AnimatedSprite.cs

using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace Desktoptale
{
    public class AnimatedSprite : IAnimatedSprite
    {
        public bool Playing { get; private set; }
        public bool Loop { get; set; }
        public int LoopPoint { get; set; }
        public double Framerate { get; set; }
        public int FrameCount { get; private set; }

        public int StartFrame
        {
            get => startFrame;
            set
            {
                startFrame = value;
                if (!Playing && CurrentFrameIndex == 0) CurrentFrameIndex = value;
            }
        }

        public int CurrentFrameIndex { get; set; }
        public Point FrameSize { get; }

        private Texture2D spritesheet;
        private bool justStarted;
        private TimeSpan nextFrameUpdate;
        private int startFrame;

        public AnimatedSprite(Texture2D spritesheet, int frameCount)
        {
            this.spritesheet = spritesheet;
            this.FrameCount = frameCount;
            FrameSize = new Point(spritesheet.Width / frameCount, spritesheet.Height);
        }
    
        public void Play()
        {
            Playing = true;
            justStarted = true;
        }

        public void Pause()
        {
            Playing = false;
        }

        public void Stop()
        {
            Playing = false;
            CurrentFrameIndex = StartFrame;
        }

        public void Update(GameTime gameTime)
        {
            if (Playing && FrameCount > 1)
            {
                if (justStarted)
                {
                    TimeSpan nextScheduledUpdate = Framerate == 0 ? TimeSpan.MaxValue : gameTime.TotalGameTime + TimeSpan.FromSeconds(1 / Framerate);
                    nextFrameUpdate = nextScheduledUpdate;
                    justStarted = false;
                }
            
                if (nextFrameUpdate < gameTime.TotalGameTime)
                {
                    TimeSpan nextScheduledUpdate = Framerate == 0 ? TimeSpan.MaxValue : gameTime.TotalGameTime + TimeSpan.FromSeconds(1 / Framerate);
                    nextFrameUpdate = nextScheduledUpdate;

                    if (CurrentFrameIndex < FrameCount - 1)
                    {
                        CurrentFrameIndex++;
                    }
                    else
                    {
                        if (Loop) CurrentFrameIndex = LoopPoint;
                    }
                }
            }
        }

        public void Draw(SpriteBatch spriteBatch,
            Vector2 position,
            Color color, 
            float rotation, 
            Vector2 origin, 
            Vector2 scale, 
            SpriteEffects effects, 
            float layerDepth)
        {
            Rectangle sourceRectangle = new Rectangle(CurrentFrameIndex * FrameSize.X, 0, FrameSize.X, FrameSize.Y);
            spriteBatch.Draw(spritesheet, position, sourceRectangle, color, rotation, origin, scale, effects, layerDepth);
        }
    }
}