Adding an interpolation systemHEADmain

12 files changed, 447 insertions, 108 deletions

diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/actor/GridBoardActor.java b/core/src/main/java/coffee/liz/abstractionengine/app/actor/GridBoardActor.java
new file mode 100644
index 0000000..3c7a82a
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/actor/GridBoardActor.java
@@ -0,0 +1,68 @@
+package coffee.liz.abstractionengine.app.actor;
+
+import coffee.liz.abstractionengine.app.Theme;
+import coffee.liz.abstractionengine.entity.EntityType;
+import coffee.liz.ecs.math.Mat2;
+import coffee.liz.ecs.math.Vec2;
+import coffee.liz.ecs.math.Vec2f;
+import com.badlogic.gdx.graphics.Color;
+import com.badlogic.gdx.graphics.g2d.Batch;
+import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
+import com.badlogic.gdx.scenes.scene2d.Actor;
+import lombok.RequiredArgsConstructor;
+import lombok.Setter;
+
+import java.util.List;
+
+@RequiredArgsConstructor
+public class GridBoardActor extends Actor {
+	private final ShapeRenderer shapeRenderer;
+	private final Vec2<Integer> gridSize;
+
+	@Setter
+	private Vec2<Float> cellSize;
+
+	@Setter
+	private List<RenderableEntity> entities = List.of();
+
+	@Override
+	public void draw(final Batch batch, final float parentAlpha) {
+		batch.end();
+
+		shapeRenderer.setProjectionMatrix(batch.getProjectionMatrix());
+		shapeRenderer.setTransformMatrix(batch.getTransformMatrix());
+		shapeRenderer.begin(ShapeRenderer.ShapeType.Filled);
+
+		if (cellSize != null) {
+			final float dotRadius = Math.min(cellSize.getX(), cellSize.getY()) * 0.07f;
+			shapeRenderer.setColor(Theme.BG_PATTERN);
+			Mat2.init(gridSize, pos -> {
+				final Vec2<Float> center = pos.floatValue().plus(Vec2f.builder().x(0.5f).y(0.5f).build())
+						.scale(cellSize);
+				shapeRenderer.circle(center.getX(), center.getY(), dotRadius);
+				return center;
+			});
+		}
+
+		for (final RenderableEntity entity : entities) {
+			shapeRenderer.setColor(getEntityColor(entity.entityType()));
+			shapeRenderer.rect(entity.position().getX(), entity.position().getY(), entity.size().getX(),
+					entity.size().getY());
+		}
+
+		shapeRenderer.end();
+		batch.begin();
+	}
+
+	private static Color getEntityColor(final EntityType type) {
+		return switch (type) {
+			case WALL -> Theme.MUTED;
+			case PLAYER -> Theme.PRIMARY;
+			case ABSTRACTION -> Theme.SECONDARY;
+			default -> Color.GREEN;
+		};
+	}
+
+	public record RenderableEntity(EntityType entityType, Vec2<Float> position, Vec2<Float> size) {
+	}
+}
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/config/Settings.java b/core/src/main/java/coffee/liz/abstractionengine/app/config/Settings.java
index 3d8be7a..01d84a3 100644
--- a/core/src/main/java/coffee/liz/abstractionengine/app/config/Settings.java
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/config/Settings.java
@@ -9,7 +9,7 @@ import lombok.Getter;
 @Getter
 public class Settings {
 	@Builder.Default
-	private boolean skipIntro = true;
+	private boolean skipIntro = false;
 	@Builder.Default
 	private boolean playMusic = true;
 
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/GameScreen.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/GameScreen.java
index f9402d1..3ddef91 100644
--- a/core/src/main/java/coffee/liz/abstractionengine/app/screen/GameScreen.java
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/GameScreen.java
@@ -1,150 +1,64 @@
 package coffee.liz.abstractionengine.app.screen;
 
