ArcGIS API: Drawing circle fixing center - arcgis-js-api

I am using ArcGIS API v4.8 and the drawing tools to draw circle on my map.
1 issue I notice is when I draw a circle, the center of the circle moves when I move my mouse resizing the circle rather than fixed at the point of the 1st mouse click starts:
How do I fix the center regardless of how I move the radius of the circle? What is missing in my code?
const options = {view, layer: tempGraphicsLayer, pointSymbol, polylineSymbol, polygonSymbol}
let sketchViewModel = new SketchViewModel(options)
let drawCircleButton = document.getElementById('circleButton')
drawCircleButton.onclick = function () {
clear()
isDrawLine = false
sketchViewModel.create('polygon', {mode: 'click'})
sketchViewModel.create('circle')
}
EDIT:
I have found a similar sample, choose the Draw Circle tool, start drawing a circle on the map, you will notice that the center of the circle moves when you move your mouse, I want it to fix the center instead.
The problem when the center moves along with your mouse move is that the circle drawn is not accurate, as I want to start with the center of the circle I want, the circle can expand outward but the center should not move.

That is because the circle, in the given example, is being draw inside the square object. Basically your start and end point are representing corners, not the center point and outer layer of the circle. So every time you expand circle object, it expands from one corner, while the rest is dragging along your mouse.
Visual example:
There are workarounds for this of course. I've made a small sample code of one of the possible ways to draw a circle from a fixed center point.
https://jsfiddle.net/wLd46g8k/9/
Basically I used an ArcGis JS API 4.x constructor called Circle, where you pass a starting point and radius. In my example I've calculated the radius from these two points.
function drawCircle(){//draws the circle
graphicsLayer.graphics.removeAll();
var graphic = new Graphic({
geometry: new Circle({//circle constructor
center: startPoint,//pass the pointer-down event X Y as a starting point
radius: Math.floor(Math.sqrt(Math.pow(startPoint.x - endPoint.x, 2) + Math.pow(startPoint.y - endPoint.y, 2)))
}), //calculates endpoint distance from the startpoint and pass it as a radius
symbol: {//circle design
type: "simple-fill",
color: "orange",
style: "solid",
outline:{
color:"darkorange",
width:4
}
}
});
graphicsLayer.graphics.add(graphic);//adds the circle
};

Related

Polyline drawn is showing below buildings

The polyline is drawn showing below building.
(source: gifyu.com)
How can I get the polyline top of all layers
please suggest
adding polyline as
var coordinates = locationsArrToAdd.map({ (location: CLLocation!) -> CLLocationCoordinate2D in
return location.coordinate
})
let polyline = MKPolyline(coordinates: &coordinates, count: locationsArrToAdd.count)
self.mapView.addOverlays([polyline], level: .aboveLabels)
According to Apple, the highest available level you can add an overlay to is the MKOverlayLevel.aboveOverlays constant you are currently using. However, their documentation states that this will:
Place the overlay above map labels, shields, or point-of-interest icons but below annotations and 3D projections of buildings.
From what I can see, the best solution is to disabled buildings in 3D mode, so that your polylines are visible:
self.mapView.showsBuildings = false

Qt5 QtChart drop vertical lines while using QScatterSeries

When I am using QScatterSeries, I can very easily draw point at (x, y). However, instead of points I would like to draw short lines, like in the figure below. How can I get about doing so?
I tried using RectangleMarker, but it just draws a fat square. I would prefer a thin line about 2px wide and 20px in height.
Is there a way I can add custom marker shapes?
Here are the code and the settings I use to transform my points into lines :
//create scatter series to draw point
m_pSeries1 = new QtCharts::QScatterSeries();
m_pSeries1->setName("trig");
m_pSeries1->setMarkerSize(100.0);
//draw a thin rectangle (50 to 50)
QPainterPath linePath;
linePath.moveTo(50, 0);
linePath.lineTo(50, 100);
linePath.closeSubpath();
//adapt the size of the image with the size of your rectangle
QImage line1(100, 100, QImage::Format_ARGB32);
line1.fill(Qt::transparent);
QPainter painter1(&line1);
painter1.setRenderHint(QPainter::Antialiasing);
painter1.setPen(QColor(0, 0, 0));
painter1.setBrush(painter1.pen().color());
painter1.drawPath(linePath);
//attach your image of rectangle to your series
m_pSeries1->setBrush(line1);
m_pSeries1->setPen(QColor(Qt::transparent));
//then use the classic QtChart pipeline...
You can play the marker size, the dimension of the image and the drawing pattern in the painter to adapt the size and shape of the rectangle to obtain a line.
In the picture, it's the black line. As you can see you can repeat the process for other series.
Keep in mind that you cannot use the openGL acceleration:
m_pSeries0->setUseOpenGL(true);
My work is based on the QtCharts/QScatterSeries example : QScatterSeries example
Hope it will help you.
Florian

How to rotate an object from its center when using Object3d.lookAt()

