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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
NAME
VOGL - A very ordinary GL Like Library.
DESCRIPTION
VOGL is a library of C routines which try to allow a pro-
grammer to write programs which can be moved to machines
which have the Silicon Graphics GL library on them. It is
based entirely on the VOGLE graphics library, and as a
result can handle circles, curves, arcs, patches, and
polygons in a device independent fashion. Simple hidden line
removal is also available via polygon backfacing. Access to
hardware text and double buffering of drawings depends on
the driver. There is also a FORTRAN interface but as it
goes through the C routines FORTRAN users are warned that
arrays are in row-column order in C. Both the long FORTRAN
names and the shortened six character names are supported.
People interested in using software text should see the
hershey library, HERSHEY(3).
Some routines are only available in VOGL. If you include
them in programs it is advisable to put #ifdef VOGL ...
#endif around them. The constant VOGL is defined whenever a
VOGL header file is included.
It should be noted that there are a number of routines that
take the type Angle for some of their parameters. All angles
specified this way are actually Integer Tenths Of Degrees.
(Don't ask!)
Include files.
There are two include files provided with vogl: vogl.h and
vodevice.h. The file vogl.h has the type definitions and
function interfaces, ideally it is included where you would
include gl.h on an SGI. The file vodevice.h has the devices
in it, and it is included where you would include device.h
on an SGI.
The following is a brief summary of the VOGL subroutines.
Using X toolkits ans Sunview
For X11 and Sunview based applications, it is posible for
VOGL to use a window that is supplied by that application's
toolkit. Under these circumstances, the toolkit is is
responsible for handling of all input events, and VOGL sim-
ply draws into the supplied window. These calls are only
available from C. Also see the directories examples/xt,
examples/xview and examples/sunview.
For X based toolkits the following two calls may be used:
VOGL 1.2.8 Last change: 12 Oct 1993 1
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
vo_xt_window(display, xwin, width, height)
Tells VOGL to use the supplied window xwin
vo_xt_window(display, xwin, width, height)
Display *display;
Window xwin;
int width, height;
This routine should be called before calling "ginit()".
vo_xt_win_size(width, height)
Tells VOGL that the supplied window has changed size.
vo_xt_win_size(width, height)
int width, height;
For sunview based applications the following two calls may be
used:
vo_sunview_canvas(canvas, width, height)
Tells VOGL to use the supplied sunview canvas canvas
vo_sunview_canvas(canvas, width, height)
Canvas canvas;
int width, height;
This routine should be called before calling "ginit()".
vo_sunview_canvas_size(width, height)
Tells VOGL that the supplied canvas has changed size.
vo_sunview_canvas_size(width, height)
int width, height;
Device routines.
vinit(device)
Tell VOGL what the device is. This routine needs to be
called if the environment variable VDEVICE isn't set,
or if the value in VDEVICE is not to be used.
Fortran:
subroutine vinit(device, len)
character *(*) device
integer len
C:
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
vinit(device);
char *device;
Note 1 :- Current available devices are:
tek - tektronix 4010 and compatibles
hpgl - HP Graphics language and compatibles
dxy - roland DXY plotter language
postscript - monochrome postscript devices
ppostscript - monochrome postscript devices (portrait mode)
cps - colour postscript devices
pcps - colour postscript devices (portrait mode)
grx - the GRX library that is part of DJGPP.
- (little tested)
sun - Sun workstations running sunview
X11 - X windows (SUN's Openwindows etc etc)
decX11 - the decstation (old) window manager
This is only included in case you need it.
apollo - Apollo workstations
NeXT - NeXTStep
hercules - IBM PC hercules graphics card
cga - IBM PC cga graphics card
ega - IBM PC ega graphics card
vga - IBM PC vga graphics card
sigma - IBM PC sigma graphics card.
mswin - MS-windoze (little tested).
Sun, X11, decX11, apollo, hercules, cga
and ega support double buffering.
Note 2 :- If device is a NULL or a null string the value
of the environment variable "VDEVICE" is taken as the
device type to be opened.
