Simple Real-Time Chart (MFC)

[MFC version] mfcdemo/RealTimeDemoDlg.cpp
// RealTimeDemoDlg.cpp : implementation file
//

#include "stdafx.h"
#include "resource.h"
#include "RealTimeDemoDlg.h"
#include <math.h>

#ifdef _DEBUG
#define new DEBUG_NEW
#endif

/////////////////////////////////////////////////////////////////////////////
// CRealTimeDemoDlg dialog

static const int DataRateTimer = 1;
static const int ChartUpdateTimer = 2;

// 250ms per data point, chart contains 1 min of data = 240 data points.
static const int DataInterval = 250;
static const int sampleSize = 240;

//
// Constructor
//
CRealTimeDemoDlg::CRealTimeDemoDlg(CWnd* pParent /*=NULL*/)
    : CDialog(IDD_REALTIMEDEMO, pParent)
{
}

void CRealTimeDemoDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    DDX_Control(pDX, IDC_GammaValue, m_ValueC);
    DDX_Control(pDX, IDC_BetaValue, m_ValueB);
    DDX_Control(pDX, IDC_AlphaValue, m_ValueA);
    DDX_Control(pDX, IDC_ChartViewer, m_ChartViewer);
    DDX_Control(pDX, IDC_RunPB, m_RunPB);
    DDX_Control(pDX, IDC_UpdatePeriod, m_UpdatePeriod);
    //}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CRealTimeDemoDlg, CDialog)
    ON_WM_TIMER()
    ON_BN_CLICKED(IDC_RunPB, OnRunPB)
    ON_BN_CLICKED(IDC_FreezePB, OnFreezePB)
    ON_CBN_SELCHANGE(IDC_UpdatePeriod, OnSelchangeUpdatePeriod)
    ON_CONTROL(CVN_ViewPortChanged, IDC_ChartViewer, OnViewPortChanged)
END_MESSAGE_MAP()

//
// Initialization
//
BOOL CRealTimeDemoDlg::OnInitDialog()
{
    CDialog::OnInitDialog();

    //
    // Initialize member variables
    //

    // Allocate memory for the data series and initialize to Chart::NoValue
    m_timeStamps.resize(sampleSize, Chart::NoValue);
    m_dataSeriesA.resize(sampleSize, Chart::NoValue);
    m_dataSeriesB.resize(sampleSize, Chart::NoValue);
    m_dataSeriesC.resize(sampleSize, Chart::NoValue);

    m_extBgColor = getDefaultBgColor();     // Default background color

    // Set m_nextDataTime to the current time. It is used by the real time random number 
    // generator so it knows what timestamp should be used for the next data point.
    SYSTEMTIME st;
    GetLocalTime(&st);
    m_nextDataTime = Chart::chartTime(st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, 
        st.wSecond) + st.wMilliseconds / 1000.0;

    //
    // Initialize controls
    //

    // Set up the data acquisition mechanism. In this demo, we just use a timer to get a 
    // sample every 250ms.
    SetTimer(DataRateTimer, DataInterval, 0);

    // The chart update rate (in ms)
    m_UpdatePeriod.SelectString(0, _T("250"));
    
    // Load icons for the Run/Freeze buttons
    loadButtonIcon(IDC_RunPB, IDI_RunPB, 100, 20);
    loadButtonIcon(IDC_FreezePB, IDI_FreezePB, 100, 20);

    // Initially set the Run mode
    m_RunPB.SetCheck(1);
    OnRunPB();

    return TRUE;
}

//
// User clicks on the Run pushbutton
//
void CRealTimeDemoDlg::OnRunPB() 
{
    // Enable chart update timer
    CString s;
    m_UpdatePeriod.GetLBText(m_UpdatePeriod.GetCurSel(), s);
    SetTimer(ChartUpdateTimer, _tcstol(s, 0, 0), 0);
}

//
// User clicks on the Freeze pushbutton
//
void CRealTimeDemoDlg::OnFreezePB() 
{
    // Disable chart update timer
    KillTimer(ChartUpdateTimer);    
}

//
// Handles timer events
//
void CRealTimeDemoDlg::OnTimer(UINT_PTR nIDEvent) 
{
    switch (nIDEvent)
    {
    case DataRateTimer:
        // Is data acquisition timer - get a new data sample
        getData();
        break;
    case ChartUpdateTimer:
        // Is chart update timer - request chart update
        m_ChartViewer.updateViewPort(true, false);      
        break;
    }
    
