IntersectingTrianglesImplementationTest

// original facebook post:
// https://www.facebook.com/groups/javaharikrishna/permalink/1596271237165097/

// Implementation class:
// https://pastebin.com/xjyyaBm0

// Related "Six Sided Star" classes:
// Implementation:
// https://pastebin.com/7g2keFVE
// Tests:
// https://pastebin.com/zmdNaJ7k

import junit.framework.TestCase;

import java.util.BitSet;

public class IntersectingTrianglesImplementationTest extends TestCase {

    public void testSingleTriangleLines1() {
        assertSingleTriangleLinesEquals(new String[]{
                "*",
        }, 1);
    }

    public void testSingleTriangleLines2() {
        assertSingleTriangleLinesEquals(new String[]{
                " *",
                "* *",
        }, 2);
    }

    public void testSingleTriangleLines3() {
        assertSingleTriangleLinesEquals(new String[]{
                "  *",
                " * *",
                "* * *",
        }, 3);
    }

    public void testSingleTriangleLines4() {
        assertSingleTriangleLinesEquals(new String[]{
                "   *",
                "  * *",
                " *   *",
                "* * * *",
        }, 4);
    }

    public void testSingleTriangleLines5() {
        assertSingleTriangleLinesEquals(new String[]{
                "    *",
                "   * *",
                "  *   *",
                " *     *",
                "* * * * *",
        }, 5);
    }

    private static void assertSingleTriangleLinesEquals(final String[] expectedStarPattern, final int triangleLines) {
        assertEquals("Error in test data: Number of lines should match;", expectedStarPattern.length, triangleLines);
        for (int lineIndex = 0; lineIndex < triangleLines; ++lineIndex) {
            final BitSet starsOnThisLine = new BitSet();
            IntersectingTriangles.setTriangleBits(starsOnThisLine, triangleLines, lineIndex);
            assertEquals("Line index <" + lineIndex + "> of <" + triangleLines + "> line triangle;",
                    expectedStarPattern[lineIndex], IntersectingTriangles.bitsToStars(starsOnThisLine));
        }
    }

}