Merge pull request #806 from DavidFidge/sprites

Fix bugs in SpriteSheetAnimation

src/cs/MonoGame.Extended/Sprites/SpriteSheetAnimation.cs

@@ -41,7 +41,7 @@ namespace MonoGame.Extended.Sprites
         public new bool IsComplete => CurrentTime >= AnimationDuration;
 
         public float AnimationDuration => IsPingPong
-            ? (KeyFrames.Length*2 - 2)*FrameDuration
+            ? (KeyFrames.Length*2 - (IsLooping ? 2 : 1))*FrameDuration
             : KeyFrames.Length*FrameDuration;
 
         public TextureRegion2D CurrentFrame => KeyFrames[CurrentFrameIndex];
@@ -59,10 +59,10 @@ namespace MonoGame.Extended.Sprites
         {
             if (IsComplete)
             {
-                OnCompleted?.Invoke();
-
                 if (IsLooping)
-                    CurrentTime -= AnimationDuration;
+                    CurrentTime %= AnimationDuration;
+                else
+                    OnCompleted?.Invoke();
             }
 
             if (KeyFrames.Length == 1)
@@ -76,10 +76,15 @@ namespace MonoGame.Extended.Sprites
 
             if (IsPingPong)
             {
-                frameIndex = frameIndex%(length*2 - 2);
+                if (IsComplete)
+                    frameIndex = 0;
+                else
+                {
+                    frameIndex = frameIndex % (length * 2 - 2);
 
-                if (frameIndex >= length)
-                    frameIndex = length - 2 - (frameIndex - length);
+                    if (frameIndex >= length)
+                        frameIndex = length - 2 - (frameIndex - length);
+                }
             }
 
             if (IsLooping)

