How to efficiently implement a 7-segment display?

Question

I want to construct a 7 segment display (as shown below). When you input a number, the script will read the input number and light up the respective segment (change the spriterenderer color to red) to display the number.

But I think the code has become too long, since there is 0-9 digit to display, I need 10 if statements, 8 scripts and the function of each statement is to light up the respective segment so it displays the number correctly.

Is there any better way to make the code shorter?

using UnityEngine;

public class ClockController :  MonoBehaviour
{
    Rect1 rect1;
    Rect2 rect2;
    Rect3 rect3;
    public GameObject othergameobjectrect2;
    public GameObject othergameobjectrect3;

    void Start()
    {
        int x = 1;
        if (x == 1)
        {
            rect1 = GetComponent<Rect1>();
            rect1.Rectangle1();
           
            rect2 = othergameobjectrect2.GetComponent<Rect2>();
            rect2.Rectangle2();

            rect3 = othergameobjectrect3.GetComponent<Rect3>();
            rect3.Rectangle3();

        }
    }
}

using UnityEngine;

public class Rect3 : MonoBehaviour
{
    public void Rectangle3()
    {
        GetComponent<SpriteRenderer>().color = Color.red;
        
    }
}

using UnityEngine;

public class Rect2 : MonoBehaviour
{
    public void Rectangle2()
    {
         GetComponent<SpriteRenderer>().color = Color.red; 
    }
}

using UnityEngine;

public class Rect1 : MonoBehaviour
{   
    public void Rectangle1()
    {    
        GetComponent<SpriteRenderer>().color = Color.red;    
    }
}

Answer 1

I'd attack it something like this...

Have one script that represents the digit as a whole, and assign to that script in the Inspector an array of SpriteRenderers representing the seven segments. They don't need their own custom scripts, since the only functionality we need from them is setting the colour, which the built-in SpriteRenderer component has already.

Then store a lookup table that encodes which segments should be on for each digit value.

When we set the clock digit to a new number, we can loop over all our segments, and set them to the corresponding state from the lookup table for that value.

The one tricky part here is that you need to assign your segment references to the correct array slots so they get the right value from the lookup table, but that should be easy enough to do with a little care.

public class ClockDigit : MonoBehaviour {

    //  Assuming you number your segments as follows:
    //   -- 0 --
    //  |       |
    //  5       1
    //  |       |
    //   -- 6 --
    //  |       |
    //  4       2
    //  |       |
    //   -- 3 --

    // Store a lookup table for which segments 
    // should be active when displaying each digit.
    static readonly bool[,] SEGMENT_IS_ACTIVE = new bool[,] {

        {true,  true,  true,  true,  true,  true,  false}, // 0
        {false, true,  true,  false, false, false, false}, // 1
        {true,  true,  false, true,  true,  false, true }, // 2
        {true,  true,  true,  true,  false, false, true }, // 3
        {false, true,  true,  false, false, true,  true }, // 4
        {true,  false, true,  true,  false, true,  true }, // 5
        {true,  false, true,  true,  true,  true,  true }, // 6
        {true,  true,  true,  false, false, false, false}, // 7
        {true,  true,  true,  true,  true,  true,  true }, // 8
        {true,  true,  true,  true,  false, true,  true }  // 9
    };    

    public Color32 activeColour = Color.red;
    public Color32 inactiveColour = Color.black;

    public SpriteRenderer[] segments = new SpriteRenderer[7];

    public void Display(int number) {
        var digit = number % 10;
        if (digit < 0) digit *= -1;

        for (int i = 0; i < 7; i++) {
            if (SEGMENT_IS_ACTIVE[digit, i]) {
                segments[i].color = activeColour;
            } else {
                segments[i].color = inactiveColour;
            }
        }
    }   
}

Answer 2

As mentioned by @D.Kallan stack exchanges are not normally a good place to ask about making things run more efficiently so much as about how to make them run (for example "How to I make my 7-segment display code run faster?" vs. "How do I make a 7-segment display?"). That being said your problem is pretty simple and easy to clean up.

public class SevenSegmentNumber : MonoBehaviour
{
    // Segment layout
    //  0   --
    // 1 2 |  |
    //  3   --
    // 4 5 |  |
    //  6   -- 
    public List<SpriteRenderer> segments = new List<SpriteRenderer>();
    public Color onColor = Color.red;
    public COlor offColor = Color.black;

    public void SetDisplayValue(int digit)
    {
        int value = digit % 10;

        switch (value)
        {
           case 0:
               segments[0].color = onColor;
               segments[1].color = onColor;
               segments[2].color = onColor;
               segments[3].color = offColor;
               segments[4].color = onColor;
               segments[5].color = onColor;
               segments[6].color = onColor;
               break;
            case 1:
               segments[0].color = offColor;
               segments[1].color = offColor;
               segments[2].color = onColor;
               segments[3].color = offColor;
               segments[4].color = offColor;
               segments[5].color = onColor;
               segments[6].color = offColor;
               break;
            // Fill in the rest here
        }
    }
}

public class SevenSegmentDisplay : MonoBehaviour
{
    public List<SevenSegmentNumber> digitDisplays = new List<SevenSegmentNumber>();
    
    private void Awake()
    {
        SetDisplayValue(0);
    }

    public void SetDisplayValue(int value)
    {
        int remainder = value;

        for (int digitId = 0; digitId < digitDisplays.Count; digitId++)
        {
            digitDisplays[digitId].SetDisplayValue(remainder % 10);
            remainder = remainder / 10;
        }
    }
}

Basically your problem is coming from the fact that you are writing unique scripts for every single game object rather than just one for each type (ex. "NpcBob", "NpcJim", "NpcJoe" scripts vs a single "Npc" script). I would suggest you check out some doing tutorials to learn a bit more about how to make generic scripts that can help you prevent this kind of scripting issue from coming up again. This will be especially helpful if you need to change your seven-segment display to show letters/strings, binary numbers, hex numbers, or punctuation.