Module glium::texture::buffer_texture

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A BufferTexture is a special kind of one-dimensional texture that gets its data from a buffer. Buffer textures have very limited capabilities compared to other texture types.

A buffer texture is composed of two things:

  • A buffer.
  • A texture.

The BufferTexture object derefs to a Buffer, which allows you to modify the content of the buffer just like any other buffer type.

The texture aspect of the buffer texture is very limited. The only thing you can do is use the texture for sampling or image load/store in your shaders. You can’t upload or read the texture, it doesn’t have any mipmap, etc.

Formats

In order to build a BufferTexture, the elements of the buffer must implement the TextureBufferContent trait. Even though a buffer can hold any type of data, a buffer texture only supports some precise formats of data.

Support for various formats has been added in OpenGL over time. The following formats have the most chances of being supported:

  • F16F16F16F16
  • F32F32F32
  • F32F32F32F32
  • U32U32U32
  • I32I32I32
  • U8U8U8U8
  • I8I8I8I8
  • U16U16U16U16
  • I16I16I16I16
  • U32U32U32U32 (unsigned only)
  • I32I32I32I32 (signed only)

Buffer texture type

The template parameter that you use for BufferTexture defines the content of the buffer. For example a BufferTexture<(u8, u8, u8, u8)> contains a list of four-component texels where each texel is a u8. However this data can be interpreted in two different ways: either as a normalized floating-point (where 0 is interpreted as 0.0 and 255 interpreted as 1.0) or as an integral value.

For this reason, you need to pass a BufferTextureType when creating the buffer texture.

This type also corresponds to the type of sampler that you must use in your GLSL code. In order to sample from a buffer texture of type Float you need to use a samplerBuffer, in order to sample from a buffer texture of type Integral you need to use a isamplerBuffer, and in order to sample from a buffer texture of type Unsigned you need to use a usamplerBuffer. Using the wrong type will result in an error.

Structs

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Traits