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I have a web app that renders svg elements from cartesian points (lines, paths, etc) that come from a database.
I have a requirement that an end user can upload an svg file (icons) and drag the icon to fit within specific bounds of the points already defined and rendered in the app.
For example (see snippet), a user can upload the 'x' icon and drag it near the green line defined by two points, which should result in the icon being snapped and resized to the line - the upper left corner snapped to the line start point, and the width of the icon extending to the line end point. Same is true for the file icon being snapped to the red line. This is done dynamically during drag with js. I have omitted the js from the snippet to keep things simple, as I am confident that the answer lies with svg attributes and or style that I can set with js, but the svg properties/values are what I cannot pin down.
What I have tried - everything, I think. Given that I am nesting svg elements, I took the BBox values as an offset to used the x and y attributes on the icon svg element, and that moved it, but not to the start point. I also tried translate without success. I am able to move and resize, but not to the coordinates I need. I do not want to change the icon svg at all if possible, so i'd prefer to leave its viewBox as-is.
<svg height="700" width="700" fill="#e6e6e6" xmlns="http://www.w3.org/2000/svg">
<svg viewBox="0 0 512 512">
<path d="M443.6,387.1L312.4,255.4l131.5-130c5.4-5.4,5.4-14.2,0-19.6l-37.4-37.6c-2.6-2.6-6.1-4-9.8-4c-3.7,0-7.2,1.5-9.8,4 L256,197.8L124.9,68.3c-2.6-2.6-6.1-4-9.8-4c-3.7,0-7.2,1.5-9.8,4L68,105.9c-5.4,5.4-5.4,14.2,0,19.6l131.5,130L68.4,387.1 c-2.6,2.6-4.1,6.1-4.1,9.8c0,3.7,1.4,7.2,4.1,9.8l37.4,37.6c2.7,2.7,6.2,4.1,9.8,4.1c3.5,0,7.1-1.3,9.8-4.1L256,313.1l130.7,131.1 c2.7,2.7,6.2,4.1,9.8,4.1c3.5,0,7.1-1.3,9.8-4.1l37.4-37.6c2.6-2.6,4.1-6.1,4.1-9.8C447.7,393.2,446.2,389.7,443.6,387.1z"/>
</svg>
<svg viewBox="0 0 380 511.7">
<path fill-rule="nonzero" d="M26.18 0h221.14c3.1 0 5.85 1.51 7.56 3.84l122.88 145.08a9.27 9.27 0 0 1 2.21 6.05l.03 330.55c0 7.13-2.98 13.68-7.72 18.42l-.03.04c-4.75 4.74-11.29 7.72-18.43 7.72H26.18c-7.13 0-13.69-2.96-18.45-7.71l-.03-.04C2.97 499.22 0 492.69 0 485.52V26.18C0 19 2.95 12.46 7.68 7.72l.04-.04C12.46 2.95 19 0 26.18 0zm335.06 164.7c-134.78-5.58-134.35-17.38-129.82-134.02l.45-11.92H26.18c-2.05 0-3.91.83-5.26 2.16a7.482 7.482 0 0 0-2.16 5.26v459.34c0 2.02.84 3.88 2.18 5.23 1.36 1.35 3.22 2.19 5.24 2.19h327.64c2.01 0 3.86-.85 5.22-2.2 1.35-1.36 2.2-3.21 2.2-5.22V164.7zM250.25 27.32l-.15 4.01c-3.73 96.04-4.22 109.01 100.23 114.16L250.25 27.32z"/>
</svg>
<line x1="100" y1="20" x2="200" y2="20" stroke="green" />
<line x1="300" y1="20" x2="350" y2="20" stroke="red" />
</svg>
strong text
Although there may be several ways to accomplish this, I figured out one way that I am going to move forward with. The confusion with this was primarily due to my lack of understanding of the svg viewBox and how the coordinate system works.
