// Draw a "spiral" arc defined by circle arcs around a center, a start and an end radius
void spiralArcTo( QPainterPath& path, const QPointF& center, qreal startAngle, qreal startRadius, qreal endAngle, qreal endRadius, int direction )
{
// start point
QPointF A = circlePoint( center, startRadius, startAngle );
// end point
QPointF B = circlePoint( center, endRadius, endAngle );
// middle points
qreal deltaAngle;
deltaAngle = endAngle - startAngle;
if ( direction * deltaAngle < 0.0 )
deltaAngle = deltaAngle + direction * 2 * M_PI;
QPointF I1 = circlePoint( center, 0.75 * startRadius + 0.25 * endRadius, startAngle + 0.25 * deltaAngle );
QPointF I2 = circlePoint( center, 0.50 * startRadius + 0.50 * endRadius, startAngle + 0.50 * deltaAngle );
QPointF I3 = circlePoint( center, 0.25 * startRadius + 0.75 * endRadius, startAngle + 0.75 * deltaAngle );
qreal cRadius;
QPointF cCenter;
// first circle arc
if ( ! pointsToCircle( A, I1, I2, cCenter, cRadius ) )
{
// aligned points => draw a straight line
path.lineTo( I2 );
}
else
{
// angles in the new circle
qreal a1 = atan2( cCenter.y() - A.y(), A.x() - cCenter.x() );
qreal a2 = atan2( cCenter.y() - I2.y(), I2.x() - cCenter.x() );
pathArcTo( path, cCenter, cRadius, a1, a2, direction );
}
// second circle arc
if ( ! pointsToCircle( I2, I3, B, cCenter, cRadius ) )
{
// aligned points => draw a straight line
path.lineTo( B );
}
else
{
// angles in the new circle
qreal a1 = atan2( cCenter.y() - I2.y(), I2.x() - cCenter.x() );
qreal a2 = atan2( cCenter.y() - B.y(), B.x() - cCenter.x() );
pathArcTo( path, cCenter, cRadius, a1, a2, direction );
}
}
/**
* Updates the preview points (if necessary)
*
*/
void EFX::updatePreview()
{
if (m_previewPointArray == NULL)
return;
int stepCount = 128;
int step = 0;
float stepSize = (float)(1) / ((float)(stepCount) / (M_PI * 2.0));
float i = 0;
float *x = new float;
float *y = new float;
/* Resize the array to contain stepCount points */
m_previewPointArray->resize(stepCount);
if (m_algorithm == KCircleAlgorithmName)
{
/* Draw a preview of a circle */
for (i = 0; i < (M_PI * 2.0); i += stepSize)
{
circlePoint(this, i, x, y);
m_previewPointArray->setPoint(step++,
static_cast<int> (*x),
static_cast<int> (*y));
}
}
else if (m_algorithm == KEightAlgorithmName)
{
/* Draw a preview of a eight */
for (i = 0; i < (M_PI * 2.0); i += stepSize)
{
eightPoint(this, i, x, y);
m_previewPointArray->setPoint(step++,
static_cast<int> (*x),
static_cast<int> (*y));
}
}
else if (m_algorithm == KLineAlgorithmName)
{
/* Draw a preview of a line */
for (i = 0; i < (M_PI * 2.0); i += stepSize)
{
linePoint(this, i, x, y);
m_previewPointArray->setPoint(step++,
static_cast<int> (*x),
static_cast<int> (*y));
}
}
else if (m_algorithm == KDiamondAlgorithmName)
{
/* Draw a preview of a diamond */
for (i = 0; i < (M_PI * 2.0); i += stepSize)
{
diamondPoint(this, i, x, y);
m_previewPointArray->setPoint(step++,
static_cast<int> (*x),
static_cast<int> (*y));
}
}
else if (m_algorithm == KTriangleAlgorithmName)
{
/* Draw a preview of a triangle */
for (i = 0; i < (M_PI * 2.0); i += stepSize)
{
trianglePoint(this, i, x, y);
m_previewPointArray->setPoint(step++,
static_cast<int> (*x),
static_cast<int> (*y));
}
}
else if (m_algorithm == KLissajousAlgorithmName)
