GLCOMPRESSEDTEXIMAGE(3G)

📦

version 1.1 · 7 versions

1.1 · centos-stream 9 (latest)
arch rolling
1.1 · fedora 43
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1.0~svn33624 · debian trixie, ubuntu questing

, in centos-stream 9

💅 GLCOMPRESSEDTEXIMAGE(3G) 💅

okay so bestie, this is the 3G manual page for glCompressedTexImage3D, and we are diving in. buckle up 🎀

✨ NAME ✨

glCompressedTexImage3D — specify a three-dimensional texture image in a compressed format 🦋

🧚 C SPECIFICATION 🧚

void glCompressedTexImage3D(GLenum target, GLint level,
                            GLenum internalformat, GLsizei width,
                            GLsizei height, GLsizei depth, GLint border,
                            GLsizei imageSize, const GLvoid * data);

🌸 PARAMETERS 🌸

target — which texture slot we're loading into, bestie. has to be one of: GL_TEXTURE_3D, GL_PROXY_TEXTURE_3D, GL_TEXTURE_2D_ARRAY, or GL_PROXY_TEXTURE_2D_ARRAY.
level — the level-of-detail number, aka which mipmap stage u mean. level 0 is the base image level, and level n is the *n*th mipmap reduction image.
internalformat — the format of the compressed image data that's chillin' at address data.
width — how wide the texture image is. good news: literally all implementations support 3D texture images that are at least 16 texels wide.
height — how tall it is. and yeah, all implementations support 3D texture images that are at least 16 texels high too 💖
depth — how deep. same deal: all implementations support 3D texture images that are at least 16 texels deep.
border — this value must be 0. that's it. that's the whole vibe. don't fight it.
imageSize — the number of unsigned bytes of image data, starting at the address that data points to.
data — a pointer to the compressed image data in memory. the actual goods.

🔥 DESCRIPTION 🔥

texturing is what lets elements of an image array be read by shaders. iconic behavior honestly.

glCompressedTexImage3D loads a previously defined, and retrieved, compressed three-dimensional texture image — but only if target is GL_TEXTURE_3D (see glTexImage3D()).

if target is GL_TEXTURE_2D_ARRAY, then data is treated as an array of compressed 2D textures. cute, flexible, we love.

if target is GL_PROXY_TEXTURE_3D or GL_PROXY_TEXTURE_2D_ARRAY, no data is read from data — instead all of the texture image state gets recalculated, checked for consistency, and checked against what the implementation can actually handle. if the implementation can't handle a texture of the requested texture size, it sets all of the image state to 0, but — plot twist — it does not generate an error (see glGetError()). and if u wanna query for an entire mipmap array, use an image array level greater than or equal to 1.

internalformat must be a known compressed image format (like GL_RGTC) or an extension-specified compressed-texture format. here's the lore: when a texture is loaded with glTexImage2D() using a generic compressed texture format (e.g., GL_COMPRESSED_RGB), the GL picks one of its extensions that supports compressed textures. so to load that compressed texture image using glCompressedTexImage3D, u query the compressed texture image's size and format using glGetTexLevelParameter(). iykyk 🫶

if a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer()) while a texture image is specified, then data is treated as a byte offset into the buffer object's data store. sneaky but valid.

if the compressed data are arranged into fixed-size blocks of texels, the pixel storage modes can be used to select a sub-rectangle from a larger containing rectangle. these pixel storage modes operate in exactly the same way as they do for glTexImage1D(). and in the description below, we're denoting by bs, bw, bh, and bd the values of pixel storage modes GL_UNPACK_COMPRESSED_BLOCK_SIZE, GL_UNPACK_COMPRESSED_BLOCK_WIDTH, GL_UNPACK_COMPRESSED_BLOCK_HEIGHT, and GL_UNPACK_COMPRESSED_BLOCK_DEPTH, respectively. so: bs is the compressed block size in bytes, and bw, bh, and bd are the compressed block width, height, and depth in pixels. got it? good 💅