The key to this is defining a new viewBox value for each nested svg based on its BBox coordinates. The purpose of doing this is to frame the drawing without 'whitespace' to enable its placement at the desired coordinates. Once you have the BBox data, you can set the viewBox and do some simple math to properly set the desired height and width (both of which must be defined for the nested svg). After updating the viewBox, width, and height, you can then move the svg to the new location.
$( document ).ready(function() {
const svg = document.querySelectorAll('svg.a');
svg.forEach(x => {
setSvg(x);
});
});
function setSvg(svg){
const { xMin, xMax, yMin, yMax } = [...svg.children].reduce((acc, el) => {
const { x, y, width, height } = el.getBBox();
if (!acc.xMin || x < acc.xMin) acc.xMin = x;
if (!acc.xMax || x + width > acc.xMax) acc.xMax = x + width;
if (!acc.yMin || y < acc.yMin) acc.yMin = y;
if (!acc.yMax || y + height > acc.yMax) acc.yMax = y + height;
return acc;
}, {});
const viewbox = `${xMin} ${yMin} ${xMax - xMin} ${yMax - yMin}`;
let newWidth = $(svg).attr('data-new-width');
let newPosition = $(svg).attr('data-new-position');
let newHeight = newWidth*(yMax - yMin)/(xMax - xMin);
svg.setAttribute('width', newWidth);
svg.setAttribute('height', newHeight);
svg.setAttribute('x', newPosition.split(",")[0]);
svg.setAttribute('y', newPosition.split(",")[1]);
svg.setAttribute('viewBox', viewbox);
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<svg height="700" width="700" fill="#e6e6e6" xmlns="http://www.w3.org/2000/svg">
<svg class="a" data-new-width="100" data-new-position="100,20" viewBox="0 0 512 512">
<path d="M443.6,387.1L312.4,255.4l131.5-130c5.4-5.4,5.4-14.2,0-19.6l-37.4-37.6c-2.6-2.6-6.1-4-9.8-4c-3.7,0-7.2,1.5-9.8,4 L256,197.8L124.9,68.3c-2.6-2.6-6.1-4-9.8-4c-3.7,0-7.2,1.5-9.8,4L68,105.9c-5.4,5.4-5.4,14.2,0,19.6l131.5,130L68.4,387.1 c-2.6,2.6-4.1,6.1-4.1,9.8c0,3.7,1.4,7.2,4.1,9.8l37.4,37.6c2.7,2.7,6.2,4.1,9.8,4.1c3.5,0,7.1-1.3,9.8-4.1L256,313.1l130.7,131.1 c2.7,2.7,6.2,4.1,9.8,4.1c3.5,0,7.1-1.3,9.8-4.1l37.4-37.6c2.6-2.6,4.1-6.1,4.1-9.8C447.7,393.2,446.2,389.7,443.6,387.1z"/>
</svg>
<svg class="a" data-new-width="50" data-new-position="300,20" viewBox="0 0 380 511.7">
<path fill-rule="nonzero" d="M26.18 0h221.14c3.1 0 5.85 1.51 7.56 3.84l122.88 145.08a9.27 9.27 0 0 1 2.21 6.05l.03 330.55c0 7.13-2.98 13.68-7.72 18.42l-.03.04c-4.75 4.74-11.29 7.72-18.43 7.72H26.18c-7.13 0-13.69-2.96-18.45-7.71l-.03-.04C2.97 499.22 0 492.69 0 485.52V26.18C0 19 2.95 12.46 7.68 7.72l.04-.04C12.46 2.95 19 0 26.18 0zm335.06 164.7c-134.78-5.58-134.35-17.38-129.82-134.02l.45-11.92H26.18c-2.05 0-3.91.83-5.26 2.16a7.482 7.482 0 0 0-2.16 5.26v459.34c0 2.02.84 3.88 2.18 5.23 1.36 1.35 3.22 2.19 5.24 2.19h327.64c2.01 0 3.86-.85 5.22-2.2 1.35-1.36 2.2-3.21 2.2-5.22V164.7zM250.25 27.32l-.15 4.01c-3.73 96.04-4.22 109.01 100.23 114.16L250.25 27.32z"/>
</svg>
<line x1="100" y1="20" x2="200" y2="20" stroke="green" />
<line x1="300" y1="20" x2="350" y2="20" stroke="red" />
</svg>
I want to move an animated gif along an svg path on scroll, I've been trying to adapt Text moving along an SVG <textPath> but it's not working. I'd like to know what the best solution is.
