使用鼠标在HTML5画布上绘制
我想使用鼠标在HTML画布上绘制(例如,绘制签名、绘制名称等) 我该如何实现这个呢?谷歌搜索了这个(“html5画布绘制程序”)。看起来像是你需要的使用鼠标在HTML5画布上绘制,html,canvas,gesture,gesture-recognition,Html,Canvas,Gesture,Gesture Recognition,我想使用鼠标在HTML画布上绘制(例如,绘制签名、绘制名称等) 我该如何实现这个呢?谷歌搜索了这个(“html5画布绘制程序”)。看起来像是你需要的 如果您在执行此操作时遇到问题,请告诉我。它使用processing.js并具有更改颜色和使绘图点越来越大和越来越小的功能 <html> <head> <!--script librarires--> <script type="text/javascript" src="processing.js">
如果您在执行此操作时遇到问题,请告诉我。它使用processing.js并具有更改颜色和使绘图点越来越大和越来越小的功能
<html>
<head>
<!--script librarires-->
<script type="text/javascript" src="processing.js"></script>
<script type="text/javascript" src="init.js"></script>
<!--styles -->
<style type="text/css" src="stylesheet.css">
</style>
</head>
<body>
<!--toolbox -->
<div id="draggable toolbox"></div>
<script type="application/processing">
// new script
int prevx, prevy;
int newx, newy;
boolean cliked;
color c1 = #000000;
int largeur=2;
int ps = 20;
int px = 50;
int py = 50;
void setup() {
size(500,500);
frameRate(25);
background(50);
prevx = mouseX;
prevy = mouseY;
cliked = false;
}
void draw() {
//couleur
noStroke(0);
fill(#FFFFFF);//blanc
rect(px, py, ps, ps);
fill(#000000);
rect(px, py+(ps), ps, ps);
fill(#FF0000);
rect(px, py+(ps*2), ps, ps);
fill(#00FF00);
rect(px, py+(ps*3), ps, ps);
fill(#FFFF00);
rect(px, py+(ps*4), ps, ps);
fill(#0000FF);
rect(px, py+(ps*5), ps, ps);
//largeur
fill(#FFFFFF);
rect(px, py+(ps*7), ps, ps);
fill(#FFFFFF);
rect(px, py+(ps*8), ps, ps);
stroke(#000000);
line(px+2, py+(ps*7)+(ps/2), px+(ps-2), py+(ps*7)+(ps/2));
line(px+(ps/2), py+(ps*7)+1, px+(ps/2), py+(ps*8)-1);
line(px+2, py+(ps*8)+(ps/2), px+(ps-2), py+(ps*8)+(ps/2));
if(cliked==false){
prevx = mouseX;
prevy = mouseY;
}
if(mousePressed) {
cliked = true;
newx = mouseX;
newy = mouseY;
strokeWeight(largeur);
stroke(c1);
line(prevx, prevy, newx, newy);
prevx = newx;
prevy = newy;
}else{
cliked= false;
}
}
void mouseClicked() {
if (mouseX>=px && mouseX<=(px+ps)){
//couleur
if (mouseY>=py && mouseY<=py+(ps*6)){
c1 = get(mouseX, mouseY);
}
//largeur
if (mouseY>=py+(ps*7) && mouseY<=py+(ps*8)){
largeur += 2;
}
if (mouseY>=py+(ps*8) && mouseY<=py+(ps*9)){
if (largeur>2){
largeur -= 2;
}
}
}
}
</script><canvas></canvas>
</body>
</html>
//新剧本
int-prevx,prevy;
int newx,newy;
布尔陈词滥调;
颜色c1=#000000;
int largeur=2;
int-ps=20;
int-px=50;
int-py=50;
无效设置(){
尺寸(500500);
帧率(25);
背景(50);
prevx=鼠标;
prevy=老鼠;
陈词滥调=错误;
}
作废提款(){
//库勒
仰泳(0);
填充(#FFFFFF);//布兰科
rect(px,py,ps,ps);
填写(#000000);
rect(px,py+(ps),ps,ps);
填充(#FF0000);
rect(px,py+(ps*2),ps,ps);
填充(#00FF00);
rect(px,py+(ps*3),ps,ps);
填充(#FFFF00);
rect(px,py+(ps*4),ps,ps);
填充(#0000FF);
rect(px,py+(ps*5),ps,ps);
//大户
填充(#FFFFFF);
rect(px,py+(ps*7),ps,ps);
填充(#FFFFFF);
rect(px,py+(ps*8),ps,ps);
冲程(#000000);
线(px+2,py+(ps*7)+(ps/2),px+(ps-2),py+(ps*7)+(ps/2));
线(px+(ps/2),py+(ps*7)+1,px+(ps/2),py+(ps*8)-1);
线(px+2,py+(ps*8)+(ps/2),px+(ps-2),py+(ps*8)+(ps/2));
