voxel/Player.cs

using OpenTK.Mathematics;
using OpenTK.Windowing.GraphicsLibraryFramework;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

namespace Voxel
{
    public class Player : Entity
    {
        private World _world;
        public double lastClick = 0;
        public readonly float mouseCooldown = 0.2f;
        private int _blockIndex = 0;
        private Blocks _selectedBlock = Blocks.Dirt;

        public Player(Vector3 startPos, World world) : base(startPos, 0.5f, 1.8f, world)
        {

        }

        public void PlaceBlock()
        {
            var (success, hit, x, y, z, normal) = _world.Raycast(Camera.Position, Camera.Front.Normalized(), 8);
            if (!success) return;

            x += normal.X;
            y += normal.Y;
            z += normal.Z;

            _world.SetBlock(x, y, z, _selectedBlock);
        }

        public void BreakBlock()
        {
            var (success, hit, x, y, z, normal) = _world.Raycast(Camera.Position, Camera.Front.Normalized(), 8);
            if (!success) return;

            _world.SetBlock(x, y, z, Blocks.Air);
        }

        public void Update(float deltaTime)
        {
            Camera.Position = Position + Vector3.UnitY * 0.5f;
            Rotation = Camera.Yaw;

            if (lastClick > 0)
            {
                lastClick -= deltaTime;
                if (lastClick < 0) lastClick = 0;
            }

            if (!Input.GetMouseButton(MouseButton.Right) && !Input.GetMouseButton(MouseButton.Left))
            {
                lastClick = 0;
            }

            if (Input.GetMouseButton(MouseButton.Right) && lastClick == 0)
            {
                lastClick = mouseCooldown;

                PlaceBlock();
            }

            if (Input.GetMouseButton(MouseButton.Left) && lastClick == 0)
            {
                lastClick = mouseCooldown;

                BreakBlock();
            }

            if (Input.GetKey(Keys.W))
                ApplyLocalVelocity(0, -5 * deltaTime);

            if (Input.GetKey(Keys.Space) && OnGround)
            {
                Velocity = new Vector3(Velocity.X, 0.5f, Velocity.Z);
                OnGround = false;
                Console.WriteLine("Jump");
            }
        }

        public void ApplyLocalVelocity(float x, float z)
        {
            Vector3 localVelocity = new Vector3(x, 0, z);

            float yaw = MathHelper.DegreesToRadians(Rotation);
            float cos = MathF.Cos(yaw); // yaw in radians
            float sin = MathF.Sin(yaw);

            Vector3 worldVelocity = new Vector3(
                localVelocity.X * cos - localVelocity.Z * sin,
                Velocity.Y,
                localVelocity.X * sin + localVelocity.Z * cos
            );

            Velocity = worldVelocity;
        }

        public void SwitchBlock(bool inverted)
        {
            var keys = BlockDefinitions.Blocks.Keys.ToList();

            if (inverted)
                if (_blockIndex == 0)
                    _blockIndex = keys.Count -1;
                else
                    _blockIndex -= 1;
            else
                _blockIndex += 1;

            _blockIndex = _blockIndex % keys.Count;
            _selectedBlock = keys[_blockIndex];
            Console.WriteLine(_selectedBlock);
        }
    }
}