Note 3 :- after init it is wise to explicitly
clear the screen.
e.g.: in C
color(BLACK);
clear();
or in Fortran
call color(BLACK)
call clear
ginit()
Open the graphics device and do the basic initialisa-
tion. This routine is marked for obsolescence. The rou-
tine winopen (see below) should be used instead. Note:
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
this automatically causes a REDRAW event to appear as
the first event in the event queue.
Fortran:
subroutine ginit
C:
ginit()
winopen(title)
Open the graphics device and do the basic initialisa-
tion. This routine should be used instead of ginit.
Note: this automatically causes a REDRAW event to
appear as the first event in the event queue.
Fortran:
subroutine winopen(title, len)
character*(*) title
integer len
C:
winopen(title)
char *title;
gexit()
Reset the window/terminal (must be the last VOGL rou-
tine called)
Fortran:
subroutine gexit
C:
gexit()
voutput(path)
Redirect output from *next* ginit to file given by
path. This routine only applies to devices drivers that
write to stdout e.g. postscript and hpgl.
Fortran:
subroutine voutput(path, len)
character*(*) path
integer len
C:
voutput(path)
char *path;
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
vnewdev(device)
Reinitialize VOGL to use a new device without changing
attributes, viewport etc. (eg. window and viewport
specifications)
Fortran:
subroutine vnewdev(device, len)
character *(*) device
integer len
C:
vnewdev(device)
char *device;
getplanes() Returns the number of bit planes (or color
planes) for a particular device. The number of colors
displayable by the device is then 2**(nplanes-1)
Fortran:
integer function getplanes()
C:
long
getplanes()
Routines for controling flushing or syncronisation
On some devices (particularly X11) considerable speedups in
display can be achieved by not flushing each graphics primi-
tive call to the actual display until necessary. VOGL
automatically delays flushing under in following cases:
- Within a callobj() call.
- Within curves and patches.
- Within bgn*/end* calls.
- When double buffering (the flush is only done withing swapbuffers).
There are two user routines (which are NOT GL compatible)
that can be used to control flushing.
vsetflush(yesno)
Set global flushing status. If yesno = 0 (.false.) then
don't do any flushing (except in swapbuffers(), or
vflush()). If yesno = 1 (.true.) then do the flushing
as described above.
Fortran:
subroutine vsetflush(yesno)
logical yesno
C:
void
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
vsetflush(yesno)
int yesno;
vflush()
Call the device flush or syncronisation routine. This
forces a flush.
Fortran:
subroutine vflush
C:
void
vflush();
Routines For Setting Up Windows.
Some devices are basically window orientated - like sunview
and X11. You can give VOGL some information about the window
that it will use with these routines. These can make your
code very device dependent. Both routines take arguments
which are in device space. (0, 0) is the bottom left hand
corner in device space. To have any effect these routines
must be called before ginit or winopen. For the X11 device,
an entry may be made in your .Xdefaults file of the form
vogl.Geometry =150x500+550+50 (where you specify your
geometry as you please).
prefposition(x1, x2, y1, y2)
Specify the preferred position of the window opened by
the *next* winopen.
Fortran:
subroutine prefposition(x1, x2, y1, y2)
integer x1, x2, y1, y2
C:
prefposition(x1, x2, y1, y2)
long x1, x2, y1, y2
prefsize(width, height)
Specify the preferred width and height of the window
opened by the *next* winopen.
Fortran:
subroutine prefsize(width, height)
integer width, height
C:
prefsize(width, height)
long width, height;
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
reshapeviewport
This is occasionally used in Iris GL if a REDRAW event
rolls up. While VOGL is unlikely to ever provide a
REDRAW event (except possibly the first event in the
event queue) the call is provided for compatibility.
Fortran:
subroutine reshap
C:
reshapeviewport()
General Routines.
clear()
Clears the current viewport to the current colour.
Fortran:
subroutine clear
C:
clear()
color(col)
Set the current colour. The standard colours are as
follows:
black = 0 red = 1 green = 2 yellow = 3
blue = 4 magenta = 5 cyan = 6 white = 7.
These are included in vogl.h as:
BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN and WHITE.