    CDialog::OnTimer(nIDEvent);
}

//
// View port changed event
//
void CRealTimeDemoDlg::OnViewPortChanged()
{
    drawChart(&m_ChartViewer);
}

//
// User changes the chart update period
//
void CRealTimeDemoDlg::OnSelchangeUpdatePeriod() 
{
    if (m_RunPB.GetCheck())
    {
        // Call freeze then run to use the new chart update period
        OnFreezePB();
        OnRunPB();
    }   
}

//
// A utility to shift a new data value into a data array
//
static void shiftData(double *data, int len, double newValue)
{
    memmove(data, data + 1, sizeof(*data) * (len - 1));
    data[len - 1] = newValue;
}

//
// The data acquisition routine. In this demo, this is invoked every 250ms.
//
void CRealTimeDemoDlg::getData()
{
    // The current time in millisecond resolution
    SYSTEMTIME st;
    GetLocalTime(&st);
    double now = Chart::chartTime(st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, 
        st.wSecond) + st.wMilliseconds / 1000.0;
    
    // This is our formula for the random number generator
    do
    {
        // Get a data sample
        double p = m_nextDataTime * 4;
        double dataA = 20 + cos(p * 129241) * 10 + 1 / (cos(p) * cos(p) + 0.01);
        double dataB = 150 + 100 * sin(p / 27.7) * sin(p / 10.1);
        double dataC = 150 + 100 * cos(p / 6.7) * cos(p / 11.9);

        // Shift the values into the arrays
        shiftData(&m_dataSeriesA[0], (int)m_dataSeriesA.size(), dataA);
        shiftData(&m_dataSeriesB[0], (int)m_dataSeriesB.size(), dataB);
        shiftData(&m_dataSeriesC[0], (int)m_dataSeriesC.size(), dataC);
        shiftData(&m_timeStamps[0], (int)m_timeStamps.size(), m_nextDataTime);

        m_nextDataTime += DataInterval / 1000.0;
    }
    while (m_nextDataTime < now);

    //
    // We provide some visual feedback to the latest numbers generated, so you can see the
    // data being generated.
    //
    char buffer[1024];
    
    sprintf_s(buffer, sizeof(buffer), "%.2f", m_dataSeriesA[sampleSize - 1]);
    m_ValueA.SetWindowText(CString(buffer));

    sprintf_s(buffer, sizeof(buffer), "%.2f", m_dataSeriesB[sampleSize - 1]);
    m_ValueB.SetWindowText(CString(buffer));

    sprintf_s(buffer, sizeof(buffer), "%.2f", m_dataSeriesC[sampleSize - 1]);
    m_ValueC.SetWindowText(CString(buffer));
}

//
// Draw the chart and display it in the given viewer
//
void CRealTimeDemoDlg::drawChart(CChartViewer *viewer)
{
    // Create an XYChart object 600 x 270 pixels in size, with light grey (f4f4f4) 
    // background, black (000000) border, 1 pixel raised effect, and with a rounded frame.
    XYChart *c = new XYChart(600, 270, 0xf4f4f4, 0x000000, 1);
    c->setRoundedFrame(m_extBgColor);
    
    // Set the plotarea at (55, 62) and of size 520 x 175 pixels. Use white (ffffff) 
    // background. Enable both horizontal and vertical grids by setting their colors to 
    // grey (cccccc). Set clipping mode to clip the data lines to the plot area.
    c->setPlotArea(55, 62, 520, 175, 0xffffff, -1, -1, 0xcccccc, 0xcccccc);
    c->setClipping();

    // Add a title to the chart using 15 pts Times New Roman Bold Italic font, with a light
    // grey (dddddd) background, black (000000) border, and a glass like raised effect.
    c->addTitle("Field Intensity at Observation Satellite", "Times New Roman Bold Italic",
        15)->setBackground(0xdddddd, 0x000000, Chart::glassEffect());
            
