Question A rectangle is visible although its width is 0

I'm drawing a rectangle on screen to represent player health. When player's health reaches zero, the rectangle should not be visible, however although debug log confirms that its width is zero, it's still visible on the screen.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class UI : MonoBehaviour
6. {
7.     Texture2D texture;
8.     GUIStyle guiStyle;
9.     bool started;
10.     public GameObject drone;
11.     DroneControl droneControl;
12.    
13.     void Start()
14.     {
15.     }
16.  
17.     private void OnGUI()
18.     {
19.         if (!started)
20.         {
21.             texture= new Texture2D(1,1);
22.             texture.SetPixel(0, 0, Color.cyan);
23.             texture.wrapMode = TextureWrapMode.Repeat;
24.             texture.Apply();
25.             guiStyle =new GUIStyle(GUI.skin.box);
26.             guiStyle.normal.background = texture;
27.             started = true;
28.             droneControl=drone.GetComponent<DroneControl>();
29.         }
30.         float width = droneControl.integrity / 100f * Screen.width / 2;
31.         if (width <= 0)
32.             width = 0;
33.         Rect position = new Rect(Screen.width/2-width/2,Screen.height/4*3 ,width, 10);
34.         Debug.Log(position);
35.         GUI.Box(position, GUIContent.none,guiStyle);
36.     }
37. }

 

If you check all properties in GUIStyle (Unity - Scripting API: GUIStyle (unity3d.com)) you will find that it contains "padding" property that is described as "Space from the edge of GUIStyle to the start of the contents."

If I look at the padding values for GUI.skin.box style, they are all set to 4 (Left 4, Right 4, Top 4, Bottom 4). Try to change it to zero. (I haven't tested it, so I hope this helps).

 

OnGUI is the hard way to do things usually. You should consider using the UnityEngine.UI classes.

UnityEngine.UI is now a package:

https://forum.unity.com/threads/where-did-the-ui-option-in-the-create-menu-go.1134796/#post-7290742

Annoying possible issue circa October 2021:

https://forum.unity.com/threads/unityeditor-ui-csproj-not-found.1177432/

 

Thank you