When using fortran these are included in fvogl.h as
BLACK, RED, GREEN, YELLOW, BLUE, MAGENT, CYAN and WHITE.
Fortran:
subroutine color(col)
integer col
C:
color(col)
Colorindex col;
colorf(col)
Same as color only it takes a floating point argument.
In Iris GL there are sometimes good reasons for using
this routine over color. See the GL manual for more
details.
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
Fortran:
subroutine colorf(col)
real col
C:
colorf(col)
float col;
mapcolor(indx, red, green, blue)
Set the color map index indx to the color represented
by (red, green, blue). If the device has no color map
this call does nothing.
Fortran:
subroutine mapcolor(indx, red, green, blue)
integer indx, red, green, blue
C:
mapcolor(indx, red, green, blue)
Colorindex indx;
short red, green, blue;
defbasis(id, mat)
Define basis number id to be the matrix mat.
Fortran:
subroutine defbasis(id, mat)
integer id
real mat(4, 4)
C:
defbasis(id, mat)
short id;
Matrix mat;
polymode(mode)
NOTE:- For this call to have any effect it must have
been conditionally compilied into the library. (See
polygons.c for details) Control the filling of
polygons. It expects one of the following PYM_LINE,
which means only the edges of the polygon will be drawn
and PYM_FILL which means fill the polygon (the
default). PYM_POINT and PYM_HOLLOW are also recognised
but they don't behave quite as they would with SGI GL.
Also note that in Fortran the corresponding constants
are truncated to PYM_LI, PYM_FI, PYM_PO and PYM_HO
respectivly. These appear in fvogl.h.
VOGL 1.2.8 Last change: 12 Oct 1993 8
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
Fortran:
subroutine polymode(mode)
integer mode
C:
polymode(mode)
long mode;
The Device Queue and Valuator Routines.
The available devices are defined in the header files
vodevice.h and for FORTRAN fvodevice.h
qdevice(dev)
Enable a device. Note: in VOGL the queue is of length
1.
Fortran:
subroutine qdevice(dev)
integer dev
C:
qdevice(dev)
Device dev;
unqdevice(dev)
Disable a device.
Fortran:
subroutine qdevice(dev)
integer dev
C:
qdevice(dev)
Device dev;
qread(data)
Read an event from the device queue. This routines
blocks until something happens. Note: it is important
to have called qdevice before doing this.
Fortran:
integer function qread(data)
integer*2 data
C:
long qread(data)
short *data;
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
isqueued(dev)
Check to see if device dev is enabled for queueing.
Fortran:
logical function isqueued(dev)
integer dev
C:
Boolean isqueued(dev)
short *dev;
qtest()
Check if there is anything in the queue. Note: in VOGL
the queue is only 1 entry deep.
Fortran:
logical function qtest
C:
Boolean qtest()
qreset()
Reset the device queue. This will get rid of any pend-
ing events.
Fortran:
subroutine qreset
C:
qreset()
getbutton(dev)
Returns the up (0) or down (1) state of a button.
Fortran:
logical function getbutton(dev)
integer dev
C:
Boolean getbutton(dev)
Device dev;
getvaluator(dev)
Return the current value of the valuator. Currently the
only valuators supported are MOUSEX and MOUSEY.
Fortran:
integer function getvaluator(dev)
VOGL 1.2.8 Last change: 12 Oct 1993 10
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
integer dev
C:
long getvaluator(dev)
Device dev;
Viewport Routines.
viewport(left, right, bottom, top)
Specify which part of the screen to draw in. Left,
right, bottom, and top are integer values in screen
coordinates.
Fortran:
subroutine viewport(left, right, bottom, top)
integer left, right, bottom, top
C:
viewport(left, right, bottom, top)
Screencoord left, right, bottom, top;
pushviewport()
Save current viewport on the viewport stack.
Fortran:
subroutine pushviewport
C:
pushviewport()
popviewport()
Retrieve last pushed viewport.
Fortran:
subroutine popviewport
C:
popviewport()
getviewport(left, right, bottom, top)
Returns the left, right, bottom and top limits of the
current viewport in screen coordinates.
