I have tried to apply the image adjustment options using paper.js, but it will only apply to the fillcolor.
Does anyone know how to apply brightness, contrast or other image adjustments to the raster image?
For example:
var url = 'http://images.com/q.jpg';
var raster = new paper.Raster(url);
raster.brightness = .5;
Are there any pre-defined functions available for image adjustment in paper.js?
Nope, but you can play with blend modes or opacity.
I would advise using specialized WebGL libraries like glfx or webgl-filter for image effects (I didn't try them, but they seem powerful).
function reDrawImage(lightness = 10,contrast = 1.5) {
const raster = paper.project.activeLayer.children[0] as paper.Raster
const ctx: CanvasRenderingContext2D = currentRaster.getContext(true)
const imageData = ctx.getImageData(0, 0, currentRaster.width, currentRaster.height)
for (let i = 0; i < imageData.data.length; i += 4) {
imageData.data[i] = saturate_cast(imageData.data[i] * (contrast + lightness));
imageData.data[i+1] = saturate_cast(imageData.data[i+1] * (contrast + lightness));
imageData.data[i+2] = saturate_cast(imageData.data[i+2] * (contrast + lightness));
}
raster.setImageData(imageData, new Point(0, 0))
}
function saturate_cast(num: number) {
if (num > 255) {
return 255
}
if (num < 0) {
return 0
}
return num
}
Related
I am writing a report in R Markdown, it contains multiple animated highcharts.
The animations work fine, however they all run when the html page loads (after knitting), instead of when the user scrolls to it, so essentially the animation is pointless as the user never sees it.
An example of an animated chart is at the bottom of this question.
Is there a way to make it animate when it appears? All the examples I have found use jsfiddle and I am using R Markdown.
Many thanks
library(dplyr)
library(stringr)
library(purrr)
n <- 5
set.seed(123)
df <- data.frame(x = seq_len(n) - 1) %>%
mutate(
y = 10 + x + 10 * sin(x),
y = round(y, 1),
z = (x*y) - median(x*y),
e = 10 * abs(rnorm(length(x))) + 2,
e = round(e, 1),
low = y - e,
high = y + e,
value = y,
name = sample(fruit[str_length(fruit) <= 5], size = n),
color = rep(colors, length.out = n),
segmentColor = rep(colors2, length.out = n)
)
hcs <- c("line") %>%
map(create_hc)
hcs
Ok, I worked out how to do it myself, going to post the answer here in case someone stumbles across this post in the future.
First of all, I found NOTHING on how to do this in R.
So, I decided to do this in JS, AFTER I had knitted the R Markdown document to HTML, as it wouldn't work in R Markdown.
Once it is a HTML file, open it in TextEdit or Notepad, and add the following code just before one of the charts:
<script>
(function (H) {
var pendingRenders = [];
// https://stackoverflow.com/questions/123999/how-to-tell-if-a-dom-element-is-visible-in-the-current-viewport/7557433#7557433
function isElementInViewport(el) {
var rect = el.getBoundingClientRect();
return (
rect.top >= 0 &&
rect.left >= 0 &&
rect.bottom <= (
window.innerHeight ||
document.documentElement.clientHeight
) &&
rect.right <= (
window.innerWidth ||
document.documentElement.clientWidth
)
);
}
H.wrap(H.Series.prototype, 'render', function deferRender(proceed) {
var series = this,
renderTo = this.chart.container.parentNode;
// It is appeared, render it
if (isElementInViewport(renderTo) || !series.options.animation) {
proceed.call(series);
// It is not appeared, halt renering until appear
} else {
pendingRenders.push({
element: renderTo,
appear: function () {
proceed.call(series);
}
});
}
});
function recalculate() {
pendingRenders.forEach(function (item) {
if (isElementInViewport(item.element)) {
item.appear();
H.erase(pendingRenders, item);
}
});
}
if (window.addEventListener) {
['DOMContentLoaded', 'load', 'scroll', 'resize']
.forEach(function (eventType) {
addEventListener(eventType, recalculate, false);
});
}
}(Highcharts));
</script>
The charts then animate when you scroll to them, rather than when you open the HTML file.
