Created
July 26, 2019 09:17
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Save Vadi/4c05330a8733a5fc24560bd1397f5322 to your computer and use it in GitHub Desktop.
JS Bin // source https://jsbin.com/diwukakiqe
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<!DOCTYPE html> | |
<html> | |
<head> | |
<meta charset="utf-8"> | |
<meta name="viewport" content="width=device-width"> | |
<title>JS Bin</title> | |
</head> | |
<body> | |
<div id='container'></div> | |
<script id="jsbin-javascript"> | |
"use strict"; | |
(function () { | |
var canvasWidth = window.innerWidth, | |
canvasHeight = window.innerHeight, | |
centerX = 0, | |
centerY = 0, | |
arrowHeadLen = 10; | |
var container = document.getElementById("container"); | |
container.style.position = "absolute"; | |
container.style.left = centerX + "px"; | |
container.style.top = centerY + "px"; | |
var canvas = document.createElement("canvas"); | |
canvas.id = "c"; | |
canvas.width = canvasWidth; | |
canvas.height = canvasHeight; | |
container.append(canvas); | |
var ctx = canvas.getContext("2d"); | |
ctx.lineWidth = 2; | |
var startX = 0, | |
startY = 0, | |
storedLines = [], | |
isDown = false; | |
canvas.addEventListener("mousedown", handleMouseDown); | |
canvas.addEventListener("mousemove", handleMouseMove); | |
canvas.addEventListener("mouseup", handleMouseUp); | |
function handleMouseDown(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
var _getMousePos = getMousePos(canvas, e); | |
var x = _getMousePos.x; | |
var y = _getMousePos.y; | |
isDown = true; | |
startX = x; | |
startY = y; | |
} | |
function handleMouseUp(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
isDown = false; | |
var _getMousePos2 = getMousePos(canvas, e); | |
var x = _getMousePos2.x; | |
var y = _getMousePos2.y; | |
storedLines.push({ x0: startX, y0: startY, x1: x, y1: y }); | |
draw(); | |
} | |
function handleMouseMove(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
if (!isDown) return; | |
draw(); | |
var _getMousePos3 = getMousePos(canvas, e); | |
var x = _getMousePos3.x; | |
var y = _getMousePos3.y; | |
drawLine(ctx, { x0: startX, y0: startY, x1: x, y1: y }); | |
} | |
function getMousePos(canvas, evt) { | |
var rect = canvas.getBoundingClientRect(); | |
return { | |
x: evt.clientX - rect.left, | |
y: evt.clientY - rect.top | |
}; | |
} | |
function draw(e) { | |
ctx.clearRect(0, 0, canvas.width, canvas.height); | |
for (var i = 0; i < storedLines.length; i++) { | |
drawLine(ctx, storedLines[i]); | |
// Drawing the arrow heads after rendering the arrow. | |
drawArrow(ctx, storedLines[i]); | |
} | |
} | |
function drawLine(ctx, g) { | |
ctx.beginPath(); | |
ctx.moveTo(g.x0, g.y0); | |
ctx.lineTo(g.x1, g.y1); | |
ctx.stroke(); | |
} | |
// Function to draw the arrow heads. | |
function drawArrow(ctx, g) { | |
var x0 = g.x0; | |
var x1 = g.x1; | |
var y0 = g.y0; | |
var y1 = g.y1; | |
var diffX = x1 - x0; | |
var diffY = y1 - y0; | |
var arrowAngle = Math.atan2(diffY, diffX); | |
drawStartArrow(ctx, x0, y0, arrowAngle); | |
drawEndArrow(ctx, x1, y1, arrowAngle); | |
} | |
// Function to draw the arrow head at the starting point of the line. | |
function drawStartArrow(ctx, x0, y0, arrowAngle) { | |
ctx.beginPath(); | |
// Starting coordinate of line. | |
ctx.lineTo(x0, y0); | |
// Draw arrow head in the negative direction of the starting point. | |
ctx.lineTo(x0 + arrowHeadLen * Math.cos(arrowAngle - Math.PI / 6), y0 + arrowHeadLen * Math.sin(arrowAngle - Math.PI / 6)); | |
// Again move back to the starting coordinate. | |
ctx.moveTo(x0, y0); | |
// Draw arrow head in the positive direction of the starting point. | |
ctx.lineTo(x0 + arrowHeadLen * Math.cos(arrowAngle + Math.PI / 6), y0 + arrowHeadLen * Math.sin(arrowAngle + Math.PI / 6)); | |
ctx.stroke(); | |
} | |
// Function to draw the arrow head at the ending point of the line. | |
function drawEndArrow(ctx, x1, y1, arrowAngle) { | |
ctx.beginPath(); | |
// Ending coordinate of line. | |
ctx.lineTo(x1, y1); | |
// Draw arrow head in the negative direction of the ending point. | |
ctx.lineTo(x1 - arrowHeadLen * Math.cos(arrowAngle - Math.PI / 6), y1 - arrowHeadLen * Math.sin(arrowAngle - Math.PI / 6)); | |
