Cleanup.

include/bx/inline/math.inl

@@ -691,461 +691,6 @@ namespace bx
 		mtxQuatTranslation(_result, quat, _translation);
 	}
 
-	inline void mtxLookAtImpl(float* _result, const float* _eye, const float* _view, const float* _up)
-	{
-		float up[3] = { 0.0f, 1.0f, 0.0f };
-		if (NULL != _up)
-		{
-			up[0] = _up[0];
-			up[1] = _up[1];
-			up[2] = _up[2];
-		}
-
-		float tmp[4];
-		vec3Cross(tmp, up, _view);
-
-		float right[4];
-		vec3Norm(right, tmp);
-
-		vec3Cross(up, _view, right);
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = right[0];
-		_result[ 1] = up[0];
-		_result[ 2] = _view[0];
-
-		_result[ 4] = right[1];
-		_result[ 5] = up[1];
-		_result[ 6] = _view[1];
-
-		_result[ 8] = right[2];
-		_result[ 9] = up[2];
-		_result[10] = _view[2];
-
-		_result[12] = -vec3Dot(right, _eye);
-		_result[13] = -vec3Dot(up, _eye);
-		_result[14] = -vec3Dot(_view, _eye);
-		_result[15] = 1.0f;
-	}
-
-	inline void mtxLookAtLh(float* _result, const float* _eye, const float* _at, const float* _up)
-	{
-		float tmp[4];
-		vec3Sub(tmp, _at, _eye);
-
-		float view[4];
-		vec3Norm(view, tmp);
-
-		mtxLookAtImpl(_result, _eye, view, _up);
-	}
-
-	inline void mtxLookAtRh(float* _result, const float* _eye, const float* _at, const float* _up)
-	{
-		float tmp[4];
-		vec3Sub(tmp, _eye, _at);
-
-		float view[4];
-		vec3Norm(view, tmp);
-
-		mtxLookAtImpl(_result, _eye, view, _up);
-	}
-
-	inline void mtxLookAt(float* _result, const float* _eye, const float* _at, const float* _up)
-	{
-		mtxLookAtLh(_result, _eye, _at, _up);
-	}
-
-	template<Handness::Enum HandnessT>
-	inline void mtxProjXYWH(float* _result, float _x, float _y, float _width, float _height, float _near, float _far, bool _oglNdc)
-	{
-		const float diff = _far-_near;
-		const float aa = _oglNdc ? (     _far+_near)/diff : _far/diff;
-		const float bb = _oglNdc ? (2.0f*_far*_near)/diff : _near*aa;
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = _width;
-		_result[ 5] = _height;
-		_result[ 8] = (Handness::Right == HandnessT) ?    _x :  -_x;
-		_result[ 9] = (Handness::Right == HandnessT) ?    _y :  -_y;
-		_result[10] = (Handness::Right == HandnessT) ?   -aa :   aa;
-		_result[11] = (Handness::Right == HandnessT) ? -1.0f : 1.0f;
-		_result[14] = -bb;
-	}
-
-	template<Handness::Enum HandnessT>
-	inline void mtxProjImpl(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, float _far, bool _oglNdc)
-	{
-		const float invDiffRl = 1.0f/(_rt - _lt);
-		const float invDiffUd = 1.0f/(_ut - _dt);
-		const float width  =  2.0f*_near * invDiffRl;
-		const float height =  2.0f*_near * invDiffUd;
-		const float xx     = (_rt + _lt) * invDiffRl;
-		const float yy     = (_ut + _dt) * invDiffUd;
-		mtxProjXYWH<HandnessT>(_result, xx, yy, width, height, _near, _far, _oglNdc);
-	}
-
-	template<Handness::Enum HandnessT>
-	inline void mtxProjImpl(float* _result, const float _fov[4], float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<HandnessT>(_result, _fov[0], _fov[1], _fov[2], _fov[3], _near, _far, _oglNdc);
-	}
-
-	template<Handness::Enum HandnessT>
-	inline void mtxProjImpl(float* _result, float _fovy, float _aspect, float _near, float _far, bool _oglNdc)
-	{
-		const float height = 1.0f/ftan(toRad(_fovy)*0.5f);
-		const float width  = height * 1.0f/_aspect;