if(cliked==false){
prevx=鼠标;
prevy=老鼠;
}
如果(鼠标按下){
陈词滥调=正确;
newx=鼠标;
纽伊=老鼠;
冲程重量(较大);
中风(c1);
行(prevx,prevy,newx,newy);
prevx=newx;
prevy=newy;
}否则{
陈词滥调=错误;
}
}
void mouseClicked(){
如果(mouseX>=px&&mouseX=py&&mouseY=py+(ps*7)和&mouseY=py+(ps*8)和&mouseY2){
较大者-=2;
}
}
}
}
检查此项。这将指引您正确的方向以下是使用画布创建绘图应用程序的最简单方法:
mousedown
、mousemove
和mouseup
事件侦听器附加到画布DOMmousedown
上,获取鼠标坐标,并使用moveTo()
方法定位图形光标,使用beginPath()
方法开始新的图形路径mousemove
上,使用lineTo()
连续向路径添加一个新点,并使用stroke()
为最后一段上色mouseup
上,设置一个标志以禁用图形从那里,您可以添加各种其他功能,例如让用户能够选择线条厚度、颜色、笔划,甚至图层。这是一个工作示例
变量画布,ctx,标志=false,
prevX=0,
currX=0,
prevY=0,
咖喱=0,
dot_标志=假;
var x=“黑色”,
y=2;
函数init(){
canvas=document.getElementById('can');
ctx=canvas.getContext(“2d”);
w=画布宽度;
h=画布高度;
canvas.addEventListener(“mousemove”,函数(e){
findxy('move',e)
},假);
canvas.addEventListener(“鼠标向下”,函数(e){
findxy('down',e)
},假);
canvas.addEventListener(“mouseup”,函数(e){
findxy('up',e)
},假);
canvas.addEventListener(“mouseout”,函数(e){
findxy('out',e)
},假);
}
功能颜色(obj){
开关(对象id){
案例“绿色”:
x=“绿色”;
打破
案例“蓝色”:
x=“蓝色”;
打破
案例“红色”:
x=“红色”;
打破
案例“黄色”:
x=“黄色”;
打破
案例“橙色”:
x=“橙色”;
打破
案例“黑色”:
x=“黑色”;
打破
“白色”案例:
x=“白色”;
打破
}
如果(x=“白色”)y=14;
否则y=2;
}
函数绘图(){
ctx.beginPath();
ctx.moveTo(prevX,prevY);
ctx.lineTo(咖喱,咖喱);
ctx.strokeStyle=x;
ctx.lineWidth=y;
ctx.stroke();
ctx.closePath();
}
函数擦除(){
var m=确认(“想要清算”);
如果(m){
ctx.clearRect(0,0,w,h);
document.getElementById(“canvasimg”).style.display=“无”;
}
}
函数save(){
document.getElementById(“canvasimg”).style.border=“2px solid”;
var dataURL=canvas.toDataURL();
document.getElementById(“canvasimg”).src=dataURL;
document.getElementById(“canvasimg”).style.display=“inline”;
}
函数findxy(res,e){
如果(res=='down'){
prevX=currX;
prevY=咖喱;
currX=e.clientX-canvas.offsetLeft;
currY=e.clientY-canvas.offsetTop;
flag=true;
dot_flag=true;
if(dot_标志){
ctx.beginPath();
ctx.fillStyle=x;
ctx.fillRect(currX,currY,2,2);
ctx.closePath();
dot_标志=假;
}
}
如果(res==“向上”| res==“向外”){
flag=false;
}
如果(res=='move'){
国际单项体育联合会(旗){
prevX=currX;
prevY=咖喱;
currX=e.clientX-canvas.offsetLeft;
currY=e.clientY-canvas.offsetTop;
draw();
}
}
}
选择颜色
橡皮擦
我也在寻找将此方法用于签名的方法,我在上找到了一个示例
我已将以下代码添加到
Html:
Alco支票
<div id="sketch">
<canvas id="paint"></canvas>
</div>
(function() {
var canvas = document.querySelector('#paint');
var ctx = canvas.getContext('2d');
var sketch = document.querySelector('#sketch');
var sketch_style = getComputedStyle(sketch);
canvas.width = parseInt(sketch_style.getPropertyValue('width'));
canvas.height = parseInt(sketch_style.getPropertyValue('height'));
var mouse = {x: 0, y: 0};
var last_mouse = {x: 0, y: 0};
/* Mouse Capturing Work */
canvas.addEventListener('mousemove', function(e) {
last_mouse.x = mouse.x;
last_mouse.y = mouse.y;
mouse.x = e.pageX - this.offsetLeft;
mouse.y = e.pageY - this.offsetTop;
}, false);
/* Drawing on Paint App */
ctx.lineWidth = 5;
ctx.lineJoin = 'round';
ctx.lineCap = 'round';
