I´m trying to draw an arc using mouse events with paper.js
The user must be able to draw an arc from 0 degree to 360 degree.
The issue that I´m facing is that I can draw 270 degree arc but more than 270, the arc flips to another quadrant.
Start point must be located anywhere
A sketch can be found here:
http://sketch.paperjs.org/#V/0.12.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
and this is the implemented code:
var arc_cse;
var radius=200;
var center=new Point(400,400);
var start=new Point(400,500);
var c1 = new Path.Circle({
center: center,
radius: 2,
fillColor: 'black'
});
arc_cse = new Path({
strokeColor: 'red',
strokeWidth: 1,
strokeCap: 'round',
});
tool.onMouseMove = function(event) {
var p=new Point(event.point.x,event.point.y);
var v1=start-center;
var v2=p-center;
var angle=(v2.angleInRadians-v1.angleInRadians);
var arcval=arc_CRD(v1.angleInRadians,v2.angleInRadians,angle,center,radius);
arc_cse.remove();
arc_cse= new Path.Arc(arcval);
}
function arc_CRD(alpha1,alpha2,angle,center,radius){
return {
from: {
x: center.x + radius*Math.cos(alpha1),
y: center.y + radius*Math.sin(alpha1)
},
through: {
x: center.x + radius * Math.cos(alpha1 + (alpha2-alpha1)/2),
y: center.y + radius * Math.sin(alpha1 + (alpha2-alpha1)/2)
},
to: {
x: center.x + radius*Math.cos(alpha1+(alpha2-alpha1)),
y: center.y + radius*Math.sin(alpha1+(alpha2-alpha1))
},
strokeColor: 'red',
strokeWidth: 3,
strokeCap: 'round'
}
}
Thanks in advance
There are certainly tons of ways to do this but here's how I would do it: sketch.
This should help you finding the proper solution to your own use case.
function dot(point, color) {
const item = new Path.Circle({ center: point, radius: 5, fillColor: color });
item.removeOnMove();
}
function drawArc(from, center, mousePoint) {
const radius = (from - center).length;
const circle = new Path.Circle(center, radius);
const to = circle.getNearestPoint(mousePoint);
const middle = (from + to) / 2;
const throughVector = (middle - center).normalize(radius);
const angle = (from - center).getDirectedAngle(to - center);
const through = angle <= 0
? center + throughVector
: center - throughVector;
const arc = new Path.Arc({
from,
through,
to,
strokeColor: 'red',
strokeWidth: 2
});
circle.removeOnMove();
arc.removeOnMove();
// Visual helpers
dot(from, 'orange');
dot(center, 'black');
dot(mousePoint, 'red');
dot(to, 'blue');
dot(middle, 'lime');
dot(through, 'purple');
circle.strokeColor = 'black';
return arc;
}
function onMouseMove(event) {
drawArc(view.center + 100, view.center, event.point);
}
Edit
In answer to your comment, here is a more mathematical approach: sketch.
This is based on your code and has exactly the same behavior so you should have no difficulty using it.
The key of both implementation is the Point.getDirectedAngle() method which allow you to adapt the behavior depending on the through point side.
const center = new Point(400, 400);
const start = new Point(400, 500);
const c1 = new Path.Circle({
center: center,
radius: 2,
fillColor: 'black'
});
let arc;
function getArcPoint(from, center, angle) {
return center + (from - center).rotate(angle);
}
function drawArc(from, center, mousePoint) {
const directedAngle = (from - center).getDirectedAngle(mousePoint - center);
const counterClockwiseAngle = directedAngle < 0
? directedAngle
: directedAngle - 360;
const through = getArcPoint(from, center, counterClockwiseAngle / 2);
const to = getArcPoint(from, center, counterClockwiseAngle);
return new Path.Arc({
from,
through,
to,
strokeColor: 'red',
strokeWidth: 1,
strokeCap: 'round'
});
}
function onMouseMove(event) {
if (arc) {
arc.remove();
}
arc = drawArc(start, center, event.point);
}
Related
Using the sample code from Konvajs.org as a base (https://konvajs.org/docs/sandbox/Multi-touch_Scale_Stage.html), I have added a large SVG to a layer (4096 x 3444) to experiment with zoom / pan of a vector-based map, base64 encoded SVG in this instance. Initial impressions are good however during testing I experience an odd bug where during a pinch the view of the map would snap to a different location on the map not the area that I centred on.
