LiangBarskyTest.java

packagecom.thealgorithms.lineclipping;

importstaticorg.junit.jupiter.api.Assertions.assertEquals;
importstaticorg.junit.jupiter.api.Assertions.assertNotNull;
importstaticorg.junit.jupiter.api.Assertions.assertNull;

importcom.thealgorithms.lineclipping.utils.Line;
importcom.thealgorithms.lineclipping.utils.Point;
importorg.junit.jupiter.api.Test;

/**
 * @author shikarisohan
 * @since 10/5/24
 */
classLiangBarskyTest {

LiangBarskylb = newLiangBarsky(1.0, 1.0, 10.0, 10.0);

@Test
voidtestLineCompletelyInside() {
Lineline = newLine(newPoint(2.0, 2.0), newPoint(8.0, 8.0));
LineclippedLine = lb.liangBarskyClip(line);

assertNotNull(clippedLine, "Line should not be null.");
assertEquals(line, clippedLine, "Line inside the window should remain unchanged.");
 }

@Test
voidtestLineCompletelyOutside() {
Lineline = newLine(newPoint(12.0, 12.0), newPoint(15.0, 18.0));
LineclippedLine = lb.liangBarskyClip(line);

assertNull(clippedLine, "Line should be null because it's completely outside.");
 }

@Test
voidtestLinePartiallyInside() {
Lineline = newLine(newPoint(5.0, 5.0), newPoint(12.0, 12.0));
LineexpectedClippedLine = newLine(newPoint(5.0, 5.0), newPoint(10.0, 10.0)); // Clipped at (10, 10)
LineclippedLine = lb.liangBarskyClip(line);

assertNotNull(clippedLine, "Line should not be null.");
assertEquals(expectedClippedLine, clippedLine, "Line should be clipped correctly.");
 }

@Test
voidtestDiagonalLineThroughClippingWindow() {
Lineline = newLine(newPoint(0.0, 0.0), newPoint(12.0, 12.0));
LineexpectedClippedLine = newLine(newPoint(1.0, 1.0), newPoint(10.0, 10.0)); // Clipped at both boundaries
LineclippedLine = lb.liangBarskyClip(line);

assertNotNull(clippedLine, "Line should not be null.");
assertEquals(expectedClippedLine, clippedLine, "Diagonal line should be clipped correctly.");
 }

@Test
voidtestVerticalLineClipping() {
Lineline = newLine(newPoint(5.0, 0.0), newPoint(5.0, 12.0));
LineexpectedClippedLine = newLine(newPoint(5.0, 1.0), newPoint(5.0, 10.0)); // Clipped at yMin and yMax
LineclippedLine = lb.liangBarskyClip(line);

assertNotNull(clippedLine, "Line should not be null.");
assertEquals(expectedClippedLine, clippedLine, "Vertical line should be clipped correctly.");
 }
}