ChartDirector 6.0 (C++ Edition)

Round Meter




This example demonstrates the basic steps in creating a round meter.

A round meter can be created with the following steps:

Source Code Listing

[The following code is available in "cppdemo/roundmeter". 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 value to display on the meter
    double value = 72.3;

    // Create an AngularMeter object of size 250 x 250 pixels with transparent background
    AngularMeter *m = new AngularMeter(250, 250, Chart::Transparent);

    // Center at (125, 125), scale radius = 111 pixels, scale angle -145 to +145 degrees
    m->setMeter(125, 125, 111, -145, 145);

    // Add a very light grey (0xeeeeee) circle with radius 123 pixels as background
    m->addRing(0, 123, 0xeeeeee);
    // Add a grey (0xcccccc) ring between radii 116 and 123 pixels as border
    m->addRing(116, 123, 0xcccccc);

    // Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units
    m->setScale(0, 100, 10, 5, 1);

    // Set the scale label style to 15pt Arial Italic. Set the major/minor/micro tick lengths to
    // 12/9/6 pixels pointing inwards, and their widths to 2/1/1 pixels.
    m->setLabelStyle("ariali.ttf", 15);
    m->setTickLength(-12, -9, -6);
    m->setLineWidth(0, 2, 1, 1);

    // Add a smooth color scale to the meter
    double smoothColorScale[] = {0, 0x3333ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xdddd00, 100,
        0xff0000};
    m->addColorScale(DoubleArray(smoothColorScale, (int)(sizeof(smoothColorScale) / sizeof(
        smoothColorScale[0]))));

    // Add a text label centered at (125, 175) with 15pt Arial Italic font
    m->addText(125, 175, "CPU", "ariali.ttf", 15, Chart::TextColor, Chart::Center);

    // Add a red (0xff0000) pointer at the specified value
    m->addPointer2(value, 0xff0000);

    // Output the chart
    m->makeChart("roundmeter.png");

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