-import coffee.liz.abstractionengine.AbstractionEngineGridWorld;
 import coffee.liz.abstractionengine.app.AbstractionEngineGame;
-import coffee.liz.abstractionengine.app.Theme;
-import coffee.liz.abstractionengine.entity.EntityFactory;
-import coffee.liz.abstractionengine.entity.EntityType;
-import coffee.liz.abstractionengine.grid.component.GridInputState;
-import coffee.liz.abstractionengine.grid.component.GridPosition;
+import coffee.liz.abstractionengine.app.screen.game.FrameState;
+import coffee.liz.abstractionengine.app.screen.game.GameScreenWorld;
+import coffee.liz.abstractionengine.app.screen.game.system.GameWorldManagementSystem;
+import coffee.liz.abstractionengine.app.utils.FunctionUtils;
 import coffee.liz.ecs.math.Vec2;
-import coffee.liz.ecs.math.Vec2f;
 import coffee.liz.ecs.math.Vec2i;
 import com.badlogic.gdx.Gdx;
 import com.badlogic.gdx.Screen;
-import com.badlogic.gdx.graphics.Color;
-import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
-import com.badlogic.gdx.utils.ScreenUtils;
+import com.badlogic.gdx.utils.viewport.FitViewport;
 import lombok.RequiredArgsConstructor;
 
 import java.time.Duration;
-import java.util.Set;
 
 @RequiredArgsConstructor
 public class GameScreen implements Screen {
 	private final AbstractionEngineGame game;
-	private static final Vec2<Integer> GAME_GRID_SIZE = Vec2i.builder().x(30).y(30).build();
-	private final static Duration GRID_INTERPOLATION_TIME = Duration.ofMillis(60);
+	private static final Vec2<Integer> GAME_GRID_SIZE = Vec2i.builder().x(20).y(20).build();
 
-	private final AbstractionEngineGridWorld gameWorld = new AbstractionEngineGridWorld(GAME_GRID_SIZE);
-	private Duration sinceUpdate = Duration.ZERO;
+	private GameScreenWorld outerWorld;
+	private FitViewport viewport;
 
-	/**
-	 * Screen lifecycle hook.
-	 */
 	@Override
 	public void show() {
-		EntityFactory.populateRect(GAME_GRID_SIZE, gameWorld, EntityFactory.Wall::addToWorld);
-		EntityFactory.Player.addToWorld(gameWorld, Vec2i.builder().y(20).x(10).build());
-		EntityFactory.Abstraction.addToWorld(gameWorld, Vec2i.builder().y(20).x(12).build());
-		EntityFactory.Abstraction.addToWorld(gameWorld, Vec2i.builder().y(20).x(13).build());
+		viewport = new FitViewport(AbstractionEngineGame.WORLD_SIZE.getX(), AbstractionEngineGame.WORLD_SIZE.getY());
+		outerWorld = new GameScreenWorld(GAME_GRID_SIZE, viewport);
+		outerWorld.getSystem(GameWorldManagementSystem.class).populateLevel();
+		viewport.update(Gdx.graphics.getWidth(), Gdx.graphics.getHeight(), true);
+		render(0);
 	}
 
