Animation

This project showcases the fundamentals of creating smooth animations. The application features a moving rectangle that glides across the screen, illustrating key concepts such as frame independence and real-time rendering.

In this app, you'll learn how to manage timing, handle graphics rendering, and implement basic animation principles. Whether you're a beginner looking to understand the basics of animation or an experienced developer seeking a refresher, this project provides a hands-on approach to mastering animation techniques.

Code Walkthrough

Welcome to the Animation project! In this lesson, we'll break down the code line by line, helping you understand how it works. This project demonstrates the fundamentals of creating smooth animations using a Windows Form application. Let's dive right in!

Animation is the art of creating the illusion of motion by displaying a series of static images in quick succession. In our app, we use animation to make it appear as though our rectangle is moving towards the right. To ensure that our animation runs smoothly on all devices, we have designed it to be frame-independent. This means that our animation is not affected by changes in the frame rate, ensuring a consistent and seamless experience for all users.

The Breakdown

Setting Up the Environment

Option Explicit On

What It Does: This line ensures that all variables must be declared before they are used.
Why It Matters: This helps prevent errors caused by typos in variable names, making your code cleaner and easier to debug.

The Main Class

Public Class Form1

What It Does: This line defines a new class named Form1, which represents our main application window.
Why It Matters: All the code inside this class will define the behavior and appearance of our form. Think of this as the blueprint for our application.

Buffered Graphics

Private Context As New BufferedGraphicsContext
Private Buffer As BufferedGraphics
Private ReadOnly MinimumMaxBufferSize As New Size(1280, 720)
Private BackgroundColor As Color = Color.Black

What It Does:
- Context manages the buffered graphics, which allows for smoother rendering.
- Buffer holds our drawing operations before rendering them on the screen.
- MinimumMaxBufferSize sets the minimum size for our graphics buffer.
- BackgroundColor defines the color of the background (black).
Why It Matters: Buffered graphics improve performance by reducing flickering and providing smoother animations.

Rectangle Structure

Private Structure RectangleDouble

What It Does: This defines a structure named RectangleDouble that represents a rectangle with double-precision coordinates and dimensions.
Why It Matters: Structures are useful for grouping related data together. In this case, we are grouping properties that define a rectangle.

Rectangle Properties

Public X, Y, Width, Height, Velocity As Double
Public Brush As Brush

What It Does:
- X and Y represent the position of the rectangle.
- Width and Height define the size of the rectangle.
- Velocity determines how fast the rectangle moves.
- Brush is used to fill the rectangle with color.
Why It Matters: These properties allow us to manipulate the rectangle's position, size, and appearance easily.

Constructor

Public Sub New(x As Double, y As Double, width As Double, height As Double,
               velocity As Double, brush As Brush)
    Me.X = x
    Me.Y = y
    Me.Width = width
    Me.Height = height
    Me.Velocity = velocity
    Me.Brush = brush
End Sub

What It Does: This constructor initializes a new rectangle with specified values for its position, size, velocity, and color.
Why It Matters: Constructors are special methods that create and set up new instances of a class or structure. This allows us to easily create rectangles with different properties.

Methods for Movement

Public Sub MoveRight(ByVal deltaTime As TimeSpan)
    X += Velocity * deltaTime.TotalSeconds
End Sub

What It Does: This method moves the rectangle to the right based on its velocity and the elapsed time since the last frame.
Why It Matters: The formula used is Displacement = Velocity x Delta Time. This ensures that the rectangle moves smoothly regardless of the frame rate.

Wraparound Method

Public Sub Wraparound(ByVal clientRectangle As Rectangle)
    If X > clientRectangle.Right Then
        X = clientRectangle.Left - Width
    End If
End Sub

What It Does: This method checks if the rectangle has exited the right side of the client area. If it has, it reappears on the left side.
Why It Matters: This creates a continuous animation effect, making it appear as if the rectangle is endlessly moving across the screen.

Combine Movement and Wraparound

Public Sub MoveRightAndWraparound(ByVal clientRectangle As Rectangle, ByVal deltaTime As TimeSpan)
    MoveRight(deltaTime)
    Wraparound(clientRectangle)
End Sub

What It Does: This method combines the movement and wraparound logic, making it easy to call both in one function.
Why It Matters: This simplifies the code and makes it more readable.

Center Vertically

Public Sub CenterVertically(ByVal clientRectangle As Rectangle)
    Y = clientRectangle.Height / 2 - Height / 2
End Sub

What It Does: This method centers the rectangle vertically in the client area of our form.
Why It Matters: Centering helps in positioning the rectangle aesthetically within the window.

Delta Time Structure

Private Structure DeltaTimeStructure

What It Does: This structure tracks the timing information for our animation, including the current and last frame times and the elapsed time between them.
Why It Matters: Accurate timing is crucial for smooth animations.