Note: The JSFIDDLE I got the code from was from here:
https://jsfiddle.net/gh/get/library/pure/highcharts/highcharts/tree/master/samples/highcharts/studies/appear/
I am using the blur effect on the d3 map as given here: http://geoexamples.blogspot.in/2014/01/d3-map-styling-tutorial-ii-giving-style.html?
But after using this method (because of how the data is loaded..using datum) my zoom functionality behaves randomly. Irrespective of where I click it zooms to the same point. Also, the animations have become very slow after using the filter.
Is there any other way to achieve blur? Or a solution to this problem?
Any help?
Thanks.
This is the code for the world creation in case when filtering is required (use of datum as per the code on the above site).
d3.json("world-110m2.json", function(error, world) {
g.insert("path")
.datum(topojson.feature(world, world.objects.land))
.attr("d", path);
g.insert("path")
.datum(topojson.mesh(world, world.objects.countries, function(a, b) { return a !== b; }))
.attr("d", path)
.append("path");
g.selectAll("path")
.on("click", click);})
This is the code used in case filtering is not required (No use of datum - maybe the datum is causing the issue)
d3.json("world-110m2.json", function(error,topology) {
g.selectAll("path")
.data(topojson.object(topology, topology.objects.countries)
.geometries)
.enter()
.append("path")
.attr("d",path)
.on("click", click);)}
This is the zoom function: got the code from here: http://bl.ocks.org/mbostock/2206590
function click(d) {
var x, y, k;
var centered;
if (d && centered !== d) {
var centroid = path.centroid(d);
x = centroid[0];
y = centroid[1];
k = 4;
centered = d;
} else {
x = width / 2;
y = height / 2;
k = 1;
centered = null;
}
if (active === d) return reset();
g.selectAll(".active").classed("active", false);
d3.select(this).classed("active", active = d);
var b = path.bounds(d);
g.selectAll("path")
.classed("active", centered && function(d) { return d === centered; });
g.transition()
.duration(750)
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")scale(" + k + ")translate(" + -x + "," + -y + ")")
.style("stroke-width", 1.5 / k + "px");
}
The blur filter consumes lots of resources, as indicated in the post. Speciallly if you combine it with other filters.
One solution would be using Canvas instead of SVG. Here you have some filters using the Canvas element. It should be possible to achieve the same result.
I can't find why the zoom stops working, but the performance is slower because you use all the data, so you are applying the filter to all the data instead of using only the part of the word you are showing, so you are using a much bigger image when you zoom.
I am using Open Flash Charts v2. I have been trying to make Conditional line graph. But I couldn't find any straight forward way, example or any class for producing Conditional charts.
Example of Conditional Graph
So I thought to use some techniques to emulate conditional graph ,I made separate Line object for values above limit range and then this line is used to overlap the plotted line.
This techniques works some what ok ,but there are problems with it,
How to color or place the conditional colored line exactly above the limit.
Remove tooltip and dot from limit line.
Tooltip of conditional line(red) and plotted line(green) are both shown ,I only need tooltip of green line.
