diff --git a/src/bezierline.cpp b/src/bezierline.cpp index 6c702dc..4654ef7 100644 --- a/src/bezierline.cpp +++ b/src/bezierline.cpp @@ -5,6 +5,8 @@ #include #include #include +#include +#include BezierLine::BezierLine(){ } @@ -118,6 +120,27 @@ QList BezierLine::getPoints(){ return QList(); } +QPointF BezierLine::calculateBezierPoint(const QPointF &begin, const QPointF &begin_control, const QPointF &end_control, const QPointF &end, qreal t){ + QPointF p_b = qPow(1.0-t, 3) * begin + + 3 * qPow(1.0 - t, 2) * t * begin_control + + 3 * qPow(t, 2) * (1.0 - t) * end_control + + qPow(t, 3) * end; + return p_b; +} + +QPointF BezierLine::calculateBezierDerivative(const QPointF &begin, const QPointF &begin_control, const QPointF &end_control, const QPointF &end, qreal t){ + QPointF p_b = 3 * qPow(1.0-t, 2) * (begin_control - begin) + + 6 * (1.0 - t) * t * (end_control - begin_control) + + 3 * qPow(t, 2) * (end - end_control); + return p_b; +} + +QPointF BezierLine::calculateBezierSecondDerivative(const QPointF &begin, const QPointF &begin_control, const QPointF &end_control, const QPointF &end, qreal t){ + QPointF p_b = 6 * (1.0-t) * (end_control - 2 * begin_control + begin) + + 6 * t * (end - 2 * end_control + begin_control); + return p_b; +} + void BezierLine::paint(QPainter* painter, const QStyleOptionGraphicsItem* /*option*/, QWidget* /*widget*/){ QPen position_pen, control_pen, line_pen; @@ -163,13 +186,39 @@ void BezierLine::paint(QPainter* painter, const QStyleOptionGraphicsItem* /*opti while(t < 1.0){ - QPointF p_b = qPow(1.0-t, 3) * (it-1)->position + - 3 * qPow(1.0 - t, 2) * t * (it-1)->control_after + - 3 * qPow(t, 2) * (1.0 - t) * it->control_before + - qPow(t, 3) * it->position; + auto p_b = calculateBezierPoint((it-1)->position, (it-1)->control_after, it->control_before, it->position, t); + auto p_b_1 = calculateBezierDerivative((it-1)->position, (it-1)->control_after, it->control_before, it->position, t); + auto p_b_2 = calculateBezierSecondDerivative((it-1)->position, (it-1)->control_after, it->control_before, it->position, t); + + Eigen::Matrix2d p_b_concat = (Eigen::Matrix2d() << p_b_1.x(), p_b_2.x(), + p_b_1.y(), p_b_2.y()).finished(); + + Eigen::Vector2d p_b_1_eig = (Eigen::Vector2d() << p_b_1.x(), p_b_1.y()).finished(); + + auto nom = p_b_concat.determinant(); + auto denom = qPow(p_b_1_eig.norm(), 3); + + auto curvature = nom / denom; + + painter->setPen(control_pen); painter->drawEllipse(p_b.x() - 1, p_b.y() - 1, 2, 2); + + QPen curvature_pen; + curvature = std::clamp(curvature, 0.0001, 1.0); + + + + int hue = 250 + (std::log10(abs(curvature)) + 4) / 4 * 110; + QColor curvature_color; + + curvature_color.setHsl(hue, 255, 127, 255); + + curvature_pen.setWidth(2); + curvature_pen.setStyle(Qt::SolidLine); + curvature_pen.setColor(curvature_color); + painter->setPen(curvature_pen); painter->drawLine(last, p_b); last = p_b; t += delta;

q_pen_drawer

Commit Details

adds curvature coloring in the line drawing

Author

Committer

Parent commits

Changes

Changed Files (6)