src/cs/Tests/MonoGame.Extended.Tests/Sprites/SpriteSheetAnimationTests.cs

@@ -0,0 +1,910 @@
+using System;
+using Microsoft.Xna.Framework;
+using MonoGame.Extended.Sprites;
+using MonoGame.Extended.TextureAtlases;
+using Xunit;
+
+namespace MonoGame.Extended.Tests.Sprites
+{
+    public class SpriteSheetAnimationTests
+    {
+        [Theory]
+        [InlineData(0, 0)]
+        [InlineData(0, 0.9f)]
+        [InlineData(1, 1f)]
+        [InlineData(1, 1.9f)]
+        [InlineData(0, 2f)]
+        [InlineData(0, 2.9f)]
+        [InlineData(1, 3f)]
+        [InlineData(0, 4f)]
+        [InlineData(1, 5f)]
+        public void Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Fact]
+        public void Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete_Over_Multiple_Updates()
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(0));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Theory]
+        [InlineData(0, 0.9f)]
+        [InlineData(1, 1f)]
+        [InlineData(1, 1.1f)]
+        [InlineData(1, 1.9f)]
+        public void Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Theory]
+        [InlineData(1, 2f)]
+        [InlineData(1, 3f)]
+        [InlineData(1, 4f)]
+        public void Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Complete_When_AnimationDuration_Is_Reached(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.True(isCompleteFired);
+        }
+
+        [Fact]
+        public void Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Complete_When_AnimationDuration_Is_Reached_Over_Multiple_Updates()
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(0));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.True(isCompleteFired);
+
+            isCompleteFired = false; // Reset isCompleteFired for next execution
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired); // Event is not fired again as animation was already completed
+        }
+
+        [Theory]
+        [InlineData(1, 0)]
+        [InlineData(1, 0.9f)]
+        [InlineData(0, 1f)]
+        [InlineData(0, 1.9f)]
+        [InlineData(1, 2f)]
+        [InlineData(1, 2.9f)]
+        [InlineData(0, 3f)]
+        [InlineData(1, 4f)]
+        [InlineData(0, 5f)]
+        public void Reversed_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                true,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Fact]
+        public void Reversed_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete_Over_Multiple_Updates()
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                true,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(0));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Theory]
+        [InlineData(1, 0.9f)]
+        [InlineData(0, 1f)]
+        [InlineData(0, 1.1f)]
+        [InlineData(0, 1.9f)]
+        public void Reversed_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Theory]
+        [InlineData(0, 2f)]
+        [InlineData(0, 3f)]
+        [InlineData(0, 4f)]
+        public void Reversed_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Complete_When_AnimationDuration_Is_Reached(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.True(isCompleteFired);
+        }
+
+        [Fact]
+        public void Reversed_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Complete_When_AnimationDuration_Is_Reached_Over_Multiple_Updates()
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(0));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.True(isCompleteFired);
+
+            isCompleteFired = false; // Reset isCompleteFired for next execution
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);  // Event is not fired again as animation was already completed;
+        }
+
+        [Theory]
+        [InlineData(0, 0)]
+        [InlineData(0, 0.9f)]
+        [InlineData(1, 1f)]
+        [InlineData(1, 1.9f)]
+        [InlineData(0, 2f)]
+        [InlineData(0, 2.9f)]
+        [InlineData(1, 3f)]
+        [InlineData(0, 4f)]
+        [InlineData(1, 5f)]
+        [InlineData(0, 6f)]
+        [InlineData(1, 7f)]
+        [InlineData(0, 8f)]
+        public void PingPong_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                true,
+                false,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Fact]
+        public void PingPong_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete_Over_Multiple_Updates()
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                true,
+                false,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(0));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Theory]
+        [InlineData(0, 0.9f)]
+        [InlineData(1, 1f)]
+        [InlineData(1, 1.9f)]
+        [InlineData(0, 2f)]
+        [InlineData(0, 2.9f)]
+        public void PingPong_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false,
+                false,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Theory]
+        [InlineData(0, 3f)]
+        [InlineData(0, 4f)]
+        [InlineData(0, 5f)]
+        public void PingPong_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Complete_When_AnimationDuration_Is_Reached(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false,
+                false,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.True(isCompleteFired);
+        }
+
+        [Fact]
+        public void PingPong_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Complete_When_AnimationDuration_Is_Reached_Over_Multiple_Updates()
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+            var textureRegion2D3 = new TextureRegion2D("Region 3", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2, textureRegion2D3 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1, 2 },
+                1,
+                false,
+                false,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(0));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[2], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.True(isCompleteFired);
+
+            isCompleteFired = false; // Reset isCompleteFired for next execution
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired); // Event is not fired again as animation was already completed
+        }
+
+        [Theory]
+        [InlineData(1, 0)]
+        [InlineData(1, 0.9f)]
+        [InlineData(0, 1f)]
+        [InlineData(0, 1.9f)]
+        [InlineData(1, 2f)]
+        [InlineData(1, 2.9f)]
+        [InlineData(0, 3f)]
+        [InlineData(1, 4f)]
+        [InlineData(0, 5f)]
+        [InlineData(1, 6f)]
+        [InlineData(0, 7f)]
+        [InlineData(1, 8f)]
+        public void Reversed_PingPong_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                true,
+                true,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Fact]
+        public void Reversed_PingPong_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete_Over_Multiple_Updates()
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                true,
+                true,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(0));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Theory]
+        [InlineData(1, 0.9f)]
+        [InlineData(0, 1f)]
+        [InlineData(0, 1.9f)]
+        [InlineData(1, 2f)]
+        [InlineData(1, 2.9f)]
+        public void Reversed_PingPong_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Not_Complete(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false,
+                true,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+        }
+
+        [Theory]
+        [InlineData(1, 3f)]
+        [InlineData(1, 4f)]
+        [InlineData(1, 5f)]
+        public void Reversed_PingPong_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Complete_When_AnimationDuration_Is_Reached(int expectedTextureRegionIndex, float time)
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1 },
+                1,
+                false,
+                true,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(time));
+
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[expectedTextureRegionIndex], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.True(isCompleteFired);
+        }
+
+        [Fact]
+        public void Reversed_PingPong_Non_Looping_SpriteSheetAnimation_Should_Return_Correct_Frame_And_Complete_When_AnimationDuration_Is_Reached_Over_Multiple_Updates()
+        {
+            var textureRegion2D1 = new TextureRegion2D("Region 1", null, new Rectangle());
+            var textureRegion2D2 = new TextureRegion2D("Region 2", null, new Rectangle());
+            var textureRegion2D3 = new TextureRegion2D("Region 3", null, new Rectangle());
+
+            var textureRegions = new[] { textureRegion2D1, textureRegion2D2, textureRegion2D3 };
+
+            var spriteSheetAnimationData = new SpriteSheetAnimationData(
+                new[] { 0, 1, 2 },
+                1,
+                false,
+                true,
+                true
+            );
+
+            var spriteSheetAnimation = new SpriteSheetAnimation("Test", textureRegions, spriteSheetAnimationData);
+
+            var isCompleteFired = false;
+            spriteSheetAnimation.OnCompleted += () => isCompleteFired = true;
+
+            spriteSheetAnimation.Play();
+
+            var gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(0));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[2], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[0], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[1], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[2], spriteSheetAnimation.CurrentFrame);
+            Assert.False(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired);
+
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[2], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.True(isCompleteFired);
+
+            isCompleteFired = false; // Reset isCompleteFired for next execution
+            gameTime = new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1));
+            spriteSheetAnimation.Update(gameTime);
+
+            Assert.Equal(textureRegions[2], spriteSheetAnimation.CurrentFrame);
+            Assert.True(spriteSheetAnimation.IsComplete);
+            Assert.False(isCompleteFired); // Event is not fired again as animation was already completed
+        }
+    }
+}