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ChannelDataModel

Namespace: DISPLIB  ·  Library: Display Library

#include <disp/channeldatamodel.h>

class DISPLIB::ChannelDataModel

Circular-buffer Qt model exposing a rolling window of the live FIFF stream as a table.

Keeps a per-channel Eigen::MatrixXd ring buffer of the most recent N seconds, tracks bad-channel flags, trigger annotations and the active SSP / compensation / filter operators so the delegate can render the pre-processed signal without touching the raw buffer.

Inheritance​

Public Methods​

ChannelDataModel(parent)​

init(pFiffInfo)​

Initialise with channel metadata from a FiffInfo.

Parameters:

  • pFiffInfo : QSharedPointer<FiffInfo> The FiffInfo describing the channels.

setData(data, firstSample)​

Replace all stored data with the provided matrix (channels × samples).

The absolute index of the first column is firstSample.

Parameters:

  • data : const Eigen::MatrixXd & Channels × samples matrix (double precision).

  • firstSample : int Absolute sample index of column 0.

appendData(data)​

Append new samples to the ring buffer.

Oldest samples are dropped when the internal capacity (maxStoredSamples) is exceeded.

Parameters:

  • data : const Eigen::MatrixXd & Channels × newSamples matrix.

clearData()​

Override the per-channel-type amplitude scale.

Key = FIFF channel kind constant (e.g. FIFFV_MEG_CH), value = physical amplitude.

Parameters:

  • scaleMap Map from FIFF kind to amplitude max. Clear all stored sample data without affecting channel metadata. After this call totalSamples() == 0 and firstSample() == 0. Emits dataChanged().

setScaleMap(scaleMap)​

setScaleMapFromStrings(scaleMap)​

setVirtualChannels(virtualChannels)​

Set extra browser-level virtual channels appended after the FIFF channels.

Parameters:

  • virtualChannels : const QVector< ChannelDisplayInfo > & Display metadata for each appended virtual channel.

setSignalColor(color)​

Set the signal line colour for all channels.

Individual channel colours are derived from this base colour by type.

Parameters:

  • color : const QColor & The base signal colour.

setMaxStoredSamples(n)​

Set the maximum number of samples to keep in the ring buffer.

When samples are appended beyond this limit, the oldest are dropped. Set to 0 (default) for unlimited storage.

Parameters:

  • n : int Maximum sample count per channel, or 0 for unlimited.

setChannelBad(channelIdx, bad)​

Mark/unmark a channel as bad.

Parameters:

  • channelIdx : int Zero-based channel index.

  • bad : bool True to mark bad.

setRemoveDC(remove)​

Enable or disable DC (mean) removal applied on-the-fly during rendering.

When enabled each channel's mean amplitude over the requested window is subtracted.

Parameters:

  • remove : bool true = subtract mean, false = raw data.

removeDC()​

setDetrendMode(mode)​

detrendMode()​

channelCount()​

firstSample()​

totalSamples()​

sfreq()​

Sampling frequency in Hz; 0 if no FiffInfo attached.

channelInfo(channelIdx)​

Display metadata for the given channel.

Parameters:

  • channelIdx : int Zero-based channel index.

Returns:

  • ChannelDisplayInfo — ChannelDisplayInfo struct with name, colour, amplitudeMax, bad flag.

channelRms(channelIdx, firstSample, lastSample)​

Compute the RMS amplitude of a channel over a sample window.

Samples outside the buffer are silently ignored. Capped internally at 1000 samples for rendering-thread safety.

Parameters:

  • channelIdx : int Zero-based channel index.

  • firstSample : int Absolute first sample (inclusive).

  • lastSample : int Absolute last sample (exclusive).

Returns:

  • float — RMS in raw (physical) units, or 0 if no data is available.

decimatedVertices(channelIdx, firstSample, lastSample, pixelWidth, vboFirstSample)​

Return a flat float array ready for VBO upload.

The array contains interleaved (x_offset, y_amplitude) pairs.

When samplesPerPixel <= 1 (zoomed in), raw samples are returned. When samplesPerPixel > 1 (zoomed out), min/max decimation is applied so that at most 2 * pixelWidth vertices are returned.

Parameters:

  • channelIdx : int Zero-based channel index.

  • firstSample : int Absolute sample index of the first desired sample.

  • lastSample : int Absolute sample index (exclusive) of the last desired sample.

  • pixelWidth : int Destination viewport width in pixels.

  • vboFirstSample : int & The absolute sample index stored at VBO vertex 0 (= firstSample, returned for the UBO uniform).

Returns:

  • QVector< float > — Flat float array: [x0, y0, x1, y1, ...] where x is offset from vboFirstSample.

sampleValueAt(channelIdx, sample)​

Return the raw sample value at a specific absolute sample index for the given channel.

Returns 0 if the sample is outside the buffer or channel index is out of range.

Parameters:

  • channelIdx : int Zero-based channel index.

  • sample : int Absolute sample index.

Returns:

  • float — Sample value in physical units, or 0 if unavailable.

Authors of this file​