src/corelib/tools/qline.cpp File Reference

#include "qline.h"
#include "qdebug.h"
#include "qdatastream.h"
#include <private/qnumeric_p.h>
#include <math.h>

Include dependency graph for qline.cpp:

Go to the source code of this file.

Defines
#define	M_2PI   6.28318530717958647692528676655900576
#define	SAME_SIGNS(a, b)   ((a) * (b) >= 0)
Functions
QDebug	operator<< (QDebug d, const QLine &p)
static bool	qt_linef_intersect (qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)
QDebug	operator<< (QDebug d, const QLineF &p)

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Define Documentation

#define M_2PI   6.28318530717958647692528676655900576

Definition at line 230 of file qline.cpp.

Referenced by QLineF::angle().

#define SAME_SIGNS	(	a,
		b		)	((a) * (b) >= 0)

Definition at line 501 of file qline.cpp.

Referenced by qt_linef_intersect().

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Function Documentation

QDebug operator<<	(	QDebug	d,
		const QLineF &	p
	)

Definition at line 625 of file qline.cpp.

{
    d << "QLineF(" << p.p1() << "," << p.p2() << ")";
    return d;
}

QDebug operator<<	(	QDebug	d,
		const QLine &	p
	)

Definition at line 184 of file qline.cpp.

{
    d << "QLine(" << p.p1() << "," << p.p2() << ")";
    return d;
}

static bool qt_linef_intersect	(	qreal	x1,
		qreal	y1,
		qreal	x2,
		qreal	y2,
		qreal	x3,
		qreal	y3,
		qreal	x4,
		qreal	y4
	)			[static]

Definition at line 504 of file qline.cpp.

References SAME_SIGNS.

Referenced by QLineF::intersect().

{
    qreal a1, a2, b1, b2, c1, c2; /* Coefficients of line eqns. */
    qreal r1, r2, r3, r4;         /* 'Sign' values */

    a1 = y2 - y1;
    b1 = x1 - x2;
    c1 = x2 * y1 - x1 * y2;

    r3 = a1 * x3 + b1 * y3 + c1;
    r4 = a1 * x4 + b1 * y4 + c1;

    if ( r3 != 0 && r4 != 0 && SAME_SIGNS( r3, r4 ))
        return false;

    a2 = y4 - y3;
    b2 = x3 - x4;
    c2 = x4 * y3 - x3 * y4;

    r1 = a2 * x1 + b2 * y1 + c2;
    r2 = a2 * x2 + b2 * y2 + c2;

    if ( r1 != 0 && r2 != 0 && SAME_SIGNS( r1, r2 ))
        return false;

    return true;
}

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