diff options
| -rw-r--r-- | scatterplot.cpp | 56 |
1 files changed, 50 insertions, 6 deletions
diff --git a/scatterplot.cpp b/scatterplot.cpp index 4cdeedf..fe65384 100644 --- a/scatterplot.cpp +++ b/scatterplot.cpp @@ -18,7 +18,8 @@ static const float GLYPH_OUTLINE_WIDTH = 2.0f; static const QColor GLYPH_OUTLINE_COLOR(0, 0, 0); static const QColor GLYPH_OUTLINE_COLOR_SELECTED(20, 255, 225); -// Cosshair settings +// Brush settings +static const float BRUSHING_MAX_DIST = 20.0f; static const float CROSSHAIR_LENGTH = 8.0f; static const float CROSSHAIR_THICKNESS1 = 1.0f; static const float CROSSHAIR_THICKNESS2 = 0.5f; @@ -35,8 +36,11 @@ public: ~QuadTree(); bool insert(float x, float y, int value); int query(float x, float y) const; + int nearestTo(float x, float y) const; +private: bool subdivide(); + void nearestTo(float x, float y, int &nearest, float &dist) const; QRectF m_bounds; float m_x, m_y; @@ -115,15 +119,49 @@ bool QuadTree::insert(float x, float y, int value) return true; } +int QuadTree::nearestTo(float x, float y) const +{ + if (!m_nw) { + return m_value; + } + + int nearest = -1; + float dist = 1.0f / 0.0f; + m_nw->nearestTo(x, y, nearest, dist); + m_ne->nearestTo(x, y, nearest, dist); + m_sw->nearestTo(x, y, nearest, dist); + m_se->nearestTo(x, y, nearest, dist); + if (dist < BRUSHING_MAX_DIST) + return nearest; + + return -1; +} + +void QuadTree::nearestTo(float x, float y, int &nearest, float &dist) const +{ + if (m_nw) { + m_nw->nearestTo(x, y, nearest, dist); + m_ne->nearestTo(x, y, nearest, dist); + m_sw->nearestTo(x, y, nearest, dist); + m_se->nearestTo(x, y, nearest, dist); + } else { + float d = (m_x - x)*(m_x - x) + (m_y - y)*(m_y - y); + if (d < dist) { + nearest = m_value; + dist = d; + } + } +} + int QuadTree::query(float x, float y) const { if (!m_bounds.contains(x, y)) { + // There is no way we could find the point return -1; } if (m_nw) { - int q; - + int q = -1; q = m_nw->query(x, y); if (q >= 0) return q; q = m_ne->query(x, y); @@ -131,7 +169,7 @@ int QuadTree::query(float x, float y) const q = m_sw->query(x, y); if (q >= 0) return q; q = m_se->query(x, y); - if (q >= 0) return q; + return q; } return m_value; @@ -579,7 +617,10 @@ void Scatterplot::mouseReleaseEvent(QMouseEvent *event) void Scatterplot::hoverEnterEvent(QHoverEvent *event) { QPointF pos = event->posF(); - m_brushedItem = m_quadtree->query(pos.x(), pos.y()); + int item = m_quadtree->query(pos.x(), pos.y()); + m_brushedItem = item < 0 + ? m_quadtree->nearestTo(pos.x(), pos.y()) + : item; emit itemInteractivelyBrushed(m_brushedItem); update(); @@ -588,7 +629,10 @@ void Scatterplot::hoverEnterEvent(QHoverEvent *event) void Scatterplot::hoverMoveEvent(QHoverEvent *event) { QPointF pos = event->posF(); - m_brushedItem = m_quadtree->query(pos.x(), pos.y()); + int item = m_quadtree->query(pos.x(), pos.y()); + m_brushedItem = item < 0 + ? m_quadtree->nearestTo(pos.x(), pos.y()) + : item; emit itemInteractivelyBrushed(m_brushedItem); update(); |