<svg id="text-container" viewBox="0 0 1000 194" xmlns="http://www.w3.org/2000/svg">
<path id="text-curve" d="M0 100s269.931 86.612 520 0c250.069-86.612 480 0 480 0" fill="none"/>
<text y="40" font-size="2.1em">
<textPath id="text-path" href="#text-curve">
<img src="../imagesIndex/originals/dragon.gif" height="194px"/>
</textPath>
</text>
</svg>
I can get Text moving along the SVG curve but not the image. I've tried expanding the SVG viewbox, shrinking the image with the defined height above, I've tried changing the SVG <textPath to <path it didn't work. I'm getting nowhere.
The image appears, but it won't move along the SVG's path.
Here's the Javascript
<script>
console.clear();
var textPath = document.querySelector('#text-path');
var textContainer = document.querySelector('#text-container');
var path = document.querySelector( textPath.getAttribute('href') );
var pathLength = path.getTotalLength();
console.log(pathLength);
function updateTextPathOffset(offset){
textPath.setAttribute('startOffset', offset);
}
updateTextPathOffset(pathLength);
function onScroll(){
requestAnimationFrame(function(){
var rect = textContainer.getBoundingClientRect();
var scrollPercent = rect.y / window.innerHeight;
console.log(scrollPercent);
updateTextPathOffset( scrollPercent * 2 * pathLength );
});
}
window.addEventListener('scroll',onScroll);
</script>
Apologies if this question is a duplicate. I do have a Greensock GSAP, ShockinglyGreen subscription, all libraries available, but I'm yet to dig into it.
Here's some sample code to position an SVG <image> element at a position along a path determined by the page scroll.
var path = document.querySelector('#text-curve');
var cat = document.querySelector('#cat');
var catWidth = 40;
var catHeight = 40;
function updateImagePosition(offset) {
let pt = path.getPointAtLength(offset * path.getTotalLength());
cat.setAttribute("x", pt.x - catWidth/2);
cat.setAttribute("y", pt.y - catHeight/2);
}
// From: https://stackoverflow.com/questions/2387136/cross-browser-method-to-determine-vertical-scroll-percentage-in-javascript
function getScrollFraction() {
var h = document.documentElement,
b = document.body,
st = 'scrollTop',
sh = 'scrollHeight';
return (h[st]||b[st]) / ((h[sh]||b[sh]) - h.clientHeight);
}
function onScroll() {
updateImagePosition( getScrollFraction() );
}
updateImagePosition(0);
window.addEventListener('scroll', onScroll);
body {
min-height: 1000px;
}
svg {
display: block;
position: sticky;
top: 20px;
}
<svg id="text-container" viewBox="0 0 1000 194">
<path id="text-curve" d="M0 100s269.931 86.612 520 0c250.069-86.612 480 0 480 0" fill="none" stroke="gold"/>
<image id="cat" x="0" y="100" xlink:href="https://placekitten.com/40/40"/>
</svg>
I have a code that displays the percentage as a circle. Is it possible to do something to make the animation start from the top, to the right, and not like now, it starts from the right. Is it possible to round this line? Is there any other, better code to do something like that? I'm only interested in vanillaJS.
var circle = document.querySelector('circle');
var radius = circle.r.baseVal.value;
var circumference = radius * 2 * Math.PI;
circle.style.strokeDasharray = circumference;
circle.style.strokeDashoffset = circumference;
function setProgress(percent) {
var offset = circumference - percent / 100 * circumference;
circle.style.strokeDashoffset = offset;
}
setProgress(60);
<svg class="progress-ring" width="120" height="120">
<circle class="progress-ring__circle" stroke="#000" stroke-width="8" fill="transparent" r="56" cx="60" cy="60">
</svg>
As I've commented you may rotate the svg element transform:rotate(-90deg). Alternatively you may rotate the circle. Also you can use a path instead of a circle and make it start at the top.