-	/**
-	 * Screen render hook.
-	 *
-	 * @param delta
-	 *            time since last frame
-	 */
 	@Override
 	public void render(final float delta) {
-		game.viewport.apply();
-		sinceUpdate = sinceUpdate.plus(Duration.ofMillis((int) (delta * 1000)));
-		if (GRID_INTERPOLATION_TIME.compareTo(sinceUpdate) > 0) {
-			return;
-		} else {
-			sinceUpdate = Duration.ZERO;
-		}
-
-		ScreenUtils.clear(Theme.BG);
-
-		final GridInputState state = GridInputState.builder().movement(getMovementVector()).build();
-		gameWorld.update(state);
-
-		final Vec2<Float> cellSize = computeCellSize();
-		game.shapeRenderer.setProjectionMatrix(game.batch.getProjectionMatrix());
-		game.shapeRenderer.setTransformMatrix(game.batch.getTransformMatrix());
-		game.shapeRenderer.begin(ShapeRenderer.ShapeType.Filled);
-		gameWorld.query(Set.of(GridPosition.class, EntityType.class)).forEach(entity -> {
-			final EntityType type = entity.get(EntityType.class);
-			final GridPosition position = entity.get(GridPosition.class);
-
-			final Vec2<Float> drawPos = position.getPosition().floatValue().scale(cellSize);
-			game.shapeRenderer.setColor(getEntityColor(type));
-			game.shapeRenderer.rect(drawPos.getX(), drawPos.getY(), cellSize.getX(), cellSize.getY());
-		});
-		game.shapeRenderer.end();
-	}
-
-	private Vec2<Integer> getMovementVector() {
-		return game.settings.getKeyBinds().filterActiveActions(Gdx.input::isKeyPressed).stream().reduce(Vec2i.ZERO,
-				(movement, action) -> {
-					final Vec2<Integer> velocity = switch (action) {
-						case MOVE_UP -> Vec2i.NORTH;
-						case MOVE_DOWN -> Vec2i.SOUTH;
-						case MOVE_LEFT -> Vec2i.WEST;
-						case MOVE_RIGHT -> Vec2i.EAST;
-					};
-					return movement.plus(velocity);
-				}, Vec2::plus);
-	}
-
-	private Color getEntityColor(final EntityType type) {
-		return switch (type) {
-			case WALL -> Theme.BORDER;
-			case PLAYER -> Theme.PRIMARY;
-			case ABSTRACTION -> Theme.SECONDARY;
-			default -> Color.GREEN;
-		};
+		viewport.apply();
+		final FrameState state = FrameState.builder().settings(game.settings).isKeyPressed(Gdx.input::isKeyPressed)
+				.build();
+		outerWorld.update(state, Duration.ofMillis((long) (delta * 1000)));
 	}
 
-	/**
-	 * Screen resize hook.
-	 *
-	 * @param width
-	 *            new width in pixels
-	 * @param height
-	 *            new height in pixels
-	 */
 	@Override
 	public void resize(final int width, final int height) {
-		game.viewport.update(width, height);
+		viewport.update(width, height, true);
 	}
 
-	/**
-	 * Screen lifecycle hook.
-	 */
 	@Override
 	public void pause() {
-
 	}
 
-	/**
-	 * Screen lifecycle hook.
-	 */
 	@Override
 	public void resume() {
-
 	}
 
-	/**
-	 * Screen lifecycle hook.
-	 */
 	@Override
 	public void hide() {
-
+		dispose();
 	}
 