-		mtxProjXYWH<HandnessT>(_result, 0.0f, 0.0f, width, height, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProj(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProj(float* _result, const float _fov[4], float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Left>(_result, _fov, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProj(float* _result, float _fovy, float _aspect, float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Left>(_result, _fovy, _aspect, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProjLh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProjLh(float* _result, const float _fov[4], float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Left>(_result, _fov, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProjLh(float* _result, float _fovy, float _aspect, float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Left>(_result, _fovy, _aspect, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProjRh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Right>(_result, _ut, _dt, _lt, _rt, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProjRh(float* _result, const float _fov[4], float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Right>(_result, _fov, _near, _far, _oglNdc);
-	}
-
-	inline void mtxProjRh(float* _result, float _fovy, float _aspect, float _near, float _far, bool _oglNdc)
-	{
-		mtxProjImpl<Handness::Right>(_result, _fovy, _aspect, _near, _far, _oglNdc);
-	}
-
-	template<NearFar::Enum NearFarT, Handness::Enum HandnessT>
-	inline void mtxProjInfXYWH(float* _result, float _x, float _y, float _width, float _height, float _near, bool _oglNdc)
-	{
-		float aa;
-		float bb;
-		if (BX_ENABLED(NearFar::Reverse == NearFarT) )
-		{
-			aa = _oglNdc ?       -1.0f :   0.0f;
-			bb = _oglNdc ? -2.0f*_near : -_near;
-		}
-		else
-		{
-			aa = 1.0f;
-			bb = _oglNdc ? 2.0f*_near : _near;
-		}
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = _width;
-		_result[ 5] = _height;
-		_result[ 8] = (Handness::Right == HandnessT) ?    _x :  -_x;
-		_result[ 9] = (Handness::Right == HandnessT) ?    _y :  -_y;
-		_result[10] = (Handness::Right == HandnessT) ?   -aa :   aa;
-		_result[11] = (Handness::Right == HandnessT) ? -1.0f : 1.0f;
-		_result[14] = -bb;
-	}
-
-	template<NearFar::Enum NearFarT, Handness::Enum HandnessT>
-	inline void mtxProjInfImpl(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
-	{
-		const float invDiffRl = 1.0f/(_rt - _lt);
-		const float invDiffUd = 1.0f/(_ut - _dt);
-		const float width  =  2.0f*_near * invDiffRl;
-		const float height =  2.0f*_near * invDiffUd;
-		const float xx     = (_rt + _lt) * invDiffRl;
-		const float yy     = (_ut + _dt) * invDiffUd;
-		mtxProjInfXYWH<NearFarT,HandnessT>(_result, xx, yy, width, height, _near, _oglNdc);
-	}
-
-	template<NearFar::Enum NearFarT, Handness::Enum HandnessT>
-	inline void mtxProjInfImpl(float* _result, const float _fov[4], float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFarT,HandnessT>(_result, _fov[0], _fov[1], _fov[2], _fov[3], _near, _oglNdc);
-	}
-
-	template<NearFar::Enum NearFarT, Handness::Enum HandnessT>
-	inline void mtxProjInfImpl(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
-	{
-		const float height = 1.0f/ftan(toRad(_fovy)*0.5f);
-		const float width  = height * 1.0f/_aspect;
-		mtxProjInfXYWH<NearFarT,HandnessT>(_result, 0.0f, 0.0f, width, height, _near, _oglNdc);