If you want to use a path this is how you do it:
In this case the path starts at the top M60,4
Next comes an arc where both radiuses are 56. The first arc ends at 60,116
Follows a second arc A56,56,0 0 1 60,4 and finnaly you close the path z
For the circumference you don't need to know the radius. You can do var circumference = circle.getTotalLength(); where getTotalLength is a method that is returning the total length of a path.
var circle = document.querySelector('path');
var circumference = circle.getTotalLength();
circle.style.strokeDasharray = circumference;
circle.style.strokeDashoffset = circumference;
function setProgress(percent) {
var offset = circumference - percent / 100 * circumference;
circle.style.strokeDashoffset = offset;
}
setProgress(60);
<svg class="progress-ring" width="120" height="120">
<path fill="none" class="progress-ring__circle" stroke="black" stroke-linecap="round" stroke-width="8" d="M60,4A56,56,0 0 1 60,116A56,56,0 0 1 60,4z" />
</svg>
First of all, Welcome on StackOverflow.
I think you have a trigonometry problem here. You have a trigonometric circle with your code and it start like others trigonometric circles at the right :
A simple solution is to rotate your circle with CSS :
svg{
transform: rotate(-90deg);
}
How do I generate hexagons in random positions on the svg canvas?
Currently, my code uses
.attr("points", "50,25 86,45.83 86,87.5 50,108.3 14,87.53 14,45.83")
which hardcodes the current position of the hexagon. How can I generate other hexagons in different positions while maintaining the hexagonal shape?
Y would create a symbol with a viewBox attribute:
<symbol id="poly" viewBox="14 25 72 83.3">
<polygon points="50,25 86,45.83 86,87.5 50,108.3 14,87.53 14,45.83" />
</symbol>
Since the symbol has a viewBox attribute you can reuse the symbol with <use> and you can specify the position of the hexagon (x and y attributes) and it's size (width and height attributes)
svg{border:1px solid}
<svg viewBox="0 0 500 250">
<symbol id="poly" viewBox="14 25 72 83.3">
<polygon points="50,25 86,45.83 86,87.5 50,108.3 14,87.53 14,45.83" />
</symbol>
<use xlink:href="#poly" x="20" y="20" width="50" height="57.85" />
<use xlink:href="#poly" x="200" y="120" width="100" height="115.7" />
</svg>
Of course the x and y can be random. Also the width or the height can be random. However keep in mind that the other size should be proportional.
