ChartDirector 6.0 (C++ Edition)

Glass Multi-Bar Chart




This example demonstrates a multi-bar chart with glass shading effect for bars and gradient color for plot area background.

Glass lighting is a complex shading effect that gives a look and feel of tinted glass or semi-transparent plastic material. This effect involves glare and variation of lighting caused by reflection and refraction inside the material.

Source Code Listing

[The following code is available in "cppdemo/glassmultibar". 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 data for the bar chart
    double data0[] = {100, 125, 245, 147, 67};
    double data1[] = {85, 156, 179, 211, 123};
    double data2[] = {97, 87, 56, 267, 157};
    const char *labels[] = {"Mon", "Tue", "Wed", "Thur", "Fri"};

    // Create a XYChart object of size 540 x 375 pixels
    XYChart *c = new XYChart(540, 375);

    // Add a title to the chart using 18pt Times Bold Italic font
    c->addTitle("Average Weekly Network Load", "timesbi.ttf", 18);

    // Set the plotarea at (50, 55) and of 440 x 280 pixels in size. Use a vertical gradient color
    // from light blue (f9f9ff) to blue (6666ff) as background. Set border and grid lines to white
    // (ffffff).
    c->setPlotArea(50, 55, 440, 280, c->linearGradientColor(0, 55, 0, 335, 0xf9f9ff, 0x6666ff), -1,
        0xffffff, 0xffffff);

    // Add a legend box at (50, 28) using horizontal layout. Use 10pt Arial Bold as font, with
    // transparent background.
    c->addLegend(50, 28, false, "arialbd.ttf", 10)->setBackground(Chart::Transparent);

    // Set the x axis labels
    c->xAxis()->setLabels(StringArray(labels, (int)(sizeof(labels) / sizeof(labels[0]))));

    // Draw the ticks between label positions (instead of at label positions)
    c->xAxis()->setTickOffset(0.5);

    // Set axis label style to 8pt Arial Bold
    c->xAxis()->setLabelStyle("arialbd.ttf", 8);
    c->yAxis()->setLabelStyle("arialbd.ttf", 8);

    // Set axis line width to 2 pixels
    c->xAxis()->setWidth(2);
    c->yAxis()->setWidth(2);

    // Add axis title
    c->yAxis()->setTitle("Throughput (MBytes Per Hour)");

    // Add a multi-bar layer with 3 data sets
    BarLayer *layer = c->addBarLayer(Chart::Side);
    layer->addDataSet(DoubleArray(data0, (int)(sizeof(data0) / sizeof(data0[0]))), 0xff0000,
        "Server #1");
    layer->addDataSet(DoubleArray(data1, (int)(sizeof(data1) / sizeof(data1[0]))), 0x00ff00,
        "Server #2");
    layer->addDataSet(DoubleArray(data2, (int)(sizeof(data2) / sizeof(data2[0]))), 0xff8800,
        "Server #3");

    // Set bar border to transparent. Use glass lighting effect with light direction from left.
    layer->setBorderColor(Chart::Transparent, Chart::glassEffect(Chart::NormalGlare, Chart::Left));

    // Configure the bars within a group to touch each others (no gap)
    layer->setBarGap(0.2, Chart::TouchBar);

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

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