Tighten levelImages layout about ktx-specification HOT 5 CLOSED

I agree with these suggested changes. Please submit a PR for the z_slice change. For the other, what do you think of adding a new section Validity or something like that where we can gather this and issue #11 and other similar things?

from ktx-specification.

pixel{Depth,Height,Width} also need to be replaced with something that represents those values for uncompressed textures and the number of texel blocks for compressed textures. I suggest a postscript to the levelImages structure to give the definitions.

for each array_element in numberOfArrayElements 
   for each face in numberOfFaces 
       for each z_slice_of_blocks in num_blocks_z
           for each row_of_blocks in num_blocks_y
               for each block in num_blocks_x
                   Byte data[format-specific-number-of-bytes] 
               end
           end
       end
   end
end

where
num_blocks_{zyx} is

[stem]
+++
ceil(pixel{Depth,Height,Width} / texel_block_{depth,height,width})
+++

and texel_block_{depth,height,width} are 1 for uncompressed formats and the block size in that dimension for block compressed formats as given in that format's section of the Khronos Data Formats specification. A block is a single pixel for uncompressed formats and texel_block_{depth,width,height} pixels for block compressed formats.

This needs a :stem: in the attributes in the doc header to enable AsciiMathML processing. My attempt at mixing sh shortcuts with AsciiMathML will likely not work. It may be necessary to write separate equations for each item.

from ktx-specification.

@lexaknyazev what do you think of the idea of adding a Validity section in which we gather all the conditions that must be satisfied for a file to be considered valid?

from ktx-specification.

That seems to be more of a document design choice. We could put each restriction next to corresponding field description, or group all of them into a separate section. Given that KTX2 spec is quite compact, I don't see much difference.

from ktx-specification.

@lexaknyazev, let's not bother with a new section then. Please file a PR using adding the additional restriction where you see fit and using something like my updated comment above for the z_slice fix. Feel free to improve on what I've written.

from ktx-specification.