ChartDirector 6.0 (C++ Edition)

Soft Multi-Bar Chart




This example demonstrates a multi-bar chart with soft lighting effects for bars and gradient color for plot area background.

Soft lighting is a special shading effect that look like gradient coloring. In this example, soft lighting effect is applied to the bars with the light coming from the left direction.

See Soft Bar Shading for another example of soft lighting effect with the light coming from the left direction.

Source Code Listing

[The following code is available in "cppdemo/softmultibar". 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 red (ffdddd) to dark red (880000) as background. Set border and grid lines to
    // white (ffffff).
    c->setPlotArea(50, 55, 440, 280, c->linearGradientColor(0, 55, 0, 335, 0xffdddd, 0x880000), -1,
        0xffffff, 0xffffff);

    // Add a legend box at (50, 25) using horizontal layout. Use 10pt Arial Bold as font, with
    // transparent background.
    c->addLegend(50, 25, 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 and 4 pixels 3D depth
    BarLayer *layer = c->addBarLayer(Chart::Side, 4);
    layer->addDataSet(DoubleArray(data0, (int)(sizeof(data0) / sizeof(data0[0]))), 0xffff00,
        "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]))), 0x9999ff,
        "Server #3");

    // Set bar border to transparent. Use soft lighting effect with light direction from top.
    layer->setBorderColor(Chart::Transparent, Chart::softLighting(Chart::Top));

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

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

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