Fix camera tilt function to prevent orientation flipping

Author: Forchapeatl

src/webgl/p5.Camera.js

@@ -2448,17 +2448,34 @@ p5.Camera = class Camera {
     rotatedCenter[1] += this.eyeY;
     rotatedCenter[2] += this.eyeZ;
 
+    // Compute new up vector to prevent flipping
+    let forward = createVector(
+        rotatedCenter[0] - this.eyeX,
+        rotatedCenter[1] - this.eyeY,
+        rotatedCenter[2] - this.eyeZ
+    ).normalize();
+
+    let up = createVector(this.upX, this.upY, this.upZ);
+    let right = p5.Vector.cross(forward, up).normalize(); // Right vector
+    up = p5.Vector.cross(right, forward).normalize(); // Corrected up vector
+    
+    
     this.camera(
       this.eyeX,
       this.eyeY,
       this.eyeZ,
       rotatedCenter[0],
       rotatedCenter[1],
       rotatedCenter[2],
-      this.upX,
-      this.upY,
-      this.upZ
+      this.up.x,
+      this.up.y,
+      this.up.z
     );
+
+    // Update up vector
+    this.upX = up.x;
+    this.upY = up.y;
+    this.upZ = up.z;
   }
 
   /**