WebGLRenderingContext: compressedTexSubImage2D() method
The WebGLRenderingContext.compressedTexSubImage2D()
method of the WebGL API specifies a
two-dimensional sub-rectangle for a 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
js
// WebGL 1:
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, srcData)
// Additionally available in WebGL 2:
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, imageSize, offset)
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, srcData)
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, srcData, srcOffset)
compressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, srcData, srcOffset, srcLengthOverride)
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
-
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_s3tc_srgb
extension:ext.COMPRESSED_SRGB_S3TC_DXT1_EXT
ext.COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
ext.COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
ext.COMPRESSED_SRGB_ALPHA_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_astc
extension:ext.COMPRESSED_RGBA_ASTC_4x4_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR
ext.COMPRESSED_RGBA_ASTC_5x4_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR
ext.COMPRESSED_RGBA_ASTC_5x5_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR
ext.COMPRESSED_RGBA_ASTC_6x5_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR
ext.COMPRESSED_RGBA_ASTC_6x6_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR
ext.COMPRESSED_RGBA_ASTC_8x5_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR
ext.COMPRESSED_RGBA_ASTC_8x6_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR
ext.COMPRESSED_RGBA_ASTC_8x8_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR
ext.COMPRESSED_RGBA_ASTC_10x5_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR
ext.COMPRESSED_RGBA_ASTC_10x6_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR
ext.COMPRESSED_RGBA_ASTC_10x6_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR
ext.COMPRESSED_RGBA_ASTC_10x10_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR
ext.COMPRESSED_RGBA_ASTC_12x10_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR
ext.COMPRESSED_RGBA_ASTC_12x12_KHR ext.COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR
- When using the
EXT_texture_compression_bptc
extension:ext.COMPRESSED_RGBA_BPTC_UNORM_EXT
ext.COMPRESSED_SRGB_ALPHA_BPTC_UNORM_EXT
ext.COMPRESSED_RGB_BPTC_SIGNED_FLOAT_EXT
ext.COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_EXT
- When using the
EXT_texture_compression_rgtc
extension:ext.COMPRESSED_RED_RGTC1_EXT
ext.COMPRESSED_SIGNED_RED_RGTC1_EXT
ext.COMPRESSED_RED_GREEN_RGTC2_EXT
ext.COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT
- When using the
imageSize
-
A
GLsizei
specifying the number of bytes to read from the buffer bound togl.PIXEL_UNPACK_BUFFER
. offset
-
A
GLintptr
specifying the offset in bytes from which to read from the buffer bound togl.PIXEL_UNPACK_BUFFER
. srcData
-
A
TypedArray
or aDataView
that will be used as a data store for the compressed image data in memory.
Return value
None (undefined
).
Examples
js
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
Specification |
---|
WebGL Specification # COMPRESSEDTEXSUBIMAGE2D |
Browser compatibility
BCD tables only load in the browser
See also
- Using WebGL extensions
WebGLRenderingContext.getExtension()
WebGLRenderingContext.compressedTexImage2D()
WEBGL_compressed_texture_s3tc
WEBGL_compressed_texture_s3tc_srgb
WEBGL_compressed_texture_etc
WEBGL_compressed_texture_pvrtc
WEBGL_compressed_texture_astc
EXT_texture_compression_bptc
EXT_texture_compression_rgtc