-	/**
-	 * Screen cleanup hook.
-	 */
 	@Override
 	public void dispose() {
-
-	}
-
-	private Vec2<Float> computeCellSize() {
-		return Vec2f.builder().x(game.viewport.getWorldWidth() / GAME_GRID_SIZE.getX())
-				.y(game.viewport.getWorldHeight() / GAME_GRID_SIZE.getY()).build();
+		FunctionUtils.wrapCheckedException(outerWorld::close);
 	}
 }
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/FrameState.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/FrameState.java
new file mode 100644
index 0000000..3f31530
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/FrameState.java
@@ -0,0 +1,16 @@
+package coffee.liz.abstractionengine.app.screen.game;
+
+import coffee.liz.abstractionengine.app.config.Settings;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import java.util.function.Predicate;
+
+@Builder
+@Getter
+@RequiredArgsConstructor
+public final class FrameState {
+	private final Settings settings;
+	private final Predicate<Integer> isKeyPressed;
+}
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/GameScreenWorld.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/GameScreenWorld.java
new file mode 100644
index 0000000..f6385f6
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/GameScreenWorld.java
@@ -0,0 +1,19 @@
+package coffee.liz.abstractionengine.app.screen.game;
+
+import coffee.liz.abstractionengine.app.screen.game.system.GameWorldManagementSystem;
+import coffee.liz.abstractionengine.app.screen.game.system.GridInterpolationSystem;
+import coffee.liz.abstractionengine.app.screen.game.system.InputSystem;
+import coffee.liz.abstractionengine.app.screen.game.system.RenderSystem;
+import coffee.liz.ecs.DAGWorld;
+import coffee.liz.ecs.math.Vec2;
+import com.badlogic.gdx.utils.viewport.FitViewport;
+
+import java.util.Map;
+
+public class GameScreenWorld extends DAGWorld<FrameState> {
+	public GameScreenWorld(final Vec2<Integer> gridSize, final FitViewport viewport) {
+		super(Map.of(InputSystem.class, new InputSystem(), GameWorldManagementSystem.class,
+				new GameWorldManagementSystem(gridSize), GridInterpolationSystem.class, new GridInterpolationSystem(),
+				RenderSystem.class, new RenderSystem(viewport, gridSize)));
+	}
+}
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/component/GridEntityRef.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/component/GridEntityRef.java
new file mode 100644
index 0000000..788d530
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/component/GridEntityRef.java
@@ -0,0 +1,11 @@
+package coffee.liz.abstractionengine.app.screen.game.component;
+
+import coffee.liz.ecs.model.Component;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
+public final class GridEntityRef implements Component {
+	private final int gridEntityId;
+}
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/component/InterpolatedPosition.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/component/InterpolatedPosition.java
new file mode 100644
index 0000000..6700575
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/component/InterpolatedPosition.java
@@ -0,0 +1,18 @@
+package coffee.liz.abstractionengine.app.screen.game.component;
+
+import coffee.liz.ecs.math.Vec2;
+import coffee.liz.ecs.model.Component;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
+public final class InterpolatedPosition implements Component {
+	private final Vec2<Float> from;
+	private final Vec2<Float> to;
+	private final Vec2<Float> current;
+
+	public static InterpolatedPosition atRest(final Vec2<Float> position) {
+		return new InterpolatedPosition(position, position, position);
+	}
+}
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/GameWorldManagementSystem.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/GameWorldManagementSystem.java
new file mode 100644
index 0000000..74355d1
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/GameWorldManagementSystem.java
@@ -0,0 +1,100 @@
+package coffee.liz.abstractionengine.app.screen.game.system;
+
+import coffee.liz.abstractionengine.AbstractionEngineGridWorld;
+import coffee.liz.abstractionengine.app.screen.game.FrameState;