I'm drawing texts and computing their bounding boxes. I always want the texts to show their face to the camera and so I'm using following lines:
textArr.forEach(function(text) {
var textGeo = d.geometry;
text.lookAt(camera.position)
})
It's working fine but it rotates from top left corner and I can't change the axis of rotation:
How can I make it rotate from center of the text while using .lookAt()?
Try center the pivot using
THREE.GeometryUtils.center(textGeo)

KineticJS doesn't update object's position at initial onResize call

This is an experiment with KineticJS and its goal is to simply keep an objected centered in the screen, as the window gets resized.
It works fine except that it doesn't center the object (a circle) at the initial resize event handler call. As I start resizing - and keep doing it - the circle gets centered. But initially the circle starts at the top left corner of the screen (0,0).
$(document).ready( function(){
$(window).resize(onResize);
var stage = new Kinetic.Stage({
container: 'container',
width: $(container).width(),
height: $(container).height()
});
var layer = new Kinetic.Layer();
var circle = new Kinetic.Circle({ radius: 70, fill: 'red' });
layer.add(circle);
stage.add(layer);
function onResize(){
$(container).css('height', window.innerHeight - 20);
stage.setWidth($(container).width());
stage.setHeight($(container).height());
updatePosition();
}
function updatePosition(){
circle.setPosition(stage.getWidth() / 2, stage.getHeight() / 2);
}
// initial call
onResize();
});
Any clue on why that happens? Thanks
http://jsfiddle.net/ME2cX/2
Yeah, you are missing a call to draw the stage after the onResize function is called.
Your order of events is to add things to the stage, then place the circle in the center, but the stage (or layer) needs to be drawn again to account for the new position of the circle.
In the jsfiddle, I placed 3 draw functions, I recommend you choose one of the
layer.draw()
functions rather than the
stage.draw();

dojox.drawing.Drawing - custom tool to create rectangle with rounded corners

I'm working with dojox.drawing.Drawing to create a simple diagramming tool. I have created a custom tool to draw rounded rectangle by extending dojox.drawing.tools.Rect as shown below -
dojo.provide("dojox.drawing.tools.custom.RoundedRect");
dojo.require("dojox.drawing.tools.Rect");
dojox.drawing.tools.custom.RoundedRect = dojox.drawing.util.oo.declare(
dojox.drawing.tools.Rect,
function(options){
},
{
customType:"roundedrect"
}
);
dojox.drawing.tools.custom.RoundedRect.setup = {
name:"dojox.drawing.tools.custom.RoundedRect",
tooltip:"Rounded Rect",
iconClass:"iconRounded"
};
dojox.drawing.register(dojox.drawing.tools.custom.RoundedRect.setup, "tool");
I was able to add my tool to the toolbar and use it to draw a rectagle on canvas. Now, I would like to customize the rectangle created by my custom tool to have rounded corners, but I'm not able to figure out how.
I have checked the source of dojox.drawing.tools.Rect class as well as it's parent dojox.drawing.stencil.Rect class and I can see the actual rectangle being created in dojox.drawing.stencil.Rect as follows -
_create: function(/*String*/shp, /*StencilData*/d, /*Object*/sty){
// summary:
// Creates a dojox.gfx.shape based on passed arguments.
// Can be called many times by implementation to create
// multiple shapes in one stencil.
//
//console.log("render rect", d)
//console.log("rect sty:", sty)
this.remove(this[shp]);
this[shp] = this.container.createRect(d)
.setStroke(sty)
.setFill(sty.fill);
this._setNodeAtts(this[shp]);
}
In dojox.gfx, rounded corners can be added to a a rectangle by setting r property.
With this context, could anybody please provide answers to my following questions?
What's the mechanism in dojox.drawing to customize the appearance of rectangle to have
rounded corners?
In the code snippet above, StencilData is passed to createRect call. What's the mechanism to customize this data? Can the r property of a rectangle that governs rounded corners be set in this data?
Adding rounded rectangles programmatically is easy. In the tests folder you'll find test_shadows.html which has a line that adds a rectangle with rounded corners:
myDrawing.addStencil("rect", {data:{x:50, y:175, width:100, height:50, r:10}});
You create a data object with x,y,width,height, and a value for r (otherwise it defaults to 0).
If you wanted to do it by extending rect, the easiest way to do it would just be to set the value in the constructor function (data.r=10, for example), or you could create a pointsToData function to override Rect's version. Either you would have set the value for this.data.r, or the default:
pointsToData: function(/*Array*/p){
// summary:
// Converts points to data
p = p || this.points;
var s = p[0];
var e = p[2];
this.data = {
x: s.x,
y: s.y,
width: e.x-s.x,
height: e.y-s.y,
r:this.data.r || 10
};
return this.data;
},
In that example I give r the value 10 as the default, instead of 0 as it was before. This works because every time stencil goes to draw your rect, it converts canvas x,y points (all stencils remember their points) to data (which gfx uses to draw). In other words this function will always be called before rect renders.