Here is the code (map base64 code removed due to length):
// by default Konva prevent some events when node is dragging
// it improve the performance and work well for 95% of cases
// we need to enable all events on Konva, even when we are dragging a node
// so it triggers touchmove correctly
Konva.hitOnDragEnabled = true;
var width = window.innerWidth;
var height = window.innerHeight;
var stage = new Konva.Stage({
container: 'container',
width: width,
height: height,
draggable: true,
});
var layer = new Konva.Layer();
var triangle = new Konva.RegularPolygon({
x: 190,
y: stage.height() / 2,
sides: 3,
radius: 80,
fill: 'green',
stroke: 'black',
strokeWidth: 4,
});
var circle = new Konva.Circle({
x: 380,
y: stage.height() / 2,
radius: 70,
fill: 'red',
stroke: 'black',
strokeWidth: 4,
});
let bg = new Konva.Image({
width: 4096,
height: 3444
});
layer.add(bg);
var image = new Image();
image.onload = function() {
bg.image(image);
layer.draw();
};
image.src = 'data:image/svg+xml;base64,...';
function getDistance(p1, p2) {
return Math.sqrt(Math.pow(p2.x - p1.x, 2) + Math.pow(p2.y - p1.y, 2));
}
function getCenter(p1, p2) {
return {
x: (p1.x + p2.x) / 2,
y: (p1.y + p2.y) / 2,
};
}
var lastCenter = null;
var lastDist = 0;
stage.on('touchmove', function (e) {
e.evt.preventDefault();
var touch1 = e.evt.touches[0];
var touch2 = e.evt.touches[1];
if (touch1 && touch2) {
// if the stage was under Konva's drag&drop
// we need to stop it, and implement our own pan logic with two pointers
if (stage.isDragging()) {
stage.stopDrag();
}
var p1 = {
x: touch1.clientX,
y: touch1.clientY,
};
var p2 = {
x: touch2.clientX,
y: touch2.clientY,
};
if (!lastCenter) {
lastCenter = getCenter(p1, p2);
return;
}
var newCenter = getCenter(p1, p2);
var dist = getDistance(p1, p2);
if (!lastDist) {
lastDist = dist;
}
// local coordinates of center point
var pointTo = {
x: (newCenter.x - stage.x()) / stage.scaleX(),
y: (newCenter.y - stage.y()) / stage.scaleX(),
};
var scale = stage.scaleX() * (dist / lastDist);
stage.scaleX(scale);
stage.scaleY(scale);
// calculate new position of the stage
var dx = newCenter.x - lastCenter.x;
var dy = newCenter.y - lastCenter.y;
var newPos = {
x: newCenter.x - pointTo.x * scale + dx,
y: newCenter.y - pointTo.y * scale + dy,
};
stage.position(newPos);
lastDist = dist;
lastCenter = newCenter;
}
});
stage.on('touchend', function () {
lastDist = 0;
lastCenter = null;
});
layer.add(triangle);
layer.add(circle);
stage.add(layer);
I am unsure if this is due to the large size of the image and / or canvas or an inherent flaw in the example code from Konvas.js. This has been tested, with the same results, on 2 models of iPad Pro, iPhone X & 11, Android Pixel 3, 5 and 6 Pro.
Here is the code on codepen as an example: https://codepen.io/mr-jose/pen/WNXgbdG
Any help would be appreciated, thanks!
I faced the same issue and discovered that it was caused by the dragging functionality of the stage. Everytime if (stage.isDragging()) evaluated to true, the jump happened.
For me what worked was setting draggable to false while pinch zooming and back to true on touch end.
stage.on('touchmove', function (e) {
...
if (touch1 && touch2) {
stage.draggable(false);
....
}
});
stage.on('touchend', function (e) {
...
stage.draggable(true);
});
I have a simple setup where use clicks location and creates a label with text.
What i would like to be able to do is resize on zoom, so that label is relative size always. Currently label is huge when i zoom in covering key areas.
code:
createTag() {
return new Konva.Tag({
// omitted for brevity
})
}
createLabel(x: number, y: number) {
return new Konva.Label({
x: x,
y: y,
opacity: 0.75
});
}
createText() {
return new Konva.Text({
// omitted for brevity
});
}
createMarker(point: any) {
var label = createLabel(point.x, point.y);
var tag = createTag();
var text = createText();
label.add(tag);
label.add(text);
this.layer.add(label);
this.stage.add(this.layer);
}
Mouse click event listener
this.stage.on('click', function (e) {
// omitted for brevity
var pointer = this.getRelativePointerPosition();
createMarker(pointer);
// omitted for brevity
}
this.stage.on('wheel', function (e) {
// zoom code
});
How can i resize the labels to be relative size of the canvas?
