GUISizer

/*
 * Script GUISizer by Sergey Mohov (http://sergeymohov.com)
 *
 * Original idea for the resize algorithm by Simon Wittber (http://entitycrisis.blogspot.fr/)
 *
 * Feel free to reproduce this and use for any commercial or non-commercial projects.
 *
 * Although you don't have to, it would be nice of you to mention my name and link to my website
 * if you decide to put this on the Wiki or expand.
 *
 * If you have questions, email me: sergey@sergeymohov.com
 *
 * */

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public static class GUISizer
{
    //get the screen resolution once, then adjust the GUI size to that resolution
    public static float WIDTH = 960;
    public static float HEIGHT = 600;

    //Get the button sizes
    public const float SMALL_BUTTON_WIDTH = 100f;
    public const float SMALL_BUTTON_HEIGHT = 50f;
    public const float MEDIUM_BUTTON_WIDTH = 200f;
    public const float MEDIUM_BUTTON_HEIGHT = 100f;
    public const float LARGE_BUTTON_WIDTH = 300f;
    public const float LARGE_BUTTON_HEIGHT = 100f;
    public const float BUTTON_GAP = 10f;

    private static int fontSizeDefault = 12; //GUI skin's font size should be reset to its default value every time

    static List<Matrix4x4> stack = new List<Matrix4x4> ();

    //call this funtion in the beginning of OnGUI
    static public void BeginGUI(PositionDef elementsPosition = PositionDef.middle)
    {
        stack.Add (GUI.matrix);
        Matrix4x4 m = new Matrix4x4 ();
        float w = (float)Screen.width;
        float h = (float)Screen.height;
        float aspect = w / h;
        float scale = 1f;
        Vector3 offset = Vector3.zero;

        if(aspect < (WIDTH/HEIGHT))
        {
            //screen is taller
            switch(elementsPosition)
            {
                case PositionDef.topLeft:
                    scale = (Screen.width/WIDTH);
                    break;
                case PositionDef.topMiddle:
                    scale = (Screen.width/WIDTH);
                    break;
                case PositionDef.topRight:
                    scale = (Screen.width/WIDTH);
                    break;
                case PositionDef.bottomLeft:
                    scale = (Screen.width/WIDTH);
                    offset.y += (Screen.height - (HEIGHT * scale));
                    break;
                case PositionDef.bottomMiddle:
                    scale = (Screen.width/WIDTH);
                    offset.y += (Screen.height - (HEIGHT * scale));
                    break;
                case PositionDef.bottomRight:
                    scale = (Screen.width/WIDTH);
                    offset.y += (Screen.height - (HEIGHT * scale));
                    break;
                case PositionDef.left:
                    scale = (Screen.width/WIDTH);
                    offset.y += (Screen.height - (HEIGHT * scale)) * 0.5f;
                    break;
                case PositionDef.right:
                    scale = (Screen.width/WIDTH);
                    offset.y += (Screen.height - (HEIGHT * scale)) * 0.5f;
                    break;
                case PositionDef.middle:
                    scale = (Screen.width/WIDTH);
                    offset.y += (Screen.height - (HEIGHT * scale)) * 0.5f;
                    break;
                default:
                    scale = (Screen.width/WIDTH);
                    offset.y += (Screen.height - (HEIGHT * scale)) * 0.5f;
                    break;
            }
        }
        else
        {
            //screen is wider
            switch(elementsPosition)
            {
                case PositionDef.topLeft:
                    scale = (Screen.height / HEIGHT);
                    break;
                case PositionDef.topMiddle:
                    scale = (Screen.height / HEIGHT);
                    offset.x += (Screen.width - (WIDTH * scale)) * 0.5f;
                    break;
                case PositionDef.topRight:
                    scale = (Screen.height / HEIGHT);
                    offset.x += (Screen.width - (WIDTH * scale));
                    break;
                case PositionDef.bottomLeft:
                    scale = (Screen.height / HEIGHT);
                    break;
                case PositionDef.bottomMiddle:
                    scale = (Screen.height / HEIGHT);
                    offset.x += (Screen.width - (WIDTH * scale)) * 0.5f;
                    break;
                case PositionDef.bottomRight:
                    scale = (Screen.height / HEIGHT);
                    offset.x += (Screen.width - (WIDTH * scale));
                    break;
                case PositionDef.left:
                    scale = (Screen.height / HEIGHT);
                    break;
                case PositionDef.right:
                    scale = (Screen.height / HEIGHT);
                    offset.x += (Screen.width - (WIDTH * scale));
                    break;
                case PositionDef.middle:
                    scale = (Screen.height / HEIGHT);
                    offset.x += (Screen.width - (WIDTH * scale)) * 0.5f;
                    break;
                default:
                    scale = (Screen.height / HEIGHT);
                    offset.x += (Screen.width - (WIDTH * scale)) * 0.5f;
                    break;
            }
        }

        m.SetTRS(offset, Quaternion.identity, Vector3.one * scale);
        GUI.matrix *= m;
    }

