ChartDirector 6.0 (C++ Edition)

Semicircle Meter




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

A semicircle meter can be created with the following steps:

Source Code Listing

[The following code is available in "cppdemo/semicirclemeter". 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 = 72.55;

    // Create an AngularMeter object of size 300 x 180 pixels with transparent background
    AngularMeter *m = new AngularMeter(300, 180, Chart::Transparent);

    // Center at (150, 150), scale radius = 128 pixels, scale angle -90 to +90 degrees
    m->setMeter(150, 150, 128, -90, 90);

    // Add a pale grey (0xeeeeee) scale background of 148 pixels radius, with a 10 pixel thick light
    // grey (0xcccccc) border
    m->addScaleBackground(148, 0xeeeeee, 10, 0xcccccc);

    // Meter scale is 0 - 100, with major tick every 20 units, minor tick every 10 units, and micro
    // tick every 5 units
    m->setScale(0, 100, 20, 10, 5);

    // Set the scale label style to 15pt Arial Italic. Set the major/minor/micro tick lengths to
    // 16/16/10 pixels pointing inwards, and their widths to 2/1/1 pixels.
    m->setLabelStyle("ariali.ttf", 16);
    m->setTickLength(-16, -16, -10);
    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 (150, 125) with 15pt Arial Italic font
    m->addText(150, 125, "CPU", "ariali.ttf", 15, Chart::TextColor, Chart::BottomCenter);

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

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

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