var faceCanvas=document.getElementById('face');
var faceCtx=faceCanvas.getContext('2d');
var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
var cw,ch;
$myslider=$('#myslider');
$myslider.val(50);
var PI=Math.PI;
var cupTop=78;
var cupBottom=295;
var dxx=19;
var dyy=34;
var l={x0:41,y0:cupTop,x1:74,y1:cupBottom};
var r={x0:249,y0:cupTop,x1:218,y1:cupBottom};
var t={
x0:l.x0,
y0:l.y0,
x1:l.x0+dxx,
y1:r.y0+dyy,
x2:r.x0-dxx,
y2:r.y0+dyy,
x3:r.x0,
y3:r.y0
};
var b={
x0:l.x1,
y0:l.y1,
x1:l.x1+dxx,
y1:r.y1+dyy,
x2:r.x1-dxx,
y2:r.y1+dyy,
x3:r.x1,
y3:r.y1
};
var topOffset=40;
var imgCount=2;
var cup=new Image();
cup.crossOrigin='anonymous';
cup.onload=start;
var pic=new Image();
pic.crossOrigin='anonymous';
pic.onload=start;
cup.src="https://dl.dropboxusercontent.com/u/139992952/multple/PaperCup.png";
pic.src='https://dl.dropboxusercontent.com/u/139992952/multple/avatars1.jpg';
function start(){
if(--imgCount>0){return;}
cw=canvas.width=faceCanvas.width=cup.width;
ch=canvas.height=faceCanvas.height=cup.height;
draw();
face();
$myslider.change(function(){
var value=parseInt($(this).val())/100;
topOffset=(l.y1-l.y0-pic.height)*value;
draw();
face();
});
}
function face(){
//
var lm=(l.y1-l.y0)/(l.x1-l.x0);
var lb=l.y1-(lm*l.x1);
//
var rm=(r.y1-r.y0)/(r.x1-r.x0);
var rb=r.y1-(rm*r.x1);
faceCtx.clearRect(0,0,faceCanvas.width,faceCanvas.height);
for(var y=0;y<pic.height;y++){
var yy=cupTop+topOffset+y;
var leftX=(yy-lb)/lm;
var rightX=(yy-rb)/rm;
var width=rightX-leftX;
faceCtx.drawImage(
pic,
0,y,pic.width,1,
leftX,yy,width,1
);
}
var yy=cupTop+topOffset;
var p0={x:(yy-lb)/lm,y:cupTop+topOffset};
var p3={x:(yy-rb)/rm,y:cupTop+topOffset};
var p1={x:p0.x+dxx,y:p0.y+dyy};
var p2={x:p3.x-dxx,y:p3.y+dyy};
var points=calcPointsOnBezier(p0,p1,p2,p3);
for(var x in points){
var y=points[x];
ctx.drawImage(faceCanvas, x,0,1,ch, x,y-yy,1,ch);
}
}
function calcPointsOnBezier(p0,p1,p2,p3){
var points={};
for(var x=parseInt(p0.x);x<parseInt(p3.x+1);x++){
points[x]=p0.y;
}
for(var i=0;i<1000;i++){
var t=i/1000;
var pt=getCubicBezierXYatT(p0,p1,p2,p3,t);
points[parseInt(pt.x)]=parseInt(pt.y);
}
return(points);
}
function draw(){
ctx.strokeStyle='gold';
ctx.clearRect(0,0,cw,ch);
ctx.drawImage(cup,0,0);
// diagnostic();
}
function diagnostic(){
ctx.beginPath();
ctx.moveTo(l.x0,l.y0);
ctx.lineTo(l.x1,l.y1);
ctx.moveTo(r.x0,r.y0);
ctx.lineTo(r.x1,r.y1);
ctx.lineWidth=3;
ctx.stroke();
ctx.beginPath();
ctx.moveTo(t.x0,t.y0);
ctx.bezierCurveTo(t.x1,t.y1, t.x2,t.y2, t.x3,t.y3);
ctx.stroke();
ctx.beginPath();
ctx.moveTo(b.x0,b.y0);
ctx.bezierCurveTo(b.x1,b.y1, b.x2,b.y2, b.x3,b.y3);
ctx.stroke();
}
function getCubicBezierXYatT(startPt,controlPt1,controlPt2,endPt,T){
var x=CubicN(T,startPt.x,controlPt1.x,controlPt2.x,endPt.x);
var y=CubicN(T,startPt.y,controlPt1.y,controlPt2.y,endPt.y);
return({x:x,y:y});
}
// cubic helper formula at T distance
function CubicN(T, a,b,c,d) {
var t2 = T * T;
var t3 = t2 * T;
return a + (-a * 3 + T * (3 * a - a * T)) * T
+ (3 * b + T * (-6 * b + b * 3 * T)) * T
+ (c * 3 - c * 3 * T) * t2
+ d * t3;
}
body{ background-color: ivory; }
canvas{border:1px solid red;}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
Vertical Position:<input id=myslider type=range min=0 max=100 value=50><br>
<canvas id="canvas" width=300 height=300></canvas>
<canvas id="face" width=300 height=300 hidden></canvas>
몇 가지 초기 오류가 있습니다. CSS를 사용하여 캔버스 크기를 설정하는 경우 (너비와 높이를 직접 사용하는 경우에만 해당), 대상 너비 1 픽셀을 사용하여 이미지를 draw합니다 (이미지의 너비가 1 픽셀 인 이유 설명) 캔버스를 직접 사용하면 패브릭 내부를 업데이트하지 않습니다 (대신 패브릭 메서드를 사용해야합니다). 이렇게하면 패브릭과 상호 작용할 때 캔버스가 비어있게됩니다. – K3N
drawImage의 코드를 도와 주시겠습니까? 이런 식으로하고 싶습니다 - http://stackoverflow.com/questions/26403646/fabric-js-html-5-image-curving-options – user3752437