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// Copyright (C) 2025 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "ecggraph.h"
#include "mainwindow.h"
#include <QRandomGenerator>
#include <QColor>
#include <cmath>
ECGGraph::ECGGraph()
{
// Empty space size in percentages of data
m_clearAmount = m_dataLength * 0.04f;
}
void ECGGraph::initialize()
{
m_waveData.fill(0, m_dataLength);
m_spo2Data.fill(0, m_dataLength);
}
// Paint all waves
void ECGGraph::paintWaves(QCanvasPainter *painter, float x, float y, float w, float h)
{
m_theme = &m_mainWindow->m_theme;
m_painter = painter;
m_lineWidth = m_mainWindow->m_px * 2.5f;
// Update heartDataIndex and clearDataIndex
m_heartDataIndex++;
if (m_heartDataIndex >= m_dataLength)
m_heartDataIndex = 0;
m_clearDataIndex = (m_heartDataIndex + m_clearAmount) % m_dataLength;
// Paint the graph lines
const float graphHeight = h * 0.5f;
const float graphWidth = w;
float posX = x;
float posY = y;
paintWave(posX, posY, graphWidth, graphHeight);
posY += graphHeight;
paintSpo2Wave(posX, posY, graphWidth, graphHeight);
if (m_beatDataIndex != -1) {
// Beat is progressing
m_beatDataIndex++;
if (m_beatDataIndex > 7)
m_beatDataIndex = -1;
}
m_currentFrame++;
}
void ECGGraph::paintWave(float x, float y, float w, float h)
{
auto p = m_painter;
p->setStrokeStyle(m_theme->graph1());
p->setLineWidth(m_lineWidth);
const float xMove = float(w) / m_dataLength;
const float hC = h * 0.5f;
const auto &data = m_waveData;
p->setLineJoin(QCanvasPainter::LineJoin::Bevel);
p->beginPath();
if (m_clearDataIndex > m_heartDataIndex) {
// Stroke with 2 lines
// Before the space
const float firstY = y + hC - hC * data.constFirst();
p->moveTo(x, firstY);
for (int i = 1; i < m_heartDataIndex; i++) {
const float d = data.at(i);
p->lineTo(x + i * xMove, y + hC - hC * d);
}
// After the space
const float firstY2 = y + hC - hC * data.at(m_clearDataIndex);
p->moveTo(x + m_clearDataIndex * xMove, firstY2);
for (int i = m_clearDataIndex + 1; i < m_dataLength; i++) {
const float d = data.at(i);
p->lineTo(x + i * xMove, y + hC - hC * d);
}
} else {
// Stroke with 1 line
const float firstY = y + hC + hC * data.at(m_clearDataIndex);
p->moveTo(x + m_clearDataIndex * xMove, firstY);
for (int i = m_clearDataIndex + 1; i < m_heartDataIndex; i++) {
const float d = data.at(i);
p->lineTo(x + i * xMove, y + hC - hC * d);
}
}
p->stroke();
}
void ECGGraph::paintSpo2Wave(float x, float y, float w, float h)
{
auto p = m_painter;
p->setStrokeStyle(m_theme->graph2());
p->setLineWidth(m_lineWidth);
const float xMove = float(w) / m_dataLength;
const float hC = h * 0.5f;
const auto &data = m_spo2Data;
p->setLineJoin(QCanvasPainter::LineJoin::Bevel);
p->beginPath();
if (m_clearDataIndex > m_heartDataIndex) {
// Stroke with 2 lines
// Before the space
const float firstY = y + hC - hC * data.constFirst();
p->moveTo(x, firstY);
for (int i = 1; i < m_heartDataIndex; i++) {
const float d = data.at(i);
p->lineTo(x + i * xMove, y + hC - hC * d);
}
// After the space
const float firstY2 = y + hC - hC * data.at(m_clearDataIndex);
p->moveTo(x + m_clearDataIndex * xMove, firstY2);
for (int i = m_clearDataIndex + 1; i < m_dataLength; i++) {
const float d = data.at(i);
p->lineTo(x + i * xMove, y + hC - hC * d);
}
} else {
// Stroke with 1 line
const float firstY = y + hC - hC * data.at(m_clearDataIndex);
p->moveTo(x + m_clearDataIndex * xMove, firstY);
for (int i = m_clearDataIndex + 1; i < m_heartDataIndex; i++) {
const float d = data.at(i);
p->lineTo(x + i * xMove, y + hC - hC * d);
}
}
p->stroke();
}
// Update new data at index
void ECGGraph::updateData(float hr)
{
//auto *rand = QRandomGenerator::global();
m_pulseRate = 60 * (60.0f / hr);
// Start a beat?
if (m_currentFrame > m_beatFrame + m_pulseRate) {
m_beatFrame = m_currentFrame;
m_beatDataIndex = 0;
}
if (!m_attached) {
fillEmptyData();
} else if (m_beatDataIndex >= 0) {
fillBeatData();
} else {
fillRandomData();
}
// Update SpO2
// Beat state 0...1
const float beatState = float(m_currentFrame - m_beatFrame) / (m_pulseRate + 1);
// Generate something that looks like SpO2, synchronized with beats.
float sp = std::sin(-1.5f + beatState * M_PI * 2);
const float spPhaseVarying =
2.8f + 0.3f * (std::sin(0.123 * m_currentFrame) + std::cos(0.141 * m_currentFrame));
sp += 0.6 * std::sin(spPhaseVarying + beatState * M_PI * 4);
const float spSizeVarying =
0.05f * (std::sin(0.14 * m_currentFrame) + std::cos(0.24 * m_currentFrame));
sp *= 0.4 + spSizeVarying;
// Add random interference.
//const float spRand = 0.02f;
//sp += 0.5f * spRand - spRand * rand->generateDouble();
m_spo2Data[m_heartDataIndex] = sp;
}
void ECGGraph::fillEmptyData()
{
m_waveData[m_heartDataIndex] = 0;
}
void ECGGraph::fillRandomData()
{
auto *rand = QRandomGenerator::global();
if (m_defibrillator)
m_waveData[m_heartDataIndex] = rand->generateDouble() * 1.2f - 0.6f;
else
m_waveData[m_heartDataIndex] = rand->generateDouble() * 0.05f - 0.025f;
}
// Create random data which looks like heart beat
void ECGGraph::fillBeatData()
{
auto *rand = QRandomGenerator::global();
const int i = m_beatDataIndex;
float value = 0;
float r = float(rand->generateDouble());
if (i == 0)
value = r * 0.1f + 0.1f;
else if (i == 1)
value = r * 0.2f - 0.1f;
else if (i == 2)
value = r * 0.4f + 0.6f;
else if (i == 3)
value = r * 0.1f - 0.05f;
else if (i == 4)
value = r * 0.4f - 0.8f;
else if (i == 5)
value = r * 0.2f - 0.05f;
else if (i == 6)
value = r * 0.1f - 0.05f;
else if (i == 7)
value = r * 0.1f + 0.15f;
m_waveData[m_heartDataIndex] = value;
}