ctx.strokeStyle = 'blue';
canvas.addEventListener('mousedown', function(e) {
canvas.addEventListener('mousemove', onPaint, false);
}, false);
canvas.addEventListener('mouseup', function() {
canvas.removeEventListener('mousemove', onPaint, false);
}, false);
var onPaint = function() {
ctx.beginPath();
ctx.moveTo(last_mouse.x, last_mouse.y);
ctx.lineTo(mouse.x, mouse.y);
ctx.closePath();
ctx.stroke();
};
}());
<canvas id="canvas" width="490" height="220"></canvas>
context = document.getElementById('canvas').getContext("2d");
$('#canvas').mousedown(function(e){
var mouseX = e.pageX - this.offsetLeft;
var mouseY = e.pageY - this.offsetTop;
paint = true;
addClick(e.pageX - this.offsetLeft, e.pageY - this.offsetTop);
redraw();
});
$('#canvas').mouseup(function(e){
paint = false;
});
$('#canvas').mouseleave(function(e){
paint = false;
});
var clickX = new Array();
var clickY = new Array();
var clickDrag = new Array();
var paint;
function addClick(x, y, dragging)
{
clickX.push(x);
clickY.push(y);
clickDrag.push(dragging);
}
//Also redraw
function redraw(){
context.clearRect(0, 0, context.canvas.width, context.canvas.height); // Clears the canvas
context.strokeStyle = "#df4b26";
context.lineJoin = "round";
context.lineWidth = 5;
for(var i=0; i < clickX.length; i++) {
context.beginPath();
if(clickDrag[i] && i){
context.moveTo(clickX[i-1], clickY[i-1]);
}else{
context.moveTo(clickX[i]-1, clickY[i]);
}
context.lineTo(clickX[i], clickY[i]);
context.closePath();
context.stroke();
}
}
<html>
<script type="text/javascript">
var canvas, canvasimg, backgroundImage, finalImg;
var mouseClicked = false;
var prevX = 0;
var currX = 0;
var prevY = 0;
var currY = 0;
var fillStyle = "black";
var globalCompositeOperation = "source-over";
var lineWidth = 2;
function init() {
var imageSrc = '/abstract-geometric-pattern_23-2147508597.jpg'
backgroundImage = new Image();
backgroundImage.src = imageSrc;
canvas = document.getElementById('can');
finalImg = document.getElementById('finalImg');
canvasimg = document.getElementById('canvasimg');
canvas.style.backgroundImage = "url('" + imageSrc + "')";
canvas.addEventListener("mousemove", handleMouseEvent);
canvas.addEventListener("mousedown", handleMouseEvent);
canvas.addEventListener("mouseup", handleMouseEvent);
canvas.addEventListener("mouseout", handleMouseEvent);
}
function getColor(btn) {
globalCompositeOperation = 'source-over';
lineWidth = 2;
switch (btn.getAttribute('data-color')) {
case "green":
fillStyle = "green";
break;
case "blue":
fillStyle = "blue";
break;
case "red":
fillStyle = "red";
break;
case "yellow":
fillStyle = "yellow";
break;
case "orange":
fillStyle = "orange";
break;
case "black":
fillStyle = "black";
break;
case "eraser":
globalCompositeOperation = 'destination-out';
fillStyle = "rgba(0,0,0,1)";
lineWidth = 14;
break;
}
}
function draw(dot) {
var ctx = canvas.getContext("2d");
ctx.beginPath();
