endlin(3G)endlin(3G)NAME
bgnlin, endlin - delimit the vertices of a line
FORTRAN 77 SPECIFICATION
subroutine bgnlin
subroutine endlinPARAMETERS
none
DESCRIPTION
Vertices specified after bgnlin and before endlin are interpreted as
endpoints of a series of line segments. Use the v routine to specify a
vertex. The first vertex connects to the second; the second connects to
the third; and so on until the next-to-last vertex connects to the last
one. The last vertex does not connect to the first vertex. Use bgnclo
to connect the first and last points. All segments use the current
linestyle, which is reset prior to the first segment and continues
through subsequent segments.
Between bgnlin and endlin, you can issue only the following Graphics
Library routines: c, color, cpack, lmbind, lmcolo, lmdef, n, RGBcol, t,
and v. lmdef and lmbind can be used to respecify only materials and
their properties. If the color changes between a pair of vertices, the
color of the line segment will be constant if the current shading model
is FLAT and interpolated if the current shading model is GOURAU. In
color map mode, the colors vary through the color map; to get reasonable
results, the color map should contain a ramp.
There is no limit to the number of vertices that can be specified between
bgnlin and endlin. After endlin, the current graphics position is
undefined.
By default, line vertices are forced to the nearest pixel center prior to
scan conversion. Line accuracy is improved when this coercion is
defeated with the subpix command. Subpixel vertex positioning is
especially important when lines are scan-converted with antialiasing
enabled (see linesm).
SEE ALSO
bgnclo, c, linesm, linewi, lsrepe, scrsub, setlin, shadem, subpix, v
BUGS
On the IRIS-4D B and G models, and on the Personal Iris without Turbo
Graphics, if the color changes between a pair of vertices, the color of
the line segment will be constant regardless of the current shading
model.
On the IRIS-4D GT and GTX models, if the color changes between a pair of
vertices, the color of the line segment will be interpolated regardless
of the current shading model.
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endlin(3G)endlin(3G)
On the IRIS-4D B and G models, the linestyle is reset at the start of
each segment, rather than only at the start of the first segment.
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