mmozeiko

> Inverses exist for each operation, which makes decryption possible.

It is worth mentioning that in modern AES usage this feature does not really matter, because block cipher is used in CTR mode. In CTR block cipher is used to create long keystream bytes (pretty much one-time-pad key). This keystream gets xor'ed with plaintext to get ciphertext. Then getting from ciphertext back to plaintext is exactly the same xor operation with same keystream, no inverse AES operations needed.

xor swap trick was useful in older simd (sse1/sse2) when based on some condition you want to swap values or not:

  tmp = (a ^ b) & mask
  a ^= tmp
  b ^= tmp

If mask = 0xfff...fff then a/b will be swapped, otherwise if mask = 0 then they'll remain the same.

How does it compare to rendering SVG by Direct2D itself? When using ID2D1DeviceContext5::DrawSvgDocument method, and ID2D1SvgDocument can be loaded from file with ID2D1DeviceContext5::CreateSvgDocument + SHCreateStreamOnFileW.

Ah, I see. Yeah, then the current approach is fine.

From what I understand from code those unwarps are just doing matrix multiply to get unwraped pixel location? In this case doing these operations directly in fragment shader instead of texture lookup will be faster. Memory bandwidth is not free. But simple ALU like this (just couple FMA's) can easily hide in shadow of texture sampling that happens afterwards. So simply upload those undistortion matrices (mat1 & mat2) as uniforms and do matrix multiply in shader for adjusting texcoords.

There's also Windows.Graphics.Capture. It allows to get texture not only for whole desktop, but just individual windows.

If you change logic and/or to bitwise and/or then it'll be branchless.