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<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QPointArray Class Reference</h1>
<p>The QPointArray class provides an array of points.
<a href="#details">More...</a>
<p><tt>#include <<a href="qpointarray-h.html">qpointarray.h</a>></tt>
<p>Inherits <a href="qmemarray.html">QMemArray</a><QPoint>.
<p><a href="qpointarray-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li class=fn><a href="#QPointArray"><b>QPointArray</b></a> ()</li>
<li class=fn><a href="#~QPointArray"><b>~QPointArray</b></a> ()</li>
<li class=fn><a href="#QPointArray-2"><b>QPointArray</b></a> ( int size )</li>
<li class=fn><a href="#QPointArray-3"><b>QPointArray</b></a> ( const QPointArray & a )</li>
<li class=fn><a href="#QPointArray-4"><b>QPointArray</b></a> ( const QRect & r, bool closed = FALSE )</li>
<li class=fn>QPointArray & <a href="#operator-eq"><b>operator=</b></a> ( const QPointArray & a )</li>
<li class=fn>QPointArray <a href="#copy"><b>copy</b></a> () const</li>
<li class=fn>void <a href="#translate"><b>translate</b></a> ( int dx, int dy )</li>
<li class=fn>QRect <a href="#boundingRect"><b>boundingRect</b></a> () const</li>
<li class=fn>void <a href="#point"><b>point</b></a> ( uint index, int * x, int * y ) const</li>
<li class=fn>QPoint <a href="#point-2"><b>point</b></a> ( uint index ) const</li>
<li class=fn>void <a href="#setPoint"><b>setPoint</b></a> ( uint index, int x, int y )</li>
<li class=fn>void <a href="#setPoint-2"><b>setPoint</b></a> ( uint i, const QPoint & p )</li>
<li class=fn>bool <a href="#putPoints"><b>putPoints</b></a> ( int index, int nPoints, int firstx, int firsty, ... )</li>
<li class=fn>bool <a href="#putPoints-3"><b>putPoints</b></a> ( int index, int nPoints, const QPointArray & from, int fromIndex = 0 )</li>
<li class=fn>void <a href="#makeArc"><b>makeArc</b></a> ( int x, int y, int w, int h, int a1, int a2 )</li>
<li class=fn>void <a href="#makeEllipse"><b>makeEllipse</b></a> ( int x, int y, int w, int h )</li>
<li class=fn>void <a href="#makeArc-2"><b>makeArc</b></a> ( int x, int y, int w, int h, int a1, int a2, const QWMatrix & xf )</li>
<li class=fn>QPointArray <a href="#cubicBezier"><b>cubicBezier</b></a> () const</li>
</ul>
<h2>Related Functions</h2>
<ul>
<li class=fn>QDataStream & <a href="#operator-lt-lt"><b>operator<<</b></a> ( QDataStream & s, const QPointArray & a )</li>
<li class=fn>QDataStream & <a href="#operator-gt-gt"><b>operator>></b></a> ( QDataStream & s, QPointArray & a )</li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QPointArray class provides an array of points.
<p>
<p> A QPointArray is an array of <a href="qpoint.html">QPoint</a> objects. In addition to the
functions provided by <a href="qmemarray.html">QMemArray</a>, QPointArray provides some
point-specific functions.
<p> For convenient reading and writing of the point data use
setPoints(), <a href="#putPoints">putPoints</a>(), <a href="#point">point</a>(), and <a href="#setPoint">setPoint</a>().
<p> For geometry operations use <a href="#boundingRect">boundingRect</a>() and <a href="#translate">translate</a>(). There
is also the <a href="qwmatrix.html#map">QWMatrix::map</a>() function for more general
transformations of QPointArrays. You can also create arcs and
ellipses with <a href="#makeArc">makeArc</a>() and <a href="#makeEllipse">makeEllipse</a>().
<p> Among others, QPointArray is used by <a href="qpainter.html#drawLineSegments">QPainter::drawLineSegments</a>(),
<a href="qpainter.html#drawPolyline">QPainter::drawPolyline</a>(), <a href="qpainter.html#drawPolygon">QPainter::drawPolygon</a>() and
<a href="qpainter.html#drawCubicBezier">QPainter::drawCubicBezier</a>().
<p> Note that because this class is a QMemArray, copying an array and
modifying the copy modifies the original as well, i.e. a <a href="shclass.html#shallow-copy">shallow copy</a>. If you need a <a href="shclass.html#deep-copy">deep copy</a> use <a href="#copy">copy</a>() or <a href="qmemarray.html#detach">detach</a>(), for example:
<p> <pre>
void drawGiraffe( const QPointArray & r, QPainter * p )
{
QPointArray tmp = r;
tmp.<a href="qmemarray.html#detach">detach</a>();
// some code that modifies tmp
p->drawPoints( tmp );
}
</pre>
<p> If you forget the tmp.detach(), the const array will be modified.
