微信小程序小组件 基于Canvas实现直播点赞气泡效果

drawImage:function(data){[/align]    var that = this    var p10= data[0][0];  /* 三阶贝塞尔曲线起点坐标值*/    var p11= data[0][1];  /* 三阶贝塞尔曲线第一个控制点坐标值*/    var p12= data[0][2];  /* 三阶贝塞尔曲线第二个控制点坐标值*/    var p13= data[0][3];  /* 三阶贝塞尔曲线终点坐标值*/    var p20= data[1][0];    var p21= data[1][1];    var p22= data[1][2];    var p23= data[1][3];    var p30= data[2][0];    var p31= data[2][1];    var p32= data[2][2];    var p33= data[2][3];    var t = factor.t;    /*计算多项式系数 （下同）*/      var cx1 = 3*(p11.x-p10.x);    var bx1 = 3*(p12.x-p11.x)-cx1;    var ax1 = p13.x-p10.x-cx1-bx1;    var cy1 = 3*(p11.y-p10.y);    var by1 = 3*(p12.y-p11.y)-cy1;    var ay1 = p13.y-p10.y-cy1-by1;    var xt1 = ax1*(t*t*t)+bx1*(t*t)+cx1*t+p10.x;    var yt1 = ay1*(t*t*t)+by1*(t*t)+cy1*t+p10.y;    var cx2 = 3*(p21.x-p20.x);    var bx2 = 3*(p22.x-p21.x)-cx2;    var ax2 = p23.x-p20.x-cx2-bx2;    var cy2 = 3*(p21.y-p20.y);    var by2 = 3*(p22.y-p21.y)-cy2;    var ay2 = p23.y-p20.y-cy2-by2;    var xt2 = ax2*(t*t*t)+bx2*(t*t)+cx2*t+p20.x;    var yt2 = ay2*(t*t*t)+by2*(t*t)+cy2*t+p20.y;    var cx3 = 3*(p31.x-p30.x);    var bx3 = 3*(p32.x-p31.x)-cx3;    var ax3 = p33.x-p30.x-cx3-bx3;    var cy3 = 3*(p31.y-p30.y);    var by3 = 3*(p32.y-p31.y)-cy3;    var ay3 = p33.y-p30.y-cy3-by3;    /*计算xt yt的值 */    var xt3 = ax3*(t*t*t)+bx3*(t*t)+cx3*t+p30.x;    var yt3 = ay3*(t*t*t)+by3*(t*t)+cy3*t+p30.y;    factor.t +=factor.speed;    ctx.drawImage("../../images/heart1.png",xt1,yt1,30,30);    ctx.drawImage("../../images/heart2.png",xt2,yt2,30,30);    ctx.drawImage("../../images/heart3.png",xt3,yt3,30,30);    ctx.draw();    if(factor.t>1){      factor.t=0;      cancelAnimationFrame(timer);      that.startTimer();    }else{      timer =requestAnimationFrame(function(){        that.drawImage([[{x:30,y:400},{x:70,y:300},{x:-50,y:150},{x:30,y:0}],[{x:30,y:400},{x:30,y:300},{x:80,y:150},{x:30,y:0}],[{x:30,y:400},{x:0,y:90},{x:80,y:100},{x:30,y:0}]])     })    }}

cx = 3 * ( x1 - x0 )bx = 3 * ( x2 - x1 ) - cxax = x3 - x0 - cx - bxcy = 3 * ( y1 - y0 )    by = 3 * ( y2 - y1 ) - cyay = y3 - y0 - cy - byx(t) = ax * t ^ 3 + bx * t ^ 2 + cx * t + x0y(t) = ay * t ^ 3 + by * t ^ 2 + cy * t + y0