    // Add a legend box at the top of the plot area with 9pts Arial Bold font. We set the 
    // legend box to the same width as the plot area and use grid layout (as opposed to 
    // flow or top/down layout). This distributes the 3 legend icons evenly on top of the 
    // plot area.
    LegendBox *b = c->addLegend2(55, 33, 3, "Arial Bold", 9);
    b->setBackground(Chart::Transparent, Chart::Transparent);
    b->setWidth(520);

    // Configure the y-axis with a 10pts Arial Bold axis title
    c->yAxis()->setTitle("Intensity (V/m)", "Arial Bold", 10);

    // Configure the x-axis to auto-scale with at least 75 pixels between major tick and 
    // 15  pixels between minor ticks. This shows more minor grid lines on the chart.
    c->xAxis()->setTickDensity(75, 15);

    // Set the axes width to 2 pixels
    c->xAxis()->setWidth(2);
    c->yAxis()->setWidth(2);

    // Now we add the data to the chart. 
    double lastTime = m_timeStamps[sampleSize - 1];
    if (lastTime != Chart::NoValue)
    {
        // Set up the x-axis to show the time range in the data buffer
        c->xAxis()->setDateScale(lastTime - DataInterval * sampleSize / 1000, lastTime);
        
        // Set the x-axis label format
        c->xAxis()->setLabelFormat("{value|hh:nn:ss}");

        // Create a line layer to plot the lines
        LineLayer *layer = c->addLineLayer();

        // The x-coordinates are the timeStamps.
        layer->setXData(vectorToArray(m_timeStamps));

        // The 3 data series are used to draw 3 lines. Here we put the latest data values
        // as part of the data set name, so you can see them updated in the legend box.
        char buffer[1024];

        sprintf_s(buffer, sizeof(buffer), "Alpha: <*bgColor=FFCCCC*> %.2f ", m_dataSeriesA.back());
        layer->addDataSet(vectorToArray(m_dataSeriesA), 0xff0000, buffer);
        
        sprintf_s(buffer, sizeof(buffer), "Beta: <*bgColor=CCFFCC*> %.2f ", m_dataSeriesB.back());
        layer->addDataSet(vectorToArray(m_dataSeriesB), 0x00cc00, buffer);
        
        sprintf_s(buffer, sizeof(buffer), "Gamma: <*bgColor=CCCCFF*> %.2f ", m_dataSeriesC.back());
        layer->addDataSet(vectorToArray(m_dataSeriesC), 0x0000ff, buffer);
    }

    // Set the chart image to the WinChartViewer
    viewer->setChart(c);
    delete c;
}

/////////////////////////////////////////////////////////////////////////////
// General utilities

//
// Get the default background color
//
int CRealTimeDemoDlg::getDefaultBgColor()
{
    LOGBRUSH LogBrush; 
    HBRUSH hBrush = (HBRUSH)SendMessage(WM_CTLCOLORDLG, (WPARAM)CClientDC(this).m_hDC, 
        (LPARAM)m_hWnd); 
    ::GetObject(hBrush, sizeof(LOGBRUSH), &LogBrush); 
    int ret = LogBrush.lbColor;
    return ((ret & 0xff) << 16) | (ret & 0xff00) | ((ret & 0xff0000) >> 16);
}

//
// Load an icon resource into a button
//
void CRealTimeDemoDlg::loadButtonIcon(int buttonId, int iconId, int width, int height)
{
    // Resize the icon to match the screen DPI for high DPI support
    HDC screen = ::GetDC(0);
    double scaleFactor = GetDeviceCaps(screen, LOGPIXELSX) / 96.0;
    ::ReleaseDC(0, screen);
    width = (int)(width * scaleFactor + 0.5);
    height = (int)(height * scaleFactor + 0.5);

    GetDlgItem(buttonId)->SendMessage(BM_SETIMAGE, IMAGE_ICON, (LPARAM)::LoadImage(
        AfxGetResourceHandle(), MAKEINTRESOURCE(iconId), IMAGE_ICON, width, height, LR_DEFAULTCOLOR));
}

//
// Convert std::vector to a DoubleArray
//
DoubleArray CRealTimeDemoDlg::vectorToArray(const std::vector<double>& v, int startIndex, int length)
{
    if ((length < 0) || (length + startIndex > (int)v.size()))
        length = ((int)v.size()) - startIndex;
    return (length <= 0) ? DoubleArray() : DoubleArray(&(v[startIndex]), length);
}