There are many possible solutions. If you are changing scale of the whole stage, then you can just apply reversed scale to the label, so its absolute scale will be always 1.
var width = window.innerWidth;
var height = window.innerHeight;
var stage = new Konva.Stage({
container: 'container',
width: width,
height: height,
});
var layer = new Konva.Layer();
stage.add(layer);
var circle = new Konva.Circle({
x: stage.width() / 2,
y: stage.height() / 2,
radius: 50,
fill: 'green',
});
layer.add(circle);
// tooltip
var tooltip = new Konva.Label({
x: circle.x(),
y: circle.y(),
opacity: 0.75,
});
layer.add(tooltip);
tooltip.add(
new Konva.Tag({
fill: 'black',
pointerDirection: 'down',
pointerWidth: 10,
pointerHeight: 10,
lineJoin: 'round',
shadowColor: 'black',
shadowBlur: 10,
shadowOffsetX: 10,
shadowOffsetY: 10,
shadowOpacity: 0.5,
})
);
tooltip.add(
new Konva.Text({
text: 'Try to zoom with wheel',
fontFamily: 'Calibri',
fontSize: 18,
padding: 5,
fill: 'white',
})
);
var scaleBy = 1.01;
stage.on('wheel', (e) => {
e.evt.preventDefault();
var oldScale = stage.scaleX();
var pointer = stage.getPointerPosition();
var mousePointTo = {
x: (pointer.x - stage.x()) / oldScale,
y: (pointer.y - stage.y()) / oldScale,
};
var newScale =
e.evt.deltaY > 0 ? oldScale * scaleBy : oldScale / scaleBy;
stage.scale({ x: newScale, y: newScale });
// apply reversed scale to label
// so its absolte scale is still 1
tooltip.scale({ x: 1 / newScale, y: 1 / newScale })
var newPos = {
x: pointer.x - mousePointTo.x * newScale,
y: pointer.y - mousePointTo.y * newScale,
};
stage.position(newPos);
});
<script src="https://unpkg.com/konva#8.3.0/konva.min.js"></script>
<div id="container"></div>
I'm struggling to implement a little things on canvas with KineticJS.
I want to create a circle + a line which form a group (plane).
The next step is to allow the group to rotate around itself with a button that appears when you click on the group.
My issue is that when I click on the rotate button, it does not rotate near the button but elsewhere. Have a look :
My rotation atm : http://hpics.li/b46b73a
I want the rotate button to be near the end of the line. Not far away..
I tried to implement it on jsfiddle but I'm kinda new and I didn't manage to put it correctly , if you could help me on that, I would be thankful !
http://jsfiddle.net/49nn0ydh/1/
function radians (degrees) {return degrees * (Math.PI/180)}
function degrees (radians) {return radians * (180/Math.PI)}
function angle (cx, cy, px, py) {var x = cx - px; var y = cy - py; return Math.atan2 (-y, -x)}
function distance (p1x, p1y, p2x, p2y) {return Math.sqrt (Math.pow ((p2x - p1x), 2) + Math.pow ((p2y - p1y), 2))}
jQuery (function(){
var stage = new Kinetic.Stage ({container: 'kineticDiv', width: 1200, height:600})
var layer = new Kinetic.Layer(); stage.add (layer)
// group avion1
var groupPlane1 = new Kinetic.Group ({
x: 150, y: 150,
draggable:true
}); layer.add (groupPlane1)
// avion 1
var plane1 = new Kinetic.Circle({
radius: 10,
stroke: "darkgreen",
strokeWidth: 3,
}); groupPlane1.add(plane1);
var trackPlane1 = new Kinetic.Line({
points: [10, 0, 110, 0],
stroke: "darkgreen",
strokeWidth: 2
}); groupPlane1.add(trackPlane1);
groupPlane1.on('click', function() {
controlGroup.show();
});
groupPlane1.setOffset (plane1.getWidth() * plane1.getScale().x / 2, plane1.getHeight() * plane1.getScale().y / 2)
var controlGroup = new Kinetic.Group ({
x: groupPlane1.getPosition().x + 120,
y: groupPlane1.getPosition().y ,
opacity: 1, draggable: true,
}); layer.add (controlGroup)
var signRect2 = new Kinetic.Rect({
x:-8,y: -6,
width: 20,
height: 20,
fill: 'white',
opacity:0
});
controlGroup.add(signRect2);
var sign = new Kinetic.Path({
x: -10, y: -10,
data: 'M12.582,9.551C3.251,16.237,0.921,29.021,7.08,38.564l-2.36,1.689l4.893,2.262l4.893,2.262l-0.568-5.36l-0.567-5.359l-2.365,1.694c-4.657-7.375-2.83-17.185,4.352-22.33c7.451-5.338,17.817-3.625,23.156,3.824c5.337,7.449,3.625,17.813-3.821,23.152l2.857,3.988c9.617-6.893,11.827-20.277,4.935-29.896C35.591,4.87,22.204,2.658,12.582,9.551z',
scale: {x:0.5, y:0.5}, fill: 'black'
}); controlGroup.add (sign)
controlGroup.setDragBoundFunc (function (pos) {
var groupPos = groupPlane1.getPosition();
var rotation = degrees (angle (groupPos.x, groupPos.y, pos.x, pos.y));
var dis = distance (groupPos.x, groupPos.y, pos.x, pos.y);
groupPlane1.setRotationDeg (rotation);
layer.draw()
return pos
})
controlGroup.on ('dragend', function() {
controlGroup.hide();
layer.draw()
})
controlGroup.hide();
layer.draw()
})
You can adjust the rotation point by setting the offsetX and offsetY of the group.
