I’ve learned a few things since the last post, where we complemented AutoCAD’s new JavaScript API with some additional .NET functionality to work around an issue that existed in the code we’d developed in the previous two posts.
Firstly, I found out there’s a better way for your jig to display transient graphics than via “manual” calls to addTransient(), updateTransient() and eraseTransient(). Acad.Jig exposes an update() function you can call, passing in the xml fragment representing your geometry. The jig will manage the display of the transient and clear it at the end. (Thanks to Sherry Tan for pointing me in this direction.) To make this work, you’ll need to assign your jig to a variable that’s in scope during its execution.
The problem is that this mechanism still exhibits the issue we had to work around last time: when you click on the circumference of a transient circle, the click doesn’t make it through. So I’ve modified the comments in today’s code to reflect the ideal implementation, but it doesn’t change our need to work around the current problematic behaviour.
The other two things I learned are that the jig – as we implemented it last time – doesn’t work well with a non-standard (i.e. non-world) UCS and that it causes very bad things to happen when you try to run it in two separate drawing windows at the same time. The first of these is a problem we’ll address in today’s post, the second is something I need to check in with some colleagues on: it may simply be a limitation of the current implementation that it doesn’t work well in an MDI context. We’ll see.
So, how do we get the jig working properly in an arbitrary UCS? There’s a handy method available that allows us to transform from the current UCS to WCS, e.g.:
wcsPoint = Acad.Editor.CurrentViewport.ucsToWorld(ucsPoint);
We only need to use this to transform the picked centre-point of the circle into WCS.
One thing I struggled with: I had trouble getting distance acquisition to work properly in an arbitrary UCS inside our jig, so I ended up ditching it in favour of acquiring a second point and then calculating the distance to the centre-point manually. Which is why we now have a distanceBetween() function that uses Pythagoras’ theorem to calculate the distance between two points.
No changes were needed to the C# code we saw last time (which is still needed), but here are the updates to the JavaScript code. Its CJ command should now work well in any User Coordinate System you can define inside AutoCAD:
var doc = Acad.Application.activedocument;
var center = new Acad.Point3d(0, 0, 0);
var ucsCenter;
var radius = 0;
var jig;
function pointToString(pt) {
var ret =
pt.x.toString() + "," +
pt.y.toString() + "," +
pt.z.toString();
return ret;
}
function distanceBetween(pt1, pt2) {
var dist =
Math.sqrt(
(pt2.x - pt1.x) * (pt2.x - pt1.x) +
(pt2.y - pt1.y) * (pt2.y - pt1.y) +
(pt2.z - pt1.z) * (pt2.z - pt1.z)
);
return dist;
}
function createCircle(cen, rad, first) {
// Build an XML string containing data to create
// an AcGiTransient that represents the circle
var cursor = '';
var drawable =
'<?xml version="1.0" encoding="utf-8"?>' +
'<drawable ' +
'xmlns="http://www.autodesk.com/AutoCAD/drawstream.xsd" ' +
'xmlns:t="http://www.autodesk.com/AutoCAD/transient.xsd" '+
't:onmouseover="onmouseover"' + cursor + '>' +
'<graphics id="id1"><circle center ="' + pointToString(cen) +
'" radius ="' + rad.toString() + '"/>' +
'</graphics></drawable>';
return drawable;
}
function circleJig() {
function onJigUpdate(args) {
var res = JSON.parse(args);
if (res) {
// We calculate the distance in the WCS
// (using distance input we'd just do this:
// radius = res.distance; )
var point =
new Acad.Point3d(res.point.x, res.point.y, res.point.z);
radius = distanceBetween(center, point);
// Use it to create the XML for a transient
// circle and ask for it to be displayed
//var x = createCircle(center, radius);
//jig.update(x, onJigContinue, onJigError);
drawCircle(center, radius);
}
return true;
}
function onJigComplete(args) {
clearCircle();
var res = JSON.parse(args);
if (res && res.dragStatus == Acad.DragStatus.kNormal) {
Acad.Editor.executeCommandAsync(
'_.CIRCLE ' + pointToString(ucsCenter) + ' ' + radius
);
}
}
function onJigContinue(args) {
}
function onJigError(args) {
clearCircle();
write('\nUnable to create circle: ' + args);
}
function onPointSelected(args) {
try {
var res = JSON.parse(args);
if (res) {
// Extract and transform our circle's center
ucsCenter =
new Acad.Point3d(
res.value.x,
res.value.y,
res.value.z
);
center = Acad.Editor.CurrentViewport.ucsToWorld(ucsCenter);
// Draw the circle with an initial 0 radius
drawCircle(center, 0);
// Set up our jig options
var opts =
new Acad.JigPromptPointOptions('Point on radius');
opts.userInputControls =
Acad.UserInputControls.kAccept3dCoordinates;
// Run the jig to select the distance
jig = new Acad.DrawJig(onJigUpdate, opts);
Acad.Editor.drag(jig).then(onJigComplete, onJigError);
}
}
catch (ex) {
write('\nException: ' + ex + '\n');
}
}
function onPointError(args) {
write('\nUnable to select point: ' + args);
}
// Ask the user to select the center point before we
// start the jig
var opts = new Acad.PromptPointOptions('Select center');
Acad.Editor.getPoint(opts).then(
onPointSelected, onPointError
);
}
// Our extensions to the AutoCAD Shaping Layer
function drawCircle(cen, rad) {
execAsync(
JSON.stringify({
functionName: 'NetDrawCircle',
invokeAsCommand: false,
functionParams: {
center: cen,
radius: rad
}
}),
onInvokeSuccess,
onInvokeError
);
}
function clearCircle() {
execAsync(
JSON.stringify({
functionName: 'NetClearCircle',
invokeAsCommand: false,
functionParams: undefined
}),
onInvokeSuccess,
onInvokeError
);
}
function onInvokeSuccess(result) {
write("\n");
}
function onInvokeError(result) {
write("\nOnInvokeError: " + result);
}
Acad.Editor.addCommand(
"JIG_CMDS",
"CJ",
"CJ",
Acad.CommandFlag.MODAL,
circleJig
);
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