Texture Filtering

Introduction

Texture filtering controls how Gum samples textures (sprites, NineSlices, and fonts) when they are drawn at a size that differs from their native resolution. When a texture is scaled up or down, the renderer must decide how to map source texels to screen pixels. Gum supports two modes:

• Point — nearest-neighbor sampling. Each screen pixel takes the color of the single nearest texel, keeping edges crisp and hard. This is the right choice for pixel-art, where blurring would ruin the intended look. Point is the default.
• Linear — bilinear sampling. Each screen pixel blends the nearest texels, producing a smooth, antialiased result when scaled. This suits high-resolution art and UI that is rendered at many sizes.

Filtering is a render-state setting applied globally or per layer. It is not a property of an individual sprite — you cannot make one sprite point-filtered and another linear-filtered within the same layer.

Setting the Global Filter

Renderer.TextureFilter is a global static that controls filtering for everything Gum draws. Set it once at startup:

// Initialize
RenderingLibrary.Graphics.Renderer.TextureFilter =
    Microsoft.Xna.Framework.Graphics.TextureFilter.Linear;

Renderer.TextureFilter defaults to Point, so a game renders with crisp, pixel-art filtering unless you change it.

Per-Layer Override

A layer can override the global filter through its IsLinearFilteringEnabled property, a nullable bool:

• true — force Linear filtering on this layer.
• false — force Point filtering on this layer.
• null (default) — inherit the global Renderer.TextureFilter.

// Initialize
layer.IsLinearFilteringEnabled = true;

This lets you, for example, keep crisp Point filtering for a pixel-art game world while smoothing a single scaled overlay layer (or the reverse). For more on layers, see Ordering, Layers, and Popups.

Relationship to the Tool's Texture Filter Setting

The Gum tool exposes the same Point/Linear choice as a Texture Filter project property — see Project Properties. To apply texture filtering at runtime, set Renderer.TextureFilter (or a per-layer override) in code as shown above.