svgcanvas/test/tests/ellipse2.js

32 lines
1017 B
JavaScript

export default function ellipse2(ctx) {
// Draw a cylinder using ellipses and lines.
var w = 100, h = 100, rx = 50, ry = 10;
var scaleX = 1.5, scaleY = 2.5;
ctx.scale(scaleX, scaleY);
ctx.translate(100, 75);
ctx.beginPath();
ctx.moveTo(-w / 2, -h / 2 + ry);
// upper arc top
ctx.ellipse(0, -h / 2 + ry, rx, ry, Math.PI, 0, Math.PI, 0);
ctx.moveTo(-w / 2, -h / 2 + ry);
// upper arc bottom
ctx.ellipse(0, -h / 2 + ry, rx, ry, Math.PI, 0, Math.PI, 1);
ctx.moveTo(-w / 2, -h / 2 + ry);
// left line
ctx.lineTo(-w / 2, + h / 2 - ry);
// lower arc
ctx.ellipse(0, h / 2 - ry, rx, ry, Math.PI, 0, Math.PI, 1);
// right line
ctx.lineTo(w / 2, -h / 2 + ry);
ctx.moveTo(-w / 2, -h / 2 + ry);
ctx.closePath();
// Remove scale before stroking because the SVG conversion is not correctly
// scaling the stroke as well. Without this the pixel differences are too
// high.
ctx.scale(1 / scaleX, 1 / scaleY);
ctx.stroke();
};