<p> <p>See also <a href="qpainter.html">QPainter</a>, <a href="qwmatrix.html">QWMatrix</a>, <a href="qmemarray.html">QMemArray</a>, <a href="graphics.html">Graphics Classes</a>, <a href="images.html">Image Processing Classes</a>, and <a href="shared.html">Implicitly and Explicitly Shared Classes</a>.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="QPointArray"></a>QPointArray::QPointArray ()
</h3>
<p> Constructs a null point array.
<p> <p>See also <a href="qmemarray.html#isNull">isNull</a>().
<h3 class=fn><a name="QPointArray-2"></a>QPointArray::QPointArray ( int size )
</h3>
<p> Constructs a point array with room for <em>size</em> points. Makes a
null array if <em>size</em> == 0.
<p> <p>See also <a href="qmemarray.html#resize">resize</a>() and <a href="qmemarray.html#isNull">isNull</a>().
<h3 class=fn><a name="QPointArray-3"></a>QPointArray::QPointArray ( const <a href="qpointarray.html">QPointArray</a> & a )
</h3>
<p> Constructs a <a href="shclass.html#shallow-copy">shallow copy</a> of the point array <em>a</em>.
<p> <p>See also <a href="#copy">copy</a>() and <a href="qmemarray.html#detach">detach</a>().
<h3 class=fn><a name="QPointArray-4"></a>QPointArray::QPointArray ( const <a href="qrect.html">QRect</a> & r, bool closed = FALSE )
</h3>
Constructs a point array from the rectangle <em>r</em>.
<p> If <em>closed</em> is FALSE, then the point array just contains the
following four points in the listed order: r.topLeft(),
r.topRight(), r.bottomRight() and r.bottomLeft().
<p> If <em>closed</em> is TRUE, then a fifth point is set to r.topLeft().
<h3 class=fn><a name="~QPointArray"></a>QPointArray::~QPointArray ()
</h3>
<p> Destroys the point array.
<h3 class=fn><a href="qrect.html">QRect</a> <a name="boundingRect"></a>QPointArray::boundingRect () const
</h3>
Returns the bounding rectangle of the points in the array, or
<a href="qrect.html">QRect</a>(0,0,0,0) if the array is empty.
<h3 class=fn><a href="qpointarray.html">QPointArray</a> <a name="copy"></a>QPointArray::copy () const
</h3>
<p> Creates a <a href="shclass.html#deep-copy">deep copy</a> of the array.
<p> <p>See also <a href="qmemarray.html#detach">detach</a>().
<h3 class=fn><a href="qpointarray.html">QPointArray</a> <a name="cubicBezier"></a>QPointArray::cubicBezier () const
</h3>
Returns the Bezier points for the four control points in this
array.
<h3 class=fn>void <a name="makeArc"></a>QPointArray::makeArc ( int x, int y, int w, int h, int a1, int a2 )
</h3>
Sets the points of the array to those describing an arc of an
ellipse with size, width <em>w</em> by height <em>h</em>, and position (<em>x</em>,
<em>y</em>), starting from angle <em>a1</em> and spanning by angle <em>a2</em>. The
resulting array has sufficient resolution for pixel accuracy (see
the overloaded function which takes an additional <a href="qwmatrix.html">QWMatrix</a>
parameter).
<p> Angles are specified in 16ths of a degree, i.e. a full circle
equals 5760 (16*360). Positive values mean counter-clockwise,
whereas negative values mean the clockwise direction. Zero degrees
is at the 3 o'clock position.
<p> See the <a href="qcanvasellipse.html#anglediagram">angle diagram</a>.
<h3 class=fn>void <a name="makeArc-2"></a>QPointArray::makeArc ( int x, int y, int w, int h, int a1, int a2, const <a href="qwmatrix.html">QWMatrix</a> & xf )
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Sets the points of the array to those describing an arc of an
ellipse with width <em>w</em> and height <em>h</em> and position (<em>x</em>, <em>y</em>),
starting from angle <em>a1</em>, and spanning angle by <em>a2</em>, and
transformed by the matrix <em>xf</em>. The resulting array has
sufficient resolution for pixel accuracy.
<p> Angles are specified in 16ths of a degree, i.e. a full circle
equals 5760 (16*360). Positive values mean counter-clockwise,
whereas negative values mean the clockwise direction. Zero degrees
is at the 3 o'clock position.
<p> See the <a href="qcanvasellipse.html#anglediagram">angle diagram</a>.