Conditional Line Graph Problem illustrated
Source Code: // C#
var chart = new OpenFlashChart.OpenFlashChart();
var data1 = new List<double?> { 1, 3, 4, 5, 2, 1, 6, 7 };//>4=
var overlap = new List<double?> { null, null, 4, 5, null, null, null, null };
var overlap2 = new List<double?> { null, null, null, null, null, null, 6, 7 };
var limitData = new List<double?> { 4, 4, 4, 4, 4, 4, 4, 4 };
var line1 = new Line();
line1.Values = data1;
//line1.HaloSize = 0;
line1.Width = 2;
line1.DotSize = 5;
line1.DotStyleType.Tip = "#x_label#<br>#val#";
line1.Colour = "#37c855";
line1.Tooltip = "#val#";
var overLine = new Line();
overLine.Values = overlap;
//overLine.HaloSize = 0;
overLine.Width = 2;
overLine.DotSize = 5;
overLine.DotStyleType.Tip = "#x_label#<br>#val#";
overLine.Colour = "#d81417";
overLine.Tooltip = "#val#";
var overLine2 = new Line();
overLine2.Values = overlap2;
//overLine2.HaloSize = 0;
overLine2.Width = 2;
overLine2.DotSize = 5;
//overLine2.DotStyleType.Tip = "#x_label#<br>#val#";
//overLine2.DotStyleType.Type = DotType.DOT;
overLine2.Colour = "#d81417";
overLine2.Tooltip = "#val#";
var limit = new Line();
limit.Values = limitData;
limit.Width = 2;
limit.Colour = "#ff0000";
limit.HaloSize = -1;
limit.DotSize = -1;
// limit.DotStyleType.Tip = "";
limit.DotStyleType.Type = null;
//limit.Tooltip = "";
chart.AddElement(line1);
chart.AddElement(overLine);
chart.AddElement(overLine2);
chart.AddElement(limit);
chart.Y_Legend = new Legend("Experiment");
chart.Title = new Title("Conditional Line Graph");
chart.Y_Axis.SetRange(0, 10);
chart.X_Axis.Labels.Color = "#e43456";
chart.X_Axis.Steps = 4;
chart.Tooltip = new ToolTip("#val#");
chart.Tooltip.Shadow = true;
chart.Tooltip.Colour = "#e43456";
chart.Tooltip.MouseStyle = ToolTipStyle.CLOSEST;
Response.Clear();
Response.CacheControl = "no-cache";
Response.Write(chart.ToPrettyString());
Response.End();
Note:
I have already downloaded the OFC (Open Flash Charts) source ,If I modify the OFC Line.as source than how would I be able to generate json for the changed graph ? ,b/c I'm currently using .Net library for the json generation for OFC charts,please do let me know this also.
Update:
I have modified the source code on the advice of David Mears I'm using FlashDevelop for ActionScript.
P.S: I'm open for ideas if another library can do this job.
If you don't mind a little rebuilding, you can get the source of OFC here and modify the Line.solid_line() method in open-flash-chart/charts/Line.as to do this fairly easily.
In order to set the extra chart details through JSON using the .NET library, you'll also have to modify OpenFlashChart/LineBase.cs to add alternative colour and boundary properties. I'm not hugely familiar with .NET, but based on the existing properties you might add something like this:
private double boundary;
private string altcolour;
[JsonProperty("boundary")]
public virtual double Boundary
{
set { this.boundary = value; }
get { return this.boundary; }
}
[JsonProperty("alt-colour")]
public virtual string AltColour
{
set { this.altcolour = value; }
get { return this.altcolour; }
}
Then I believe the following should work in Line.as:
public function solid_line(): void {
var first:Boolean = true;
var i:Number;
var tmp:Sprite;
var x:Number;
var y:Number;
var last_e:Element;
var ratio:Number;
for ( i=0; i < this.numChildren; i++ ) {
// Step through every child object.
tmp = this.getChildAt(i) as Sprite;
// Only include data Elements, ignoring extra children such as line masks.
if( tmp is Element )
{
var e:Element = tmp as Element;
if( first )
{
if (this.props.get('alt-colour') != Number.NEGATIVE_INFINITY) {
if (e._y >= this.props.get_colour('boundary'))
{
// Line starts below boundary, set alt line colour.
this.graphics.lineStyle( this.props.get_colour('width'), this.props.get_colour('alt-colour') );
}
else
{
// Line starts above boundary, set normal line colour.
this.graphics.lineStyle( this.props.get_colour('width'), this.props.get_colour('colour') );
}
}
// Move to the first point.
this.graphics.moveTo(e.x, e.y);
x = e.x;
y = e.y;
first = false;
}
else
{
if (this.props.get('alt-colour') != Number.NEGATIVE_INFINITY) {
if (last_e._y < this.props.get_colour('boundary') && e._y >= this.props.get_colour('boundary'))
{
// Line passes below boundary. Draw first section and switch to alt colour.