    //call this function in the end of OnGUI
    static public void EndGUI()
    {
        GUI.matrix = stack[stack.Count - 1];
        stack.RemoveAt (stack.Count - 1);
    }

    //enum that defines position presets
    public enum PositionDef
    {
        topLeft,
        topMiddle,
        topRight,
        bottomLeft,
        bottomMiddle,
        bottomRight,
        left,
        right,
        middle
    }

    //enum that defines size presets
    public enum SizeDef
    {
        small,
        medium,
        big
    }

    #region methods
    //a method that converts GUIParams into a Rect
    public static Rect MakeRect (GUIParams guiParams)
    {
        Rect rectangle = new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height);

        return rectangle;
    }

    //draws a button and returns true if it was pressed
    public static bool ButtonPressed(GUIParams guiParams)
    {
        GUI.skin.button.fontSize = (int)guiParams.fontSize;
        if (GUI.Button(new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height), guiParams.text))
        {
            GUI.skin.button.fontSize = fontSizeDefault;
            return true;
        }
        else
        {
            GUI.skin.button.fontSize = fontSizeDefault;
            return false;
        }
    }

    //overload method that lets you make custom font sizes
    public static bool ButtonPressed(GUIParams guiParams, int customFontSize)
    {
        GUI.skin.button.fontSize = customFontSize;
        if (GUI.Button(new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height), guiParams.text))
        {
            GUI.skin.button.fontSize = fontSizeDefault;
            return true;
        }
        else
        {
            GUI.skin.button.fontSize = fontSizeDefault;
            return false;
        }
    }

    //draws a label
    public static void MakeLabel(GUIParams guiParams, string additionalText = "")
    {
        GUI.skin.label.fontSize = (int)guiParams.fontSize;
        GUI.Label(new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height), guiParams.text + additionalText);
        GUI.skin.label.fontSize = fontSizeDefault;
    }

    //overload method that lets you make custom font sizes
    public static void MakeLabel(GUIParams guiParams, int customFontSize, string additionalText = "")
    {
        GUI.skin.label.fontSize = customFontSize;
        GUI.Label(new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height), guiParams.text + additionalText);
        GUI.skin.label.fontSize = fontSizeDefault;
    }

    #endregion

    #region overload methods that let you define a custom style for your GUI element
    //draws a button and returns true if it was pressed
    public static bool ButtonPressed(GUIParams guiParams, GUIStyle style)
    {
        GUI.skin.button.fontSize = (int)guiParams.fontSize;
        if (GUI.Button(new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height), guiParams.text, style))
        {
            GUI.skin.button.fontSize = fontSizeDefault;
            return true;
        }
        else
        {
            GUI.skin.button.fontSize = fontSizeDefault;
            return false;
        }
    }

    //overload method that lets you make custom font sizes
    public static bool ButtonPressed(GUIParams guiParams, int customFontSize, GUIStyle style)
    {
        GUI.skin.button.fontSize = customFontSize;
        if (GUI.Button(new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height), guiParams.text, style))
        {
            GUI.skin.button.fontSize = fontSizeDefault;
            return true;
        }
        else
        {
            GUI.skin.button.fontSize = fontSizeDefault;
            return false;
        }
    }

    //draws a label
    public static void MakeLabel(GUIParams guiParams, GUIStyle style , string additionalText = "")
    {
        GUI.skin.label.fontSize = (int)guiParams.fontSize;
        GUI.Label(new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height), guiParams.text + additionalText, style);
        GUI.skin.label.fontSize = fontSizeDefault;
    }

    //overload method that lets you make custom font sizes
    public static void MakeLabel(GUIParams guiParams, int customFontSize, GUIStyle style , string additionalText = "")
    {
        GUI.skin.label.fontSize = customFontSize;
        GUI.Label(new Rect(guiParams.x, guiParams.y, guiParams.width, guiParams.height), guiParams.text + additionalText, style);
        GUI.skin.label.fontSize = fontSizeDefault;
    }
    #endregion


    //struct for GUI elements
    public struct GUIParams
    {
        //position of the button on screen
        public float x;
        public float y;

        //size of the button
        public float width;
        public float height;

        /*size of the font of the text written on the button, proportional to the length of the button
        instead of writing 7 more constructors for custom font sizes, you can override the font in all methods that draw GUI elements*/
        public float fontSize;

        public string text; //text written in the button

        #region Default style constructors
        //default everything
        public GUIParams(string guiText)
        {
            text = guiText;

            //size defaults to medium
            Vector2 buttonSize = SetSize(SizeDef.medium);
            width = buttonSize.x;
            height = buttonSize.y;