-	}
-
-	inline void mtxProjInf(float* _result, const float _fov[4], float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _fov, _near, _oglNdc);
-	}
-
-	inline void mtxProjInf(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
-	}
-
-	inline void mtxProjInf(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _fovy, _aspect, _near, _oglNdc);
-	}
-
-	inline void mtxProjInfLh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
-	}
-
-	inline void mtxProjInfLh(float* _result, const float _fov[4], float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _fov, _near, _oglNdc);
-	}
-
-	inline void mtxProjInfLh(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _fovy, _aspect, _near, _oglNdc);
-	}
-
-	inline void mtxProjInfRh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Right>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
-	}
-
-	inline void mtxProjInfRh(float* _result, const float _fov[4], float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Right>(_result, _fov, _near, _oglNdc);
-	}
-
-	inline void mtxProjInfRh(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Default,Handness::Right>(_result, _fovy, _aspect, _near, _oglNdc);
-	}
-
-	inline void mtxProjRevInfLh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Reverse,Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
-	}
-
-	inline void mtxProjRevInfLh(float* _result, const float _fov[4], float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Reverse,Handness::Left>(_result, _fov, _near, _oglNdc);
-	}
-
-	inline void mtxProjRevInfLh(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Reverse,Handness::Left>(_result, _fovy, _aspect, _near, _oglNdc);
-	}
-
-	inline void mtxProjRevInfRh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Reverse,Handness::Right>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
-	}
-
-	inline void mtxProjRevInfRh(float* _result, const float _fov[4], float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Reverse,Handness::Right>(_result, _fov, _near, _oglNdc);
-	}
-
-	inline void mtxProjRevInfRh(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
-	{
-		mtxProjInfImpl<NearFar::Reverse,Handness::Right>(_result, _fovy, _aspect, _near, _oglNdc);
-	}
-
-	template<Handness::Enum HandnessT>
-	inline void mtxOrthoImpl(float* _result, float _left, float _right, float _bottom, float _top, float _near, float _far, float _offset, bool _oglNdc)
-	{
-		const float aa = 2.0f/(_right - _left);
-		const float bb = 2.0f/(_top - _bottom);
-		const float cc = (_oglNdc ? 2.0f : 1.0f) / (_far - _near);
-		const float dd = (_left + _right )/(_left   - _right);
-		const float ee = (_top  + _bottom)/(_bottom - _top  );
-		const float ff = _oglNdc
-			? (_near + _far)/(_near - _far)
-			:  _near        /(_near - _far)
-			;
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = aa;
-		_result[ 5] = bb;
-		_result[10] = (Handness::Right == HandnessT) ? -cc : cc;
-		_result[12] = dd + _offset;
-		_result[13] = ee;
-		_result[14] = ff;
-		_result[15] = 1.0f;
-	}
-
-	inline void mtxOrtho(float* _result, float _left, float _right, float _bottom, float _top, float _near, float _far, float _offset, bool _oglNdc)
-	{
-		mtxOrthoImpl<Handness::Left>(_result, _left, _right, _bottom, _top, _near, _far, _offset, _oglNdc);