ratio = (this.props.get_colour('boundary') - last_e._y) / (e._y - last_e._y);
this.graphics.lineTo(last_e.x + (e.x - last_e.x) * ratio, last_e.y + (e.y - last_e.y) * ratio);
this.graphics.lineStyle( this.props.get_colour('width'), this.props.get_colour('alt-colour') );
}
else if (last_e._y >= this.props.get_colour('boundary') && e._y < this.props.get_colour('boundary'))
{
// Line passes above boundary. Draw first section and switch to normal colour.
ratio = (this.props.get_colour('boundary') - last_e._y) / (e._y - last_e._y);
this.graphics.lineTo(last_e.x + (e.x - last_e.x) * ratio, last_e.y + (e.y - last_e.y) * ratio);
this.graphics.lineStyle( this.props.get_colour('width'), this.props.get_colour('colour') );
}
}
// Draw a line to the next point.
this.graphics.lineTo(e.x, e.y);
}
last_e = e;
}
}
if ( this.props.get('loop') ) {
// close the line loop (radar charts)
this.graphics.lineTo(x, y);
}
}
With the new open-flash-chart.swf, you should be able to just set your new properties on line1:
line1.Boundary = 4;
line1.AltColour = "#d81417";
I am trying to scale a skeleton to match to the sizes of another skeleton.
My algoritm do the following:
Find the distance between two joints of the origin skeleton and the destiny skeleton using phytagorean teorem
divide this two distances to find a multiply factor.
Multiply each joint by this factor.
Here is my actual code:
public static Skeleton ScaleToMatch(this Skeleton skToBeScaled, Skeleton skDestiny)
{
Joint newJoint = new Joint();
double distanciaOrigem = 0;
double distanciaDestino = 0;
double fator = 1;
SkeletonPoint pos = new SkeletonPoint();
foreach (BoneOrientation bo in skToBeScaled.BoneOrientations)
{
distanciaOrigem = FisioKinectCalcs.Distance3DBetweenJoint(skToBeScaled.Joints[bo.StartJoint], skToBeScaled.Joints[bo.EndJoint]);
distanciaDestino = FisioKinectCalcs.Distance3DBetweenJoint(skDestiny.Joints[bo.StartJoint], skDestiny.Joints[bo.EndJoint]);
if (distanciaOrigem > 0 && distanciaDestino > 0)
{
fator = (distanciaDestino / distanciaOrigem);
newJoint = skToBeScaled.Joints[bo.EndJoint]; // escaling only the end joint as the BoneOrientatios starts from HipCenter, i am scaling from center to edges.
// applying the new values to the joint
pos = new SkeletonPoint()
{
X = (float)(newJoint.Position.X * fator),
Y = (float)(newJoint.Position.Y * fator),
Z = (float)(newJoint.Position.Z * fator)
};
newJoint.Position = pos;
skToBeScaled.Joints[bo.EndJoint] = newJoint;
}
}
return skToBeScaled;
}
Every seems to work fine except for the hands and foots
Look at this images
I have my own skeleton over me, and my skeleton scaled to the sizes of another person, but the hands and foots still crazy. (but code looks right)
Any suggestion?
It's hard to say without running the code, but it somewhat "looks good".
What I would validate though, is your
if (distanciaOrigem > 0 && distanciaDestino > 0)
If distanciaOrigem is very close to 0, but even just epsilon away from 0, it won't be picked up by the if, and then
fator = (distanciaDestino / distanciaOrigem);
Will result in a very large number!
