New rectangle methods for retrieving edges

util/geometry/src/main/java/jetbrains/jetpad/geometry/DoubleRectangle.java

@@ -17,9 +17,10 @@
 
 import com.google.common.collect.Range;
 
-import java.util.ArrayList;
 import java.util.List;
 
+import static java.util.Arrays.asList;
+
 public class DoubleRectangle {
   public static DoubleRectangle span(DoubleVector leftTop, DoubleVector rightBottom) {
     return new DoubleRectangle(leftTop, rightBottom.subtract(leftTop));
@@ -136,13 +137,36 @@ public double distance(DoubleVector to) {
     return result;
   }
 
-  public Iterable<DoubleSegment> getParts() {
-    List<DoubleSegment> result = new ArrayList<>();
-    result.add(new DoubleSegment(origin, origin.add(new DoubleVector(dimension.x, 0))));
-    result.add(new DoubleSegment(origin, origin.add(new DoubleVector(0, dimension.y))));
-    result.add(new DoubleSegment(origin.add(dimension), origin.add(new DoubleVector(dimension.x, 0))));
-    result.add(new DoubleSegment(origin.add(dimension), origin.add(new DoubleVector(0, dimension.y))));
-    return result;
+  public DoubleSegment getLeftEdge() {
+    return new DoubleSegment(
+        origin,
+        new DoubleVector(getLeft(), getBottom())
+    );
+  }
+
+  public DoubleSegment getTopEdge() {
+    return new DoubleSegment(
+        origin,
+        new DoubleVector(getRight(), getTop())
+    );
+  }
+
+  public DoubleSegment getRightEdge() {
+    return new DoubleSegment(
+        origin.add(dimension),
+        new DoubleVector(getRight(), getTop())
+    );
+  }
+
+  public DoubleSegment getBottomEdge() {
+    return new DoubleSegment(
+        origin.add(dimension),
+        new DoubleVector(getLeft(), getBottom())
+    );
+  }
+
+  public List<DoubleSegment> getParts() {
+    return asList(getTopEdge(), getLeftEdge(), getRightEdge(), getBottomEdge());
   }
 
   @Override

util/geometry/src/test/java/jetbrains/jetpad/geometry/AllTests.java

@@ -21,7 +21,9 @@
 @RunWith(Suite.class)
 @Suite.SuiteClasses({
     DistanceTest.class,
+    DoubleRectangleEdgesTest.class,
     DoubleRectangleIntersectionTest.class,
+    DoubleRectangleTest.class,
     DoubleSegmentIntersectionTest.class,
     DoubleVectorOperationsTest.class,
     RectanglesTest.class,

util/geometry/src/test/java/jetbrains/jetpad/geometry/DoubleRectangleEdgesTest.java

@@ -0,0 +1,60 @@
+package jetbrains.jetpad.geometry;
+
+import org.junit.Test;
+
+import static java.util.Arrays.asList;
+import static org.junit.Assert.assertEquals;
+
+public class DoubleRectangleEdgesTest {
+
+  private static final double LEFT = 5.;
+  private static final double RIGHT = 15.;
+
+  private static final double TOP = 40.;
+  private static final double BOTTOM = 60.;
+
+  private static final DoubleVector LEFT_TOP = new DoubleVector(LEFT, TOP);
+  private static final DoubleVector LEFT_BOTTOM = new DoubleVector(LEFT, BOTTOM);
+  private static final DoubleVector RIGHT_TOP = new DoubleVector(RIGHT, TOP);
+  private static final DoubleVector RIGHT_BOTTOM = new DoubleVector(RIGHT, BOTTOM);
+
+  private static final DoubleSegment LEFT_EDGE = edge(LEFT_TOP, LEFT_BOTTOM);
+  private static final DoubleSegment BOTTOM_EDGE = edge(RIGHT_BOTTOM, LEFT_BOTTOM);
+  private static final DoubleSegment RIGHT_EDGE = edge(RIGHT_BOTTOM, RIGHT_TOP);
+  private static final DoubleSegment TOP_EDGE = edge(LEFT_TOP, RIGHT_TOP);
+
+  private static final DoubleRectangle RECTANGLE = new DoubleRectangle(LEFT_TOP, RIGHT_BOTTOM.subtract(LEFT_TOP));
+
+  @Test
+  public void getLeftEdge() {
+    assertEquals(LEFT_EDGE, RECTANGLE.getLeftEdge());
+  }
+
+  @Test
+  public void getTopEdge() {
+    assertEquals(TOP_EDGE, RECTANGLE.getTopEdge());
+  }
+
+  @Test
+  public void getRightEdge() {
+    assertEquals(RIGHT_EDGE, RECTANGLE.getRightEdge());
+  }
+
+  @Test
+  public void getBottomEdge() {
+    assertEquals(BOTTOM_EDGE, RECTANGLE.getBottomEdge());
+  }
+
+  @Test
+  public void getParts() {
+    assertEquals(
+        asList(TOP_EDGE, LEFT_EDGE, RIGHT_EDGE, BOTTOM_EDGE),
+        RECTANGLE.getParts()
+    );
+  }
+
+  private static DoubleSegment edge(DoubleVector start, DoubleVector end) {
+    return new DoubleSegment(start, end);
+  }
+
+}