svgedit/cypress/integration/unit/math.js

import { NS } from '../../../instrumented/svgcanvas/namespaces.js';
import * as math from '../../../instrumented/svgcanvas/math.js';

describe('math', function () {
  const svg = document.createElementNS(NS.SVG, 'svg');

  it('Test svgedit.math package', function () {
    assert.ok(math);
    assert.ok(math.transformPoint);
    assert.ok(math.isIdentity);
    assert.ok(math.matrixMultiply);
    assert.equal(typeof math.transformPoint, typeof function () { /* empty fn */ });
    assert.equal(typeof math.isIdentity, typeof function () { /* empty fn */ });
    assert.equal(typeof math.matrixMultiply, typeof function () { /* empty fn */ });
  });

  it('Test svgedit.math.transformPoint() function', function () {
    const { transformPoint } = math;

    const m = svg.createSVGMatrix();
    m.a = 1; m.b = 0;
    m.c = 0; m.d = 1;
    m.e = 0; m.f = 0;
    let pt = transformPoint(100, 200, m);
    assert.equal(pt.x, 100);
    assert.equal(pt.y, 200);

    m.e = 300; m.f = 400;
    pt = transformPoint(100, 200, m);
    assert.equal(pt.x, 400);
    assert.equal(pt.y, 600);

    m.a = 0.5; m.b = 0.75;
    m.c = 1.25; m.d = 2;
    pt = transformPoint(100, 200, m);
    assert.equal(pt.x, 100 * m.a + 200 * m.c + m.e);
    assert.equal(pt.y, 100 * m.b + 200 * m.d + m.f);
  });

  it('Test svgedit.math.isIdentity() function', function () {
    assert.ok(math.isIdentity(svg.createSVGMatrix()));

    const m = svg.createSVGMatrix();
    m.a = 1; m.b = 0;
    m.c = 0; m.d = 1;
    m.e = 0; m.f = 0;
    assert.ok(math.isIdentity(m));
  });

  it('Test svgedit.math.matrixMultiply() function', function () {
    const mult = math.matrixMultiply;
    const { isIdentity } = math;

    // translate there and back
    const tr1 = svg.createSVGMatrix().translate(100, 50);
    const tr2 = svg.createSVGMatrix().translate(-90, 0);
    const tr3 = svg.createSVGMatrix().translate(-10, -50);
    let I = mult(tr1, tr2, tr3);
    assert.ok(isIdentity(I), 'Expected identity matrix when translating there and back');

    // rotate there and back
    // TODO: currently Mozilla fails this when rotating back at -50 and then -40 degrees
    // (b and c are *almost* zero, but not zero)
    const rotThere = svg.createSVGMatrix().rotate(90);
    const rotBack = svg.createSVGMatrix().rotate(-90); // TODO: set this to -50
    const rotBackMore = svg.createSVGMatrix().rotate(0); // TODO: set this to -40
    I = mult(rotThere, rotBack, rotBackMore);
    assert.ok(isIdentity(I), 'Expected identity matrix when rotating there and back');

    // scale up and down
    const scaleUp = svg.createSVGMatrix().scale(4);
    const scaleDown = svg.createSVGMatrix().scaleNonUniform(0.25, 1);
    const scaleDownMore = svg.createSVGMatrix().scaleNonUniform(1, 0.25);
    I = mult(scaleUp, scaleDown, scaleDownMore);
    assert.ok(isIdentity(I), 'Expected identity matrix when scaling up and down');

    // test multiplication with its inverse
    I = mult(rotThere, rotThere.inverse());
    assert.ok(isIdentity(I), 'Expected identity matrix when multiplying a matrix by its inverse');
    I = mult(rotThere.inverse(), rotThere);
    assert.ok(isIdentity(I), 'Expected identity matrix when multiplying a matrix by its inverse');
  });

  it('Test svgedit.math.transformBox() function', function () {
    const { transformBox } = math;

    const m = svg.createSVGMatrix();
    m.a = 1; m.b = 0;
    m.c = 0; m.d = 1;
    m.e = 0; m.f = 0;

    const r = transformBox(10, 10, 200, 300, m);
    assert.equal(r.tl.x, 10);
    assert.equal(r.tl.y, 10);
    assert.equal(r.tr.x, 210);
    assert.equal(r.tr.y, 10);
    assert.equal(r.bl.x, 10);
    assert.equal(r.bl.y, 310);
    assert.equal(r.br.x, 210);
    assert.equal(r.br.y, 310);
    assert.equal(r.aabox.x, 10);
    assert.equal(r.aabox.y, 10);
    assert.equal(r.aabox.width, 200);
    assert.equal(r.aabox.height, 300);
  });
});