+import coffee.liz.abstractionengine.app.screen.game.component.GridEntityRef;
+import coffee.liz.abstractionengine.app.screen.game.component.InterpolatedPosition;
+import coffee.liz.abstractionengine.app.utils.FunctionUtils;
+import coffee.liz.abstractionengine.entity.EntityFactory;
+import coffee.liz.abstractionengine.entity.EntityType;
+import coffee.liz.abstractionengine.grid.component.GridInputState;
+import coffee.liz.abstractionengine.grid.component.GridPosition;
+import coffee.liz.ecs.math.Vec2;
+import coffee.liz.ecs.math.Vec2i;
+import coffee.liz.ecs.model.Entity;
+import coffee.liz.ecs.model.System;
+import coffee.liz.ecs.model.World;
+import lombok.Getter;
+
+import java.time.Duration;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class GameWorldManagementSystem implements System<FrameState> {
+	private final AbstractionEngineGridWorld gridWorld;
+	private final Vec2<Integer> gridSize;
+	private final Map<Integer, Entity> gridToOuterMap = new HashMap<>();
+
+	@Getter
+	private boolean stepped = false;
+
+	public GameWorldManagementSystem(final Vec2<Integer> gridSize) {
+		this.gridSize = gridSize;
+		this.gridWorld = new AbstractionEngineGridWorld(gridSize);
+	}
+
+	public void populateLevel() {
+		EntityFactory.populateRect(gridSize, gridWorld, EntityFactory.Wall::addToWorld);
+		EntityFactory.Player.addToWorld(gridWorld, Vec2i.builder().y(10).x(10).build());
+		EntityFactory.Abstraction.addToWorld(gridWorld, Vec2i.builder().y(10).x(12).build());
+		EntityFactory.Abstraction.addToWorld(gridWorld, Vec2i.builder().y(10).x(13).build());
+		gridWorld.update(GridInputState.builder().movement(Vec2i.ZERO).build());
+	}
+
+	@Override
+	public Collection<Class<? extends System<FrameState>>> getDependencies() {
+		return Set.of(InputSystem.class);
+	}
+
+	@Override
+	public void update(final World<FrameState> world, final FrameState state, final Duration dt) {
+		final InputSystem inputSystem = world.getSystem(InputSystem.class);
+		final Vec2<Integer> movement = inputSystem.getStepMovement();
+
+		stepped = !movement.equals(Vec2i.ZERO);
+		if (stepped) {
+			final GridInputState gridInput = GridInputState.builder().movement(movement).build();
+			gridWorld.update(gridInput);
+		}
+
+		syncEntities(world);
+	}
+
+	private void syncEntities(final World<FrameState> outerWorld) {
+		final Set<Entity> gridEntities = gridWorld.query(Set.of(GridPosition.class, EntityType.class));
+		final Set<Integer> seenGridIds = new HashSet<>();
+
+		for (final Entity gridEntity : gridEntities) {
+			seenGridIds.add(gridEntity.getId());
+
+			if (!gridToOuterMap.containsKey(gridEntity.getId())) {
+				final Entity outer = outerWorld.createEntity();
+				final Vec2<Float> pos = gridEntity.get(GridPosition.class).getPosition().floatValue();
+				outer.add(new GridEntityRef(gridEntity.getId()));
+				outer.add(gridEntity.get(EntityType.class));
+				outer.add(InterpolatedPosition.atRest(pos));
+				gridToOuterMap.put(gridEntity.getId(), outer);
+			} else if (stepped) {
+				final Entity outer = gridToOuterMap.get(gridEntity.getId());
+				final InterpolatedPosition current = outer.get(InterpolatedPosition.class);
+				final Vec2<Float> newTarget = gridEntity.get(GridPosition.class).getPosition().floatValue();
+				outer.add(new InterpolatedPosition(current.getCurrent(), newTarget, current.getCurrent()));
+			}
+		}
+
+		final Set<Integer> removedIds = new HashSet<>(gridToOuterMap.keySet());
+		removedIds.removeAll(seenGridIds);
+		for (final int removedId : removedIds) {
+			final Entity outer = gridToOuterMap.remove(removedId);
+			outerWorld.removeEntity(outer);
+		}
+	}
+
+	@Override
+	public void close() {
+		FunctionUtils.wrapCheckedException(gridWorld::close);
+	}
+}
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/GridInterpolationSystem.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/GridInterpolationSystem.java
new file mode 100644
index 0000000..2e4826d
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/GridInterpolationSystem.java
@@ -0,0 +1,46 @@
