raycast cursor

app/src/main/java/chess/view/DDDrender/Camera.java

@@ -1,7 +1,9 @@
 package chess.view.DDDrender;
 
 import org.joml.Matrix4f;
+import org.joml.Vector2f;
 import org.joml.Vector3f;
+import org.joml.Vector4f;
 
 public class Camera {
     public static final float fov = 70.0f;
@@ -14,7 +16,6 @@ public class Camera {
     private final float distance = 1.5f;
     private final float camHeight = 1.5f;
 
-
     private float aspectRatio;
     private float angle;
 
@@ -22,7 +23,7 @@ public class Camera {
 
     public Camera() {
         this.pos = new Vector3f(0.0f, camHeight, 0.0f);
-        this.angle = 0.0f;
+        setRotateAngle(0.0f);
     }
 
     public void move(float x, float y) {
@@ -80,4 +81,22 @@ public class Camera {
     public Matrix4f getViewMatrix() {
         return new Matrix4f().lookAt(pos, center, up);
     }
+
+    public Vector2f getCursorWorldFloorPos(Vector2f screenPos, int windowWidth, int windowHeight) {
+        float relativeX = (screenPos.x / (float) windowWidth * 2.0f) - 1.0f;
+        float relativeY = 1.0f - (screenPos.y / (float) windowHeight * 2.0f);
+
+        Vector4f rayClip = new Vector4f(relativeX, relativeY, -1.0f, 1.0f);
+
+        Vector4f rayEye = getPerspectiveMatrix().invert().transform(rayClip);
+
+        rayEye = new Vector4f(rayEye.x, rayEye.y, -1.0f, 0.0f);
+
+        Vector4f rayWorld = getViewMatrix().invert().transform(rayEye);
+
+        float lambda = -this.pos.y / rayWorld.y;
+
+        return new Vector2f(lambda * rayWorld.x + this.pos.x, lambda *
+                rayWorld.z + this.pos.z);
+    }
 }

app/src/main/java/chess/view/DDDrender/DDDPlacement.java

@@ -5,12 +5,17 @@ import org.joml.Vector2f;
 import chess.model.Coordinate;
 
 class DDDPlacement {
-	static public Vector2f coordinates_to_vector(Coordinate coo) {
+	public static Vector2f coordinates_to_vector(Coordinate coo) {
 		return coordinates_to_vector(coo.getX(), coo.getY());
 	}
 
-	static public Vector2f coordinates_to_vector(float x, float y) {
+	public static Vector2f coordinates_to_vector(float x, float y) {
 		return new Vector2f(1.0f - 0.125f - x * 0.250f, 1.0f - 0.125f - y * 0.250f);
 	}
 
+	public static Coordinate vector_to_coordinates(Vector2f pos) {
+		int x = (int) ((1.0f - pos.x) * 4.0f);
+		int y = (int) ((1.0f - pos.y) * 4.0f);
+		return new Coordinate(x, y);
+	}
 }

app/src/main/java/chess/view/DDDrender/DDDView.java

@@ -28,11 +28,23 @@ public class DDDView extends GameAdaptator {
 		this.world = new World(new Camera());
 		this.window = new Window(this.renderer, this.world);
 		this.window.OnCellClick.connect(this::onCellClick);
+		this.window.OnCellEnter.connect(this::onCellEnter);
+		this.window.OnCellExit.connect(this::onCellExit);
 	}
 
 	// Invoked when a cell is clicked
 	private void onCellClick(Coordinate coordinate) {
+		System.out.println("Cell clicked : " + coordinate);
+	}
 
+	// Invoked when a cell is hovered
+	private void onCellEnter(Coordinate coordinate) {
+		System.out.println("Enter : " + coordinate);
+	}
+
+	// Invoked when a cell is not hovered anymore
+	private void onCellExit(Coordinate coordinate) {
+		System.out.println("Exit : " + coordinate);
 	}
 
 	private Piece pieceAt(Coordinate pos) {

app/src/main/java/chess/view/DDDrender/Window.java

@@ -1,5 +1,6 @@
 package chess.view.DDDrender;
 
+import org.joml.Vector2f;
 import org.lwjgl.*;
 import org.lwjgl.glfw.*;
 import org.lwjgl.opengl.*;
@@ -35,7 +36,11 @@ public class Window {
 	private final Queue<Runnable> tasks;
 	private final List<Consumer<Float>> regularTasks;
 
+	private Coordinate lastCell = null;
+
 	public final Signal1<Coordinate> OnCellClick = new Signal1<>();
+	public final Signal1<Coordinate> OnCellEnter = new Signal1<>();
+	public final Signal1<Coordinate> OnCellExit = new Signal1<>();
 
 	public Window(Renderer renderer, World world) {
 		this.renderer = new Renderer();
@@ -143,6 +148,32 @@ public class Window {
 		}
 	}
 
+	private void checkCursor(int windowWidth, int windowHeight) {
+		double x[] = new double[1];
+		double y[] = new double[1];
+		glfwGetCursorPos(this.window, x, y);
+		Vector2f cursorPos = this.cam.getCursorWorldFloorPos(new Vector2f((float) x[0], (float) y[0]), windowWidth, windowHeight);
+		Coordinate selectedCell = DDDPlacement.vector_to_coordinates(cursorPos);
+		if (this.lastCell == null) {
+			this.lastCell = selectedCell;
+			if (selectedCell.isValid())
+				this.OnCellEnter.emit(selectedCell);
+		}
+		else if (!this.lastCell.equals(selectedCell)) {
+			if (this.lastCell.isValid())
+				this.OnCellExit.emit(this.lastCell);
+			if (selectedCell.isValid())
+				this.OnCellEnter.emit(selectedCell);
+			this.lastCell = selectedCell;
+		}
+		glfwSetMouseButtonCallback(this.window, (window, button, action, mods) -> {
+			if (button == GLFW_MOUSE_BUTTON_1 && action == GLFW_PRESS) {
+				if (this.lastCell.isValid())
+					this.OnCellClick.emit(this.lastCell);
+			}
+		});
+	}
+
 	private void loop() {
 		// This line is critical for LWJGL's interoperation with GLFW's
 		// OpenGL context, or any context that is managed externally.
@@ -186,6 +217,8 @@ public class Window {
 			// invoked during this call.
 			glfwPollEvents();
 
+			checkCursor(width[0], height[0]);
+
 			executeTasks(deltaTime);
 
 			glfwGetWindowSize(window, width, height);