I would suggest to smooth the factor so it generally fits the proper scale. Try this code:
private static Dictionary<JointType, double> jointFactors = null;
static CalibrationUtils()
{
InitJointFactors();
}
public static class EnumUtil
{
public static IEnumerable<T> GetValues<T>()
{
return Enum.GetValues(typeof(T)).Cast<T>();
}
}
private static void InitJointFactors()
{
var jointTypes = EnumUtil.GetValues<JointType>();
jointFactors = new Dictionary<JointType, double>();
foreach(JointType type in jointTypes)
{
jointFactors.Add(type, 0);
}
}
private static double SmoothenFactor(JointType jointType, double factor, int weight)
{
double currentValue = jointFactors[jointType];
double newValue = 0;
if(currentValue != 0)
newValue = (weight * currentValue + factor) / (weight + 1);
else
newValue = factor;
jointFactors[jointType] = newValue;
return newValue;
}
When it comes to factor usage just use the SmoothenFactor method first:
public static Skeleton ScaleToMatch(this Skeleton skToBeScaled, Skeleton skDestiny, double additionalFactor = 1)
{
Joint newJoint = new Joint();
double distanceToScale = 0;
double distanceDestiny = 0;
double factor = 1;
int weight = 500;
SkeletonPoint pos = new SkeletonPoint();
Skeleton newSkeleton = null;
KinectHelper.CopySkeleton(skToBeScaled, ref newSkeleton);
SkeletonPoint hipCenterPosition = newSkeleton.Joints[JointType.HipCenter].Position;
foreach(BoneOrientation bo in skToBeScaled.BoneOrientations)
{
distanceToScale = Distance3DBetweenJoints(skToBeScaled.Joints[bo.StartJoint], skToBeScaled.Joints[bo.EndJoint]);
distanceDestiny = Distance3DBetweenJoints(skDestiny.Joints[bo.StartJoint], skDestiny.Joints[bo.EndJoint]);
if(distanceToScale > 0 && distanceDestiny > 0)
{
factor = (distanceDestiny / distanceToScale) * additionalFactor;
newJoint = skToBeScaled.Joints[bo.EndJoint]; // escaling only the end joint as the BoneOrientatios starts from HipCenter, i am scaling from center to edges.
factor = SmoothenFactor(newJoint.JointType, factor, weight);
pos = new SkeletonPoint()
{
X = (float)((newJoint.Position.X - hipCenterPosition.X) * factor + hipCenterPosition.X),
Y = (float)((newJoint.Position.Y - hipCenterPosition.Y) * factor + hipCenterPosition.Y),
Z = (float)((newJoint.Position.Z - hipCenterPosition.Z) * factor + hipCenterPosition.Z)
};
newJoint.Position = pos;
newSkeleton.Joints[bo.EndJoint] = newJoint;
}
}
return newSkeleton;
}
I also modified your ScaleToMatch method as you see. There was a need to move joints in relation to HipCenter position. Also new positions are saved to a new Skeleton instance so they are not used in further vector calculations.
Experiment with the weight but since our bones length is constant you can use big numbers like 100 and more to be sure that wrong Kinect readings do not disturb the correct scale.
Here's an example of how it helped with scaling HandRight joint position:
The weight was set to 500. The resulting factor is supposed to be around 2 (because the base skeleton was purposely downscaled by a factor of 2).
I hope it helps!
I am trying to draw a continuous curved line in flash. There are many methods but none of the ones I have found so far quite fit my requirements. First of all, I want to use the flash graphic api's curveTo() method. I DO NOT want to simulate a curve with hundreds of calls to lineTo() per curved line segment. It is my experience and understanding that line segments are processor heavy. Flash's quadratic bezier curve should take less CPU power. Please challenge this assumption if you think I am wrong.
I also do not want to use a pre-made method that takes the entire line as an argument (eg mx.charts.chartClasses.GraphicsUtilities.drawPolyline()).
The reason is that I will need to modify the logic eventually to add decorations to the line I am drawing, so I need something I understand at its lowest level.
I have currently created a method that will draw a curve given 3 points, using the mid-point method found here.