+package coffee.liz.abstractionengine.app.screen.game.system;
+
+import coffee.liz.abstractionengine.app.screen.game.FrameState;
+import coffee.liz.abstractionengine.app.screen.game.component.InterpolatedPosition;
+import coffee.liz.ecs.math.Vec2;
+import coffee.liz.ecs.math.Vec2f;
+import coffee.liz.ecs.model.System;
+import coffee.liz.ecs.model.World;
+
+import java.time.Duration;
+import java.util.Collection;
+import java.util.Set;
+
+public class GridInterpolationSystem implements System<FrameState> {
+	private static final Duration INTERPOLATION_TIME = Duration.ofMillis(50);
+
+	private Duration elapsed = Duration.ZERO;
+
+	@Override
+	public Collection<Class<? extends System<FrameState>>> getDependencies() {
+		return Set.of(GameWorldManagementSystem.class);
+	}
+
+	@Override
+	public void update(final World<FrameState> world, final FrameState state, final Duration dt) {
+		final GameWorldManagementSystem gameWorldSystem = world.getSystem(GameWorldManagementSystem.class);
+
+		if (gameWorldSystem.isStepped()) {
+			elapsed = Duration.ZERO;
+		}
+
+		elapsed = elapsed.plus(dt);
+		final float t = Math.min(1.0f, (float) elapsed.toMillis() / INTERPOLATION_TIME.toMillis());
+
+		world.query(Set.of(InterpolatedPosition.class)).forEach(entity -> {
+			final InterpolatedPosition pos = entity.get(InterpolatedPosition.class);
+			final Vec2<Float> interpolated = lerp(pos.getFrom(), pos.getTo(), t);
+			entity.add(new InterpolatedPosition(pos.getFrom(), pos.getTo(), interpolated));
+		});
+	}
+
+	private static Vec2<Float> lerp(final Vec2<Float> from, final Vec2<Float> to, final float t) {
+		return Vec2f.builder().x(from.getX() + (to.getX() - from.getX()) * t)
+				.y(from.getY() + (to.getY() - from.getY()) * t).build();
+	}
+}
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/InputSystem.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/InputSystem.java
new file mode 100644
index 0000000..b3af099
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/InputSystem.java
@@ -0,0 +1,73 @@
+package coffee.liz.abstractionengine.app.screen.game.system;
+
+import coffee.liz.abstractionengine.app.config.KeyBinds;
+import coffee.liz.abstractionengine.app.screen.game.FrameState;
+import coffee.liz.ecs.math.Vec2;
+import coffee.liz.ecs.math.Vec2i;
+import coffee.liz.ecs.model.World;
+import lombok.Getter;
+
+import java.time.Duration;
+import java.util.Collection;
+import java.util.Set;
+
+public class InputSystem implements coffee.liz.ecs.model.System<FrameState> {
+	private static final Duration INITIAL_DELAY = Duration.ofMillis(300);
+	private static final Duration REPEAT_INTERVAL = Duration.ofMillis(100);
+
+	private KeyBinds.Action heldAction = null;
+	private Duration heldTime = Duration.ZERO;
+	private boolean pastInitialDelay = false;
+
+	@Getter
+	private Vec2<Integer> stepMovement = Vec2i.ZERO;
+
+	@Override
+	public Collection<Class<? extends coffee.liz.ecs.model.System<FrameState>>> getDependencies() {
+		return Set.of();
+	}
+
+	@Override
+	public void update(final World<FrameState> world, final FrameState state, final Duration dt) {
+		final Set<KeyBinds.Action> currentlyActive = state.getSettings().getKeyBinds()
+				.filterActiveActions(state.getIsKeyPressed());
+
+		if (currentlyActive.isEmpty()) {
+			heldAction = null;
+			stepMovement = Vec2i.ZERO;
+			return;
+		}
+
+		final KeyBinds.Action active = currentlyActive.contains(heldAction)
+				? heldAction
+				: currentlyActive.iterator().next();
+
+		if (!active.equals(heldAction)) {
+			heldAction = active;
+			heldTime = Duration.ZERO;
+			pastInitialDelay = false;
+			stepMovement = actionToMovement(active);
+		} else {
+			heldTime = heldTime.plus(dt);
+			if (!pastInitialDelay && heldTime.compareTo(INITIAL_DELAY) >= 0) {
+				pastInitialDelay = true;
+				heldTime = heldTime.minus(INITIAL_DELAY);
+				stepMovement = actionToMovement(active);
+			} else if (pastInitialDelay && heldTime.compareTo(REPEAT_INTERVAL) >= 0) {
+				heldTime = heldTime.minus(REPEAT_INTERVAL);
+				stepMovement = actionToMovement(active);
+			} else {
+				stepMovement = Vec2i.ZERO;