Here is the code: http://jsfiddle.net/MTDpC/
function drawArrow(firstShape, lastShape){
var group = new Kinetic.Group();
group.previousShape = firstShape;
group.nextShape = lastShape;
var beginX = group.previousShape.getX() + group.previousShape.getChildren()[0].getWidth() / 2;
var beginY = group.previousShape.getY() + group.previousShape.getChildren()[0].getHeight();
var endX = group.nextShape.getX() + group.nextShape.getChildren()[0].getWidth() / 2;
var endY = group.nextShape.getY() - 8;
var linha = new Kinetic.Line({
points: [ beginX, beginY, endX, endY],
name: 'linha',
stroke: '#555',
strokeWidth: 4,
lineCap: 'butt'
});
var seta = new Kinetic.RegularPolygon({
x: endX,
y: endY,
sides: 3,
radius: 4,
fill: '#555',
stroke: '#555',
strokeWidth: 4,
name: 'seta'
});
seta.rotateDeg(180);
group.add(seta);
group.add(linha);
firstShape.arrow = group;
lastShape.arrow = group;
group.reposition = function(){
var beginX = this.previousShape.getX() + this.previousShape.getChildren()[0].getWidth() / 2;
var beginY = this.previousShape.getY() + this.previousShape.getChildren()[0].getHeight();
var endX = this.nextShape.getX() + this.nextShape.getChildren()[0].getWidth() / 2;
var endY = this.nextShape.getY() - 8;
this.get('.linha')[0].transitionTo({
points:[ beginX, beginY, endX, endY],
duration: 0.0000001,
});
this.get('.seta')[0].transitionTo({
x: endX,
y: endY,
duration: 0.0000001,
});
};
return group;
}
function getProcess (processText, x, y, width) {
var group = new Kinetic.Group();
var complexText = new Kinetic.Text({
text: processText + '\nX: ' + x + '\nY: ' + y,
fontSize: 12,
fontFamily: 'Calibri',
fill: '#555',
padding: 20,
align: 'center',
name: 'Texto-Processo'
});
var rect = new Kinetic.Rect({
stroke: '#555',
strokeWidth: 5,
fill: '#ddd',
width: complexText.getWidth(),
height: complexText.getHeight(),
shadowColor: 'black',
shadowBlur: 10,
shadowOffset: [10, 10],
shadowOpacity: 0.2,
cornerRadius: 10,
name: 'Quadro-Processo'
});
group.add(rect);
group.add(complexText);
group.setDraggable(true);
group.on('mouseover', function() {
document.body.style.cursor = 'pointer';
});
group.on('mouseout', function() {
document.body.style.cursor = 'default';
});
group.on('dragmove', function(){
group.getChildren()[1].setText(this.customText + "\nX: " + this.getX() + "\nY: " + this.getY());
group.arrow.reposition();
group.arrow.draw();
});
group.setX(x);
group.setY(y);
group.customText = processText;
return group;
}
var stage = new Kinetic.Stage({
container: 'container',
width: 800,
height: 600,
id: 'myCanvas'
});
var layer = new Kinetic.Layer();
var processo = getProcess('Processo de Teste de canvas 1', (stage.getWidth() / 2) - 100, 10 , 100);
processo.setId('canvas1');
layer.add(processo);
var processo2 = getProcess('Processo de Teste de canvas 2', (stage.getWidth() / 2) -100, processo.getY() + 300, processo.getX());
layer.add(processo2);
layer.add(drawArrow(processo, processo2));
// add the layer to the stage
stage.add(layer);
When one of the boxes are dragged, the arrow connecting them moves too.
As the arrow was made using 2 shapes, I want to know if is there some way to use .transtionTo at the same time, because you can see some delay between the line and the triangle that forms the arrrow when you move the bottom box.
