Black Round Meters

perldemo\blackroundmeter.pl
#!/usr/bin/perl

# The ChartDirector for Perl module is assumed to be in "../lib"
use File::Basename;
use lib (dirname($0)."/../lib") =~ /(.*)/;

use perlchartdir;

sub createChart
{
    my $chartIndex = shift;

    # The value to display on the meter
    my $value = 72.3;

    # Create an AngularMeter object of size 250 x 250 pixels with transparent background
    my $m = new AngularMeter(250, 250, $perlchartdir::Transparent);

    # Set the default text and line colors to white (0xffffff)
    $m->setColor($perlchartdir::TextColor, 0xffffff);
    $m->setColor($perlchartdir::LineColor, 0xffffff);

    # Demonstration two different meter scale angles
    if ($chartIndex % 2 == 0) {
        # Center at (125, 125), scale radius = 111 pixels, scale angle -140 to +140 degrees
        $m->setMeter(125, 125, 111, -140, 140);
    } else {
        # Center at (125, 125), scale radius = 111 pixels, scale angle -180 to +90 degrees
         $m->setMeter(125, 125, 111, -180, 90);
    }

    # Add a black (0x000000) circle with radius 123 pixels as background
    $m->addRing(0, 123, 0x000000);

    # Gradient color for the border to make it silver-like
    my $ringGradient = [1, 0x7f7f7f, 0.5, 0xd6d6d6, 0, 0xffffff, -0.5, 0xd6d6d6, -1, 0x7f7f7f];
    # Add a ring between radii 116 and 122 pixels using the silver gradient as border
    $m->addRing(116, 122, $m->relativeLinearGradient($ringGradient, 45, 122));

    # 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("Arial Italic", 15);
    $m->setTickLength(-12, -9, -6);
    $m->setLineWidth(0, 2, 1, 1);

    # Demostrate different types of color scales and glare effects and putting them at different
    # positions.
    my $smoothColorScale = [0, 0x0000ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xdddd00, 100, 0xff0000];
    my $stepColorScale = [0, 0x00aa00, 60, 0xddaa00, 80, 0xcc0000, 100];
    my $highLowColorScale = [0, 0x00ff00, 70, $perlchartdir::Transparent, 100, 0xff0000];

    if ($chartIndex == 0) {
        # Add the smooth color scale at the default position
        $m->addColorScale($smoothColorScale);
        # Add glare up to radius 116 (= region inside border)
        $m->addGlare(116);
    } elsif ($chartIndex == 1) {
        # Add the smooth color scale starting at radius 62 with zero width and ending at radius 40
        # with 22 pixels outer width
        $m->addColorScale($smoothColorScale, 62, 0, 40, 22);
        # Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees
        $m->addGlare(116, -190);
    } elsif ($chartIndex == 2) {
        # Add the smooth color scale starting at radius 111 with zero width and ending at radius 111
        # with 12 pixels inner width
        $m->addColorScale($smoothColorScale, 111, 0, 111, -12);
        # Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees and
        # rotated by 45 degrees
        $m->addGlare(116, -190, 45);
    } elsif ($chartIndex == 3) {
        # Add the high/low color scale at the default position
        $m->addColorScale($highLowColorScale);
    } elsif ($chartIndex == 4) {
        # Add the smooth color scale at radius 44 with 16 pixels outer width
        $m->addColorScale($smoothColorScale, 44, 16);
        # Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees and
        # rotated by -45 degrees
        $m->addGlare(116, -190, -45);
    } else {
        # Add the step color scale at the default position
        $m->addColorScale($stepColorScale);
    }

    # Add a text label centered at (125, 175) with 15pt Arial Italic font
    $m->addText(125, 175, "CPU", "Arial Italic", 15, $perlchartdir::TextColor, $perlchartdir::Center
        );

    # Add a readout to some of the charts as demonstration
    if (($chartIndex == 0) || ($chartIndex == 2)) {
        # Put the value label center aligned at (125, 232), using black (0x000000) 14pt Arial font
        # on a light blue (0x99ccff) background. Set box width to 50 pixels with 5 pixels rounded
        # corners.
        my $t = $m->addText(125, 232, $m->formatValue($value,
            "<*block,width=50,halign=center*>{value|1}"), "Arial", 14, 0x000000,
            $perlchartdir::BottomCenter);
        $t->setBackground(0x99ccff);
        $t->setRoundedCorners(5);
    }

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

    # Output the chart
    $m->makeChart("blackroundmeter$chartIndex.png");
}

createChart(0);
createChart(1);
createChart(2);
createChart(3);
createChart(4);
createChart(5);