Monogame-Spritesheet-Instancing

An efficient SpriteSheet Instancing class and shader inspired by MonoGame's SpriteBatch, supporting high-performance rendering and instancing for large-scale 2D projects.

The SpriteSheet class, paired with the instancing shader, enables efficient instancing of 2D objects from a sprite sheet. It offers SpriteBatch-like methods for ease of use. The class supports a single texture at a time, requiring swaps for different sprite sheets. DirectX 11 (or DX10) is required.

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Pros

• Enables efficient mass instancing of rectangles from a single sprite sheet.
• Achieves up to 80x better CPU efficiency compared to SpriteBatch using the same sprite sheet.

Cons

• Requires DirectX 11 (or DX10).
• Supports only one sprite sheet (texture) per draw call.
• Draw calls must be manually ordered for proper rendering (back-to-front).
• Custom shaders must be built on top of the SpriteSheet Instancing Shader.

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A Visual Example

Numbered by the Elements:

• A0: Normal rectangle from the sprite sheet
• B0: Rotated by π/4
• C7: Scaled up by 2 (X)
• D9: Scaled up by 2 (Y)
• G19: Vertical rectangle from the sprite sheet
• F14: Standard rectangle from the sprite sheet
• E13: Uniformly scaled up by 2 (X, Y)
• H18: Horizontal rectangle from the sprite sheet
• I10: Rotated rectangle
• J10: Blue-tinted element
• K10: Flipped Scale -1 (X, Y)
• L10: Flipped vertically Scale 1, -1 (X, Y)
• M11: Flipped horizontally Scale -1, 1 (X, Y)

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Example

This example demonstrates the (CPU) performance difference between SpriteBatch and SpriteSheet Instancing. Using a single 4K sprite sheet and random positions:

• SpriteBatch can draw 500 rectangles from the sprite sheet in approximately 1.2 ms.
• SpriteSheet Instancing can draw 42,000 rectangles from the same sprite sheet in about 1.2 ms.

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The SpriteSheet Instancing class uses following Methods

- Begin()

• Similar to MonoGame's SpriteBatch, this method collects instances into an array.
• These instances are later sent to the graphics card using a (Vertex) Instancing Buffer for efficient rendering.
• Includes an overload for changing the texture.
• Begin(Texture2D, Matrix, Blendstate, Samplestate, DepthStencilState, Rasterstate)

- Draw()

• Positions the sprite(rectangle) at its center by default.
• Offers various overloads.
• Draw(Vector2 position, Rectangle, rotation, Vector2 scale, Color)

- DrawTopLeft()

• Positions the sprite(rectangle) with the top-left corner as the origin.
• Offers various overloads.
• DrawTopLeft(Vector2 position, Rectangle, Vector2 scale, Color)

- End()

• Sends the collected instances to the graphics card using a (Vertex) Instancing Buffer.

- UpdateViewPort()

• Updates the viewport settings.
• Essential for maintaining accurate scaling and functionality when the game window size changes.

- ReturnSpritesheet()

• Returns the current Texture2D associated with the class.

- ChangeSpritesheet()

• Changes the Texture2D associated with the class.
• Cannot be called between Begin() and End().

- ChangeSpritesheetUnsave()

• Changes the Texture2D associated with the class.
• Can be called between Begin() and End().

- Dispose()

• Releases the Vertex and Index Buffers.
• Should be called when the SpriteSheet instance is no longer needed.

- LoadShaderAndTexture()

• Loads the shader and the Texture2D.
• Custom shaders should build on top of the SpriteSheet Instancing Shader.

- LoadShader()

• Loads the shader.
• Custom shaders should build on top of the SpriteSheet Instancing Shader.

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How to Use the Class

• Set the MonoGame GraphicsProfile to HiDef in your game instance: _graphics.GraphicsProfile = GraphicsProfile.HiDef;
• Create a new instance of the SpritesheetInstancing class. (note: no Texture2D is required at this point, but it can be provided later in the Begin() method)
• Call the Begin() method to prepare the instancing process by initializing the internal data with the specified spritesheet and optional rendering states. You can also define the number of elements for optimization.
• Choose a sprite element from your spritesheet and render it using the Draw() method.
• Finalize the draw call by calling the End() method.

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Aditional Info

• The view matrix functions like MonoGame's SpriteBatch, with support for custom matrices provided at the Begin() method.
• It is recommended to manually set the numberOfInstances to avoid automatic resizing of the internal array, especially when working with large numbers of elements.
  • Note that the numberOfInstances can be set higher than the actual required amount.

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The Spritesheet

The sprite sheet was created using VINZI's UV Generator. Visit VINZI´s site to learn more.