-	}
-
-	inline void mtxOrthoLh(float* _result, float _left, float _right, float _bottom, float _top, float _near, float _far, float _offset, bool _oglNdc)
-	{
-		mtxOrthoImpl<Handness::Left>(_result, _left, _right, _bottom, _top, _near, _far, _offset, _oglNdc);
-	}
-
-	inline void mtxOrthoRh(float* _result, float _left, float _right, float _bottom, float _top, float _near, float _far, float _offset, bool _oglNdc)
-	{
-		mtxOrthoImpl<Handness::Right>(_result, _left, _right, _bottom, _top, _near, _far, _offset, _oglNdc);
-	}
-
-	inline void mtxRotateX(float* _result, float _ax)
-	{
-		const float sx = fsin(_ax);
-		const float cx = fcos(_ax);
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = 1.0f;
-		_result[ 5] = cx;
-		_result[ 6] = -sx;
-		_result[ 9] = sx;
-		_result[10] = cx;
-		_result[15] = 1.0f;
-	}
-
-	inline void mtxRotateY(float* _result, float _ay)
-	{
-		const float sy = fsin(_ay);
-		const float cy = fcos(_ay);
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = cy;
-		_result[ 2] = sy;
-		_result[ 5] = 1.0f;
-		_result[ 8] = -sy;
-		_result[10] = cy;
-		_result[15] = 1.0f;
-	}
-
-	inline void mtxRotateZ(float* _result, float _az)
-	{
-		const float sz = fsin(_az);
-		const float cz = fcos(_az);
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = cz;
-		_result[ 1] = -sz;
-		_result[ 4] = sz;
-		_result[ 5] = cz;
-		_result[10] = 1.0f;
-		_result[15] = 1.0f;
-	}
-
-	inline void mtxRotateXY(float* _result, float _ax, float _ay)
-	{
-		const float sx = fsin(_ax);
-		const float cx = fcos(_ax);
-		const float sy = fsin(_ay);
-		const float cy = fcos(_ay);
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = cy;
-		_result[ 2] = sy;
-		_result[ 4] = sx*sy;
-		_result[ 5] = cx;
-		_result[ 6] = -sx*cy;
-		_result[ 8] = -cx*sy;
-		_result[ 9] = sx;
-		_result[10] = cx*cy;
-		_result[15] = 1.0f;
-	}
-
-	inline void mtxRotateXYZ(float* _result, float _ax, float _ay, float _az)
-	{
-		const float sx = fsin(_ax);
-		const float cx = fcos(_ax);
-		const float sy = fsin(_ay);
-		const float cy = fcos(_ay);
-		const float sz = fsin(_az);
-		const float cz = fcos(_az);
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = cy*cz;
-		_result[ 1] = -cy*sz;
-		_result[ 2] = sy;
-		_result[ 4] = cz*sx*sy + cx*sz;
-		_result[ 5] = cx*cz - sx*sy*sz;
-		_result[ 6] = -cy*sx;
-		_result[ 8] = -cx*cz*sy + sx*sz;
-		_result[ 9] = cz*sx + cx*sy*sz;
-		_result[10] = cx*cy;
-		_result[15] = 1.0f;
-	}
-
-	inline void mtxRotateZYX(float* _result, float _ax, float _ay, float _az)
-	{
-		const float sx = fsin(_ax);
-		const float cx = fcos(_ax);
-		const float sy = fsin(_ay);
-		const float cy = fcos(_ay);
-		const float sz = fsin(_az);
-		const float cz = fcos(_az);
-
-		memSet(_result, 0, sizeof(float)*16);
-		_result[ 0] = cy*cz;
-		_result[ 1] = cz*sx*sy-cx*sz;
-		_result[ 2] = cx*cz*sy+sx*sz;
-		_result[ 4] = cy*sz;
-		_result[ 5] = cx*cz + sx*sy*sz;
-		_result[ 6] = -cz*sx + cx*sy*sz;
-		_result[ 8] = -sy;
-		_result[ 9] = cy*sx;
-		_result[10] = cx*cy;
-		_result[15] = 1.0f;
-	};
-
-	inline void mtxSRT(float* _result, float _sx, float _sy, float _sz, float _ax, float _ay, float _az, float _tx, float _ty, float _tz)
-	{
-		const float sx = fsin(_ax);
-		const float cx = fcos(_ax);
-		const float sy = fsin(_ay);
-		const float cy = fcos(_ay);