{
/* Draw a preview of a lissajous */
for (i = 0; i < (M_PI * 2.0); i += stepSize)
{
lissajousPoint(this, i, x, y);
m_previewPointArray->setPoint(step++,
static_cast<int> (*x),
static_cast<int> (*y));
}
}
else
{
m_previewPointArray->resize(0);
}
delete x;
delete y;
}
QPolygonF curvedArrow( QPointF po, QPointF pm, QPointF pd, qreal startWidth, qreal width, qreal headSize, QgsArrowSymbolLayer::HeadType headType, qreal offset )
{
qreal circleRadius;
QPointF circleCenter;
if ( ! pointsToCircle( po, pm, pd, circleCenter, circleRadius ) || circleRadius > 10000.0 )
{
// aligned points => draw a straight arrow
return straightArrow( po, pd, startWidth, width, headSize, headType, offset );
}
// angles of each point
qreal angle_o = clampAngle( atan2( circleCenter.y() - po.y(), po.x() - circleCenter.x() ) );
qreal angle_m = clampAngle( atan2( circleCenter.y() - pm.y(), pm.x() - circleCenter.x() ) );
qreal angle_d = clampAngle( atan2( circleCenter.y() - pd.y(), pd.x() - circleCenter.x() ) );
// arc direction : 1 = counter-clockwise, -1 = clockwise
int direction = clampAngle( angle_m - angle_o ) < clampAngle( angle_m - angle_d ) ? 1 : -1;
qreal deltaAngle = angle_d - angle_o;
if ( direction * deltaAngle < 0.0 )
deltaAngle = deltaAngle + direction * 2 * M_PI;
qreal length = euclidian_distance( po, pd );
// for close points and deltaAngle < 180, draw a straight line
if ( fabs( deltaAngle ) < M_PI && ((( headType == QgsArrowSymbolLayer::HeadSingle ) && ( length < headSize ) ) ||
(( headType == QgsArrowSymbolLayer::HeadReversed ) && ( length < headSize ) ) ||
(( headType == QgsArrowSymbolLayer::HeadDouble ) && ( length < 2*headSize ) ) ) )
{
return straightArrow( po, pd, startWidth, width, headSize, headType, offset );
}
// ajust coordinates to include offset
circleRadius += offset;
po = circlePoint( circleCenter, circleRadius, angle_o );
pm = circlePoint( circleCenter, circleRadius, angle_m );
pd = circlePoint( circleCenter, circleRadius, angle_d );
qreal headAngle = direction * atan( headSize / circleRadius );
QPainterPath path;
if ( headType == QgsArrowSymbolLayer::HeadDouble )
{
// the first head
path.moveTo( po );
path.lineTo( circlePoint( circleCenter, circleRadius + direction * headSize, angle_o + headAngle ) );
pathArcTo( path, circleCenter, circleRadius + direction * width / 2, angle_o + headAngle, angle_d - headAngle, direction );
// the second head
path.lineTo( circlePoint( circleCenter, circleRadius + direction * headSize, angle_d - headAngle ) );
path.lineTo( pd );
path.lineTo( circlePoint( circleCenter, circleRadius - direction * headSize, angle_d - headAngle ) );
pathArcTo( path, circleCenter, circleRadius - direction * width / 2, angle_d - headAngle, angle_o + headAngle, -direction );
// the end of the first head
path.lineTo( circlePoint( circleCenter, circleRadius - direction * headSize, angle_o + headAngle ) );
path.lineTo( po );
}
else if ( headType == QgsArrowSymbolLayer::HeadSingle )
{
path.moveTo( circlePoint( circleCenter, circleRadius + direction * startWidth / 2, angle_o ) );
spiralArcTo( path, circleCenter, angle_o, circleRadius + direction * startWidth / 2, angle_d - headAngle, circleRadius + direction * width / 2, direction );
// the arrow head