Fortran:
subroutine getviewport(left, right, bottom, top)
integer*2 left, right, bottom, top
C:
getviewport(left, right, bottom, top)
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
Screencoord *left, *right, *bottom, *top;
Attribute Stack Routines.
The attribute stack contains details such as current color,
current line style and width, and the current font number.
If you need to prevent object calls form changing these, use
pushattributes before the call and popattributes after.
pushattributes()
Save the current attributes on the attribute stack.
Fortran:
subroutine pushattributes
C:
pushattributes()
popattributes()
Restore the attributes to what they were at the last
pushattribute().
Fortran:
subroutine popattributes
C:
popattributes()
Projection Routines.
All the projection routines define a new transformation
matrix, and consequently the world units. Parallel projec-
tions are defined by ortho or ortho2. Perspective projec-
tions can be defined by perspective and window. Note the
types Angle, etc, are defined in vogl.h. Remember angles are
in tenths of degrees.
ortho(left, right, bottom, top, near, far)
Define x (left, right), y (bottom, top), and z (near,
far) clipping planes. The near and far clipping planes
are actually specified as distances along the line of
sight. These distances can also be negative. The
actual location of the clipping planes is z = -near_d
and z = -far_d.
Fortran:
subroutine ortho(left, right, bottom, top, near_d, far_d)
real left, right, bottom, top, near_d, far_d
C:
ortho(left, right, bottom, top, near_d, far_d)
Coord left, right, bottom, top, near_d, far_d;
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
ortho2(left, right, bottom, top)
Define x (left, right), and y (bottom, top) clipping
planes.
Fortran:
subroutine ortho2(left, right, bottom, top)
real left, right, bottom, top
C:
ortho2(left, right, bottom, top)
float left, right, bottom, top;
perspective(fov, aspect, near, far)
Specify a perspective viewing pyramid in world coordi-
nates by giving a field of view, aspect ratio and the
distance from the eye of the near and far clipping
plane.
Fortran:
subroutine perspective(fov, aspect, near, far)
integer fov
real aspect, near, far
C:
perspective(fov, aspect, near, far)
Angle fov;
float aspect;
Coord near, far;
window(left, right, bot, top, near, far)
Specify a perspective viewing pyramid in world coordinates by
giving the rectangle closest to the eye (ie. at the near clipping
plane) and the distances to the near and far clipping planes.
Fortran:
subroutine window(left, right, bot, top, near, far)
real left, right, bot, top, near, far
C:
window(left, right, bot, top, near, far)
float left, right, bot, top, near, far;
Matrix Stack Routines.
pushmatrix()
Save the current transformation matrix on the matrix
stack.
Fortran:
subroutine pushmatrix
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
C:
pushmatrix()
popmatrix()
Retrieve the last matrix pushed and make it the current
transformation matrix.
Fortran:
subroutine popmatrix
C:
popmatrix()
Viewpoint Routines.
Viewpoint routines alter the current tranformation matrix.
polarview(dist, azim, inc, twist)
Specify the viewer's position in polar coordinates by
giving the distance from the viewpoint to the world
origin, the azimuthal angle in the x-y plane, measured
from the y-axis, the incidence angle in the y-z plane,
measured from the z-axis, and the twist angle about the
line of sight.
Fortran:
subroutine polarview(dist, azim, inc, twist)
real dist
integer azim, inc, twist
C:
polarview(dist, azim, inc, twist)
Coord dist;
Angle azim, inc, twist;
lookat(vx, vy, vz, px, py, pz, twist)
Specify the viewer's position by giving a viewpoint and
a reference point in world coordinates. A twist about
the line of sight may also be given.
Fortran:
subroutine lookat(vx, vy, vz, px, py, pz, twist)
real vx, vy, vz, px, py, pz
integer twist
C:
lookat(vx, vy, vz, px, py, pz, twist)
float vx, vy, vz, px, py, pz;
Angle twist;
VOGL 1.2.8 Last change: 12 Oct 1993 14
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
Move Routines.