-		const float sz = fsin(_az);
-		const float cz = fcos(_az);
-
-		const float sxsz = sx*sz;
-		const float cycz = cy*cz;
-
-		_result[ 0] = _sx * (cycz - sxsz*sy);
-		_result[ 1] = _sx * -cx*sz;
-		_result[ 2] = _sx * (cz*sy + cy*sxsz);
-		_result[ 3] = 0.0f;
-
-		_result[ 4] = _sy * (cz*sx*sy + cy*sz);
-		_result[ 5] = _sy * cx*cz;
-		_result[ 6] = _sy * (sy*sz -cycz*sx);
-		_result[ 7] = 0.0f;
-
-		_result[ 8] = _sz * -cx*sy;
-		_result[ 9] = _sz * sx;
-		_result[10] = _sz * cx*cy;
-		_result[11] = 0.0f;
-
-		_result[12] = _tx;
-		_result[13] = _ty;
-		_result[14] = _tz;
-		_result[15] = 1.0f;
-	}
-
 	inline void vec3MulMtx(float* _result, const float* _vec, const float* _mat)
 	{
 		_result[0] = _vec[0] * _mat[ 0] + _vec[1] * _mat[4] + _vec[2] * _mat[ 8] + _mat[12];
@@ -1268,123 +813,4 @@ namespace bx
 		_result[3] = -vec3Dot(normal, _va);
 	}
 
-	inline void calcLinearFit2D(float _result[2], const void* _points, uint32_t _stride, uint32_t _numPoints)
-	{
-		float sumX  = 0.0f;
-		float sumY  = 0.0f;
-		float sumXX = 0.0f;
-		float sumXY = 0.0f;
-
-		const uint8_t* ptr = (const uint8_t*)_points;
-		for (uint32_t ii = 0; ii < _numPoints; ++ii, ptr += _stride)
-		{
-			const float* point = (const float*)ptr;
-			float xx = point[0];
-			float yy = point[1];
-			sumX  += xx;
-			sumY  += yy;
-			sumXX += xx*xx;
-			sumXY += xx*yy;
-		}
-
-		// [ sum(x^2) sum(x)    ] [ A ] = [ sum(x*y) ]
-		// [ sum(x)   numPoints ] [ B ]   [ sum(y)   ]
-
-		float det = (sumXX*_numPoints - sumX*sumX);
-		float invDet = 1.0f/det;
-
-		_result[0] = (-sumX * sumY + _numPoints * sumXY) * invDet;
-		_result[1] = (sumXX * sumY - sumX       * sumXY) * invDet;
-	}
-
-	inline void calcLinearFit3D(float _result[3], const void* _points, uint32_t _stride, uint32_t _numPoints)
-	{
-		float sumX  = 0.0f;
-		float sumY  = 0.0f;
-		float sumZ  = 0.0f;
-		float sumXX = 0.0f;
-		float sumXY = 0.0f;
-		float sumXZ = 0.0f;
-		float sumYY = 0.0f;
-		float sumYZ = 0.0f;
-
-		const uint8_t* ptr = (const uint8_t*)_points;
-		for (uint32_t ii = 0; ii < _numPoints; ++ii, ptr += _stride)
-		{
-			const float* point = (const float*)ptr;
-			float xx = point[0];
-			float yy = point[1];
-			float zz = point[2];
-
-			sumX  += xx;
-			sumY  += yy;
-			sumZ  += zz;
-			sumXX += xx*xx;
-			sumXY += xx*yy;
-			sumXZ += xx*zz;
-			sumYY += yy*yy;
-			sumYZ += yy*zz;
-		}
-
-		// [ sum(x^2) sum(x*y) sum(x)    ] [ A ]   [ sum(x*z) ]
-		// [ sum(x*y) sum(y^2) sum(y)    ] [ B ] = [ sum(y*z) ]
-		// [ sum(x)   sum(y)   numPoints ] [ C ]   [ sum(z)   ]
-
-		float mtx[9] =
-		{
-			sumXX, sumXY, sumX,
-			sumXY, sumYY, sumY,
-			sumX,  sumY,  float(_numPoints),
-		};
-		float invMtx[9];
-		mtx3Inverse(invMtx, mtx);
-
-		_result[0] = invMtx[0]*sumXZ + invMtx[1]*sumYZ + invMtx[2]*sumZ;
-		_result[1] = invMtx[3]*sumXZ + invMtx[4]*sumYZ + invMtx[5]*sumZ;
-		_result[2] = invMtx[6]*sumXZ + invMtx[7]*sumYZ + invMtx[8]*sumZ;
-	}
-
-	inline void rgbToHsv(float _hsv[3], const float _rgb[3])
-	{
-		const float rr = _rgb[0];
-		const float gg = _rgb[1];
-		const float bb = _rgb[2];
-
-		const float s0 = fstep(bb, gg);
-
-		const float px = flerp(bb,        gg,         s0);
-		const float py = flerp(gg,        bb,         s0);
-		const float pz = flerp(-1.0f,     0.0f,       s0);
-		const float pw = flerp(2.0f/3.0f, -1.0f/3.0f, s0);