Constructor and Update Method

Public Sub New(currentFrame As Date, lastFrame As Date, elapsedTime As TimeSpan)
    Me.CurrentFrame = currentFrame
    Me.LastFrame = lastFrame
End Sub

What It Does: Initializes the DeltaTimeStructure with the current and last frame times.
Why It Matters: This allows us to calculate how much time has passed between frames.

Public Sub Update()
    CurrentFrame = Now
    ElapsedTime = CurrentFrame - LastFrame
    LastFrame = CurrentFrame
End Sub

What It Does: Updates the current frame's time, calculates the elapsed time since the last frame, and updates the last frame's time for the next update.
Why It Matters: This is essential for maintaining smooth animations over time.

Frame Counter Structure

Private Structure FrameCounterStructure

What It Does: This structure counts the frames rendered and tracks the timing for calculating frames per second (FPS).
Why It Matters: FPS is a critical measure of animation smoothness.

Update Method for Frame Counter

Public Sub Update()
    TimeElapsed = Now.Subtract(StartTime)
    If TimeElapsed.TotalSeconds < 1 Then
        FrameCount += 1
    Else
        FPS = $"{FrameCount} FPS"
        FrameCount = 0
        StartTime = Now
    End If
End Sub

What It Does: This method updates the frame counter and calculates the FPS, resetting the count every second.
Why It Matters: This feedback helps us understand how well the animation is performing.

Form Load Event

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    InitializeApp()
    Debug.Print($"Running...{DateTime.Now}")
End Sub

What It Does: This method initializes the application when the form loads and prints the current time to the debug console.
Why It Matters: Initialization is crucial for setting up any necessary resources before the application starts running.

Form Resize Event

Private Sub Form1_Resize(sender As Object, e As EventArgs) Handles MyBase.Resize
    If Not WindowState = FormWindowState.Minimized Then
        FPSDisplay.MoveToPosition(ClientRectangle)
        Rectangle.CenterVertically(ClientRectangle)
        DisposeBuffer()
    End If
End Sub

What It Does: This method handles resizing the window, adjusting the FPS display and rectangle size accordingly.
Why It Matters: Responsive design ensures that the application looks good and functions well regardless of the window size.

Timer Tick Event

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
    If Not WindowState = FormWindowState.Minimized Then
        UpdateFrame()
        Invalidate() ' Calls OnPaint Sub
    End If
End Sub

What It Does: This event is triggered at regular intervals (every 15 milliseconds). It updates the animation frame and redraws the form.
Why It Matters: Continuous updates are essential for smooth animations and user interaction.

OnPaint Method

Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
    AllocateBuffer()
    DrawFrame()
    Buffer?.Render(e.Graphics)
    FrameCounter.Update()
    EraseFrame()
    MyBase.OnPaint(e)
End Sub

What It Does: This method handles the rendering of graphics. It allocates a buffer, draws the current frame, and updates the frame counter.
Why It Matters: This is where all the visual elements get drawn on the screen, creating the animation effect.

Drawing the Frame

Private Sub DrawFrame()

    Buffer?.Graphics.FillRectangle(Rectangle.Brush,
                                   Rectangle.GetNearestX,
                                   Rectangle.GetNearestY,
                                   Rectangle.GetNearestWidth,
                                   Rectangle.GetNearestHeight)

    Buffer?.Graphics.DrawString(FPSDisplay.Text,
                                FPSDisplay.Font,
                                FPSDisplay.Brush,
                                FPSDisplay.Location)

End Sub

What It Does: This method fills the rectangle with the specified brush at its current position and dimensions, and it draws the FPS display string on the buffer.
Why It Matters: This is where the visual representation of the rectangle and the FPS is updated on the screen. However, it does not clear the buffer; that function is handled by the EraseFrame method.

Erasing the Frame

Private Sub EraseFrame()
    Buffer?.Graphics.Clear(BackgroundColor)
End Sub

What It Does: This method clears the buffer with the background color defined by BackgroundColor.
Why It Matters: Clearing the buffer is essential to prepare for the next frame. It ensures that previous drawings do not persist, allowing for a clean slate for the new frame rendering.

This walkthrough covers the main components of the animation project. Feel free to experiment with the code, adjust parameters, and see how they affect the animation! Understanding these principles will help you master animation techniques in Visual Basic .NET. Happy coding!

Exercises

Here are some exercises you can try to enhance your understanding of the animation project:

Change Rectangle Size
- Modify the dimensions of the rectangle in the RectangleDouble structure.
- Task: Experiment with different width and height values. Observe how the animation changes with larger or smaller rectangles.
Change Rectangle Color
- Update the RectangleBrush color in the initialization section.
- Task: Choose different colors (e.g., red, blue, green) for the rectangle. How does the visual impact change with different colors?
Adjust Rectangle Velocity
- Locate the variable that defines the rectangle's velocity.
- Task: Increase or decrease the velocity value. How does this affect the speed at which the rectangle moves across the screen?
Add Multiple Rectangles
- Create additional instances of RectangleDouble to represent multiple rectangles.
- Task: Animate them independently or in a pattern (e.g., staggered movement). How does this change the overall animation?
Implement User Controls
- Add keyboard controls to change the rectangle's size, color, or velocity while the application is running.
- Task: Use keys (e.g., arrow keys for velocity, 'C' for color change) to interactively modify the rectangle's properties.
Create a Bouncing Effect
- Modify the MoveRectangle method to make the rectangle bounce off the edges of the window.
- Task: Instead of wrapping around, change the direction when it hits the edge. What changes do you need to make in the code?
Change Background Color
- Modify the BackgroundColor variable to change the background of the form.
- Task: Experiment with different background colors and observe how they affect the visibility of the rectangle.

