Game.cs

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

namespace GitHub.Unity {
    public class Game
    {
        private Texture2D texture1 = Utility.GetTextureFromColor(Color.blue);
        private Texture2D paddleTexture;
        private float wallThickness = 2f;

        Rect paddle = new Rect(0, 0, 50, 10);
        int direction = 1;
        float paddleSpeed = 0.4f;
        float ballSpeed = 1f;
        int radius = 5;
        Rect ball;

        Rect?[,] bricks;

        Vector2 topLeft, topRight, bottomLeft, bottomRight;
        const int rows = 5;
        int cols = 0;
        const int brickSize = 30;
        const int brickPadding = 1;
        const int ballRadius = 20;

        Rect board;
        float ballAngle;
        
        // Use this for initialization
        public void Restart(Rect rect)
        {
            board = rect;
            paddleTexture = new Texture2D((int)rect.width, (int)rect.height);
            topLeft = new Vector2(rect.x, rect.y);
            topRight = new Vector2(rect.x + rect.width, rect.y);
            bottomLeft = new Vector2(rect.x, rect.y + rect.height);
            bottomRight = new Vector2(rect.x + rect.width, rect.y + rect.height);

            var centerLeft = new Vector2(topLeft.x, bottomLeft.y / 2);

            cols = Mathf.FloorToInt(rect.width / (brickSize + brickPadding));
            bricks = new Rect?[rows, cols];
            for (var row = 0; row < rows; row++)
            {
                for (var col = 0; col < cols; col++)
                {
                    bricks[row, col] = new Rect(
                        centerLeft.x + brickSize * col + brickPadding * col,
                        centerLeft.y + brickSize * row + brickPadding * row,
                        brickSize, brickSize);
                }
            }

            paddle.y = bottomLeft.y - paddle.height;
            ball = new Rect(paddle.x + paddle.width / 2, paddle.y - ballRadius, ballRadius, ballRadius);
            ballAngle = 270;
        }

        // Update is called once per frame
        public void Update()
        {
            paddle.x += direction * paddleSpeed;
            if (paddle.x + paddle.width > topRight.x || paddle.x < topLeft.x)
            {
                direction *= -1;
            }

            ball = MoveAngle(ball, ballAngle, ballSpeed);

            for (var row = 0; row < rows; row++)
            {
                for (var col = 0; col < cols; col++)
                {
                    if (bricks[row, col].HasValue) {
                        var brick = bricks[row, col].Value;
                        if (IsCollision(ball, brick)) {
                            bricks[row, col] = null;
                            ballAngle = Mathf.Repeat(ballAngle + 90, 360);
                        }
                        else {
                            GUI.DrawTexture(brick, texture1);
                        }
                    }
                }
            }

            if (ball.x <= topLeft.x || ball.x >= topRight.x) {
                ballAngle = Mathf.Repeat(ballAngle + 90, 360);
            }

            if (IsCollision(paddle, ball)) {
                ballAngle = Mathf.Repeat(ballAngle + 90, 360);
            }

            GUI.DrawTexture(paddle, texture1);
            GUI.DrawTexture(ball, Styles.SmallLogo);


        }

        bool IsCollision(Rect thing1, Rect thing2) {
            var isInSpace = thing1.y >= thing2.y && thing1.y <= thing2.y + thing2.height;
            isInSpace &= thing1.x >= thing2.x && thing1.x <= thing2.x + thing2.width;
            return isInSpace;
        }

        Rect MoveAngle(Rect v, float angle, float speed)
        {
            v.x += Mathf.Cos(angle * Mathf.Deg2Rad) * speed;
            v.y += Mathf.Sin(angle * Mathf.Deg2Rad) * speed;
            return v;
        }

        public void Click(Vector2 position)
        {
            if (position.x > paddle.x)
            {
                // move paddle right
                direction = 1;
            } else if (position.x < paddle.x)
            {
                // move paddle left
                direction = -1;
            }
        }
    }
}