There are variations on all these routines that end in 's'
and also end in 'i'. In the case of the 's' variations they
take arguments of type Scoord in C and integer*2 in FORTRAN.
In the case of the 'i' variations they take arguments of
type Icoord in C and integer in FORTRAN.
move(x, y, z)
Move current graphics position to (x, y, z). (x, y, z)
is a point in world coordinates.
Fortran:
subroutine move(x, y, z)
real x, y, z
C:
move(x, y, z)
Coord x, y, z;
rmv(deltax, deltay, deltaz)
Relative move. deltax, deltay, and deltaz are offsets
in world units.
Fortran:
subroutine rmv(deltax, deltay, deltaz)
real deltax, deltay, deltaz
C:
rmv(deltax, deltay, deltaz)
Coord deltax, deltay, deltaz;
move2(x, y)
Move graphics position to point (x, y). (x, y) is a
point in world coordinates.
Fortran:
subroutine move2(x, y)
real x, y
C:
move2(x, y)
Coord x, y;
rmv2(deltax, deltay)
Relative move2. deltax and deltay are offsets in world
units.
Fortran:
subroutine rmv2(deltax, deltay)
VOGL 1.2.8 Last change: 12 Oct 1993 15
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
real deltax, deltay
C:
rmv2(deltax, deltay)
Coord deltax, deltay;
Line routines.
These routines set the line style and line width if the
current device is capable of doing so.
deflinestyle(n, style)
Define a line style and binds it to the integer n. The
line style is a bit pattern of 16 bits width.
Fortran:
subroutine deflin(n, style)
integer n
integer style
C:
deflinestyle(n, style)
short n;
Linestyle style;
setlinestyle(n)
Sets the current line style.
Fortran:
subroutine setlin(n)
integer n
C:
setlinestyle(n)
short n;
linewidth(n)
Sets the current line width to 'n' pixels wide.
Fortran:
subroutine linewi(n)
integer n
C:
linewidth(n)
short n;
VOGL 1.2.8 Last change: 12 Oct 1993 16
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
Drawing Routines.
There are variations on all these routines that end in 's'
and also end in 'i'. In the case of the 's' variations they
take arguments of type Scoord in C and integer*2 in FORTRAN.
In the case of the 'i' variations they take arguments of
type Icoord in C and integer in FORTRAN.
draw(x, y, z)
Draw from current graphics position to (x, y, z). (x,
y, z) is a point in world coordinates.
Fortran:
subroutine draw(x, y, z)
real x, y, z
C:
draw(x, y, z)
Coord x, y, z;
rdr(deltax, deltay, deltaz)
Relative draw. deltax, deltay, and deltaz are offsets
in world units.
Fortran:
subroutine rdr(deltax, deltay, deltaz)
real deltax, deltay, deltaz
C:
rdr(deltax, deltay, deltaz)
Coord deltax, deltay, deltaz;
draw2(x, y)
Draw from current graphics position to point (x, y).
(x, y) is a point in world coordinates.
Fortran:
subroutine draw2(x, y)
real x, y
C:
draw2(x, y)
Coord x, y;
rdr2(deltax, deltay)
Relative draw2. deltax and deltay are offsets in world
units.
Fortran:
subroutine rdr2(deltax, deltay)
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VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
real deltax, deltay
C:
rdr2(deltax, deltay)
Coord deltax, deltay;
Vertex calls.
There are calls which we term 'vertex calls' which simply
specify a point in 4D, 3D or 2D. These calls take an array
which specifies the coordinates of the point. The interpre-
tation of these points is described below.
v4d(v) Specify a vertex(point) in 4D using double precision
numbers.
Fortran:
subroutine v4d(v)
real *8 v(4)
C:
v4d(v)
double v[4];
v4f(v) Specify a vertex(point) in 4D using single precision
floating point numbers.