// Again move back to the ending coordinate. | |
ctx.moveTo(x1, y1); | |
// Draw arrow head in the positive direction of the ending point. | |
ctx.lineTo(x1 - arrowHeadLen * Math.cos(arrowAngle + Math.PI / 6), y1 - arrowHeadLen * Math.sin(arrowAngle + Math.PI / 6)); | |
ctx.stroke(); | |
} | |
})(); | |
</script> | |
<script id="jsbin-source-javascript" type="text/javascript">(function() { | |
const canvasWidth = window.innerWidth, | |
canvasHeight = window.innerHeight, | |
centerX = 0, | |
centerY = 0, | |
arrowHeadLen = 10; | |
const container = document.getElementById("container"); | |
container.style.position = "absolute"; | |
container.style.left = centerX + "px"; | |
container.style.top = centerY + "px"; | |
const canvas = document.createElement("canvas"); | |
canvas.id = "c"; | |
canvas.width = canvasWidth; | |
canvas.height = canvasHeight; | |
container.append(canvas); | |
const ctx = canvas.getContext("2d"); | |
ctx.lineWidth = 2; | |
let startX = 0, | |
startY = 0, | |
storedLines = [], | |
isDown = false; | |
canvas.addEventListener("mousedown", handleMouseDown); | |
canvas.addEventListener("mousemove", handleMouseMove); | |
canvas.addEventListener("mouseup", handleMouseUp); | |
function handleMouseDown(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
let { x, y } = getMousePos(canvas, e); | |
isDown = true; | |
startX = x; | |
startY = y; | |
} | |
function handleMouseUp(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
isDown = false; | |
let { x, y } = getMousePos(canvas, e); | |
storedLines.push({ x0: startX, y0: startY, x1: x, y1: y }); | |
draw(); | |
} | |
function handleMouseMove(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
if (!isDown) return; | |
draw(); | |
let { x, y } = getMousePos(canvas, e); | |
drawLine(ctx, { x0: startX, y0: startY, x1: x, y1: y }); | |
} | |
function getMousePos(canvas, evt) { | |
var rect = canvas.getBoundingClientRect(); | |
return { | |
x: evt.clientX - rect.left, | |
y: evt.clientY - rect.top | |
}; | |
} | |
function draw(e) { | |
ctx.clearRect(0, 0, canvas.width, canvas.height); | |
for (var i = 0; i < storedLines.length; i++) { | |
drawLine(ctx, storedLines[i]); | |
// Drawing the arrow heads after rendering the arrow. | |
drawArrow(ctx, storedLines[i]); | |
} | |
} | |
function drawLine(ctx, g) { | |
ctx.beginPath(); | |
ctx.moveTo(g.x0, g.y0); | |
ctx.lineTo(g.x1, g.y1); | |
ctx.stroke(); | |
} | |
// Function to draw the arrow heads. | |
function drawArrow(ctx, g) { | |
const { x0, x1, y0, y1 } = g; | |
const diffX = x1 - x0; | |
const diffY = y1 - y0; | |
const arrowAngle = Math.atan2(diffY, diffX); | |
drawStartArrow(ctx, x0, y0, arrowAngle); | |
drawEndArrow(ctx, x1, y1, arrowAngle); | |
} | |
// Function to draw the arrow head at the starting point of the line. | |
function drawStartArrow(ctx, x0, y0, arrowAngle) { | |
ctx.beginPath(); | |
// Starting coordinate of line. | |
ctx.lineTo(x0, y0); | |
// Draw arrow head in the negative direction of the starting point. | |
ctx.lineTo( | |
x0 + arrowHeadLen * Math.cos(arrowAngle - Math.PI / 6), | |
y0 + arrowHeadLen * Math.sin(arrowAngle - Math.PI / 6) | |
); | |
// Again move back to the starting coordinate. | |
ctx.moveTo(x0, y0); | |
// Draw arrow head in the positive direction of the starting point. | |
ctx.lineTo( | |
x0 + arrowHeadLen * Math.cos(arrowAngle + Math.PI / 6), | |
y0 + arrowHeadLen * Math.sin(arrowAngle + Math.PI / 6) | |
); | |
ctx.stroke(); | |
} | |
// Function to draw the arrow head at the ending point of the line. | |
function drawEndArrow(ctx, x1, y1, arrowAngle) { | |
ctx.beginPath(); | |
// Ending coordinate of line. | |
ctx.lineTo(x1, y1); | |
// Draw arrow head in the negative direction of the ending point. | |
ctx.lineTo( | |
x1 - arrowHeadLen * Math.cos(arrowAngle - Math.PI / 6), | |
y1 - arrowHeadLen * Math.sin(arrowAngle - Math.PI / 6) | |
); | |
// Again move back to the ending coordinate. | |
ctx.moveTo(x1, y1); | |
// Draw arrow head in the positive direction of the ending point. | |
ctx.lineTo( | |
x1 - arrowHeadLen * Math.cos(arrowAngle + Math.PI / 6), | |
y1 - arrowHeadLen * Math.sin(arrowAngle + Math.PI / 6) | |
); | |
ctx.stroke(); | |
} | |