            //position defaults to middle
            Vector2 buttonPos = SetPosition(PositionDef.middle, width, height);
            x = buttonPos.x;
            y = buttonPos.y;

            fontSize = width/6;
        }

        //specify all params manually
        public GUIParams (float posX, float posY, float guiWidth, float guiHeight, string guiText)
        {
            text = guiText;

            x = posX;
            y = posY;

            width = guiWidth;
            height = guiHeight;

            fontSize = width/6;
        }

        //specify position manually, choose size from the list
        public GUIParams (float posX, float posY, SizeDef size, string guiText)
        {
            text = guiText;

            Vector2 buttonSize = SetSize(size);
            width = buttonSize.x;
            height = buttonSize.y;

            x = posX;
            y = posY;

            fontSize = width/6;
        }

        //specify size manually, choose position from the list
        public GUIParams (PositionDef position, float guiWidth, float guiHeight, string guiText)
        {
            text = guiText;

            width = guiWidth;
            height = guiHeight;

            Vector2 buttonPos = SetPosition(position, width, height);
            x = buttonPos.x;
            y = buttonPos.y;

            fontSize = width/6;
        }

        //choose size from the list, default position
        public GUIParams (SizeDef size, string guiText)
        {
            text = guiText;

            Vector2 buttonSize = SetSize(size);
            width = buttonSize.x;
            height = buttonSize.y;

            //position defaults to middle
            Vector2 buttonPos = SetPosition(PositionDef.middle, width, height);
            x = buttonPos.x;
            y = buttonPos.y;


            fontSize = width/6;
        }

        //choose position from the list, default size
        public GUIParams (PositionDef position, string guiText)
        {
            text = guiText;

            //size defaults to medium
            Vector2 buttonSize = SetSize(SizeDef.medium);
            width = buttonSize.x;
            height = buttonSize.y;

            Vector2 buttonPos = SetPosition(position, width, height);
            x = buttonPos.x;
            y = buttonPos.y;

            fontSize = width/6;
        }

        //choose size and position from the list
        public GUIParams (PositionDef position, SizeDef size, string guiText)
        {
            text = guiText;

            Vector2 buttonSize = SetSize(size);
            width = buttonSize.x;
            height = buttonSize.y;

            Vector2 buttonPos = SetPosition(position, width, height);
            x = buttonPos.x;
            y = buttonPos.y;

            fontSize = width/6;
        }
        #endregion
    }

    //button sizes can be set in this method
    private static Vector2 SetSize(SizeDef size)
    {
        Vector2 finalSize;

        switch (size)
        {
            case SizeDef.small:
                finalSize = new Vector2(SMALL_BUTTON_WIDTH, SMALL_BUTTON_HEIGHT);
                break;

            case SizeDef.medium:
                finalSize = new Vector2(MEDIUM_BUTTON_WIDTH, MEDIUM_BUTTON_HEIGHT);
                break;

            case SizeDef.big:
                finalSize = new Vector2(LARGE_BUTTON_WIDTH, LARGE_BUTTON_HEIGHT);
                break;
            default:
                Debug.LogError("Unknown button size, defaults to medium.");
                finalSize = new Vector2(MEDIUM_BUTTON_WIDTH, MEDIUM_BUTTON_HEIGHT);
                break;
        }

        return finalSize;
    }

    //button positions can be set in this method
    private static Vector2 SetPosition(PositionDef position, float width, float height)
    {
        Vector2 finalPosition;

            switch (position)
            {
                case PositionDef.topLeft:
                    finalPosition = new Vector2(BUTTON_GAP, BUTTON_GAP);
                    break;

                case PositionDef.topMiddle:
                    finalPosition = new Vector2(WIDTH/2-width/2, BUTTON_GAP);
                    break;

                case PositionDef.topRight:
                    finalPosition = new Vector2(WIDTH-width-BUTTON_GAP, BUTTON_GAP);
                    break;

                case PositionDef.bottomLeft:
                    finalPosition = new Vector2(BUTTON_GAP, HEIGHT-height-BUTTON_GAP);
                    break;

                case PositionDef.bottomMiddle:
                    finalPosition = new Vector2(WIDTH/2-width/2, HEIGHT-height-BUTTON_GAP);
                    break;

                case PositionDef.bottomRight:
                    finalPosition = new Vector2(WIDTH-width-BUTTON_GAP, HEIGHT-height-BUTTON_GAP);
                    break;

                case PositionDef.left:
                    finalPosition = new Vector2(BUTTON_GAP, HEIGHT/2-height/2);
                    break;

                case PositionDef.right:
                    finalPosition = new Vector2(WIDTH-width-BUTTON_GAP, HEIGHT/2-height/2);
                    break;

                case PositionDef.middle:
                    finalPosition = new Vector2(WIDTH/2-width/2, HEIGHT/2-height/2);
                    break;

                default:
                    finalPosition = new Vector2(WIDTH/2-width/2, HEIGHT/2-height/2);
                    Debug.LogError("Undefined position, assigned to middle.");
                    break;
            }

        return finalPosition;
    }
}