ChartDirector 7.0 (ASP/COM/VB 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

[Web Version (in ASP)] aspdemo\neonroundmeter.asp
<%@ language="vbscript" %> <% Set cd = CreateObject("ChartDirector.API") ' This script can draw different charts depending on the chartIndex Sub createChart(viewer, chartIndex) ' 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(&H007700, &H770077, &H0033dd, &H880000) mainColor = colorList(chartIndex) ' ' 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 = Int(size / 2 - 2) ' The radius of the meter scale scaleRadius = Int(outerRadius * 92 / 100) ' The radius of the inner decorative circle innerRadius = Int(scaleRadius * 40 / 100) ' The width of the color scale colorScaleWidth = Int(scaleRadius * 10 / 100) ' Major tick length tickLength = Int(scaleRadius * 10 / 100) ' Major tick width tickWidth = Int(scaleRadius * 1 / 100 + 1) ' Label font size fontSize = Int(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. Set m = cd.AngularMeter(size, size, &H000000) ' Set the default text and line colors to white (0xffffff) Call m.setColor(cd.TextColor, &Hffffff) Call m.setColor(cd.LineColor, &Hffffff) ' Set meter center and scale radius, and set the scale angle from -180 to +90 degrees Call 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 Call m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66)) ' Fill the inner circle with the same background gradient for decoration Call 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) Call m.addRing(Int(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 Call m.addRing(scaleRadius, Int(scaleRadius + scaleRadius / 80), m.adjustBrightness(mainColor, _ 2)) ' Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units Call 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. Call m.setLabelStyle("Arial Italic", fontSize) Call m.setTickLength(-tickLength, -Int(tickLength * 80 / 100), -Int(tickLength * 60 / 100)) Call m.setLineWidth(0, tickWidth, Int((tickWidth + 1) / 2), Int((tickWidth + 1) / 2)) ' Demostrate different types of color scales and glare effects and putting them at different ' positions. smoothColorScale = Array(0, &H0000ff, 25, &H0088ff, 50, &H00ff00, 75, &Hdddd00, 100, &Hff0000) stepColorScale = Array(0, &H00dd00, 60, &Hddaa00, 80, &Hdd0000, 100) highColorScale = Array(70, cd.Transparent, 100, &Hff0000) If chartIndex = 1 Then ' Add the smooth color scale just outside the inner circle Call m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth) ' Add glare up to the scale radius, concave and spanning 190 degrees Call m.addGlare(scaleRadius, -190) ElseIf chartIndex = 2 Then ' Add the high color scale at the default position Call m.addColorScale(highColorScale) ' Add glare up to the scale radius Call m.addGlare(scaleRadius) Else ' Add the step color scale just outside the inner circle Call m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth) ' Add glare up to the scale radius, concave and spanning 190 degrees and rotated by -45 ' degrees Call m.addGlare(scaleRadius, -190, -45) End If ' Add a red (0xff0000) pointer at the specified value Call m.addPointer2(value, &Hff0000) ' 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 Call m.setCap2(m.adjustBrightness(mainColor, 1.1), &H000000, &H999999) ' Output the chart Call viewer.setChart(m, cd.SVG) End Sub ' This example includes 4 charts Dim viewers(3) For i = 0 To Ubound(viewers) Set viewers(i) = cd.WebChartViewer(Request, "chart" & i) Call createChart(viewers(i), i) Next %> <!DOCTYPE html> <html> <head> <title>Neon Round Meters</title> <!-- Include ChartDirector Javascript Library to support chart interactions --> <script type="text/javascript" src="cdjcv.js"></script> </head> <body style="margin:5px 0px 0px 5px"> <div style="font:bold 18pt verdana;"> Neon Round Meters </div> <hr style="border:solid 1px #000080; background:#000080" /> <div style="font:10pt verdana; margin-bottom:1.5em"> <a href="viewsource.asp?file=<%= Request("SCRIPT_NAME") %>">View Chart Source Code</a> </div> <!-- ****** Here are the chart images ****** --> <% For i = 0 To Ubound(viewers) Call Response.Write(viewers(i).renderHTML()) Call Response.Write(" ") Next %> </body> </html>

