Improve movement of units by simply choosing the 'best' option in the

surrounding cells.

This is no path finding, but it greatly improves moving of units

src/main/java/com/fundynamic/d2tm/game/controls/battlefield/MovableSelectedMouse.java

@@ -13,6 +13,7 @@
 import com.fundynamic.d2tm.game.map.Cell;
 import com.fundynamic.d2tm.game.rendering.gui.battlefield.BattleField;
 import com.fundynamic.d2tm.math.Coordinate;
+import com.fundynamic.d2tm.math.MapCoordinate;
 
 /**
  *
@@ -63,7 +64,8 @@ public void leftClicked() {
                 attackDestructibleIfApplicable(hoveringOverEntity);
             }
         } else {
-            Coordinate target = cell.getMapCoordinate().toCoordinate();
+            MapCoordinate mapCoordinate = cell.getMapCoordinate();
+            Coordinate target = mapCoordinate.toCoordinate();
 
             EntitiesSet harvestersSelected = entitiesSetOfAllMovable.filter(Predicate.isHarvester());
             if (harvestersSelected.hasAny() && entitiesSetOfAllMovable.sameSizeAs(harvestersSelected)) {

src/main/java/com/fundynamic/d2tm/game/entities/units/Unit.java

@@ -12,10 +12,13 @@
 import com.fundynamic.d2tm.game.rendering.gui.battlefield.RenderQueue;
 import com.fundynamic.d2tm.game.types.EntityData;
 import com.fundynamic.d2tm.math.Coordinate;
+import com.fundynamic.d2tm.math.MapCoordinate;
 import com.fundynamic.d2tm.math.Random;
 import com.fundynamic.d2tm.math.Vector2D;
 import org.newdawn.slick.Graphics;
 
+import java.util.List;
+
 import static com.fundynamic.d2tm.game.map.Cell.TILE_SIZE;
 
 /**
@@ -236,22 +239,47 @@ public void chaseOrAttack(float deltaInSeconds) {
     public boolean canMoveToCell(Coordinate intendedMapCoordinatesToMoveTo) {
         EntitiesSet entities = entityRepository.findAliveEntitiesOfTypeAtVector(intendedMapCoordinatesToMoveTo.addHalfTile(), EntityType.UNIT, EntityType.STRUCTURE);
         entities = entities.exclude(this); // do not count ourselves as blocking
-        Cell cell = map.getCellByAbsoluteMapCoordinates(new Coordinate(intendedMapCoordinatesToMoveTo));
+        Cell cell = map.getCellByAbsoluteMapCoordinates(intendedMapCoordinatesToMoveTo);
 
         return entities.isEmpty() &&
                 cell.isPassable(this) &&
                 UnitMoveIntents.instance.isVectorClaimableBy(intendedMapCoordinatesToMoveTo, this);
     }
 
     public Coordinate getNextIntendedCellToMoveToTarget() {
+        List<MapCoordinate> allSurroundingCellsAsCoordinates = getAllSurroundingCellsAsCoordinates();
+        Coordinate bestCoordinate = null;
+        float closest = map.getHeight() * map.getHeight();
+
+        for (MapCoordinate mapCoordinate : allSurroundingCellsAsCoordinates) {
+            Coordinate coordinate = mapCoordinate.toCoordinate();
+            boolean canMoveToCell = canMoveToCell(coordinate);
+            if (!canMoveToCell) continue;
+
+            float distance = coordinate.addHalfTile().distance(target);
+            if (distance <= closest) {
+                closest = distance;
+                bestCoordinate = mapCoordinate.toCoordinate();
+            }
+        }
+
+        if (bestCoordinate != null) {
+            return bestCoordinate;
+        }
+
+        // fall back to old behavior if we can't find a good destination, which basically means it will try to go to the
+        // direct path which is probably blocked (else it was found in the previous statements above)
         int nextXCoordinate = coordinate.getXAsInt();
         int nextYCoordinate = coordinate.getYAsInt();
+
+        // the most direct way to target
+        Coordinate bestNextIntendedCoordinateToMoveTo = Coordinate.create(nextXCoordinate, nextYCoordinate);
+
         if (target.getXAsInt() < coordinate.getXAsInt()) nextXCoordinate -= TILE_SIZE;
         if (target.getXAsInt() > coordinate.getXAsInt()) nextXCoordinate += TILE_SIZE;
         if (target.getYAsInt() < coordinate.getYAsInt()) nextYCoordinate -= TILE_SIZE;
         if (target.getYAsInt() > coordinate.getYAsInt()) nextYCoordinate += TILE_SIZE;
-
-        return Coordinate.create(nextXCoordinate, nextYCoordinate);
+        return bestNextIntendedCoordinateToMoveTo;
     }
 
     public boolean hasNoNextCellToMoveTo() {

src/main/java/com/fundynamic/d2tm/game/rendering/gui/battlefield/BattleField.java

