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);
+    }
 }