VOGL MANUAL
NAME
DESCRIPTION
INDEX
BUGS
Routine Index
- vo_xt_window(display, xwin, width, height)
- vo_xt_win_size(width, height)
- vo_sunview_canvas(canvas, width, height)
- vo_sunview_canvas_size(width, height)
- vinit(device)
- ginit()
- winopen(title)
- gexit()
- voutput(path)
- vnewdev(device)
- getplanes()
- vsetflush(yesno)
- vflush()
- prefposition(x1, y1, x2, y2)
- prefsize(width, height)
- reshapeviewport
- clear()
- color(col)
- colorf(col)
- mapcolor(indx, red, green, blue)
- defbasis(id, mat)
- polymode(mode)
- qdevice(dev)
- unqdevice(dev)
- qread(data)
- isqueued(dev)
- qtest()
- qreset()
- getbutton(dev)
- getvaluator(dev)
- viewport(left, right, bottom, top)
- pushviewport()
- popviewport()
- getviewport(left, right, bottom, top)
- pushattributes()
- popattributes()
- ortho(left, right, bottom, top, near, far)
- ortho2(left, right, bottom, top)
- perspective(fov, aspect, near, far)
- window(left, right, bot, top, near, far)
- pushmatrix()
- popmatrix()
- polarview(dist, azim, inc, twist)
- lookat(vx, vy, vz, px, py, pz, twist)
- move(x, y, z)
- rmv(deltax, deltay, deltaz)
- move2(x, y)
- rmv2(deltax, deltay)
- deflinestyle(n, style)
- setlinestyle(n)
- linewidth(n)
- draw(x, y, z)
- rdr(deltax, deltay, deltaz)
- draw2(x, y)
- rdr2(deltax, deltay)
- v4d(v)
- v4f(v)
- v4i(v)
- v4s(v)
- circleprecision(nsegs)
- arc(x, y, radius, startang, endang)
- arcf(x, y, radius, startang, endang)
- circ(x, y, radius)
- circf(x, y, radius)
- curvebasis(id)
- curveprecision(nsegs)
- rcrv(geom)
- rcrvn(n, geom)
- crv(geom)
- crvn(n, geom)
- curveit(n)
- rect(x1, y1, x2, y2)
- rectf(x1, y1, x2, y2)
- poly2(n, points)
- polf2(n, points)
- poly(n, points)
- polf(n, points)
- backface(onoff)
- frontface(onoff)
- font(fontid)
- cmov(x, y, z)
- cmov2(x, y)
- getheight()
- getwidth()
- strwidth(s)
- charstr(str)
- translate(x, y, z)
- scale(x, y, z)
- rot(angle, axis)
- rotate(angle, axis)
- patchbasis(tbasisid, ubasisid)
- patchprecision(tseg, useg)
- patchcurves(nt, nu)
- rpatch(gx, gy, gz, gw)
- patch(gx, gy, gz)
- pnt(x, y, z)
- pnt2(x, y)
- makeobj(n)
- closeobj()
- genobj()
- getopenobj()
- callobj(n)
- isobj(n)
- delobj(n)
- gconfig
- doublebuffer
- singlebuffer
- backbuffer(Boolean)
- frontbuffer(Boolean)
- swapbuffers()
- getgpos(x, y, z, w)
- getcpos(ix, iy)
NAME
VOGL - A very ordinary GL 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 applica-
tion's toolkit. Under these circumstances, the toolkit is
is responsible for handling of all input events, and VOGL
simply draws into the supplied window. These calls are
only available from C. Also see the directories exam-
ples/xt, examples/xview and examples/sunview.
For X based toolkits the following two calls may be used:
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 can-
vas
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:
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 - postscript devices
ppostscript - postscript devices (portrait mode)
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.
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 initiali-
sation. This routine is marked for obsolescence.
The routine winopen (see below) should be used
instead.
Fortran:
subroutine ginit
C:
ginit()
winopen(title)
Open the graphics device and do the basic initiali-
sation. This routine should be used instead of
ginit.
Fortran:
subroutine winopen(title, len)
character*(*) title
integer len
C:
winopen(title)
char *title;
gexit()
Reset the window/terminal (must be the last VOGL
routine 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;
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 of the dis-
play.
On some devices (particularly X11) considerable speedups
in display can be achieved by not flushing each graphics
primitive 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 swap-
buffers(), or vflush()). If yesno = 1 (.true.)
then do the flushing as described above.
Fortran:
subroutine vsetflush(yesno)
logical yesno
C:
void
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 sun-
view 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 spec-
ify your geometry as you please).
prefposition(x1, y1, x2, y2)
Specify the preferred position of the window opened
by the *next* winopen.
Fortran:
subroutine prefposition(x1, y1, x2, y2)
integer x1, y1, x2, y2
C:
prefposition(x1, y1, x2, y2)
long x1, y1, x2, y2
prefsize(width, height)
Specify the preferred width and height of the win-
dow opened by the *next* winopen.
Fortran:
subroutine prefsize(width, height)
integer width, height
C:
prefsize(width, height)
long width, height;
reshapeviewport
This is occasionally used in Iris GL if a REDRAW
event rolls up. While VOGL is unlikely to ever pro-
vide a REDRAW event the call is provided for com-
patibility.
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 argu-
ment. In Iris GL there are sometimes good reasons
for using this routine over color. See the GL man-
ual for more details.
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 repre-
sented 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 con-
stants are truncated to PYM_LI, PYM_FI, PYM_PO and
PYM_HO respectivly. These appear in fvogl.h.
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 impor-
tant to have called qdevice before doing this.