@@ -5,7 +5,6 @@
 import com.fundynamic.d2tm.game.controls.battlefield.CellBasedMouseBehavior;
 import com.fundynamic.d2tm.game.controls.battlefield.NormalMouse;
 import com.fundynamic.d2tm.game.entities.*;
-import com.fundynamic.d2tm.game.entities.predicates.PredicateBuilder;
 import com.fundynamic.d2tm.game.map.Cell;
 import com.fundynamic.d2tm.game.map.Map;
 import com.fundynamic.d2tm.game.map.Perimeter;

src/test/java/com/fundynamic/d2tm/game/controls/battlefield/MovableSelectedMouseTest.java

@@ -1,7 +1,6 @@
 package com.fundynamic.d2tm.game.controls.battlefield;
 
 import com.fundynamic.d2tm.game.AbstractD2TMTest;
-import com.fundynamic.d2tm.game.controls.battlefield.MovableSelectedMouse;
 import com.fundynamic.d2tm.game.entities.Player;
 import com.fundynamic.d2tm.game.entities.entitiesdata.EntitiesData;
 import com.fundynamic.d2tm.game.entities.units.Unit;

src/test/java/com/fundynamic/d2tm/game/entities/EntityTest.java

@@ -1,6 +1,7 @@
 package com.fundynamic.d2tm.game.entities;
 
 import com.fundynamic.d2tm.game.AbstractD2TMTest;
+import com.fundynamic.d2tm.game.map.Cell;
 import com.fundynamic.d2tm.game.types.EntityData;
 import com.fundynamic.d2tm.math.Coordinate;
 import com.fundynamic.d2tm.math.MapCoordinate;
@@ -37,6 +38,7 @@ public void setUp() throws SlickException {
 
         entity1 = new TestableEntity(topLeftCoordinate, mock(SpriteSheet.class), entityData, player, entityRepository).
                 setName("Entity1");
+
         entity2 = new TestableEntity(topLeftCoordinate, mock(SpriteSheet.class), entityData, player, entityRepository).
                 setName("Entity2");
     }
@@ -76,6 +78,32 @@ public void getAllSurroundingCoordinatesOfAnEntity() {
         Assert.assertEquals(3, upLeftOfTopLeft.getYAsInt());
     }
 
+    @Test
+    public void getAllSurroundingCoordinatesOfAnEntityThatIsOneCellBig() {
+        EntityData entityData = new EntityData();
+        entityData.setWidth(Cell.TILE_SIZE);
+        entityData.setHeight(Cell.TILE_SIZE);
+
+        TestableEntity smallEntity = new TestableEntity(topLeftCoordinate, mock(SpriteSheet.class), entityData, player, entityRepository).
+                setName("SmallEntity");
+
+        List<MapCoordinate> allSurroundingCellsAsCoordinates = smallEntity.getAllSurroundingCellsAsCoordinates();
+
+        Assert.assertEquals(8, allSurroundingCellsAsCoordinates.size());
+
+        // we expect the first tile to be at 1 tile above and 1 tile left to the entity1:
+        MapCoordinate upLeftOfTopLeft = allSurroundingCellsAsCoordinates.get(0);
+
+        MapCoordinate topLeftMapCoordinate = this.topLeftCoordinate.toMapCoordinate();
+        Assert.assertEquals(topLeftMapCoordinate.getXAsInt() - 1, upLeftOfTopLeft.getXAsInt());
+        Assert.assertEquals(topLeftMapCoordinate.getYAsInt() - 1, upLeftOfTopLeft.getYAsInt());
+
+        MapCoordinate downRight = allSurroundingCellsAsCoordinates.get(7); // last one
+
+        Assert.assertEquals(topLeftMapCoordinate.getXAsInt() + 1, downRight.getXAsInt());
+        Assert.assertEquals(topLeftMapCoordinate.getYAsInt() + 1, downRight.getYAsInt());
+    }
+
     //////////////////////////////////////////////////
     // Event handling, subscribers, etc
     /////////////////////////////////////////////////

src/test/java/com/fundynamic/d2tm/game/entities/units/UnitTest.java

@@ -130,9 +130,9 @@ public void whenUnitDiesItSpawnsAnExplosion() {
 
     @Test
     public void verifyUnitMovesToDesiredCellItWantsToMoveToDownRightCell() {
-        Unit unit = makeUnit(UnitFacings.DOWN, unitAbsoluteMapCoordinates);
+        Unit unit = makeUnit(UnitFacings.DOWN, unitAbsoluteMapCoordinates); // 320, 320
 
-        Vector2D mapCoordinateToMoveTo = unitAbsoluteMapCoordinates.add(Vector2D.create(32, 32)); // move to right-down
+        Vector2D mapCoordinateToMoveTo = unitAbsoluteMapCoordinates.add(Vector2D.create(32, 32)); // move to right-down (352, 352)
         unit.moveTo(mapCoordinateToMoveTo); // translate to absolute coordinates
 
         assertThat(unit.getCoordinate(), is(unitAbsoluteMapCoordinates));