Here is a picture:
The problem is that the lines do not actually curve through the "real" points of the line (the gray circles). Is there a way using the power of math that I can adjust the control point so that the curve will actually pass through the "real" point? Given only the current point and its prev/next point as arguments? The code to duplicate the above picture follows. It would be great if I could modify it to meet this requirement (note the exception for first and last point).
package {
import flash.display.Shape;
import flash.display.Sprite;
import flash.display.Stage;
import flash.geom.Point;
[SWF(width="200",height="200")]
public class TestCurves extends Sprite {
public function TestCurves() {
stage.scaleMode = "noScale";
var points:Array = [
new Point(10, 10),
new Point(80, 80),
new Point(80, 160),
new Point(20, 160),
new Point(20, 200),
new Point(200, 100)
];
graphics.lineStyle(2, 0xFF0000);
var point:Point = points[0];
var nextPoint:Point = points[1];
SplineMethod.drawSpline(graphics, point, null, nextPoint);
var prevPoint:Point = point;
var n:int = points.length;
var i:int;
for (i = 2; i < n + 1; i++) {
point = nextPoint;
nextPoint = points[i]; //will eval to null when i == n
SplineMethod.drawSpline(graphics, point, prevPoint, nextPoint);
prevPoint = point;
}
//straight lines and vertices for comparison
graphics.lineStyle(2, 0xC0C0C0, 0.5);
graphics.drawCircle(points[0].x, points[0].y, 4);
for (i = 1; i < n; i++) {
graphics.moveTo(points[i - 1].x, points[i - 1].y);
graphics.lineTo(points[i].x, points[i].y);
graphics.drawCircle(points[i].x, points[i].y, 4);
}
}
}
}
import flash.display.Graphics;
import flash.geom.Point;
internal class SplineMethod {
public static function drawSpline(target:Graphics, p:Point, prev:Point=null, next:Point=null):void {
if (!prev && !next) {
return; //cannot draw a 1-dimensional line, ie a line requires at least two points
}
var mPrev:Point; //mid-point of the previous point and the target point
var mNext:Point; //mid-point of the next point and the target point
if (prev) {
mPrev = new Point((p.x + prev.x) / 2, (p.y + prev.y) / 2);
}
if (next) {
mNext = new Point((p.x + next.x) / 2, (p.y + next.y) / 2);
if (!prev) {
//This is the first line point, only draw to the next point's mid-point
target.moveTo(p.x, p.y);
target.lineTo(mNext.x, mNext.y);
return;
}
} else {
//This is the last line point, finish drawing from the previous mid-point
target.moveTo(mPrev.x, mPrev.y);
target.lineTo(p.x, p.y);
return;
}
//draw from mid-point to mid-point with the target point being the control point.
//Note, the line will unfortunately not pass through the actual vertex... I want to solve this
target.moveTo(mPrev.x, mPrev.y);
target.curveTo(p.x, p.y, mNext.x, mNext.y);
}
}
Later I will be adding arrows and things to the draw method.
I think you're looking for a Catmull-Rom spline. I've googled an AS3 implementation for you but haven't tried it so use at your own discretion:
http://actionsnippet.com/?p=1031
Ok, the Catmull-Rom spline suggestion is a good one but not exactly what I am looking for.
