healthbar.cs

using UnityEngine;
using System.Collections;

public class HealthBar : MonoBehaviour 
{
    GUIStyle healthStyle;
    GUIStyle backStyle;
    Combat combat;

    void Awake()
    {
        combat = GetComponent<Combat>();
    }

    void OnGUI()
    {
        InitStyles();

        // Draw a Health Bar

        Vector3 pos = Camera.main.WorldToScreenPoint(transform.position);
        
        // draw health bar background
        GUI.color = Color.grey;
        GUI.backgroundColor = Color.grey;
        GUI.Box(new Rect(pos.x-26, Screen.height - pos.y + 20, Combat.maxHealth/2, 7), ".", backStyle);
        
        // draw health bar amount
        GUI.color = Color.green;
        GUI.backgroundColor = Color.green;
        GUI.Box(new Rect(pos.x-25, Screen.height - pos.y + 21, combat.health/2, 5), ".", healthStyle);
    }

    void InitStyles()
    {
        if( healthStyle == null )
        {
            healthStyle = new GUIStyle( GUI.skin.box );
            healthStyle.normal.background = MakeTex( 2, 2, new Color( 0f, 1f, 0f, 1.0f ) );
        }

        if( backStyle == null )
        {
            backStyle = new GUIStyle( GUI.skin.box );
            backStyle.normal.background = MakeTex( 2, 2, new Color( 0f, 0f, 0f, 1.0f ) );
        }
    }
    
    Texture2D MakeTex( int width, int height, Color col )
    {
        Color[] pix = new Color[width * height];
        for( int i = 0; i < pix.Length; ++i )
        {
            pix[ i ] = col;
        }
        Texture2D result = new Texture2D( width, height );
        result.SetPixels( pix );
        result.Apply();
        return result;
    }
}