+			}
+		}
+	}
+
+	private static Vec2<Integer> actionToMovement(final KeyBinds.Action action) {
+		return switch (action) {
+			case MOVE_UP -> Vec2i.NORTH;
+			case MOVE_DOWN -> Vec2i.SOUTH;
+			case MOVE_LEFT -> Vec2i.WEST;
+			case MOVE_RIGHT -> Vec2i.EAST;
+		};
+	}
+}
diff --git a/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/RenderSystem.java b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/RenderSystem.java
new file mode 100644
index 0000000..344271f
--- /dev/null
+++ b/core/src/main/java/coffee/liz/abstractionengine/app/screen/game/system/RenderSystem.java
@@ -0,0 +1,74 @@
+package coffee.liz.abstractionengine.app.screen.game.system;
+
+import coffee.liz.abstractionengine.app.Theme;
+import coffee.liz.abstractionengine.app.actor.GridBoardActor;
+import coffee.liz.abstractionengine.app.screen.game.FrameState;
+import coffee.liz.abstractionengine.app.screen.game.component.InterpolatedPosition;
+import coffee.liz.abstractionengine.entity.EntityType;
+import coffee.liz.ecs.math.Vec2;
+import coffee.liz.ecs.math.Vec2f;
+import coffee.liz.ecs.model.System;
+import coffee.liz.ecs.model.World;
+import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
+import com.badlogic.gdx.scenes.scene2d.Stage;
+import com.badlogic.gdx.utils.ScreenUtils;
+import com.badlogic.gdx.utils.viewport.FitViewport;
+
+import java.time.Duration;
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+public class RenderSystem implements System<FrameState> {
+	private final FitViewport viewport;
+	private final Vec2<Integer> gridSize;
+	private final ShapeRenderer shapeRenderer;
+	private final Stage stage;
+	private final GridBoardActor boardActor;
+
+	public RenderSystem(final FitViewport viewport, final Vec2<Integer> gridSize) {
+		this.viewport = viewport;
+		this.gridSize = gridSize;
+		this.shapeRenderer = new ShapeRenderer();
+		this.stage = new Stage(viewport);
+		this.boardActor = new GridBoardActor(shapeRenderer, gridSize);
+		stage.addActor(boardActor);
+	}
+
+	@Override
+	public Collection<Class<? extends System<FrameState>>> getDependencies() {
+		return Set.of(GridInterpolationSystem.class);
+	}
+
+	@Override
+	public void update(final World<FrameState> world, final FrameState state, final Duration dt) {
+		ScreenUtils.clear(Theme.BG);
+
+		final Vec2<Float> cellSize = computeCellSize();
+		final List<GridBoardActor.RenderableEntity> renderables = world
+				.query(Set.of(InterpolatedPosition.class, EntityType.class)).stream().map(entity -> {
+					final InterpolatedPosition pos = entity.get(InterpolatedPosition.class);
+					final EntityType type = entity.get(EntityType.class);
+					final Vec2<Float> drawPos = pos.getCurrent().scale(cellSize);
+					return new GridBoardActor.RenderableEntity(type, drawPos, cellSize);
+				}).toList();
+
+		boardActor.setCellSize(cellSize);
+		boardActor.setEntities(renderables);
+
+		final float deltaSeconds = dt.toMillis() / 1000f;
+		stage.act(deltaSeconds);
+		stage.draw();
+	}
+
+	@Override
+	public void close() {
+		stage.dispose();
+		shapeRenderer.dispose();
+	}
+
+	private Vec2<Float> computeCellSize() {
+		return Vec2f.builder().x(viewport.getWorldWidth() / gridSize.getX())
+				.y(viewport.getWorldHeight() / gridSize.getY()).build();
+	}
+}
diff --git a/lwjgl3/src/main/java/coffee/liz/abstractionengine/lwjgl3/Lwjgl3Launcher.java b/lwjgl3/src/main/java/coffee/liz/abstractionengine/lwjgl3/Lwjgl3Launcher.java
index 1c67c62..21b4a23 100644
--- a/lwjgl3/src/main/java/coffee/liz/abstractionengine/lwjgl3/Lwjgl3Launcher.java
+++ b/lwjgl3/src/main/java/coffee/liz/abstractionengine/lwjgl3/Lwjgl3Launcher.java
@@ -41,7 +41,7 @@ public class Lwjgl3Launcher {
 		configuration.setHdpiMode(HdpiMode.Logical);
 
 		configuration.setWindowedMode(1024, 1024);
-		configuration.setDecorated(true);
+		configuration.setDecorated(false);
 		//// You can change these files; they are in lwjgl3/src/main/resources/ .
 		//// They can also be loaded from the root of assets/ .
 		configuration.setWindowIcon("libgdx128.png", "libgdx64.png", "libgdx32.png", "libgdx16.png");