ChartDirector 6.0 (C++ Edition)

Soft Bar Shading




This example demonstrates using soft lighting effect for bars and gradient color for plot area background. It also demonstrates putting axis ticks in between axis labels, as opposed to at the axis labels.

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 Multi-Bar Chart for another example of soft lighting effect with the light coming from the top direction.

Source Code Listing

[The following code is available in "cppdemo/softlightbar". 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 data[] = {450, 560, 630, 800, 1100, 1350, 1600, 1950, 2300, 2700};

    // The labels for the bar chart
    const char *labels[] = {"1996", "1997", "1998", "1999", "2000", "2001", "2002", "2003", "2004",
        "2005"};

    // Create a XYChart object of size 600 x 360 pixels
    XYChart *c = new XYChart(600, 360);

    // Add a title to the chart using 18pt Times Bold Italic font
    c->addTitle("Annual Revenue for Star Tech", "timesbi.ttf", 18);

    // Set the plotarea at (60, 40) and of size 500 x 280 pixels. Use a vertical gradient color from
    // light blue (eeeeff) to deep blue (0000cc) as background. Set border and grid lines to white
    // (ffffff).
    c->setPlotArea(60, 40, 500, 280, c->linearGradientColor(60, 40, 60, 280, 0xeeeeff, 0x0000cc),
        -1, 0xffffff, 0xffffff);

    // Add a multi-color bar chart layer using the supplied data. Use soft lighting effect with
    // light direction from left.
    c->addBarLayer(DoubleArray(data, (int)(sizeof(data) / sizeof(data[0]))), IntArray(0, 0)
        )->setBorderColor(Chart::Transparent, Chart::softLighting(Chart::Left));

    // Set x axis labels using the given 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);

    // Add a title to the y axis with 10pt Arial Bold font
    c->yAxis()->setTitle("USD (millions)", "arialbd.ttf", 10);

    // 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);

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

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