Re: [Mesa3d-dev] Status of s3tc patent in respect to open-source drivers and workarounds

[Philipp K. K. <pk...@sp...>]

Corbin Simpson schrieb:
> After re-reading ARB_texture_compression, it does seem like it is
> legal for extensions such as EXT_texture_compression_s3tc to fall
> back, using a basic mechanism: glGetTexLevelParameter can return
> GL_FALSE for GL_TEXTURE_COMPRESSED_ARB (now GL_TEXTURE_COMPRESSED) if
> the texture could not successfully be compressed. Issue (10) of
> ARB_texture_compression deals with this explicitly:

Yes, ARB_texture_compression allows to support decompression only. That
could probably be used to have decompression support for the S3TC
formats in Mesa. However, this does mean that
EXT_texture_compression_s3tc would be supported, since
EXT_texture_compression_s3tc does require support for encoding and the
wording in ARB_texture_compression does not change that.

Philipp