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_Arc... Procedures
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Arguments
x1, y1 Upper-left corner of bounding rectangle
x2, y2 Lower-right corner of bounding rectangle
x3, y3 Arc begins at the intersection with a line which
starts at the rectangle's center and passes through
this point
x4, y4 Arc ends at the intersection with a line which starts
at the rectangle's center and passes through this
point
wxy1, wxy2 Window coordinates of upper-left and lower-right
corners of bounding rectangle
wxy3, wxy4 Arc begins and ends at the intersection with lines
which start at the rectangle's center and pass
through these points
Description
The _Arc routines draw an arc given the bounding rectangle and
beginning and ending line endpoints in viewport coordinates.
The center of the arc is the center of the bounding rectangle
defined by points (x1,y1) and (x2,y2). The arc starts where it
intersects an imaginary line extending from the center of the arc
through (x3,y3). It is drawn counterclockwise about the center of
the arc, ending where it intersects an imaginary line extending
from the center of the arc through (x4,y4).
_Arc_wxy uses the window coordinate system. The center of the
arc is the center of the bounding rectangle defined by window
coordinates wxy1 and wxy2. The arc starts where it intersects
an imaginary line extending from the center of the rectangle
and passing though the points wxy3. Then the arc is drawn
counterclockwise and ends where it intersects an imaginary line
extending from the center of the arc through wxy4.
In both cases, the arc is drawn using the current color. Since an
arc does not define a closed area, it is not filled.
_GrStatus Returns
_GrClipped, _GrInvalidParameter, _GrNoOutput, _GrNotInProperMode