Fortran:
subroutine v4f(v)
real v(4)
C:
v4f(v)
float v[4];
v4i(v) Specify a vertex(point) in 4D using integer numbers
Fortran:
subroutine v4i(v)
integer v(4)
C:
v4i(v)
long v[4];
v4s(v) Specify a vertex(point) in 4D using short integer
numbers
VOGL 1.2.8 Last change: 12 Oct 1993 18
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
Fortran:
subroutine v4s(v)
integer *2 v(4)
C:
v4s(v)
short v[4];
There are also equivalent calls for 3D points (v3d, v3f,
v3i, v3s) and 2D points (v2d, v2f, v2i, v2s). The only
difference is the number of elements that each vertex needs
to be specified. It should also be noted the the different
data types (ie. double, float, long and short) are merely
different ways of representing the same basic coordinate
data (calling v3s with v[] = {100,200,200} is the same as
calling v3f with v[] = {100.0, 200.0, 200.0}).
The way these points are interpreted depends on what mode
has be set up with one of the calls bgnpoint, bgnline,
bgnclosedline or bgnpolygon. The bgnpoint call specifies
that the next series of vertex calls are specifying a chain
of points (dots) to be drawn. A bgnpoint is terminated with
a endpoint call.
Fortran:
subroutine bgnpoint
C:
bgnpoint()
Fortran:
subroutine endpoint
C:
endpoint()
The bgnline call specifies that the next series of vertex
calls are specifying the points on a polyline. A bgnline
is terminated with a endline call.
Fortran:
subroutine bgnline
C:
bgnline()
Fortran:
VOGL 1.2.8 Last change: 12 Oct 1993 19
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
subroutine endline
C:
endline()
The bgnclosedline call is similar to the bgnline except that
when endclosedline is called the first point given (ie. the
one first after the bgnclosedline call) is joined to the
last point given (ie. the one just before the endclosedline
call).
Fortran:
subroutine bgncloseline
C:
bgnclosedline()
Fortran:
subroutine endclosedline
C:
endclosedline()
The bgnpolygon call specifies that the next series of vertex
calls are defining a polygon. When endpolygon is called,
the polygon is closed and filled (or drawn as an outline
depending on the mode that has been set with the polymode
call if this call has been compilied into the library.
Fortran:
subroutine bgnpolygon
C:
bgnpolygon()
Fortran:
subroutine endpolygon
C:
endpolygon()
Arcs and Circles.
There are variations on all these routines that end in 's'
and also end in 'i'. In the case of the 's' variations they
VOGL 1.2.8 Last change: 12 Oct 1993 20
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
take arguments of type Scoord in C and integer*2 in FORTRAN.
In the case of the 'i' variations they take arguments of
type Icoord in C and integer in FORTRAN.
circleprecision(nsegs)
Set the number of line segments making up a circle.
Default is currently 32. The number of segments in an
arc is calculated from nsegs according the span of the
arc. This routine is only available in VOGL.
Fortran:
subroutine circleprecision(nsegs)
integer nsegs
C:
circleprecision(nsegs)
int nsegs;
arc(x, y, radius, startang, endang)
Draw an arc. x, y, and radius are values in world
units.
Fortran:
subroutine arc(x, y, radius, startang, endang)
real x, y, radius;
integer startang, endang;
C:
arc(x, y, radius, startang, endang)
Coord x, y, radius;
Angle startang, endang;
arcf(x, y, radius, startang, endang)
Draw a filled arc. x, y, and radius are values in world
units. (How the filling is done may be changed by cal-
ling polymode , if this call has been compilied into
the library).
Fortran:
subroutine arcf(x, y, radius, startang, endang)
real x, y, radius;
integer startang, endang;
C:
arcf(x, y, radius, startang, endang)
Coord x, y, radius;
Angle startang, endang;
circ(x, y, radius)
Draw a circle. x, y, and radius are values in world
units.
Fortran:
VOGL 1.2.8 Last change: 12 Oct 1993 21
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
subroutine circ(x, y, radius)
real x, y, radius
C:
circ(x, y, radius)
Coord x, y, radius;
circf(x, y, radius)
Draw a filled circle. x, y, and radius are values in
world units. How the filling is done may be changed by
calling polymode.
Fortran:
subroutine circf(x, y, radius)
real x, y, radius
C:
circf(x, y, radius)
Coord x, y, radius;
Curve Routines.
curvebasis(id)
Set the basis matrix for a curve to the matrix refer-
enced by id. The matrix and it's id are tied together
with a call to defbasis.
