Programming and Graphics

B Summary ofVogleFunctions 321

Drawing

draw (x, y, z) Draw from the current graphics position

to the point (x, y, z)

rdraw (deltax, deltay, deltaz) Relative draw

draw2 (x, y) Draw from the current graphics position

to the point (x, y)

rdraw2 (deltax,deltay) Relative draw

sdraw2 (x, y) Draw in screen coordinates, -1.0 to 1.0

rsdraw2 (deltax, deltay) Relative draw in screen units, -1.0 to 1.0

Viewport

It is possible to subdivide the screen into rectangular partitions called viewports,
and then navigate inside each partition using screen coordinates ranging from -1.0
to 1.0.

viewport (left, right, bottom, top) Specifies a portion of the screen

for drawing; the box limits: left,

right, bottom, and top are

real values in screen coordinates.

pushviewport () Save the current viewport

popviewport () Retrieve last viewport

getviewport (left, right, bottom, top) Returns limits of current viewport

in screen coordinates

Aspect details

float getaspec t() Returns the height-over-width ratio

of the display device

getfactors (wfact, hfact) Returns the width over the minimum of

the width and height of the device,

and the height over the minimum of

the width and height of the device

getdisplaysize (w, h) Returns width and height of device in pixels

Attribute stack

pushattributes () Save the current attributes on the attribute stack

popattributes () Restore attributes to what they were

at last pushattributes