WebGLRenderingContext.compressedTexImage2D

The WebGLRenderingContext.compressedTexImage2D() method of the WebGL API specifies a two-dimensional texture image in a compressed format.

Compressed image formats must be enabled by WebGL extensions before using this method or a WebGL2RenderingContext must be used.

Syntax

// WebGL 1:
void gl.compressedTexImage2D(target, level, internalformat, width, height, border, ArrayBufferView? pixels);

// Additionally available in WebGL 2:
void gl.compressedTexImage2D(target, level, internalformat, width, height, border, GLintptr offset); 
void gl.compressedTexImage2D(target, level, internalformat, width, height, border, ArrayBufferView srcData, optional srcOffset, optional srcLengthOverride);

Parameters

target

A GLenum specifying the binding point (target) of the active 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 nth mipmap reduction level.

internalformat

A GLenum specifying the compressed image format. Compressed image formats must be enabled by WebGL extensions before using this method. Possible values:

• When using the WEBGL_compressed_texture_s3tc extension:
  • ext.COMPRESSED_RGB_S3TC_DXT1_EXT
  • ext.COMPRESSED_RGBA_S3TC_DXT1_EXT
  • ext.COMPRESSED_RGBA_S3TC_DXT3_EXT
  • ext.COMPRESSED_RGBA_S3TC_DXT5_EXT
• When using the WEBGL_compressed_texture_etc extension:
  • ext.COMPRESSED_R11_EAC
  • ext.COMPRESSED_SIGNED_R11_EAC
  • ext.COMPRESSED_RG11_EAC
  • ext.COMPRESSED_SIGNED_RG11_EAC
  • ext.COMPRESSED_RGB8_ETC2
  • ext.COMPRESSED_RGBA8_ETC2_EAC
  • ext.COMPRESSED_SRGB8_ETC2
  • ext.COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
  • ext.COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
  • ext.COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
• When using the WEBGL_compressed_texture_pvrtc extension:
  • ext.COMPRESSED_RGB_PVRTC_4BPPV1_IMG
  • ext.COMPRESSED_RGBA_PVRTC_4BPPV1_IMG
  • ext.COMPRESSED_RGB_PVRTC_2BPPV1_IMG
  • ext.COMPRESSED_RGBA_PVRTC_2BPPV1_IMG
• When using the WEBGL_compressed_texture_etc1 extension:
  • ext.COMPRESSED_RGB_ETC1_WEBGL
• When using the WEBGL_compressed_texture_atc extension:
  • ext.COMPRESSED_RGB_ATC_WEBGL
  • ext.COMPRESSED_RGBA_ATC_EXPLICIT_ALPHA_WEBGL
  • ext.COMPRESSED_RGBA_ATC_INTERPOLATED_ALPHA_WEBGL

width

A GLsizei specifying the width of the texture.

height

A GLsizei specifying the height of the texture.

border

A GLint specifying the width of the border. Must be 0.

pixels

A ArrayBufferView that be used as a data store for the compressed image data in memory.

Return value

None.

Examples

var ext = (
  gl.getExtension('WEBGL_compressed_texture_s3tc') ||
  gl.getExtension('MOZ_WEBGL_compressed_texture_s3tc') ||
  gl.getExtension('WEBKIT_WEBGL_compressed_texture_s3tc')
);

var texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, ext.COMPRESSED_RGBA_S3TC_DXT5_EXT, 512, 512, 0, textureData); 
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);

Specifications

Specification	Status	Comment
WebGL 1.0 The definition of 'compressedTexImage2D' in that specification.	Recommendation	Initial definition for WebGL.
OpenGL ES 2.0 The definition of 'glCompressedTexImage2D' in that specification.	Standard	Man page of the (similar) OpenGL ES 2.0 API.
OpenGL ES 3.0 The definition of 'glCompressedTexImage2D' in that specification.	Standard	Man page of the (similar) OpenGL ES 3.0 API.

Browser compatibility

See also

• Using WebGL extensions
• WebGLRenderingContext.compressedTexSubImage2D()
• WEBGL_compressed_texture_s3tc
• WEBGL_compressed_texture_etc
• WEBGL_compressed_texture_pvrtc
• WEBGL_compressed_texture_etc1
• WEBGL_compressed_texture_atc