NPOTTexturen

NPOTTexturen, or non-power-of-two textures, are textures whose width and height are not powers of two (for example 300x500). They are common in real-time graphics because they avoid padding to the next power-of-two and can simplify asset management, especially for irregular or dynamic sizes.

Historically, many graphics pipelines required textures to have dimensions that are powers of two to enable features like mipmapping and certain wrap modes. The OpenGL extension ARB_texture_non_power_of_two and later hardware support removed many of these restrictions, enabling NPOT textures with full capabilities on compatible GPUs. Today, major APIs such as OpenGL, DirectX, and Vulkan offer broad NPOT support. In WebGL, NPOT textures are supported but often with limitations (for example, mipmaps and certain wrap modes may be restricted on some implementations).

Technical considerations for NPOT textures include mipmapping, filtering, and wrapping. If a texture is used with mipmaps, not all environments support NPOT mipmapping unless the hardware and API provide full NPOT support. Wrap modes like REPEAT or MIRRORED_REPEAT are also dependent on the API and hardware capabilities, especially on older or restricted platforms. In general, NPOT textures can save memory when the texture dimensions are not close to a power of two, but care must be taken to ensure the target platform’s features align with the desired sampling and wrapping behavior. Data upload also requires attention to alignment and row stride, but NPOT sizes do not inherently impose different constraints from POT textures.

Common use cases for NPOT textures include user interface elements, texture atlases with irregular sizes, and procedurally generated or dynamically sized textures where padding to the next POT would be wasteful.