ChartDirector 6.0 (C++ Edition)

Custom Scatter Symbols




This example demonstrates using external image files as scatter symbols.

The chart in this example is created as 5 scatter layers using XYChart.addScatterLayer, with each layer containing one point.

The symbols for the scatter layers come from external image files. They are loaded using DataSet.setDataSymbol2.

Source Code Listing

[The following code is available in "cppdemo/scattersymbols". A MFC version of the code is available in "mfcdemo/mfcdemo" (Windows edition only). A QT version of the code is available in "qtdemo/qtdemo".]
#include "chartdir.h"

int main(int argc, char *argv[])
{
    // The XY points for the scatter chart
    double dataX[] = {200, 400, 300, 250, 500};
    double dataY[] = {40, 100, 50, 150, 250};

    // The custom symbols for the points
    const char *symbols[] = {"robot1.png", "robot2.png", "robot3.png", "robot4.png", "robot5.png"};

    // Create a XYChart object of size 450 x 400 pixels
    XYChart *c = new XYChart(450, 400);

    // Set the plotarea at (55, 40) and of size 350 x 300 pixels, with a light grey border
    // (0xc0c0c0). Turn on both horizontal and vertical grid lines with light grey color (0xc0c0c0)
    c->setPlotArea(55, 40, 350, 300, -1, -1, 0xc0c0c0, 0xc0c0c0, -1);

    // Add a title to the chart using 18pt Times Bold Itatic font.
    c->addTitle("Battle Robots", "timesbi.ttf", 18);

    // Add a title to the y axis using 12pt Arial Bold Italic font
    c->yAxis()->setTitle("Speed (km/s)", "arialbi.ttf", 12);

    // Add a title to the y axis using 12pt Arial Bold Italic font
    c->xAxis()->setTitle("Range (km)", "arialbi.ttf", 12);

    // Set the axes line width to 3 pixels
    c->xAxis()->setWidth(3);
    c->yAxis()->setWidth(3);

    // Add each point of the data as a separate scatter layer, so that they can have a different
    // symbol
    for(int i = 0; i < (int)(sizeof(dataX) / sizeof(dataX[0])); ++i) {
        double coor1[] = {dataX[i]};
        double coor2[] = {dataY[i]};
        c->addScatterLayer(DoubleArray(coor1, (int)(sizeof(coor1) / sizeof(coor1[0]))), DoubleArray(
            coor2, (int)(sizeof(coor2) / sizeof(coor2[0]))))->getDataSet(0)->setDataSymbol(symbols[i
            ]);
    }

    // Output the chart
    c->makeChart("scattersymbols.png");

    //free up resources
    delete c;
    return 0;
}