New quaternion in HLSL

[keptsecret]

No description provided.

[devshgraphicsprogramming]

okay, the promotion makes this expensive, you need to change the signature to

template <typename T, typename U=T>
NBL_CONSTEXPR_FUNC T flipSignIfRHSNegative(T val, U flip)

and then add a partial specialization of flipSignIfRHSNegative_helper<Vectorial,typename vertor_traits<Vectorial>::scalar_type>

which does

		using traits_v = hlsl::vector_traits<Vectorial>;
		using scalar_t = typename traits_v::scalar_type;

		using AsUint = typename unsigned_integer_of_size<sizeof(FloatingPoint)>::type;
		const AsUint signFlipBit = ieee754::traits<scalar_t>::signMask & ieee754::impl::bitCastToUintType(flip);
		
		Vectorial output;
		array_get<Vectorial, scalar_t> getter_v;
		for (uint32_t i = 0; i < traits_v::Dimension; ++i)
		    setter(output,i, ieee754::impl::bitCastToUintType(getter_v(val,i))^signFlipBit );

[devshgraphicsprogramming]

btw the comment about benchmark is no longer applicable, I realized that when totalPseudoAngle = 0 you have two different quaternions you can still interpolate between by a fraction which when normalized will produce a valid quaternion

(there's two 4D directions which are orthogonal, the resulting quaternion's data member is interpolated between them on shortest path / within a plane spanned by them, then after normalization its like interpolating on a 4D sphere great circle)

So we can't make the adjEnd = 0 in that case and code needs to stay as is, and all the above explanation needs to go in the comment instead of the TODO.

Btw there's a bit of a funny situation where we interpolate towards a different adjEnd when it dips slightly more than 90 degrees away from start in 4D space, thats correct but I don't yet have an understanding of why. My intuition tells me its because quaternions can represent 720 degree rotations and not just 360 due to half-angles being used in the definition, so its something to make the final rotation be performed "along the shortest path"

[devshgraphicsprogramming]

does HLSL not like the unary minus operator ?

[keptsecret]

That is the unary operator, isn't it? Only the scalar component of the inverse isn't negated for a quaternion.

[devshgraphicsprogramming]

I mean to have a this_t operator-() NBL_CONST_METHOD { instead of inverse()

even though HLSL can't overload resolve these operators for a -q call, you can still call them as q.operator-()

[devshgraphicsprogramming]

wrong check, truncated should never be 1.0 (thats kinda the point, because it reconstructs w = 1-length(xyz), I have no clue how your tests passed in a Debug build (where asserts work)

Anyway I think that it makes no sense to have a normalize specialization for truncated quaternion. so can just delete the struct

[devshgraphicsprogramming]

just get rid of the F template argument, it will be much easier

[devshgraphicsprogramming]

1. do you mean mul(pitch,mul(yaw,mul(roll,v))) or mul(roll,yaw,mul(pitch,v)))
2. around what axes https://math.stackexchange.com/questions/3526500/relating-pitch-roll-and-yaw-to-rotations-about-the-x-y-z-axis

The question is that "for our imaginary aircraft" which axis is pitch yaw roll