Semi-Circle Meter

This example demonstrates a simple half circle angular meter.

A basic angular meter can be created using the following steps:

Create an AngularMeter object using AngularMeter.AngularMeter. In this example, the background color is set to silver using silverColor and the meter border is set to have a raised effect.
Specify the orientation of the meter using AngularMeter.setMeter. This specifies the center, the radius, and the angular span of the meter.
Set the numeric scale of the meter using BaseMeter.setScale
Add a pointer to the meter using BaseMeter.addPointer

In addition to the basic angular meter, this example demonstrates the following features:

Define zones on the meter using AngularMeter.addZone. In this example, 3 zones (red, yellow and green) are defined.
Add arbitrary text boxes to the meter using BaseChart.addText. In this example, a text box is added to specify the meter unit "PSI", and another text box is added to display the data value as text.

Note that by default, the drawing ordering of the text box objects and meter pointer follow the order in which they are added to the chart. Thus this sample code adds the meter pointer last, to ensure it stays on top of the custom text boxes.

[File: phpdemo/semicirclemeter.php]

<?php
require_once("../lib/phpchartdir.php");

# The value to display on the meter
$value = 27.48;

# Create an AngularMeter object of size 200 x 115 pixels, with silver background
# color, black border, 2 pixel 3D border border and rounded corners
$m = new AngularMeter(200, 115, silverColor(), 0x000000, 2);
$m->setRoundedFrame();

# Set the meter center at (100, 100), with radius 85 pixels, and span from -90 to +90
# degress (semi-circle)
$m->setMeter(100, 100, 85, -90, 90);

# 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 0 - 60 as green (66FF66) zone
$m->addZone(0, 60, 0, 85, 0x66ff66);

# Set 60 - 80 as yellow (FFFF33) zone
$m->addZone(60, 80, 0, 85, 0xffff33);

# Set 80 - 100 as red (FF6666) zone
$m->addZone(80, 100, 0, 85, 0xff6666);

# Add a text label centered at (100, 60) with 12 pts Arial Bold font
$m->addText(100, 60, "PSI", "arialbd.ttf", 12, TextColor, Center);

# Add a text box at the top right corner of the meter showing the value formatted to
# 2 decimal places, using white text on a black background, and with 1 pixel 3D
# depressed border
$textBoxObj = $m->addText(156, 8, $m->formatValue($value, "2"), "arial.ttf", 8,
    0xffffff);
$textBoxObj->setBackground(0x000000, 0, -1);

# Add a semi-transparent blue (40666699) pointer with black border at the specified
# value
$m->addPointer($value, 0x40666699, 0x000000);

# Output the chart
header("Content-type: image/png");
print($m->makeChart2(PNG));
?>