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.
[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
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