These exercises will help you to better understand the concepts of animation and improve your programming skills in Visual Basic .NET. Feel free to experiment and combine these tasks for more complex behaviors!

More on DeltaTime

DeltaTime is a critical concept in game development and animation that refers to the time elapsed between the current frame and the last frame. This concept is essential for ensuring smooth and consistent motion, particularly in an era where games run on various hardware configurations with differing frame rates. Understanding DeltaTime allows developers to create fluid animations and responsive gameplay, enhancing the overall user experience.

Importance of DeltaTime

Frame Rate Independence: By using DeltaTime, animations and movements can remain consistent across different hardware configurations and frame rates. This means that whether a game runs at 30 FPS or 60 FPS, the gameplay remains smooth.
Smooth Animations: DeltaTime allows for smoother transitions and movements, as changes are proportional to the time elapsed. This is crucial for maintaining realism in animations.
Timing Control: DeltaTime helps manage timing for various game mechanics, such as physics calculations, animations, and input handling. It ensures that all elements of the game respond predictably to player actions.

How DeltaTime Works

Capture Time: Record the current time at the beginning of each frame.
Calculate Elapsed Time: Subtract the last recorded time from the current time to get the DeltaTime.
Apply DeltaTime: Use this value to adjust movements, animations, and other time-dependent calculations.

Example Code

Here’s a simplified example illustrating how to implement DeltaTime in a Windows Forms application.

    ' The DeltaTimeStructure represents the time difference
    ' between two frames.
    Private Structure DeltaTimeStructure

        Public CurrentFrame As DateTime
        Public LastFrame As DateTime
        Public ElapsedTime As TimeSpan

        Public Sub New(currentFrame As Date, lastFrame As Date,
                       elapsedTime As TimeSpan)

            Me.CurrentFrame = currentFrame
            Me.LastFrame = lastFrame
            Me.ElapsedTime = elapsedTime
        End Sub

        Public Sub Update()

            ' Set the current frame's time to the current system time.
            CurrentFrame = Now

            ' Calculates the elapsed time ( delta time Δt ) between the
            ' current frame and the last frame.
            ElapsedTime = CurrentFrame - LastFrame

            ' Updates the last frame's time to the current frame's time for
            ' use in the next update.
            LastFrame = CurrentFrame

        End Sub

    End Structure

    Private DeltaTime As New DeltaTimeStructure(DateTime.Now, DateTime.Now,
                                                TimeSpan.Zero)

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

      DeltaTime.Update()

      Rectangle.MoveRight(DeltaTime.ElapsedTime)

      ' Render the frame
      Invalidate() ' Calls OnPaint Sub

    End Sub

    Public Sub MoveRight(ByVal deltaTime As TimeSpan)

      ' Move the rectangle to the right.
      X += Velocity * deltaTime.TotalSeconds
      ' Displacement = Velocity x Delta Time ( Δs = V * Δt )

    End Sub

Best Practices

Keep it Simple: Use DeltaTime for essential calculations only. Avoid overcomplicating the logic to ensure maintainability.
Cap Frame Rate: Implement a frame rate cap to prevent extremely high DeltaTime values, which can lead to erratic behavior. For example, capping at 60 FPS can provide a smoother experience.
Consistent Units: Ensure that all movement speeds and calculations are consistent in terms of units (e.g., meters per second). This consistency helps in debugging and maintaining the code.

Common Pitfalls

Ignoring DeltaTime: Not using DeltaTime can result in inconsistent behavior across different devices. Always incorporate it into your calculations.
Large Frame Drops: Sudden drops in frame rate can lead to large DeltaTime values, causing movements to appear jerky or too fast. Implementing a smoothing function can help mitigate this issue.
Complex Calculations: Overusing DeltaTime in complex calculations can lead to performance issues. Keep calculations straightforward and efficient.

Related Projects

If you're interested in exploring a similar project, check out Animation C#, which is a port of this animation project. You can find the C# version in its repository: Animation C# Repository.

For more information about the original project, visit the Animation Repository.

Happy coding!

License Information

This project is shared under the MIT License, which allows you to use, modify, and distribute it freely, as long as you include the original copyright notice.

MIT License
Copyright(c) 2023 Joseph W. Lumbley

Name		Name	Last commit message	Last commit date
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Animation		Animation
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Animation.sln		Animation.sln
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README.md		README.md

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