-
-		const float s1 = fstep(px, rr);
-
-		const float qx = flerp(px, rr, s1);
-		const float qy = py;
-		const float qz = flerp(pw, pz, s1);
-		const float qw = flerp(rr, px, s1);
-
-		const float dd = qx - fmin(qw, qy);
-		const float ee = 1.0e-10f;
-
-		_hsv[0] = fabsolute(qz + (qw - qy) / (6.0f * dd + ee) );
-		_hsv[1] = dd / (qx + ee);
-		_hsv[2] = qx;
-	}
-
-	inline void hsvToRgb(float _rgb[3], const float _hsv[3])
-	{
-		const float hh = _hsv[0];
-		const float ss = _hsv[1];
-		const float vv = _hsv[2];
-
-		const float px = fabsolute(ffract(hh + 1.0f     ) * 6.0f - 3.0f);
-		const float py = fabsolute(ffract(hh + 2.0f/3.0f) * 6.0f - 3.0f);
-		const float pz = fabsolute(ffract(hh + 1.0f/3.0f) * 6.0f - 3.0f);
-
-		_rgb[0] = vv * flerp(1.0f, fsaturate(px - 1.0f), ss);
-		_rgb[1] = vv * flerp(1.0f, fsaturate(py - 1.0f), ss);
-		_rgb[2] = vv * flerp(1.0f, fsaturate(pz - 1.0f), ss);
-	}
-
 } // namespace bx

src/math.cpp

@@ -85,6 +85,461 @@ namespace bx
 		return ::fmodf(_a, _b);
 	}
 
+	void mtxLookAtImpl(float* _result, const float* _eye, const float* _view, const float* _up)
+	{
+		float up[3] = { 0.0f, 1.0f, 0.0f };
+		if (NULL != _up)
+		{
+			up[0] = _up[0];
+			up[1] = _up[1];
+			up[2] = _up[2];
+		}
+
+		float tmp[4];
+		vec3Cross(tmp, up, _view);
+
+		float right[4];
+		vec3Norm(right, tmp);
+
+		vec3Cross(up, _view, right);
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = right[0];
+		_result[ 1] = up[0];
+		_result[ 2] = _view[0];
+
+		_result[ 4] = right[1];
+		_result[ 5] = up[1];
+		_result[ 6] = _view[1];
+
+		_result[ 8] = right[2];
+		_result[ 9] = up[2];
+		_result[10] = _view[2];
+
+		_result[12] = -vec3Dot(right, _eye);
+		_result[13] = -vec3Dot(up, _eye);
+		_result[14] = -vec3Dot(_view, _eye);
+		_result[15] = 1.0f;
+	}
+
+	void mtxLookAtLh(float* _result, const float* _eye, const float* _at, const float* _up)
+	{
+		float tmp[4];
+		vec3Sub(tmp, _at, _eye);
+
+		float view[4];
+		vec3Norm(view, tmp);
+
+		mtxLookAtImpl(_result, _eye, view, _up);
+	}
+
+	void mtxLookAtRh(float* _result, const float* _eye, const float* _at, const float* _up)
+	{
+		float tmp[4];
+		vec3Sub(tmp, _eye, _at);
+
+		float view[4];
+		vec3Norm(view, tmp);
+
+		mtxLookAtImpl(_result, _eye, view, _up);
+	}
+
+	void mtxLookAt(float* _result, const float* _eye, const float* _at, const float* _up)
+	{
+		mtxLookAtLh(_result, _eye, _at, _up);
+	}
+
+	template<Handness::Enum HandnessT>
+	void mtxProjXYWH(float* _result, float _x, float _y, float _width, float _height, float _near, float _far, bool _oglNdc)
+	{
+		const float diff = _far-_near;
+		const float aa = _oglNdc ? (     _far+_near)/diff : _far/diff;
+		const float bb = _oglNdc ? (2.0f*_far*_near)/diff : _near*aa;
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = _width;
+		_result[ 5] = _height;
+		_result[ 8] = (Handness::Right == HandnessT) ?    _x :  -_x;
+		_result[ 9] = (Handness::Right == HandnessT) ?    _y :  -_y;
+		_result[10] = (Handness::Right == HandnessT) ?   -aa :   aa;
+		_result[11] = (Handness::Right == HandnessT) ? -1.0f : 1.0f;
+		_result[14] = -bb;
+	}
+
+	template<Handness::Enum HandnessT>
+	void mtxProjImpl(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, float _far, bool _oglNdc)
+	{
+		const float invDiffRl = 1.0f/(_rt - _lt);
+		const float invDiffUd = 1.0f/(_ut - _dt);