[Windows Version (in Visual Basic)] vbdemo\neonroundmeter.cls
Public Sub createChart(viewer As Object, chartIndex As Integer) Dim cd As New ChartDirector.API ' The value to display on the meter Dim value As Double value = 50 ' The main color of the four meters in this example. The other colors and gradients are derived ' from the main color. Dim colorList() colorList = Array(&H007700, &H770077, &H0033dd, &H880000) Dim mainColor As Long mainColor = colorList(chartIndex) ' ' In this example, we demonstrate how to parameterized by size, so that the chart size can be ' changed by changing just one variable. ' Dim size As Long size = 300 ' The radius of the entire meter, which is size / 2, minus 2 pixels for margin Dim outerRadius As Long outerRadius = Int(size / 2 - 2) ' The radius of the meter scale Dim scaleRadius As Long scaleRadius = Int(outerRadius * 92 / 100) ' The radius of the inner decorative circle Dim innerRadius As Long innerRadius = Int(scaleRadius * 40 / 100) ' The width of the color scale Dim colorScaleWidth As Long colorScaleWidth = Int(scaleRadius * 10 / 100) ' Major tick length Dim tickLength As Long tickLength = Int(scaleRadius * 10 / 100) ' Major tick width Dim tickWidth As Long tickWidth = Int(scaleRadius * 1 / 100 + 1) ' Label font size Dim fontSize As Long fontSize = Int(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. Dim m As AngularMeter Set m = cd.AngularMeter(size, size, &H000000) ' Set the default text and line colors to white (0xffffff) Call m.setColor(cd.TextColor, &Hffffff) Call m.setColor(cd.LineColor, &Hffffff) ' Set meter center and scale radius, and set the scale angle from -180 to +90 degrees Call m.setMeter(size / 2, size / 2, scaleRadius, -180, 90) ' Background gradient with the mainColor at the center and become darker near the border Dim bgGradient() 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 Call m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66)) ' Fill the inner circle with the same background gradient for decoration Call 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 Dim neonGradient() neonGradient = Array(0.89, cd.Transparent, 1, mainColor, 1.07, cd.Transparent) Call m.addRing(Int(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 Call m.addRing(scaleRadius, Int(scaleRadius + scaleRadius / 80), m.adjustBrightness(mainColor, _ 2)) ' Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units Call 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. Call m.setLabelStyle("ariali.ttf", fontSize) Call m.setTickLength(-tickLength, -Int(tickLength * 80 / 100), -Int(tickLength * 60 / 100)) Call m.setLineWidth(0, tickWidth, Int((tickWidth + 1) / 2), Int((tickWidth + 1) / 2)) ' Demostrate different types of color scales and glare effects and putting them at different ' positions. Dim smoothColorScale() smoothColorScale = Array(0, &H0000ff, 25, &H0088ff, 50, &H00ff00, 75, &Hdddd00, 100, &Hff0000) Dim stepColorScale() stepColorScale = Array(0, &H00dd00, 60, &Hddaa00, 80, &Hdd0000, 100) Dim highColorScale() highColorScale = Array(70, cd.Transparent, 100, &Hff0000) If chartIndex = 1 Then ' Add the smooth color scale just outside the inner circle Call m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth) ' Add glare up to the scale radius, concave and spanning 190 degrees Call m.addGlare(scaleRadius, -190) ElseIf chartIndex = 2 Then ' Add the high color scale at the default position Call m.addColorScale(highColorScale) ' Add glare up to the scale radius Call m.addGlare(scaleRadius) Else ' Add the step color scale just outside the inner circle Call m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth) ' Add glare up to the scale radius, concave and spanning 190 degrees and rotated by -45 ' degrees Call m.addGlare(scaleRadius, -190, -45) End If ' Add a red (0xff0000) pointer at the specified value Call m.addPointer2(value, &Hff0000) ' 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 Call m.setCap2(m.adjustBrightness(mainColor, 1.1), &H000000, &H999999) ' Output the chart Set viewer.Picture = m.makePicture() End Sub