source: trunk/demos/qtdemo/guidecircle.cpp@ 374

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#include "guidecircle.h"

static float PI2 = 2*3.1415f;

GuideCircle::GuideCircle(const QRectF &rect, float startAngle, float span, DIRECTION dir, Guide *follows) : Guide(follows)
{
    this->radiusX = rect.width() / 2.0;
    this->radiusY = rect.height() / 2.0;
    this->posX = rect.topLeft().x();
    this->posY = rect.topLeft().y();
    this->spanRad = span * PI2 / -360.0;
    if (dir == CCW){
        this->startAngleRad = startAngle * PI2 / -360.0;
        this->endAngleRad = startAngleRad + spanRad;
        this->stepAngleRad = this->spanRad / this->length();
    }
    else{
        this->startAngleRad = spanRad + (startAngle * PI2 / -360.0);
        this->endAngleRad = startAngle * PI2 / -360.0;
        this->stepAngleRad = -this->spanRad / this->length();
    }
}

float GuideCircle::length()
{
    return qAbs(this->radiusX * spanRad);
}

QPointF GuideCircle::startPos()
{
    return QPointF((posX + radiusX + radiusX * cos(startAngleRad)) * scaleX,
                   (posY + radiusY + radiusY * sin(startAngleRad)) * scaleY);
}

QPointF GuideCircle::endPos()
{
    return QPointF((posX + radiusX + radiusX * cos(endAngleRad)) * scaleX,
                   (posY + radiusY + radiusY * sin(endAngleRad)) * scaleY);
}

void GuideCircle::guide(DemoItem *item, float moveSpeed)
{
    float frame = item->guideFrame - this->startLength;
    QPointF end((posX + radiusX + radiusX * cos(startAngleRad + (frame * stepAngleRad))) * scaleX,
                (posY + radiusY + radiusY * sin(startAngleRad + (frame * stepAngleRad))) * scaleY);
    this->move(item, end, moveSpeed);
}