This is how I would create the use element with a random x y and width attributes:
const SVG_NS = 'http://www.w3.org/2000/svg';
const SVG_XLINK = "http://www.w3.org/1999/xlink";
//create a new use element
let use = document.createElementNS(SVG_NS, 'use');
// set the value for 'xlink:href' of the new use element
use.setAttributeNS(SVG_XLINK, 'xlink:href', '#poly');
//the random width
let w = Math.random()*50;
// the proportiopnal height
let h = w*83.3 / 75;
//set the position and the size of the use element
use.setAttributeNS(null, 'x', Math.random()*(500 - w));
use.setAttributeNS(null, 'y', Math.random()*(250 - h));
use.setAttributeNS(null, 'width', w);
use.setAttributeNS(null, 'height', h);
//Append the use element
svg.appendChild(use);
svg{border:1px solid}
<svg id="svg" viewBox="0 0 500 250">
<symbol id="poly" viewBox="14 25 72 83.3">
<polygon tran points="50,25 86,45.83 86,87.5 50,108.3 14,87.53 14,45.83" />
</symbol>
</svg>
Create a function drawHex(x,y) where you pass x and y as starting coordinates. On that function the you draw your points relative to x and y:
..."x+50,y+25 x+86,y+45.83 ... x+14,y+45.83";
Finally, create a loop that randomly generates x and y and calls the drawHex function. I'm recently working on something similar. You can take a look and my source code at this P5js experiment and then go to creaPuerta() function on https://zoada.com/lpa/js/parametrica.js
Based on Robert Longson's comment, you could do it like that:
const btn = document.getElementById('btn');
const poly = document.getElementById('poly');
btn.onclick = () => {
const transform = `translate(${getRandomArbitrary(0, 100)} ${getRandomArbitrary(0, 100)}) scale(${getRandomArbitrary(1, 5)} ${getRandomArbitrary(1, 5)})`;
poly.setAttribute('transform', transform);
};
function getRandomArbitrary(min, max) {
return Math.random() * (max - min) + min;
}
button {
display: block;
}
<button id="btn">Random</button>
<svg width=500 height=500>
<polygon id="poly" points="50,25 86,45.83 86,87.5 50,108.3 14,87.53 14,45.83"></polygon>
</svg>
I want to connect two SVG points (e.g. the centers of two circles) using arcs. If there is only one connection, the line (<path>) will be straight. If there are two connections, both will be rounded and will be symmetrical, this way:
So, in fact, there are few rules:
Everything should be symmetrical to to the imaginary line that connects the two points.
From 1, it's obvious that if the number of connections is:
odd: we do not display the straight line
even: we display the straight line
There should be a value k which defines the distance between two connections between same points.
The tangent that goes through the middle of the elliptical arc should be parallel with the straight line that connects the two points. And obviously, the middle of the line will be perpendicular to the tangent.
I'm struggling to get a formula to calculate the A parameters in the <path> element.
What I did until now is:
<path d="M100 100, A50,20 0 1,0 300,100" stroke="black" fill="transparent"/>
M100 100 is clear: that's the starting point (move to 100,100)
Last two numbers are also clear. The path ends in 300,100
I also saw that if I put 0 instead of 20, I obtain a straight line.
If I replace 1,0 with 1,1, the path is flipped.
What I don't know is how to calculate the A parameters. I read the docs, but the imagine is still unclear to me. How to calculate these values?
svg {
width: 100%;
height: 100%;
position: absolute;
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JS Bin</title>
</head>
<body>
<?xml version="1.0" standalone="no" ?>
<svg version="1.1" xmlns="http://www.w3.org/2000/svg">
<!-- Connect A(100,100) with B(300, 100) -->
<path d="M100 100, A50,0 0 1,0 300,100" stroke="black" fill="transparent" />
<path d="M100 100, A50,20 0 1,0 300,100" stroke="black" fill="transparent" />
<path d="M100 100, A50,20 0 1,1 300,100" stroke="black" fill="transparent" />
<path d="M100 100, A50,30 0 1,0 300,100" stroke="black" fill="transparent" />
<path d="M100 100, A50,30 0 1,1 300,100" stroke="black" fill="transparent" />
<!-- A(100, 100) B(300, 400) -->
<path d="M100 100, A50,0 57 1,0 300,400" stroke="black" fill="transparent" />
<path d="M100 100, A50,20 57 1,0 300,400" stroke="black" fill="transparent" />
<path d="M100 100, A50,20 57 1,1 300,400" stroke="black" fill="transparent" />
</svg>
</body>
</html>
I'm using SVG.js to create the paths.
You're making life very difficult for yourself by requiring circular arcs.
