Circular Bar Meter (2)

The following is the command line version of the code in "cppdemo/circularbarmeter2". The MFC version of the code is in "mfcdemo/mfcdemo". The Qt Widgets version of the code is in "qtdemo/qtdemo". The QML/Qt Quick version of the code is in "qmldemo/qmldemo".
#include "chartdir.h"

void createChart(int chartIndex, const char *filename)
{
    // The value to display on the meter
    double value = 85;

    // The meter radius and angle
    int radius = 50;
    double angle = value * 360.0 / 100;

    // Create an AngularMeter with transparent background
    AngularMeter* m = new AngularMeter(radius * 2 + 10, radius * 2 + 10, Chart::Transparent);

    // Set the center, radius and angular range of the meter
    m->setMeter(m->getWidth() / 2, m->getHeight() / 2, radius, 0, 360);

    // For circular bar meters, we do not need pointer or graduation, so we hide them.
    m->setMeterColors(Chart::Transparent, Chart::Transparent, Chart::Transparent);
    m->setCap(0, Chart::Transparent);

    // In this example, the circular bar has 20 segments
    int segmentCount = 20;

    // The angular step
    double angleStep = 360.0 / segmentCount;

    // The gap between segments is 4.5 degrees
    double angleGap = 4.5;

    //
    // This example demonstrates several coloring styles
    //

    // Thd default fill and blank colors
    int fillColor = 0x336699;
    int blankColor = 0xeeeeee;

    if (chartIndex >= 4) {
        // Use dark background style
        m->setColors(Chart::whiteOnBlackPalette);
        fillColor = 0x6699ff;
        blankColor = 0x222222;
    }

    if (chartIndex % 4 == 1) {
        // Alternative fill color
        fillColor = 0x00ee33;
    } else if (chartIndex % 4 == 2) {
        // Use a smooth color scale as the fill color
        int smoothColorScale[] = {0, 0x0022ff, 15, 0x0088ff, 30, 0x00ff00, 55, 0xffff00, 80,
            0xff0000, 100, 0xff0000};
        const int smoothColorScale_size = (int)(sizeof(smoothColorScale)/sizeof(*smoothColorScale));
        fillColor = m->getDrawArea()->angleGradientColor(m->getWidth() / 2, m->getHeight() / 2, 0,
            360, radius, radius - 20, IntArray(smoothColorScale, smoothColorScale_size));
    } else if (chartIndex % 4 == 3) {
        // Use a step color scale as the fill color
        int stepColorScale[] = {0, 0x0044ff, 20, 0x00ee00, 50, 0xeeee00, 70, 0xee0000, 100};
        const int stepColorScale_size = (int)(sizeof(stepColorScale)/sizeof(*stepColorScale));
        fillColor = m->getDrawArea()->angleGradientColor(m->getWidth() / 2, m->getHeight() / 2,
            -angleGap / 2, 360 - angleGap / 2, radius, radius - 20, IntArray(stepColorScale,
            stepColorScale_size));
    }

    //
    // Now we draw the segments of the bar meter
    //

    // The segment that contains the value
    int currentSegment = (int)(angle / angleStep);

    // Segments after the current segment is colored with the blank color
    for(int i = currentSegment + 1; i < segmentCount; ++i) {
        m->addRingSector(radius, radius - 20, i * angleStep, (i + 1) * angleStep - angleGap,
            blankColor);
    }

    // Segments before the current segment is colored with the fill color
    for(int i = 0; i < currentSegment; ++i) {
        m->addRingSector(radius, radius - 20, i * angleStep, (i + 1) * angleStep - angleGap,
            fillColor);
    }

    // Segment that contains the angle will be partially filled and partially blank. We need to
    // adjust the angle to compensated for the angle gap.
    double adjustedAngle = currentSegment * angleStep + (angle - currentSegment * angleStep) * (1 -
        angleGap / angleStep);

    // The blank part of the segment
    if ((currentSegment + 1) * angleStep > angle) {
        m->addRingSector(radius, radius - 20, adjustedAngle, (currentSegment + 1) * angleStep -
            angleGap, blankColor);
    }

    // The filled part of the segment.
    if (angle > currentSegment * angleStep) {
        m->addRingSector(radius, radius - 20, currentSegment * angleStep, adjustedAngle, fillColor);
    }

    // Add a label at the center to display the value
    m->addText(m->getWidth() / 2, m->getHeight() / 2, m->formatValue(value, "{value}"), "Arial", 25,
        Chart::TextColor, Chart::Center)->setMargin(0);

    // Output the chart
    m->makeChart(filename);

    //free up resources
    delete m;

}

int main(int argc, char *argv[])
{
    createChart(0, "circularbarmeter20.png");
    createChart(1, "circularbarmeter21.png");
    createChart(2, "circularbarmeter22.png");
    createChart(3, "circularbarmeter23.png");
    createChart(4, "circularbarmeter24.png");
    createChart(5, "circularbarmeter25.png");
    createChart(6, "circularbarmeter26.png");
    createChart(7, "circularbarmeter27.png");
    return 0;
}