Fortran:
integer function qread(data)
integer*2 data
C:
long qread(data)
short *data;
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
pending 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)
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)
Screencoordleft, 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)
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 popat-
tributes 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 clip-
ping 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;
ortho2(left, right, bottom, top)
Define x (left, right), and y (bottom, top) clip-
ping 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
coordinates 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
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;
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 argu-
ments 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 off-
sets 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)
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;
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 argu-
ments 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 off-
sets 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)
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 inter-
pretation of these points is described below.
v4d(v) Specify a vertex(point) in 4D using double preci-
sion 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 preci-
sion 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
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 termi-
nated 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:
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 end-
closedline call).
Fortran:
subroutine bgncloseline
C:
bgnclosedline()
Fortran:
subroutine endclosedline
C:
endclosedline()
The bgnpolygon call specifies that the next series of ver-
tex 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 take arguments of type Scoord in C and integer*2 in
FORTRAN. In the case of the 'i' variations they take argu-
ments 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 calling 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:
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 ref-
erenced 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)
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 performs 'n' iterations.
Fortran:
subroutine curveit(n)
integer n
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 argu-
ments 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
provided by the user.
Fortran:
subroutine poly2(n, points)
integer n
real points(2, n)
C:
poly2(n, points)
long n;
Coord points[][2];
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 pro-
vided 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
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 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:
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
variations with the extensions 'i' and 's' also
apply here.
Fortran:
subroutine cmov(x, y, z)
real x, y, z;
C:
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()
getwidth()
Return the maximum width in the current font.
Fortran:
integer function getwidth
C:
long
getwidth()
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;
charstr(str)
Draw the text in string at the current position.
Fortran:
subroutine charst(str, len)
character*(*) str
integer len
C:
charstr(str)
char *str;
Transformations Routines.
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.
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 num-
ber 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;
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
associated 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)
C:
rpatch(gx, gy, gz, gw)
Matrix gx, gy, gz, gw;
patch(gx, gy, gz)
Draws a patch in the current basis, according to
the geometry matrices gx, gy, and gz.
Fortran:
subroutine patch(gx, gy, gz)
real gx(4,4), gy(4,4), gz(4,4)
C:
patch(gx, gy, gz)
Matrix gx, gy, gz;
Point 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 argu-
ments of type Icoord in C and integer in FORTRAN.
pnt(x, y, z)
Draw a point at x, y, z
Fortran:
subroutine pnt(x, y, z)
real x, y, z
C:
pnt(x, y, z)
Coord x, y, z;
pnt2(x, y)
Draw a point at x, y.
Fortran:
subroutine pnt2(x, y)
real x, y
C:
pnt2(x, y)
Coord x, y;
Object Routines.
Objects are graphical entities created by the drawing rou-
tines called between makeobj and closeobj. Objects may be
called from within other objects. When an object is cre-
ated most of the calculations required by the drawing rou-
tines called within it are done up to where the calcula-
tions involve the current transformation matrix. So if you
need to draw the same thing several times on the screen
but in different places it is faster to use objects than
to call the appropriate drawing routines each time.
makeobj(n)
Commence the object number n.
Fortran:
subroutine makeobj(n)
integer n
C:
makeobj(n)
Object n;
closeobj()
Close the current object.
Fortran:
subroutine closeobj()
C:
closeobj()
genobj()
Returns a unique object identifier.
Fortran:
integer function genobj()
C:
Object
genobj()
getopenobj()
Return the number of the current object.
Fortran:
integer function getopenobj()
C:
Object
getopenobj()
callobj(n)
Draw object number n.
Fortran:
subroutine callobj(n)
integer n
C:
callobj(n)
Object n;
isobj(n)
Returns non-zero if there is an object of number n.
Fortran:
logical function isobj(n)
integer n
C:
Boolean
isobj(n)
Object n;
delobj(n)
Delete the object number n.
Fortran:
subroutine delobj(n)
integer n
C:
delobj(n)
Object n;
Double Buffering.
Where possible VOGL allows for front and back buffers to
enable things like animation and smooth updating of the
screen. Note: it isn't possible to have backbuffer and
frontbuffer true at the same time.
gconfig
With Iris GL you must call gconfig for things like
doublebuffering to take effect.
Fortran:
subroutine gconfig
C:
gconfig()
doublebuffer
Flags our intention to do double buffering.
Fortran:
subroutine doublebuffer
C:
doublebuffer()
singlebuffer
Switch back to singlebuffer mode.
Fortran:
subroutine singlebuffer
C:
singlebuffer()
backbuffer(Boolean)
Make VOGL draw in the backbuffer.
Fortran:
subroutine backbuffer(yesno)
logical yesno;
C:
backbuffer(yesno)
Boolean yesno;
frontbuffer(Boolean)
Make VOGL draw in the front buffer.
Fortran:
subroutine frontbuffer(yesno)
logical yesno;
C:
frontbuffer(yesno)
Boolean yesno;
swapbuffers()
Swap the front and back buffers.
Fortran:
subroutine swapbuffers
C:
swapbuffers()
Position Routines.
getgpos(x, y, z, w)
Gets the current graphics position in world coords.
Fortran:
subroutine getgpos(x, y, z, w)
real x, y, z
C:
getgpos(x, y, z, w)
Coord *x, *y, *z, *w;
getcpos(ix, iy)
Gets the current character position in screen
coords.
Fortran:
subroutine getcpo(ix, iy)
integer ix, iy
C:
getcpos(ix, iy)
Scoord *ix, *iy;
BUGS
Double buffering isn't supported on all devices.
The yobbarays may be turned on or they may be turned off.
VOGL 1.2 22 Apr 1992 33