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How to acclerate QLineSeries after using opengl
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I have to draw a chart with 4 lines. Each line has 6,500 points.
I've already used setUseOpenGL(true) on thoes lines
It still needs 5 or 6 seconds to draw these lines.
How can I accelerate the process?
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i've tried sth like this:
QLineSeries *lines2 = new QLineSeries(); QLineSeries *lines3 = new QLineSeries(); QLineSeries *lines4 = new QLineSeries(); lines2->setUseOpenGL(true); lines3->setUseOpenGL(true); lines4->setUseOpenGL(true); //readData int nLen = 6500; short *sData_CH0 = new short[nLen]; short *sData_CH1 = new short[nLen]; short *sData_CH2 = new short[nLen]; short *sData_CH3 = new short[nLen]; memset(sData_CH0, 0, sizeof(short)*nLen); memset(sData_CH1, 0, sizeof(short)*nLen); memset(sData_CH2, 0, sizeof(short)*nLen); memset(sData_CH3, 0, sizeof(short)*nLen); static const int nLen_Header = 160; FILE *fp; _wfopen_s(&fp,L"d:/11.ocean", L"rb"); double dLen_Binshot = 2 * 4 * nLen; __int64 nSeekL = nLen_Header + dLen_Binshot * 0; _fseeki64(fp, nSeekL, SEEK_SET); int maxY = 0; int minY = 0; fread(sData_CH0, sizeof(short), nLen, fp); fread(sData_CH1, sizeof(short), nLen, fp); fread(sData_CH2, sizeof(short), nLen, fp); fread(sData_CH3, sizeof(short), nLen, fp); fclose(fp); for (int i=0;i < nLen;i++) { if(sData_CH1[i]<(-2000)){ sData_CH1[i]=0; } if(sData_CH1[i]<(-2000)){ sData_CH1[i]=0; } if(sData_CH1[i]<minY){ minY= sData_CH1[i]; } if(sData_CH1[i]>maxY){ maxY= sData_CH1[i]; } lines2->append(QPointF(i, sData_CH1[i])); } for (int i=0;i < nLen;i++) { if(sData_CH2[i]<(-2000)){ sData_CH2[i]=0; } if(sData_CH2[i]<(-2000)){ sData_CH2[i]=0; } if(sData_CH2[i]<minY){ minY= sData_CH2[i]; } if(sData_CH2[i]>maxY){ maxY= sData_CH2[i]; } lines3->append(QPointF(i, sData_CH2[i])); } for (int i=0;i < nLen;i++) { if(sData_CH3[i]<(-2000)){ sData_CH3[i]=0; } if(sData_CH3[i]<(-2000)){ sData_CH3[i]=0; } if(sData_CH3[i]<minY){ minY= sData_CH3[i]; } if(sData_CH3[i]>maxY){ maxY= sData_CH3[i]; } lines4->append(QPointF(i, sData_CH3[i])); } QChart *chart = new QChart(); chart->addSeries(lines3); chart->addSeries(lines4); chart->addSeries(lines2); chart->createDefaultAxes(); chart->axisX()->setRange(0, 6500); chart->axisY()->setRange(minY, maxY); chart->setTitle("chart"); chartView = new ChartView(chart); chartView->setRenderHint(QPainter::Antialiasing); ui->mainChartLayout->addWidget(chartView);and it is very fast.
but when i append the points to lines after adding the lines to the chart, it took 6 second to draw the lines.
here is the code:
QLineSeries *lines2 = new QLineSeries(); QLineSeries *lines3 = new QLineSeries(); QLineSeries *lines4 = new QLineSeries(); lines2->setUseOpenGL(true); lines3->setUseOpenGL(true); lines4->setUseOpenGL(true); QChart *chart = new QChart(); chart->addSeries(lines3); chart->addSeries(lines4); chart->addSeries(lines2); chart->createDefaultAxes(); chart->axisX()->setRange(0, 6500); chart->axisY()->setRange(-200, 20000); chart->setTitle("chart"); chartView = new ChartView(chart); chartView->setRenderHint(QPainter::Antialiasing); ui->mainChartLayout->addWidget(chartView); int nLen = 6500; short *sData_CH0 = new short[nLen]; short *sData_CH1 = new short[nLen]; short *sData_CH2 = new short[nLen]; short *sData_CH3 = new short[nLen]; memset(sData_CH0, 0, sizeof(short)*nLen); memset(sData_CH1, 0, sizeof(short)*nLen); memset(sData_CH2, 0, sizeof(short)*nLen); memset(sData_CH3, 0, sizeof(short)*nLen); static const int nLen_Header = 160; FILE *fp; _wfopen_s(&fp,L"d:/11.ocean", L"rb"); double dLen_Binshot = 2 * 4 * nLen; __int64 nSeekL = nLen_Header + dLen_Binshot * 0; _fseeki64(fp, nSeekL, SEEK_SET); int maxY = 0; int minY = 0; fread(sData_CH0, sizeof(short), nLen, fp); fread(sData_CH1, sizeof(short), nLen, fp); fread(sData_CH2, sizeof(short), nLen, fp); fread(sData_CH3, sizeof(short), nLen, fp); fclose(fp); for (int i=0;i < nLen;i++) { if(sData_CH1[i]<(-2000)){ sData_CH1[i]=0; } if(sData_CH1[i]<(-2000)){ sData_CH1[i]=0; } if(sData_CH1[i]<minY){ minY= sData_CH1[i]; } if(sData_CH1[i]>maxY){ maxY= sData_CH1[i]; } lines2->append(QPointF(i, sData_CH1[i])); } for (int i=0;i < nLen;i++) { if(sData_CH2[i]<(-2000)){ sData_CH2[i]=0; } if(sData_CH2[i]<(-2000)){ sData_CH2[i]=0; } if(sData_CH2[i]<minY){ minY= sData_CH2[i]; } if(sData_CH2[i]>maxY){ maxY= sData_CH2[i]; } lines3->append(QPointF(i, sData_CH2[i])); } for (int i=0;i < nLen;i++) { if(sData_CH3[i]<(-2000)){ sData_CH3[i]=0; } if(sData_CH3[i]<(-2000)){ sData_CH3[i]=0; } if(sData_CH3[i]<minY){ minY= sData_CH3[i]; } if(sData_CH3[i]>maxY){ maxY= sData_CH3[i]; } lines4->append(QPointF(i, sData_CH3[i])); }