ctx.globalCompositeOperation = globalCompositeOperation;
if(dot){
ctx.fillStyle = fillStyle;
ctx.fillRect(currX, currY, 2, 2);
} else {
ctx.beginPath();
ctx.moveTo(prevX, prevY);
ctx.lineTo(currX, currY);
ctx.strokeStyle = fillStyle;
ctx.lineWidth = lineWidth;
ctx.stroke();
}
ctx.closePath();
}
function erase() {
if (confirm("Want to clear")) {
var ctx = canvas.getContext("2d");
ctx.clearRect(0, 0, canvas.width, canvas.height);
document.getElementById("canvasimg").style.display = "none";
}
}
function save() {
canvas.style.border = "2px solid";
canvasimg.width = canvas.width;
canvasimg.height = canvas.height;
var ctx2 = canvasimg.getContext("2d");
// comment next line to save the draw only
ctx2.drawImage(backgroundImage, 0, 0);
ctx2.drawImage(canvas, 0, 0);
finalImg.src = canvasimg.toDataURL();
finalImg.style.display = "inline";
}
function handleMouseEvent(e) {
if (e.type === 'mousedown') {
prevX = currX;
prevY = currY;
currX = e.offsetX;
currY = e.offsetY;
mouseClicked = true;
draw(true);
}
if (e.type === 'mouseup' || e.type === "mouseout") {
mouseClicked = false;
}
if (e.type === 'mousemove') {
if (mouseClicked) {
prevX = currX;
prevY = currY;
currX = e.offsetX;
currY = e.offsetY;
draw();
}
}
}
</script>
<body onload="init()">
<canvas id="can" width="400" height="400" style="position:absolute;top:10%;left:10%;border:2px solid;">
</canvas>
<div style="position:absolute;top:12%;left:43%;">Choose Color</div>
<div style="position:absolute;top:15%;left:45%;width:10px;height:10px;background:green;" data-color="green" onclick="getColor(this)"></div>
<div style="position:absolute;top:15%;left:46%;width:10px;height:10px;background:blue;" data-color="blue" onclick="getColor(this)"></div>
<div style="position:absolute;top:15%;left:47%;width:10px;height:10px;background:red;" data-color="red" onclick="getColor(this)"></div>
<div style="position:absolute;top:17%;left:45%;width:10px;height:10px;background:yellow;" data-color="yellow" onclick="getColor(this)"></div>
<div style="position:absolute;top:17%;left:46%;width:10px;height:10px;background:orange;" data-color="orange" onclick="getColor(this)"></div>
<div style="position:absolute;top:17%;left:47%;width:10px;height:10px;background:black;" data-color="black" onclick="getColor(this)"></div>
<div style="position:absolute;top:20%;left:43%;">Eraser</div>
<div style="position:absolute;top:22%;left:45%;width:15px;height:15px;background:white;border:2px solid;" data-color="eraser" onclick="getColor(this)"></div>
<canvas id="canvasimg" style="display:none;" ></canvas>
<img id="finalImg" style="position:absolute;top:10%;left:52%;display:none;" >
<input type="button" value="save" id="btn" size="30" onclick="save()" style="position:absolute;top:55%;left:10%;">
<input type="button" value="clear" id="clr" size="23" onclick="erase()" style="position:absolute;top:55%;left:15%;">
</body>
</html>