paper.js/test/tests/Matrix.js

/*
 * Paper.js - The Swiss Army Knife of Vector Graphics Scripting.
 * http://paperjs.org/
 *
 * Copyright (c) 2011 - 2014, Juerg Lehni & Jonathan Puckey
 * http://scratchdisk.com/ & http://jonathanpuckey.com/
 *
 * Distributed under the MIT license. See LICENSE file for details.
 *
 * All rights reserved.
 */

module('Matrix');
test('Decomposition: rotate()', function() {
	function testAngle(a, ea) {
		var m = new Matrix().rotate(a),
			s = 'new Matrix().rotate(' + a + ')';
		equals(m.getRotation(), Base.pick(ea, a),
			s + '.getRotation()',
			Numerical.TOLERANCE);
		comparePoints(m.getScaling(), new Point(1, 1),
			s + '.getScaling()');
	}

	testAngle(0);
	testAngle(1);
	testAngle(45);
	testAngle(90);
	testAngle(135);
	testAngle(180);
	testAngle(270, -90);
	testAngle(-1);
	testAngle(-45);
	testAngle(-90);
	testAngle(-135);
	testAngle(-180);
	testAngle(-270, 90);
});

test('Decomposition: scale()', function() {
	function testScale(sx, sy, ex, ey, ea) {
		var m = new Matrix().scale(sx, sy),
			s = 'new Matrix().scale(' + sx + ', ' + sy + ')';
		equals(m.getRotation(), ea || 0,
				s + '.getRotation()',
				Numerical.TOLERANCE);
		comparePoints(m.getScaling(), new Point(Base.pick(ex, sx),
				Base.pick(ey, sy)),
				s + '.getScaling()');
	}

	testScale(1, 1);
	testScale(1, -1, -1, 1, -180); // Decomposing results in correct flipping
	testScale(-1, 1);
	testScale(-1, -1, 1, 1, 180); // Decomposing results in correct flipping
	testScale(2, 4);
	testScale(2, -4, -2, 4, -180); // Decomposing results in correct flipping
	testScale(4, 2);
	testScale(-4, 2);
	testScale(-4, -4, 4, 4, 180); // Decomposing results in correct flipping
});

test('Decomposition: rotate() & scale()', function() {
	function testAngleAndScale(sx, sy, a, ex, ey, ea) {
		var m = new Matrix().scale(sx, sy).rotate(a),
			s = 'new Matrix().scale(' + sx + ', ' + sy + ').rotate(' + a + ')';
		equals(m.getRotation(), ea || a,
				s + '.getRotation()',
				Numerical.TOLERANCE);
		comparePoints(m.getScaling(), new Point(Base.pick(ex, sx),
				Base.pick(ey, sy)),
				s + '.getScaling()');
	}

	testAngleAndScale(2, 4, 45);
	testAngleAndScale(2, -4, 45, -2, 4, -135);
	testAngleAndScale(-2, 4, 45);
	testAngleAndScale(-2, -4, 45, 2, 4, -135);
});