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QskLinearDirection::valueAt fixed

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This commit is contained in:
Uwe Rathmann 2023-01-24 20:26:23 +01:00
parent 910a8a730f
commit f78416fc63
1 changed files with 8 additions and 4 deletions
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12
src/common/QskGradientDirection.h
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@ -71,10 +71,10 @@ class QSK_EXPORT QskLinearDirection
/*
In direction of the gradient vector, where 0.0 corresponds to
points on the perpendicular at the start and 1.0 to points on
the perpendicular of the end point ( normalized projection ).
the perpendicular of the end point.
Also corresponds to the positions of the color stops and can be
used it calculate the color at a specific position.
used to calculate the color at a specific position.
*/
qreal valueAt( const QPointF& ) const;
qreal valueAt( qreal x, qreal y ) const;
@ -262,8 +262,12 @@ inline qreal QskLinearDirection::valueAt( const QPointF& pos ) const
inline qreal QskLinearDirection::valueAt( qreal x, qreal y ) const
{
const qreal d = ( m_x2 - m_x1 ) * ( m_y2 - m_y1 );
return ( ( x - m_x1 ) * ( y - m_y1 ) + d ) / ( d + d );
// we could cache these values TODO ..
const qreal dx = m_x2 - m_x1;
const qreal dy = m_y2 - m_y1;
const qreal dot = dx * dx + dy * dy;
return ( ( x - m_x1 ) * dx + ( y - m_y1 ) * dy ) / dot;
}
inline constexpr QskConicDirection::QskConicDirection(