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PolylineObject

Namespace: DISP3DLIB  ·  Library: 3D Display Library

#include <disp3D/polylineobject.h>

class DISP3DLIB::PolylineObject

Renders an ordered sequence of points as connected line segments.

Each segment is one instance of a unit cylinder, using the same instance layout as DipoleObject and NetworkObject so the existing Dipole pipeline can draw it without a dedicated shader.

Connected line segments through an ordered list of points.

src/examples/ex_disp3d_scene/main.cpp
// Head-position track: N points draw N - 1 tube segments; repeated positions are skipped
PolylineObject track;
track.setPoints({Vector3f(0.0f, 0.0f, 0.0f), Vector3f(0.0f, 0.0f, 0.0f), Vector3f(0.001f, 0.0f, 0.0f), Vector3f(0.002f, 0.001f, 0.0f)});
track.setRadius(0.0005f);
track.setGradient(Qt::blue, Qt::red); // oldest to newest

Public Methods​

PolylineObject()​

Constructs a PolylineObject without any points.

~PolylineObject()​

Destroys the PolylineObject.

setPoints(vecPoints)​

Sets the points of the polyline.

Fewer than two points clears the object, since a single point has no segment to draw.

Parameters:

  • vecPoints : const QVector< Eigen::Vector3f > & Points in scene coordinates, in order.

clear()​

Clears all points.

setRadius(fRadius)​

Sets the radius of the drawn segments.

Parameters:

  • fRadius : float Segment radius in scene units.

setGradient(startColor, endColor)​

Sets the colours the segments are graded between from start to end.

Grading the line makes the direction of travel readable without any extra decoration.

Parameters:

  • startColor : const QColor & Colour of the first segment.

  • endColor : const QColor & Colour of the last segment.

streams()​

Returns:

  • InstancedStreams — CPU streams of the unit segment mesh and of one instance per segment.

renderKey()​

Returns:

  • const RenderKey & — Identity of this object in the renderer's GPU cache.

indexCount()​

Returns:

  • int — Number of indices in the unit segment mesh.

instanceCount()​

Returns:

  • int — Number of segment instances, one less than the number of points.

isVisible()​

Returns:

  • bool — Whether the polyline is drawn.

setVisible(bVisible)​

Sets whether the polyline is drawn.

Parameters:

  • bVisible : bool True to draw the polyline.

hasData()​

Returns:

  • bool — Whether there is at least one segment to draw.

Example​

Used in examples​

ex_disp3d_scene​

Disp3D scene data: sensor-to-surface interpolation, electrodes, MRI slices, video overlay and layers.

src/examples/ex_disp3d_scene/main.cpp, line 294
// Head-position track: N points draw N - 1 tube segments; repeated positions are skipped
PolylineObject track;
track.setPoints({Vector3f(0.0f, 0.0f, 0.0f), Vector3f(0.0f, 0.0f, 0.0f), Vector3f(0.001f, 0.0f, 0.0f), Vector3f(0.002f, 0.001f, 0.0f)});
track.setRadius(0.0005f);
track.setGradient(Qt::blue, Qt::red); // oldest to newest
ok &= expect(track.hasData() && track.instanceCount() == 2, "PolylineObject: four positions with one repeat give two segments");

Authors of this file​