'use strict';
class Renderer {
constructor(canvas){
this.canvasWidth = canvas.width;
this.canvasHeight = canvas.height;
}
drawPoints(ctx, points) {
if(points.length == 2){
ctx.beginPath();
ctx.moveTo(points[0].x * this.canvasWidth, points[0].y * this.canvasHeight);
ctx.lineTo(points[1].x * this.canvasWidth, points[1].y * this.canvasHeight);
ctx.stroke();
return;
}
ctx.beginPath();
ctx.moveTo(points[0].x * this.canvasWidth, points[0].y * this.canvasHeight);
for (var i = 1; i < points.length - 2; i++) {
var c = ((points[i].x* this.canvasWidth) + (points[i + 1].x* this.canvasWidth)) / 2,
d = ((points[i].y * this.canvasHeight) + (points[i + 1].y * this.canvasHeight)) / 2;
ctx.quadraticCurveTo(points[i].x * this.canvasWidth, points[i].y * this.canvasHeight, c, d);
}
if(i < points.length - 1){
ctx.quadraticCurveTo(
points[i].x * this.canvasWidth,
points[i].y * this.canvasHeight,
points[i + 1].x * this.canvasWidth,
points[i + 1].y * this.canvasHeight);
}
ctx.stroke();
}
drawDot(ctx, x, y){
ctx.beginPath();
ctx.arc(x * this.canvasWidth, y * this.canvasHeight, ctx.lineWidth/2, 0, 2 * Math.PI, false);
ctx.fillStyle = ctx.strokeStyle;
ctx.fill();
}
}
module.exports = Renderer;