I looked into this further and spoke to ATI. We should be generating
an invalid enum in the framework when attempting to use compressed
textures with the rectangle target. It's not supported in the driver
and is documented as such:
http://developer.apple.com/graphicsimaging/opengl/extensions/
ext_texture_rectangle.html:
* What is the status of the use of texture compression in
conjunction with this extension?
While texture compression is not specifically precluded, certain
compression schemes are incompatible with rectangular textures
thus
compressed internal textures formats, in general, are not
supported
with this extension.
- (3.8.3, pg. 129) "Compressed Texture Images"
Add the following paragraph after the second paragraph in the
section, which introduces the CompressedTexImage<n>DARB commands:
"The error INVALID_ENUM is generated if the target parameter to
one
of the CompressedTexImage<n>DARB commands is
TEXTURE_RECTANGLE_EXT."
Add the following paragraph after introducing the
CompressedTexSubImage<n>DARB commands: "The error INVALID_ENUM is
generated if the target parameter to one of the
CompressedTexSubImage<n>DARB commands is TEXTURE_RECTANGLE_EXT."
Did you check the glError() state after making the call to
glCompressTexImage2D ?