path.lineTo( circlePoint( circleCenter, circleRadius + direction * headSize, angle_d - headAngle ) );
path.lineTo( pd );
path.lineTo( circlePoint( circleCenter, circleRadius - direction * headSize, angle_d - headAngle ) );
spiralArcTo( path, circleCenter, angle_d - headAngle, circleRadius - direction * width / 2, angle_o, circleRadius - direction * startWidth / 2, -direction );
path.lineTo( circlePoint( circleCenter, circleRadius + direction * startWidth / 2, angle_o ) );
}
else if ( headType == QgsArrowSymbolLayer::HeadReversed )
{
path.moveTo( circlePoint( circleCenter, circleRadius + direction * width / 2, angle_o + headAngle ) );
spiralArcTo( path, circleCenter, angle_o + headAngle, circleRadius + direction * width / 2, angle_d, circleRadius + direction * startWidth / 2, direction );
path.lineTo( circlePoint( circleCenter, circleRadius - direction * startWidth / 2, angle_d ) );
spiralArcTo( path, circleCenter, angle_d, circleRadius - direction * startWidth / 2, angle_o + headAngle, circleRadius - direction * width / 2, - direction );
path.lineTo( circlePoint( circleCenter, circleRadius - direction * headSize, angle_o + headAngle ) );
path.lineTo( po );
path.lineTo( circlePoint( circleCenter, circleRadius + direction * headSize, angle_o + headAngle ) );
path.lineTo( circlePoint( circleCenter, circleRadius + direction * width / 2, angle_o + headAngle ) );
}
return path.toSubpathPolygons().at( 0 );
}
bool EFX::preview(QVector <QPoint>& polygon)
{
bool retval = true;
int stepCount = 128;
int step = 0;
qreal stepSize = (qreal)(1) / ((qreal)(stepCount) / (M_PI * 2.0));
qreal i = 0;
qreal x = 0;
qreal y = 0;
/* Resize the array to contain stepCount points */
polygon.resize(stepCount);
/* Since algorithm is identified by a string, we don't want to do N
string comparisons on each for loop increment. So, it's a bit faster
to check the algorithm only once and then do the looping. */
if (m_algorithm == KCircleAlgorithmName)
{
/* Draw a preview of a circle */
for (step = 0; step < stepCount; step++)
{
circlePoint(this, i, &x, &y);
polygon[step] = QPoint(int(x), int(y));
i += stepSize;
}
}
else if (m_algorithm == KEightAlgorithmName)
{
/* Draw a preview of a eight */
for (step = 0; step < stepCount; step++)
{
eightPoint(this, i, &x, &y);
polygon[step] = QPoint(int(x), int(y));
i += stepSize;
}
}
else if (m_algorithm == KLineAlgorithmName)
{
/* Draw a preview of a line */
for (step = 0; step < stepCount; step++)
{
linePoint(this, i, &x, &y);
polygon[step] = QPoint(int(x), int(y));
i += stepSize;
}
}
else if (m_algorithm == KDiamondAlgorithmName)
{
/* Draw a preview of a diamond */
for (step = 0; step < stepCount; step++)
{
diamondPoint(this, i, &x, &y);
polygon[step] = QPoint(int(x), int(y));
i += stepSize;
}
}
else if (m_algorithm == KTriangleAlgorithmName)
{
/* Draw a preview of a triangle */
for (step = 0; step < stepCount; step++)
{
trianglePoint(this, i, &x, &y);
polygon[step] = QPoint(int(x), int(y));
i += stepSize;
}
}
else if (m_algorithm == KLissajousAlgorithmName)
{
/* Draw a preview of a lissajous */
for (step = 0; step < stepCount; step++)
{
lissajousPoint(this, i, &x, &y);
polygon[step] = QPoint(int(x), int(y));
i += stepSize;
}
}
else
{
polygon.resize(0);
retval = false;
}
return retval;
}