mclosed,nclosed : boolean;
filename : string;
m,n:integer;

BEGIN
writeln('Enter name of input DXF file .');
readln(filename);
OPEN_DXF(filename);
repeat;
GET_ENT(entid,entname,layer);
if (entid=9) then
begin

GET_PLINE(mesh,mclosed,nclosed,m,n,begin_width,end_width,elev,thick);
if not mesh then
begin
writeln('Beginning polyline in layer ',layer);
repeat;
GET_ENT(entid,entname,layer);
if (entid=10) then
begin
GET_VERTEX(x,y,z,begin_width,end_width,elev,thick);
writeln(x,',',y,',',z);
end;
until entid=11; {End of polyline}
end;
end;
until entid=0;
CLOSE_DXF;
end.