ChartDirector Ver 3.0 (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 project is available in "cppdemo/scattersymbols".]
#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 18 pts Times Bold Itatic font. c->addTitle("Battle Robots", "timesbi.ttf", 18); //Add a title to the y axis using 12 pts Arial Bold Italic font c->yAxis()->setTitle("Speed (km/s)", "arialbi.ttf", 12); //Add a title to the y axis using 12 pts 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 int i; for(i = 0; i < (sizeof(dataX) / sizeof(dataX[0])); ++i) { double coor[] = {dataX[i]}; double coor2[] = {dataY[i]}; c->addScatterLayer(DoubleArray(coor, sizeof(coor)/sizeof(*coor)), DoubleArray(coor2, sizeof(coor2)/sizeof(*coor2)))->getDataSet(0 )->setDataSymbol(symbols[i]); } //output the chart c->makeChart("scattersymbols.png"); //free up resources delete c; return 0; }