If you use quadratic curves instead, then the geometry becomes very simple — just offset the central X coordinate by half the difference in Y coordinates, and vice versa.
function arc_links(dwg,x1,y1,x2,y2,n,k) {
var cx = (x1+x2)/2;
var cy = (y1+y2)/2;
var dx = (x2-x1)/2;
var dy = (y2-y1)/2;
var i;
for (i=0; i<n; i++) {
if (i==(n-1)/2) {
dwg.line(x1,y1,x2,y2).stroke({width:1}).fill('none');
}
else {
dd = Math.sqrt(dx*dx+dy*dy);
ex = cx + dy/dd * k * (i-(n-1)/2);
ey = cy - dx/dd * k * (i-(n-1)/2);
dwg.path("M"+x1+" "+y1+"Q"+ex+" "+ey+" "+x2+" "+y2).stroke({width:1}).fill('none');
}
}
}
function create_svg() {
var draw = SVG('drawing').size(300, 300);
arc_links(draw,50,50,250,50,2,40);
arc_links(draw,250,50,250,250,3,40);
arc_links(draw,250,250,50,250,4,40);
arc_links(draw,50,250,50,50,5,40);
draw.circle(50).move(25,25).fill('#fff').stroke({width:1});
draw.circle(50).move(225,25).fill('#fff').stroke({width:1});
draw.circle(50).move(225,225).fill('#fff').stroke({width:1});
draw.circle(50).move(25,225).fill('#fff').stroke({width:1});
}
create_svg();
<script src="https://cdnjs.cloudflare.com/ajax/libs/svg.js/2.3.2/svg.min.js"></script>
<div id="drawing"></div>
For drawing SVG path's arc you need 2 points and radius, there are 2 points and you just need to calculate radius for given distances.
Formula for radius:
let r = (d, x) => 0.125*d*d/x + x/2;
where:
d - distance between points
x - distance between arcs
it derived from Pythagorean theorem:
a here is a half of distance between points
let r = (d, x) => !x?1e10:0.125*d*d/x + x/2;
upd();
function upd() {
let n = +count.value;
let s = +step.value/10;
let x1 = c1.getAttribute('cx'), y1 = c1.getAttribute('cy');
let x2 = c2.getAttribute('cx'), y2 = c2.getAttribute('cy');
let dx = Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));
paths.innerHTML = [...Array(n)].map((_, i) => [
n%2&&i===n-1?0:1+parseInt(i/2),
i%2
]).map(i => `<path d="${[
'M', x1, y1,
'A', r(dx, s*i[0]), r(dx, s*i[0]), 0, 0, i[1], x2, y2
].join(' ')}"></path>`).join('');
}
<input id="count" type="range" min=1 max=9 value=5 oninput=upd() >
<input id="step" type="range" min=1 max=200 value=100 oninput=upd() >
<svg viewbox=0,0,300,100 stroke=red fill=none >
<circle id=c1 r=10 cx=50 cy=60></circle>
<circle id=c2 r=10 cx=250 cy=40></circle>
<g id=paths></g>
</svg>
Here is a solution that uses arcs, as asked for, rather than quadratic curves.
// Internal function
function connectInternal(x1,y1,x2,y2,con){
var dx=x2-x1
var dy=y2-y1
var dist=Math.sqrt(dx*dx+dy*dy)
if(dist==0 || con==0){
return "M"+x1+","+y1+"L"+x2+","+y2
}
var xRadius=dist*0.75
var yRadius=dist*0.3*(con*0.75)
var normdx=dx/dist
if(normdx<-1)normdx=-1
if(normdx>1)normdx=1
var angle=Math.acos(normdx)*180/Math.PI
if(x1>x2){
angle=-angle
}
return "M"+x1+","+y1+"A"+xRadius+","+yRadius+","+
angle+",00"+x2+","+y2+
"M"+x1+","+y1+"A"+xRadius+","+yRadius+","+
angle+",01"+x2+","+y2
}
// Returns an SVG path that represents
// "n" connections between two points.
function connect(x1,y1,x2,y2,n){
var ret=""
var con=n
if(con%2==1){
ret+=connectInternal(x1,y1,x2,y2,con)
con-=1
}
for(var i=2;i<=con;i+=2){
ret+=connectInternal(x1,y1,x2,y2,i)
}
return ret
}