<h3 class=fn>void <a name="makeEllipse"></a>QPointArray::makeEllipse ( int x, int y, int w, int h )
</h3>
Sets the points of the array to those describing an ellipse with
size, width <em>w</em> by height <em>h</em>, and position (<em>x</em>, <em>y</em>).
<p> The returned array has sufficient resolution for use as pixels.
<h3 class=fn><a href="qpointarray.html">QPointArray</a> & <a name="operator-eq"></a>QPointArray::operator= ( const <a href="qpointarray.html">QPointArray</a> & a )
</h3>
<p> Assigns a <a href="shclass.html#shallow-copy">shallow copy</a> of <em>a</em> to this point array and returns a
reference to this point array.
<p> Equivalent to <a href="qmemarray.html#assign">assign</a>(a).
<p> <p>See also <a href="#copy">copy</a>() and <a href="qmemarray.html#detach">detach</a>().
<h3 class=fn>void <a name="point"></a>QPointArray::point ( uint index, int * x, int * y ) const
</h3>
Reads the coordinates of the point at position <em>index</em> within the
array and writes them into <em>*x</em> and <em>*y</em>.
<h3 class=fn><a href="qpoint.html">QPoint</a> <a name="point-2"></a>QPointArray::point ( uint index ) const
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Returns the point at position <em>index</em> within the array.
<h3 class=fn>bool <a name="putPoints"></a>QPointArray::putPoints ( int index, int nPoints, int firstx, int firsty, ... )
</h3>
Copies <em>nPoints</em> points from the variable argument list into this
point array from position <em>index</em>, and resizes the point array if
<tt>index+nPoints</tt> exceeds the size of the array.
<p> Returns TRUE if successful, or FALSE if the array could not be
resized (typically due to lack of memory).
<p> The example code creates an array with three points (4,5), (6,7)
and (8,9), by expanding the array from 1 to 3 points:
<p> <pre>
QPointArray a( 1 );
a[0] = QPoint( 4, 5 );
a.<a href="#putPoints">putPoints</a>( 1, 2, 6,7, 8,9 ); // index == 1, points == 2
</pre>
<p> This has the same result, but here putPoints overwrites rather
than extends:
<pre>
QPointArray a( 3 );
a.<a href="#putPoints">putPoints</a>( 0, 3, 4,5, 0,0, 8,9 );
a.<a href="#putPoints">putPoints</a>( 1, 1, 6,7 );
</pre>
<p> The points are given as a sequence of integers, starting with <em>firstx</em> then <em>firsty</em>, and so on.
<p> <p>See also <a href="qmemarray.html#resize">resize</a>().
<h3 class=fn>bool <a name="putPoints-3"></a>QPointArray::putPoints ( int index, int nPoints, const <a href="qpointarray.html">QPointArray</a> & from, int fromIndex = 0 )
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> This version of the function copies <em>nPoints</em> from <em>from</em> into
this array, starting at <em>index</em> in this array and <em>fromIndex</em> in
<em>from</em>. <em>fromIndex</em> is 0 by default.
<p> <pre>
QPointArray a;
a.<a href="#putPoints">putPoints</a>( 0, 3, 1,2, 0,0, 5,6 );
// a is now the three-point array ( 1,2, 0,0, 5,6 );
QPointArray b;
b.<a href="#putPoints">putPoints</a>( 0, 3, 4,4, 5,5, 6,6 );
// b is now ( 4,4, 5,5, 6,6 );
a.<a href="#putPoints">putPoints</a>( 2, 3, b );
// a is now ( 1,2, 0,0, 4,4, 5,5, 6,6 );
</pre>
<h3 class=fn>void <a name="setPoint"></a>QPointArray::setPoint ( uint index, int x, int y )
</h3>
Sets the point at position <em>index</em> in the array to <em>(x, y)</em>.
<p>Example: <a href="themes-example.html#x231">themes/wood.cpp</a>.
<h3 class=fn>void <a name="setPoint-2"></a>QPointArray::setPoint ( uint i, const <a href="qpoint.html">QPoint</a> & p )
</h3>
<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Sets the point at array index <em>i</em> to <em>p</em>.
<h3 class=fn>void <a name="translate"></a>QPointArray::translate ( int dx, int dy )
</h3>
Translates all points in the array by <em>(dx, dy)</em>.
<hr><h2>Related Functions</h2>
<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-lt-lt"></a>operator<< ( <a href="qdatastream.html">QDataStream</a> & s, const <a href="qpointarray.html">QPointArray</a> & a )
</h3>
<p> Writes the point array, <em>a</em> to the stream <em>s</em> and returns a
reference to the stream.
<p> <p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>.
<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-gt-gt"></a>operator>> ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qpointarray.html">QPointArray</a> & a )
</h3>
<p> Reads a point array, <em>a</em> from the stream <em>s</em> and returns a
reference to the stream.
<p> <p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>.
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