})(); | |
</script></body> | |
</html> |
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Learn more about bidirectional Unicode characters
"use strict"; | |
(function () { | |
var canvasWidth = window.innerWidth, | |
canvasHeight = window.innerHeight, | |
centerX = 0, | |
centerY = 0, | |
arrowHeadLen = 10; | |
var container = document.getElementById("container"); | |
container.style.position = "absolute"; | |
container.style.left = centerX + "px"; | |
container.style.top = centerY + "px"; | |
var canvas = document.createElement("canvas"); | |
canvas.id = "c"; | |
canvas.width = canvasWidth; | |
canvas.height = canvasHeight; | |
container.append(canvas); | |
var ctx = canvas.getContext("2d"); | |
ctx.lineWidth = 2; | |
var startX = 0, | |
startY = 0, | |
storedLines = [], | |
isDown = false; | |
canvas.addEventListener("mousedown", handleMouseDown); | |
canvas.addEventListener("mousemove", handleMouseMove); | |
canvas.addEventListener("mouseup", handleMouseUp); | |
function handleMouseDown(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
var _getMousePos = getMousePos(canvas, e); | |
var x = _getMousePos.x; | |
var y = _getMousePos.y; | |
isDown = true; | |
startX = x; | |
startY = y; | |
} | |
function handleMouseUp(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
isDown = false; | |
var _getMousePos2 = getMousePos(canvas, e); | |
var x = _getMousePos2.x; | |
var y = _getMousePos2.y; | |
storedLines.push({ x0: startX, y0: startY, x1: x, y1: y }); | |
draw(); | |
} | |
function handleMouseMove(e) { | |
e.preventDefault(); | |
e.stopPropagation(); | |
if (!isDown) return; | |
draw(); | |
var _getMousePos3 = getMousePos(canvas, e); | |
var x = _getMousePos3.x; | |
var y = _getMousePos3.y; | |
drawLine(ctx, { x0: startX, y0: startY, x1: x, y1: y }); | |
} | |
function getMousePos(canvas, evt) { | |
var rect = canvas.getBoundingClientRect(); | |
return { | |
x: evt.clientX - rect.left, | |
y: evt.clientY - rect.top | |
}; | |
} | |
function draw(e) { | |
ctx.clearRect(0, 0, canvas.width, canvas.height); | |
for (var i = 0; i < storedLines.length; i++) { | |
drawLine(ctx, storedLines[i]); | |
// Drawing the arrow heads after rendering the arrow. | |
drawArrow(ctx, storedLines[i]); | |
} | |
} | |
function drawLine(ctx, g) { | |
ctx.beginPath(); | |
ctx.moveTo(g.x0, g.y0); | |
ctx.lineTo(g.x1, g.y1); | |
ctx.stroke(); | |
} | |
// Function to draw the arrow heads. | |
function drawArrow(ctx, g) { | |
var x0 = g.x0; | |
var x1 = g.x1; | |
var y0 = g.y0; | |
var y1 = g.y1; | |
var diffX = x1 - x0; | |
var diffY = y1 - y0; | |
var arrowAngle = Math.atan2(diffY, diffX); | |
drawStartArrow(ctx, x0, y0, arrowAngle); | |
drawEndArrow(ctx, x1, y1, arrowAngle); | |
} | |
// Function to draw the arrow head at the starting point of the line. | |
function drawStartArrow(ctx, x0, y0, arrowAngle) { | |
ctx.beginPath(); | |
// Starting coordinate of line. | |
ctx.lineTo(x0, y0); | |
// Draw arrow head in the negative direction of the starting point. | |
ctx.lineTo(x0 + arrowHeadLen * Math.cos(arrowAngle - Math.PI / 6), y0 + arrowHeadLen * Math.sin(arrowAngle - Math.PI / 6)); | |
// Again move back to the starting coordinate. | |
ctx.moveTo(x0, y0); | |
// Draw arrow head in the positive direction of the starting point. | |
ctx.lineTo(x0 + arrowHeadLen * Math.cos(arrowAngle + Math.PI / 6), y0 + arrowHeadLen * Math.sin(arrowAngle + Math.PI / 6)); | |
ctx.stroke(); | |
} | |
// Function to draw the arrow head at the ending point of the line. | |
function drawEndArrow(ctx, x1, y1, arrowAngle) { | |
ctx.beginPath(); | |
// Ending coordinate of line. | |
ctx.lineTo(x1, y1); | |
// Draw arrow head in the negative direction of the ending point. | |
ctx.lineTo(x1 - arrowHeadLen * Math.cos(arrowAngle - Math.PI / 6), y1 - arrowHeadLen * Math.sin(arrowAngle - Math.PI / 6)); | |
// Again move back to the ending coordinate. | |
ctx.moveTo(x1, y1); | |
// Draw arrow head in the positive direction of the ending point. | |
ctx.lineTo(x1 - arrowHeadLen * Math.cos(arrowAngle + Math.PI / 6), y1 - arrowHeadLen * Math.sin(arrowAngle + Math.PI / 6)); | |
ctx.stroke(); | |
} | |
})(); |
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