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web api instance method

WebGLRenderingContext: compressedTexSubImage2D() method

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Available in workers

The compressedTexSubImage2D() method of the WebGLRenderingContext interface of the WebGL API specifies a two-dimensional sub-rectangle for a texture image in a compressed format.

Compressed image formats are only available via the WebGL2RenderingContext or some WebGL extension.

Syntax

// WebGL 1:
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, srcData)

// Additionally available in WebGL 2:
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, srcData, srcOffset)
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, srcData, srcOffset, srcLengthOverride)
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, imageSize, offset)

Parameters

  • target
    • : A GLenum specifying the binding point (target) of the active compressed texture. Possible values:
      • gl.TEXTURE_2D: A two-dimensional texture.
      • gl.TEXTURE_CUBE_MAP_POSITIVE_X: Positive X face for a cube-mapped texture.
      • gl.TEXTURE_CUBE_MAP_NEGATIVE_X: Negative X face for a cube-mapped texture.
      • gl.TEXTURE_CUBE_MAP_POSITIVE_Y: Positive Y face for a cube-mapped texture.
      • gl.TEXTURE_CUBE_MAP_NEGATIVE_Y: Negative Y face for a cube-mapped texture.
      • gl.TEXTURE_CUBE_MAP_POSITIVE_Z: Positive Z face for a cube-mapped texture.
      • gl.TEXTURE_CUBE_MAP_NEGATIVE_Z: Negative Z face for a cube-mapped texture.
  • level
    • : A GLint specifying the level of detail. Level 0 is the base image level and level n is the n-th mipmap reduction level.
  • xoffset
    • : A GLint specifying the horizontal offset within the compressed texture image.
  • yoffset
    • : A GLint specifying the vertical offset within the compressed texture image.
  • width
    • : A GLsizei specifying the width of the compressed texture.
  • height
    • : A GLsizei specifying the height of the compressed texture.
  • format

The texture source can be provided in one of two ways: from an ArrayBuffer (possibly shared) using srcData, srcOffset, and srcLengthOverride; or, in WebGL 2, from gl.PIXEL_UNPACK_BUFFER using imageSize and offset.

  • srcData
  • srcOffset Optional
    • : (WebGL 2 only) An integer specifying the index of srcData to start reading from. Defaults to 0.
  • srcLengthOverride Optional
    • : (WebGL 2 only) An integer specifying the number of elements in srcData to read. Defaults to srcData.length - srcOffset.
  • imageSize
    • : (WebGL 2 only) A GLsizei specifying the size of the image data in bytes.
  • offset
    • : (WebGL 2 only) A GLintptr specifying the starting address in the buffer bound to gl.PIXEL_UNPACK_BUFFER.

Return value

None (undefined).

Examples

const ext =
  gl.getExtension("WEBGL_compressed_texture_s3tc") ||
  gl.getExtension("MOZ_WEBGL_compressed_texture_s3tc") ||
  gl.getExtension("WEBKIT_WEBGL_compressed_texture_s3tc");
gl.compressedTexSubImage2D(
  gl.TEXTURE_2D,
  0,
  256,
  256,
  512,
  512,
  ext.COMPRESSED_RGBA_S3TC_DXT5_EXT,
  textureData,
);

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also