Java Reference
In-Depth Information
corner. When the arc width, arc height, width and height have the same values, the result
is a circle. If the values for
width
and
height
are the same and the values of
arcWidth
and
arcHeight
are 0, the result is a square.
Methods
draw3DRect
(Fig. 13.18, line 28) and
fill3DRect
(line 29) take the same
arguments. The first two specify the
top-left
corner of the rectangle. The next two argu-
ments specify the width and height of the rectangle, respectively. The last argument deter-
mines whether the rectangle is
raised
(
true
) or
lowered
(
false
). The three-dimensional
effect of
draw3DRect
appears as two edges of the rectangle in the original color and two
edges in a slightly darker color. The three-dimensional effect of
fill3DRect
appears as two
edges of the rectangle in the original drawing color and the fill and other two edges in a
slightly darker color. Raised rectangles have the original drawing color edges at the top and
left of the rectangle. Lowered rectangles have the original drawing color edges at the
bottom and right of the rectangle. The three-dimensional effect is difficult to see in some
colors.
Methods
drawOval
and
fillOval
(lines 32-33) take the same four arguments. The
first two specify the top-left coordinate of the bounding rectangle that contains the oval.
The last two specify the width and height of the bounding rectangle, respectively.
Figure 13.21 shows an oval bounded by a rectangle. The oval touches the
center
of all four
sides of the bounding rectangle. (The bounding rectangle is
not
displayed on the screen.)
(x,y)
height
width
Fig. 13.21
|
Oval bounded by a rectangle.
An
arc
is drawn as a portion of an oval. Arc angles are measured in degrees. Arcs
sweep
(i.e., move along a curve) from a
starting angle
through the number of degrees specified
by their
arc angle
. The starting angle indicates in degrees where the arc begins. The arc
angle specifies the total number of degrees through which the arc sweeps. Figure 13.22 il-
lustrates two arcs. The left set of axes shows an arc sweeping from zero degrees to approx-
imately 110 degrees. Arcs that sweep in a
counterclockwise
direction are measured in
positive
degrees
. The set of axes on the right shows an arc sweeping from zero degrees to
approximately -110 degrees. Arcs that sweep in a
clockwise
direction are measured in
neg-
ative degrees
. Note the dashed boxes around the arcs in Fig. 13.22. When drawing an arc,
we specify a bounding rectangle for an oval. The arc will sweep along part of the oval.
Graphics
methods
drawArc
and
fillArc
for drawing arcs are summarized in Fig. 13.23.