by default, the pixel storage modes GL_UNPACK_ROW_LENGTH, GL_UNPACK_SKIP_ROWS, GL_UNPACK_SKIP_PIXELS, GL_UNPACK_IMAGE_HEIGHT and GL_UNPACK_SKIP_IMAGES are ignored for compressed images. to enable GL_UNPACK_SKIP_PIXELS and GL_UNPACK_ROW_LENGTH, both bs and bw must be non-zero. to also enable GL_UNPACK_SKIP_ROWS and GL_UNPACK_IMAGE_HEIGHT, bh must be non-zero. to also enable GL_UNPACK_SKIP_IMAGES, bd must be non-zero. and all parameters must be consistent with the compressed format to actually produce the desired results — no cap.

🎀 when selecting a sub-rectangle from a compressed image 🎀

the value of GL_UNPACK_SKIP_PIXELS must be a multiple of bw;
the value of GL_UNPACK_SKIP_ROWS must be a multiple of bw;
the value of GL_UNPACK_SKIP_IMAGES must be a multiple of bw.

(no that's not a typo, they all say bw. live with it 🙈)

⭐ `imageSize` must be equal to: ⭐

b s × width b w × height b h × depth b d

👑 ERRORS 👑

GL_INVALID_ENUM is generated if internalformat is not one of the generic compressed internal formats: GL_COMPRESSED_RED, GL_COMPRESSED_RG, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA, GL_COMPRESSED_SRGB, or GL_COMPRESSED_SRGB_ALPHA.
GL_INVALID_VALUE is generated if imageSize is not consistent with the format, dimensions, and contents of the specified compressed image data.
GL_INVALID_VALUE is generated if border is not 0.
GL_INVALID_OPERATION is generated if parameter combinations are not supported by the specific compressed internal format, as specified in the specific texture compression extension.
GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object's data store is currently mapped.
GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the data would be unpacked from the buffer object such that the memory reads required would exceed the data store size.

💀 undefined results, including abnormal program termination, are generated if data is not encoded in a manner consistent with the extension specification defining the internal compression format. like, for real, don't do that. it's giving crash.

🌈 ASSOCIATED GETS 🌈

glGetCompressedTexImage()
glGet() with argument GL_TEXTURE_COMPRESSED
glGet() with argument GL_PIXEL_UNPACK_BUFFER_BINDING
glGetTexLevelParameter() with arguments GL_TEXTURE_INTERNAL_FORMAT and GL_TEXTURE_COMPRESSED_IMAGE_SIZE

💜 VERSION SUPPORT 💜

the original page ships this as a big grid, and the grid says exactly one thing, so here it is: glCompressedTexImage3D is supported in every OpenGL version listed, with a checkmark in each column. every single one. no gaps, no notes, just slay ✨

the function

glCompressedTexImage3D

the OpenGL versions it's supported in (all of them ✔)

2.0 ✔
2.1 ✔
3.0 ✔
3.1 ✔
3.2 ✔
3.3 ✔
4.0 ✔
4.1 ✔
4.2 ✔
4.3 ✔
4.4 ✔
4.5 ✔

🦋 SEE ALSO 🦋

glActiveTexture(), glCompressedTexImage1D(), glCompressedTexImage2D(), glCompressedTexSubImage1D(), glCompressedTexSubImage2D(), glCompressedTexSubImage3D(), glCopyTexImage1D(), glCopyTexSubImage1D(), glCopyTexSubImage2D(), glCopyTexSubImage3D(), glPixelStore(), glTexImage1D(), glTexImage2D(), glTexSubImage1D(), glTexSubImage2D(), glTexSubImage3D(), glTexParameter()

🌸 COPYRIGHT 🌸

okay that's the whole page, bestie, u ate that 🫶 this little sign-off situation: the page came from [FIXME: source] and it's dated 08/09/2021. go forth and compress ur textures responsibly 💖✨🎀

📦 where this page comes from

centos-stream 9: gl-manpages 1.1-24.20190306.el9 · MIT and Open Publication
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on 2026-11-04: a language model's rewrite of the original, under its terms