+		const float width  =  2.0f*_near * invDiffRl;
+		const float height =  2.0f*_near * invDiffUd;
+		const float xx     = (_rt + _lt) * invDiffRl;
+		const float yy     = (_ut + _dt) * invDiffUd;
+		mtxProjXYWH<HandnessT>(_result, xx, yy, width, height, _near, _far, _oglNdc);
+	}
+
+	template<Handness::Enum HandnessT>
+	void mtxProjImpl(float* _result, const float _fov[4], float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<HandnessT>(_result, _fov[0], _fov[1], _fov[2], _fov[3], _near, _far, _oglNdc);
+	}
+
+	template<Handness::Enum HandnessT>
+	void mtxProjImpl(float* _result, float _fovy, float _aspect, float _near, float _far, bool _oglNdc)
+	{
+		const float height = 1.0f/ftan(toRad(_fovy)*0.5f);
+		const float width  = height * 1.0f/_aspect;
+		mtxProjXYWH<HandnessT>(_result, 0.0f, 0.0f, width, height, _near, _far, _oglNdc);
+	}
+
+	void mtxProj(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _far, _oglNdc);
+	}
+
+	void mtxProj(float* _result, const float _fov[4], float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Left>(_result, _fov, _near, _far, _oglNdc);
+	}
+
+	void mtxProj(float* _result, float _fovy, float _aspect, float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Left>(_result, _fovy, _aspect, _near, _far, _oglNdc);
+	}
+
+	void mtxProjLh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _far, _oglNdc);
+	}
+
+	void mtxProjLh(float* _result, const float _fov[4], float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Left>(_result, _fov, _near, _far, _oglNdc);
+	}
+
+	void mtxProjLh(float* _result, float _fovy, float _aspect, float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Left>(_result, _fovy, _aspect, _near, _far, _oglNdc);
+	}
+
+	void mtxProjRh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Right>(_result, _ut, _dt, _lt, _rt, _near, _far, _oglNdc);
+	}
+
+	void mtxProjRh(float* _result, const float _fov[4], float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Right>(_result, _fov, _near, _far, _oglNdc);
+	}
+
+	void mtxProjRh(float* _result, float _fovy, float _aspect, float _near, float _far, bool _oglNdc)
+	{
+		mtxProjImpl<Handness::Right>(_result, _fovy, _aspect, _near, _far, _oglNdc);
+	}
+
+	template<NearFar::Enum NearFarT, Handness::Enum HandnessT>
+	void mtxProjInfXYWH(float* _result, float _x, float _y, float _width, float _height, float _near, bool _oglNdc)
+	{
+		float aa;
+		float bb;
+		if (BX_ENABLED(NearFar::Reverse == NearFarT) )
+		{
+			aa = _oglNdc ?       -1.0f :   0.0f;
+			bb = _oglNdc ? -2.0f*_near : -_near;
+		}
+		else
+		{
+			aa = 1.0f;
+			bb = _oglNdc ? 2.0f*_near : _near;
+		}
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = _width;
+		_result[ 5] = _height;
+		_result[ 8] = (Handness::Right == HandnessT) ?    _x :  -_x;
+		_result[ 9] = (Handness::Right == HandnessT) ?    _y :  -_y;
+		_result[10] = (Handness::Right == HandnessT) ?   -aa :   aa;
+		_result[11] = (Handness::Right == HandnessT) ? -1.0f : 1.0f;
+		_result[14] = -bb;
+	}
+
+	template<NearFar::Enum NearFarT, Handness::Enum HandnessT>
+	void mtxProjInfImpl(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
+	{
+		const float invDiffRl = 1.0f/(_rt - _lt);
+		const float invDiffUd = 1.0f/(_ut - _dt);
+		const float width  =  2.0f*_near * invDiffRl;