The example from the link provided was a good starting point, but a bit inflexible. I have taken it and modified my original source code to use it. I am posting this as an answer because I think it is more modular and easier to understand than Zevan's blog post (no offense Zevan!). The following code will display the following image:
Here is the code:
package {
import flash.display.Shape;
import flash.display.Sprite;
import flash.display.Stage;
import flash.geom.Point;
[SWF(width="300",height="300")]
public class TestCurves extends Sprite {
public function TestCurves() {
stage.scaleMode = "noScale";
//draw a helpful grid
graphics.lineStyle(1, 0xC0C0C0, 0.5);
for (var x:int = 0; x <= 300; x += 10) {
graphics.moveTo(x, 0);
graphics.lineTo(x, 300);
graphics.moveTo(0, x);
graphics.lineTo(300, x);
}
var points:Array = [
new Point(40, 20),
new Point(120, 80),
new Point(120, 160),
new Point(60, 160),
new Point(60, 200),
new Point(240, 150),
new Point(230, 220),
new Point(230, 280)
];
SplineMethod.setResolution(5);
graphics.lineStyle(2, 0xF00000);
graphics.moveTo(points[0].x, points[0].y);
var n:int = points.length;
var i:int;
for (i = 0; i < n - 1; i++) {
SplineMethod.drawSpline(
graphics,
points[i], //segment start
points[i + 1], //segment end
points[i - 1], //previous point (may be null)
points[i + 2] //next point (may be null)
);
}
//straight lines and vertices for comparison
graphics.lineStyle(2, 0x808080, 0.5);
graphics.drawCircle(points[0].x, points[0].y, 4);
for (i = 1; i < n; i++) {
graphics.moveTo(points[i - 1].x, points[i - 1].y);
graphics.lineTo(points[i].x, points[i].y);
graphics.drawCircle(points[i].x, points[i].y, 4);
}
}
}
}
import flash.display.Graphics;
import flash.geom.Point;
internal class SplineMethod {
//default setting will just draw a straight line
private static var hermiteValues:Array = [0, 0, 1, 0];
public static function setResolution(value:int):void {
var resolution:Number = 1 / value;
hermiteValues = [];
for (var t:Number = resolution; t <= 1; t += resolution) {
var h00:Number = (1 + 2 * t) * (1 - t) * (1 - t);
var h10:Number = t * (1 - t) * (1 - t);
var h01:Number = t * t * (3 - 2 * t);
var h11:Number = t * t * (t - 1);
hermiteValues.push(h00, h10, h01, h11);
}
}
public static function drawSpline(target:Graphics, segmentStart:Point, segmentEnd:Point, prevSegmentEnd:Point=null, nextSegmentStart:Point=null):void {
if (!prevSegmentEnd) {
prevSegmentEnd = segmentStart;
}
if (!nextSegmentStart) {
nextSegmentStart = segmentEnd;
}
var m1:Point = new Point((segmentEnd.x - prevSegmentEnd.x) / 2, (segmentEnd.y - prevSegmentEnd.y) / 2);
var m2:Point = new Point((nextSegmentStart.x - segmentStart.x) / 2, (nextSegmentStart.y - segmentStart.y) / 2);
var n:int = hermiteValues.length;
for (var i:int = 0; i < n; i += 4) {
var h00:Number = hermiteValues[i];
var h10:Number = hermiteValues[i + 1];
var h01:Number = hermiteValues[i + 2];
var h11:Number = hermiteValues[i + 3];
var px:Number = h00 * segmentStart.x + h10 * m1.x + h01 * segmentEnd.x + h11 * m2.x;
var py:Number = h00 * segmentStart.y + h10 * m1.y + h01 * segmentEnd.y + h11 * m2.y;
target.lineTo(px, py);
}
}
}
This is not a perfect solution. But unfortunately, I cannot piece together how to accomplish what I want using curveTo(). Note that GraphicsUtilities.drawPolyLine() does accomplish what I am attempting to do--the problem there is that it is inflexible and I cannot parse the code (more importantly, it doesn't appear to properly draw acute angles--correct me if I am wrong). If anyone can provide any insight, please post. For now, the above is my answer.
I code this, I think it may help:
SWF: http://dl.dropbox.com/u/2283327/stackoverflow/SplineTest.swf
Code: http://dl.dropbox.com/u/2283327/stackoverflow/SplineTest.as
I left a lot of comments on the code. I wish it helps!
Here is the theory behind the code:
A and C are the first and last point, B is the "control point" in AS3 you can draw the curve like this:
graphics.moveTo(A.x, A.y);
graphics.curveTo(B.x, B.y, C.x, C.y);
Now, D is the mid-point of the vector AC. And the mid-point of DB is the mid-point of the curve. Now what I did in the code was to move B exactly to D+DB*2 so, if you draw the curve using that point as control point, the mid-point of the curve will be B.
PS: Sorry for my poor Enlgish