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VideoOverlay

Namespace: DISP3DLIB  ·  Library: 3D Display Library

#include <disp3D/videooverlay.h>

class DISP3DLIB::VideoOverlay

Camera-facing textured quad rendered at a focus point in the 3-D scene.

The overlay displays any live RGB/video frame "as a small cut-out view" on top of the 3-D scene. It is a billboarded square positioned at focusPosition with side length sizeMeters, textured with the latest video frame.

This class is a passive data holder: BrainRenderer owns the GPU resources (vertex buffer, texture, sampler, pipeline) and reads from here each frame.

src/examples/ex_disp3d_scene/main.cpp
VideoOverlay overlay; // CPU-side state; the renderer uploads frame() when frameGeneration() changes
overlay.setEnabled(true);
overlay.setFocusPosition(QVector3D(0.0f, 0.0f, 0.08f));
overlay.setSizeMeters(0.05f);
QImage frame(64, 48, QImage::Format_RGB32);
frame.fill(Qt::darkGreen);
overlay.setFrame(frame);
overlay.setFrame(QImage()); // null frames are ignored

Public Methods​

VideoOverlay()​

isEnabled()​

setEnabled(enabled)​

focusPosition()​

Returns:

  • QVector3D — World-space centre of the overlay quad (metres).

setFocusPosition(pos)​

sizeMeters()​

Returns:

  • float — Side length of the overlay quad (metres).

setSizeMeters(size)​

frame()​

Returns:

  • const QImage & — Latest video frame (CPU-side). Empty until a frame arrives.

hasFrame()​

setFrame(image)​

Push a new video frame; bumps the generation counter so the GPU re-uploads.

Parameters:

  • image : const QImage & New video frame; null images are ignored.

frameGeneration()​

Monotonic counter, incremented on every setFrame() call.

Returns:

  • quint64 — Current video frame generation.

opacity()​

Returns:

  • float — Overall opacity of the overlay [0..1].

setOpacity(opacity)​

upHint()​

Hint direction used as the quad's "up" axis.

When set (non-zero), the quad's long edge is perpendicular to this direction instead of using the default world-up billboard.

Returns:

  • QVector3D — Up-hint direction, or a zero vector if unset.

setUpHint(dir)​

isDepthEnabled()​

Returns:

  • bool — Whether depth-based parallax relief is enabled.

setDepthEnabled(enabled)​

setDepthFrame(image)​

Push a new monocular depth map (single-channel or RGBA grayscale).

Parameters:

  • image : const QImage & New depth map; null images are ignored.

depthFrame()​

hasDepthFrame()​

depthFrameGeneration()​

depthScale()​

Returns:

  • float — POM displacement scale in UV space [0..1].

setDepthScale(scale)​

depthSteps()​

Returns:

  • int — Number of POM ray-march steps (quality vs. performance).

setDepthSteps(steps)​

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 163
VideoOverlay overlay; // CPU-side state; the renderer uploads frame() when frameGeneration() changes
overlay.setEnabled(true);
overlay.setFocusPosition(QVector3D(0.0f, 0.0f, 0.08f));
overlay.setSizeMeters(0.05f);
QImage frame(64, 48, QImage::Format_RGB32);
frame.fill(Qt::darkGreen);
overlay.setFrame(frame);
overlay.setFrame(QImage()); // null frames are ignored
ok &= expect(overlay.isEnabled() && overlay.hasFrame() && overlay.frameGeneration() == 1 && overlay.frame().size() == QSize(64, 48),
             "VideoOverlay keeps the first frame and ignores the null one");

Authors of this file​