The problem is that the transitionTo function does not support transitioning points. Also, each time you move the object, you are creating a new transition object... which is extremely slow. You do not need transitions for this, transitions are only useful for animating things automatically when the user is not meant to control them.
Try this instead:
this.get('.linha')[0].setPoints([beginX, beginY, endX, endY]);
this.get('.seta')[0].setPosition(endX,endY);
this.getLayer().draw();
/* this.get('.linha')[0].transitionTo({ //cant transition points
points: [beginX, beginY, endX, endY],
duration: 0.0000001,
});
this.get('.seta')[0].transitionTo({ // lags because everytime you move, a new transition is created, no this would be extremely slow
x: endX,
y: endY,
duration: 0.0000001,
});
*/
http://jsfiddle.net/MTDpC/1/
works fast eh?
Another frustrating issue I have with Jvectormap, I wish to focus on a Marker on page/map load via lngLat, how would I do this? Ideally it would be good to say focus on this marker or focus on latlng. I will only be displaying 1 marker per map but I won't know the x/y just the lngLat or possibly countrycode. There might be an easier way altogether to do this so suggestions would be welcome. Thanks for your help in advanced
var markers = [ {latLng: [47.774099, -52.793427], name: "loc 1", label: "This blahblah"}]
$(function(){
$('#map1').vectorMap({
map: 'world_mill_en',
scale: ['#C8EEFF', '#0071A4'],
normalizeFunction: 'polynomial',
hoverOpacity: 0.7,
hoverColor: false,
markerStyle: {
initial: {
fill: '#F8E23B',
stroke: '#383f47'
}
},
backgroundColor: '#383f47',
markers: markers,
focusOn:{
latLng: [47.774099, -52.793427],
scale: 5
},
onMarkerLabelShow: function(event, label, index) {
label.html( ''+markers[index].label+'');
}
});
});
I needed the same thing as you and came across your unanswered question. This is the code I wrote (slash copied, pasted & modified from jVectorMap source) to solve the problem for myself. I hope you and others find it helpful.
Simply pass the scale, longitude, and latitude to setFocusLatLng.
I may attempt to get this or something similar accepted into the jVectorMap project on GitHub, so there may be a better way to do this later.
Disclaimer: Points on the edge of the map will not be centered. They should be in the view, though.
EDIT: As requested, here is the whole thing on jsfiddle:
http://jsfiddle.net/BryanTheScott/rs7H5/
EDIT: Also added the rest of the JS below:
$(function(){
var smallMap = $('#my_map_container').vectorMap({
map: 'world_mill_en',
zoomOnScroll: true,
zoomMax:5,
zoomMin:5,
regionStyle: {
initial: {
fill: '#222222',
"fill-opacity": 1,
stroke: '#444444',
"stroke-width": 1,
"stroke-opacity": 0.7
},
hover: {
"fill-opacity": 0.8,
fill: '#333333'
}
},
markerStyle: {
initial: {
fill: "#000000",
"stroke": "#7FC556",
"stroke-width": 2,
r: 3
}
},
markers: [[37.770172,-122.422771]]
});
var mapObj = $('#my_map_container').vectorMap('get', 'mapObject');
mapObj.setFocusLatLng = function(scale, lat, lng){
var point,
proj = jvm.WorldMap.maps[this.params.map].projection,
centralMeridian = proj.centralMeridian,
width = this.width - this.baseTransX * 2 * this.baseScale,
height = this.height - this.baseTransY * 2 * this.baseScale,
inset,
bbox,
scaleFactor = this.scale / this.baseScale,
centerX,
centerY;
if (lng < (-180 + centralMeridian)) {
lng += 360;
}
point = jvm.Proj[proj.type](lat, lng, centralMeridian);
inset = this.getInsetForPoint(point.x, point.y);
if (inset) {
bbox = inset.bbox;
centerX = (point.x - bbox[0].x) / (bbox[1].x - bbox[0].x);
centerY = (point.y - bbox[0].y) / (bbox[1].y - bbox[0].y);
this.setFocus(scale, centerX, centerY);
}
}
mapObj.setFocusLatLng(5, 37.770172,-122.422771);
});
Very late to the party here, but I needed a way to center on a marker even after the map had initially loaded, and here is what I came up with:
var yourMapHere = $(yourMapObject).vectorMap('get', 'mapObject');
var point = yourMapHere.latLngToPoint(yourMarkerLat, yourMarkerLng);
var x = yourMapHere.transX - point.x / yourMapHere.scale;
var y = yourMapHere.transY - point.y / yourMapHere.scale;
yourMapHere.setScale(yourScaleValueHere, x, y, true, true);