ChartDirector 6.0 (ColdFusion Edition)

Neon Round Meters


      

This examples demonstrates various shading effects to create round meters with a neon look and feel. It also demonstrates how to create meters that can easily be resized.

In this example, the code uses a single size parameter as input, and it derives all the other sizes, such as the radius of the various parts of the chart, the font size, line widths and tick lengths. This allows the chart to be easily resized by changing only one parameter.

For the colors, apart from black and white, the code only uses a single color as input. BaseChart.adjustBrightness is used to create brighter or darker versions of that color, and AngularMeter.relativeRadialGradient is used to combine them in gradients.

Source Code Listing

[File: cfdemo/neonroundmeter.cfm]
<cfscript>

// ChartDirector for ColdFusion API Access Point
cd = CreateObject("java", "ChartDirector.CFChart");

// A utility to allow us to create arrays with data in one line of code
function Array() {
    var result = ArrayNew(1);
    var i = 0;
    for (i = 1; i LTE ArrayLen(arguments); i = i + 1)
        result[i] = arguments[i];
    return result;
}

// Function to create the demo charts
function createChart(chartIndex)
{
    // Declare local variables
    var value = 0;
    var colorList = 0;
    var mainColor = 0;
    var size = 0;
    var outerRadius = 0;
    var scaleRadius = 0;
    var innerRadius = 0;
    var colorScaleWidth = 0;
    var tickLength = 0;
    var tickWidth = 0;
    var fontSize = 0;
    var m = 0;
    var bgGradient = 0;
    var neonGradient = 0;
    var smoothColorScale = 0;
    var stepColorScale = 0;
    var highColorScale = 0;

    // The value to display on the meter
    value = 50;

    // The main color of the four meters in this example. The other colors and gradients are derived
    // from the main color.
    colorList = Array("0x007700", "0x770077", "0x0033dd", "0x880000");
    mainColor = colorList[chartIndex + 1];

    //
    // In this example, we demonstrate how to parameterized by size, so that the chart size can be
    // changed by changing just one variable.
    //
    size = 300;

    // The radius of the entire meter, which is size / 2, minus 2 pixels for margin
    outerRadius = Fix(size / 2 - 2);

    // The radius of the meter scale
    scaleRadius = Fix(outerRadius * 92 / 100);

    // The radius of the inner decorative circle
    innerRadius = Fix(scaleRadius * 40 / 100);

    // The width of the color scale
    colorScaleWidth = Fix(scaleRadius * 10 / 100);

    // Major tick length
    tickLength = Fix(scaleRadius * 10 / 100);

    // Major tick width
    tickWidth = Fix(scaleRadius * 1 / 100 + 1);

    // Label font size
    fontSize = Fix(scaleRadius * 13 / 100);

    //
    // Create an angular meter based on the above parameters
    //

    // Create an AngularMeter object of the specified size. In this demo, we use black (0x000000) as
    // the background color. You can also use transparent or other colors.
    m = cd.AngularMeter(size, size, "0x000000");

    // Set the default text and line colors to white (0xffffff)
    m.setColor(cd.TextColor, "0xffffff");
    m.setColor(cd.LineColor, "0xffffff");

    // Set meter center and scale radius, and set the scale angle from -180 to +90 degrees
    m.setMeter(size / 2, size / 2, scaleRadius, -180, 90);

    // Background gradient with the mainColor at the center and become darker near the border
    bgGradient = Array(0, mainColor, 0.5, m.adjustBrightness(mainColor, 0.75), 1,
        m.adjustBrightness(mainColor, 0.15));

    // Fill the meter background with the background gradient
    m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66));

    // Fill the inner circle with the same background gradient for decoration
    m.addRing(0, innerRadius, m.relativeRadialGradient(bgGradient, innerRadius * 0.8));

    // Gradient for the neon backlight, with the main color at the scale radius fading to
    // transparent
    neonGradient = Array(0.89, cd.Transparent, 1, mainColor, 1.07, cd.Transparent);
    m.addRing(Fix(scaleRadius * 85 / 100), outerRadius, m.relativeRadialGradient(neonGradient));

    // The neon ring at the scale radius with width equal to 1/80 of the scale radius, creating
    // using a brighter version of the main color
    m.addRing(scaleRadius, Fix(scaleRadius + scaleRadius / 80), m.adjustBrightness(mainColor, 2));

    // 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, tick length and tick width. The minor and micro tick lengths are
    // 80% and 60% of the major tick length, and their widths are around half of the major tick
    // width.
    m.setLabelStyle("Arial Italic", fontSize);
    m.setTickLength( - tickLength,  - Fix(tickLength * 80 / 100),  - Fix(tickLength * 60 / 100));
    m.setLineWidth(0, tickWidth, Fix((tickWidth + 1) / 2), Fix((tickWidth + 1) / 2));

    // Demostrate different types of color scales and glare effects and putting them at different
    // positions.
    smoothColorScale = Array(0, "0x0000ff", 25, "0x0088ff", 50, "0x00ff00", 75, "0xdddd00", 100,
        "0xff0000");
    stepColorScale = Array(0, "0x00dd00", 60, "0xddaa00", 80, "0xdd0000", 100);
    highColorScale = Array(70, cd.Transparent, 100, "0xff0000");

    if (chartIndex EQ 1) {
        // Add the smooth color scale just outside the inner circle
        m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth);
        // Add glare up to the scale radius, concave and spanning 190 degrees
        m.addGlare(scaleRadius, -190);
    } else if (chartIndex EQ 2) {
        // Add the high color scale at the default position
        m.addColorScale(highColorScale);
        // Add glare up to the scale radius
        m.addGlare(scaleRadius);
    } else {
        // Add the step color scale just outside the inner circle
        m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth);
        // Add glare up to the scale radius, concave and spanning 190 degrees and rotated by -45
        // degrees
        m.addGlare(scaleRadius, -190, -45);
    }

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

    // Set the cap background to a brighter version of the mainColor, and using black (0x000000) for
    // the cap and grey (0x999999) for the cap border
    m.setCap2(m.adjustBrightness(mainColor, 1.1), "0x000000", "0x999999");

    // Output the chart
    return m.makeSession(GetPageContext(), "chart" & chartIndex);
}

chart0URL = createChart(0);
chart1URL = createChart(1);
chart2URL = createChart(2);
chart3URL = createChart(3);

</cfscript>
<html>
<body style="margin:5px 0px 0px 5px">
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    Neon Round Meters
</div>
<hr style="border:solid 1px #000080" />
<cfoutput>
<div style="font-size:9pt; font-family:verdana; margin-bottom:1.5em">
    <a href='viewsource.cfm?file=#CGI.SCRIPT_NAME#'>View Source Code</a>
</div>
<img src="getchart.cfm?#chart0URL#" />
<img src="getchart.cfm?#chart1URL#" />
<img src="getchart.cfm?#chart2URL#" />
<img src="getchart.cfm?#chart3URL#" />
</cfoutput>
</body>
</html>