Semicircle Meter with Readout

[Standalone Version] perldemo\semicirclemeterreadout.pl

#!/usr/bin/perl

# In the sample code, 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 = 66;

    # The background and border colors of the meters
    my $bgColor = [0x88ccff, 0xffdddd];
    my $borderColor = [0x000077, 0x880000];

    # Create an AngularMeter object of size 300 x 200 pixels with transparent background
    my $m = new AngularMeter(300, 200, $perlchartdir::Transparent);

    # Center at (150, 150), scale radius = 124 pixels, scale angle -90 to +90 degrees
    $m->setMeter(150, 150, 124, -90, 90);

    # Background gradient color with brighter color at the center
    my $bgGradient = [0, $m->adjustBrightness($bgColor->[$chartIndex], 3), 0.75, $bgColor->[
        $chartIndex]];

    # Add a scale background of 148 pixels radius using the background gradient, with a 13 pixel
    # thick border
    $m->addScaleBackground(148, $m->relativeRadialGradient($bgGradient), 13, $borderColor->[
        $chartIndex]);

    # 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);

    # Demostrate different types of color scales and putting them at different positions
    my $smoothColorScale = [0, 0x3333ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xdddd00, 100, 0xff0000];

    if ($chartIndex == 0) {
        # Add the smooth color scale at the default position
        $m->addColorScale($smoothColorScale);
        # Add a red (0xff0000) triangular pointer starting from 38% and ending at 60% of scale
        # radius, with a width 6 times the default
        $m->addPointer2($value, 0xff0000, -1, $perlchartdir::TriangularPointer2, 0.38, 0.6, 6);
    } else {
        # Add the smooth color scale starting at radius 124 with zero width and ending at radius 124
        # with 16 pixels inner width
        $m->addColorScale($smoothColorScale, 124, 0, 124, -16);
        # Add a red (0xff0000) pointer
        $m->addPointer2($value, 0xff0000);
    }

    # Configure a large "pointer cap" to be used as the readout circle at the center. The cap radius
    # and border width is set to 33% and 4% of the meter scale radius. The cap color is dark blue
    # (0x000044). The border color is light blue (0x66bbff) with a 60% brightness gradient effect.
    $m->setCap2($perlchartdir::Transparent, 0x000044, 0x66bbff, 0.6, 0, 0.33, 0.04);

    # Add value label at the center with light blue (0x66ddff) 28pt Arial Italic font
    $m->addText(150, 150, $m->formatValue($value, "{value|0}"), "ariali.ttf", 28, 0x66ddff,
        $perlchartdir::Center)->setMargin(0);

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

createChart(0);
createChart(1);

[CGI Version] perldemo_cgi\semicirclemeterreadout.pl

#!/usr/bin/perl

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

use perlchartdir;

# Get HTTP query parameters
use CGI;
my $query = new CGI;

# This script can draw different charts depending on the chartIndex
$chartIndex = int($query->param("img"));

# The value to display on the meter
my $value = 66;

# The background and border colors of the meters
my $bgColor = [0x88ccff, 0xffdddd];
my $borderColor = [0x000077, 0x880000];

# Create an AngularMeter object of size 300 x 200 pixels with transparent background
my $m = new AngularMeter(300, 200, $perlchartdir::Transparent);

# Center at (150, 150), scale radius = 124 pixels, scale angle -90 to +90 degrees
$m->setMeter(150, 150, 124, -90, 90);

# Background gradient color with brighter color at the center
my $bgGradient = [0, $m->adjustBrightness($bgColor->[$chartIndex], 3), 0.75, $bgColor->[$chartIndex]
    ];

# Add a scale background of 148 pixels radius using the background gradient, with a 13 pixel thick
# border
$m->addScaleBackground(148, $m->relativeRadialGradient($bgGradient), 13, $borderColor->[$chartIndex]
    );

# 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);

# Demostrate different types of color scales and putting them at different positions
my $smoothColorScale = [0, 0x3333ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xdddd00, 100, 0xff0000];

if ($chartIndex == 0) {
    # Add the smooth color scale at the default position
    $m->addColorScale($smoothColorScale);
    # Add a red (0xff0000) triangular pointer starting from 38% and ending at 60% of scale radius,
    # with a width 6 times the default
    $m->addPointer2($value, 0xff0000, -1, $perlchartdir::TriangularPointer2, 0.38, 0.6, 6);
} else {
    # Add the smooth color scale starting at radius 124 with zero width and ending at radius 124
    # with 16 pixels inner width
    $m->addColorScale($smoothColorScale, 124, 0, 124, -16);
    # Add a red (0xff0000) pointer
    $m->addPointer2($value, 0xff0000);
}

# Configure a large "pointer cap" to be used as the readout circle at the center. The cap radius and
# border width is set to 33% and 4% of the meter scale radius. The cap color is dark blue
# (0x000044). The border color is light blue (0x66bbff) with a 60% brightness gradient effect.
$m->setCap2($perlchartdir::Transparent, 0x000044, 0x66bbff, 0.6, 0, 0.33, 0.04);

# Add value label at the center with light blue (0x66ddff) 28pt Arial Italic font
$m->addText(150, 150, $m->formatValue($value, "{value|0}"), "ariali.ttf", 28, 0x66ddff,
    $perlchartdir::Center)->setMargin(0);

# Output the chart
binmode(STDOUT);
print "Content-type: image/png\n\n";
print $m->makeChart2($perlchartdir::PNG);