Fortran:
subroutine curvebasis(id)
integer id
C:
curvebasis(id)
short id;
curveprecision(nsegs)
Define the number of line segments used to draw a
curve.
Fortran:
subroutine curveprecision(nsegs)
integer nsegs
C:
curveprecision(nsegs)
short nsegs;
rcrv(geom)
Draw a rational curve.
Fortran:
subroutine rcrv(geom)
VOGL 1.2.8 Last change: 12 Oct 1993 22
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
real geom(4,4)
C:
rcrv(geom)
Coord geom[4][4];
rcrvn(n, geom)
Draw n - 3 rational curve segments. Note: n must be at
least 4.
Fortran:
subroutine rcrvn(n, geom)
integer n
real geom(4,n)
C:
rcrvn(n, geom)
long n;
Coord geom[][4];
crv(geom)
Draw a curve.
Fortran:
subroutine crv(geom)
real geom(3,4)
C:
crv(geom)
Coord geom[4][3];
crvn(n, geom)
Draw n - 3 curve segments. Note: n must be at least 4.
Fortran:
subroutine crvn(n, geom)
integer n
real geom(3,n)
C:
crvn(n, geom)
long n;
Coord geom[][3];
curveit(n)
Draw a curve segment by iterating the top matrix in the
matrix stack as a forward difference matrix. This per-
forms 'n' iterations.
Fortran:
subroutine curveit(n)
integer n
VOGL 1.2.8 Last change: 12 Oct 1993 23
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
C:
curveit(n)
short n;
Rectangles and General Polygon Routines.
See also Vertex calls above. The way in which filled
polygons (including circles and arcs) are treated depends on
the mode that has been set with the polymode call.
There are variations on all these routines that end in 's'
and also end in 'i'. In the case of the 's' variations they
take arguments of type Scoord in C and integer*2 in FORTRAN.
In the case of the 'i' variations they take arguments of
type Icoord in C and integer in FORTRAN.
rect(x1, y1, x2, y2)
Draw a rectangle.
Fortran:
subroutine rect(x1, y1, x2, y2)
real x1, y1, x1, y2
C:
rect(x1, y1, x2, y2)
Coord x1, y1, x2, y2;
rectf(x1, y1, x2, y2)
Draw a filled rectangle. (How the filling is done may
be changed by calling polymode , if this call has been
compilied into the library).
Fortran:
subroutine rectf(x1, y1, x2, y2)
real x1, y1, x1, y2
C:
rectf(x1, y1, x2, y2)
Coord x1, y1, x2, y2;
poly2(n, points)
Construct a (x, y) polygon from an array of points pro-
vided by the user.
Fortran:
subroutine poly2(n, points)
integer n
real points(2, n)
C:
poly2(n, points)
long n;
Coord points[][2];
VOGL 1.2.8 Last change: 12 Oct 1993 24
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
polf2(n, points)
Construct a filled (x, y) polygon from an array of
points provided by the user. (How the filling is done
may be changed by calling polymode , if this call has
been compilied into the library).
Fortran:
subroutine polf2(n, points)
integer n
real points(2, n)
C:
polf2(n, points)
long n;
Coord points[][2];
poly(n, points)
Construct a polygon from an array of points provided by
the user.
Fortran:
subroutine poly(n, points)
integer n
real points(3, n)
C:
poly(n, points)
long n;
float points[][3];
polf(n, points)
Construct a filled polygon from an array of points pro-
vided by the user. (How the filling is done may be
changed by calling polymode , if this call has been
compilied into the library).
Fortran:
subroutine polf(n, points)
integer n
real points(3, n)
C:
polf(n, points)
long n;
Coord points[][3];
backface(onoff)
Turns on culling of backfacing polygons. A polygon is
backfacing if it's orientation in *screen* coords is
clockwise.
Fortran:
VOGL 1.2.8 Last change: 12 Oct 1993 25
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
subroutine backface(onoff)
logical onoff
C:
backface(onoff)
Boolean onoff;
frontface(onoff)
Turns on culling of frontfacing polygons. A polygon is
frontfacing if it's orientation in *screen* coords is
anticlockwise.
Fortran:
subroutine frontface(clockwise)
logical onoff
C:
frontface(clockwise)
Boolean onoff;
Text routines.
The original VOGLE hardware fonts "small" and "large" have
the font numbers 0 and 1 respectively. The default font is
0. For X11 displays the default fonts used by the program
can be overridden by placing the following defaults in the
~/.Xdefaults file:
vogl.smallfont: <font name>
vogl.largefont: <font name>
font(fontid)
Set the current font
Fortran:
subroutine font(fontid)
integer fontid;
C:
font(fontid)
short fontid;
cmov(x, y, z)
Change the current character position. The usual varia-
tions with the extensions 'i' and 's' also apply here.
Fortran:
subroutine cmov(x, y, z)
real x, y, z;
C:
VOGL 1.2.8 Last change: 12 Oct 1993 26
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
cmov(x, y, z)
Coord x, y, z;
cmov2(x, y)
Change the current character position in x and y. The
usual variations with the extensions 'i' and 's' also
apply here.
Fortran:
subroutine cmov2(x, y)
real x, y;
C:
cmov2(x, y)
Coord x, y;
getheight()
Return the maximum height in the current font.
Fortran:
integer function getheight
C:
long
getheight()
strwidth(s)
Return the length of the string s in screen coords.
Fortran:
integer function strwidth(s, n)
character *(*) s
integer n;
C:
long
strwidth(s)
char *s;
All transformations are cumulative, so if you rotate some-
thing and then do a translate you are translating relative
to the rotated axes. If you need to preserve the current
transformation matrix use pushmatrix(), do the drawing, and
then call popmatrix() to get back where you were before.
translate(x, y, z)
Set up a translation.
VOGL 1.2.8 Last change: 12 Oct 1993 27
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
Fortran:
subroutine translate(x, y, z)
real x, y, z
C:
translate(x, y, z)
Coord x, y, z;
scale(x, y, z)
Set up scaling factors in x, y, and z axis.
Fortran:
subroutine scale(x, y, z)
real x, y, z
C:
scale(x, y, z)
Coord x, y, z;
rot(angle, axis)
Set up a rotation in axis axis. Axis is one of 'x',
'y', or 'z'. The angle in this case is a real number
in degrees.
Fortran:
subroutine rot(angle, axis)
real angle
character axis
C:
rot(angle, axis)
float angle;
char axis;
rotate(angle, axis)
Set up a rotation in axis axis. Axis is one of 'x',
'y', or 'z', and the angle is in tenths of degrees.
Makes you feel sentimental doesn't it.
Fortran:
subroutine rotate(angle, axis)
integer angle
character axis
C:
rotate(angle, axis)
Angle angle;
char axis;
VOGL 1.2.8 Last change: 12 Oct 1993 28
VOGL(3) C LIBRARY FUNCTIONS VOGL(3)
Patch Routines.
patchbasis(tbasisid, ubasisid)
Define the t and u basis matrix id's of a patch. It is
assumed that tbasisid and ubasisid have matrices asso-
ciated with them already (this is done using the
defbasis call).
Fortran:
subroutine patchbasis(tid, uid)
integer tid, uid
C:
patchbasis(tid, ubid)
long tid, uid
patchprecision(tseg, useg)
Set the minimum number of line segments making up
curves in a patch.
Fortran:
subroutine patchprecision(tseg, useg)
integer tseg, useg
C:
patchprecision(tseg, useg)
long tseg, useg;
patchcurves(nt, nu)
Set the number of curves making up a patch.
Fortran:
subroutine patchcurves(nt, nu)
integer nt, nu
C:
patchcurves(nt, nu)
long nt, nu;
rpatch(gx, gy, gz, gw)
Draws a rational patch in the current basis, according
to the geometry matrices gx, gy, gz, and gw.
Fortran:
subroutine rpatch(gx, gy, gz, gw)
real gx(4,4), gy(4,4), gz(4,4), gw(4,4)