+		const float height =  2.0f*_near * invDiffUd;
+		const float xx     = (_rt + _lt) * invDiffRl;
+		const float yy     = (_ut + _dt) * invDiffUd;
+		mtxProjInfXYWH<NearFarT,HandnessT>(_result, xx, yy, width, height, _near, _oglNdc);
+	}
+
+	template<NearFar::Enum NearFarT, Handness::Enum HandnessT>
+	void mtxProjInfImpl(float* _result, const float _fov[4], float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFarT,HandnessT>(_result, _fov[0], _fov[1], _fov[2], _fov[3], _near, _oglNdc);
+	}
+
+	template<NearFar::Enum NearFarT, Handness::Enum HandnessT>
+	void mtxProjInfImpl(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
+	{
+		const float height = 1.0f/ftan(toRad(_fovy)*0.5f);
+		const float width  = height * 1.0f/_aspect;
+		mtxProjInfXYWH<NearFarT,HandnessT>(_result, 0.0f, 0.0f, width, height, _near, _oglNdc);
+	}
+
+	void mtxProjInf(float* _result, const float _fov[4], float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _fov, _near, _oglNdc);
+	}
+
+	void mtxProjInf(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
+	}
+
+	void mtxProjInf(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _fovy, _aspect, _near, _oglNdc);
+	}
+
+	void mtxProjInfLh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
+	}
+
+	void mtxProjInfLh(float* _result, const float _fov[4], float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _fov, _near, _oglNdc);
+	}
+
+	void mtxProjInfLh(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Left>(_result, _fovy, _aspect, _near, _oglNdc);
+	}
+
+	void mtxProjInfRh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Right>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
+	}
+
+	void mtxProjInfRh(float* _result, const float _fov[4], float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Right>(_result, _fov, _near, _oglNdc);
+	}
+
+	void mtxProjInfRh(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Default,Handness::Right>(_result, _fovy, _aspect, _near, _oglNdc);
+	}
+
+	void mtxProjRevInfLh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Reverse,Handness::Left>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
+	}
+
+	void mtxProjRevInfLh(float* _result, const float _fov[4], float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Reverse,Handness::Left>(_result, _fov, _near, _oglNdc);
+	}
+
+	void mtxProjRevInfLh(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Reverse,Handness::Left>(_result, _fovy, _aspect, _near, _oglNdc);
+	}
+
+	void mtxProjRevInfRh(float* _result, float _ut, float _dt, float _lt, float _rt, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Reverse,Handness::Right>(_result, _ut, _dt, _lt, _rt, _near, _oglNdc);
+	}
+
+	void mtxProjRevInfRh(float* _result, const float _fov[4], float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Reverse,Handness::Right>(_result, _fov, _near, _oglNdc);
+	}
+
+	void mtxProjRevInfRh(float* _result, float _fovy, float _aspect, float _near, bool _oglNdc)
+	{
+		mtxProjInfImpl<NearFar::Reverse,Handness::Right>(_result, _fovy, _aspect, _near, _oglNdc);
+	}
+
+	template<Handness::Enum HandnessT>
+	void mtxOrthoImpl(float* _result, float _left, float _right, float _bottom, float _top, float _near, float _far, float _offset, bool _oglNdc)
+	{
+		const float aa = 2.0f/(_right - _left);
+		const float bb = 2.0f/(_top - _bottom);
+		const float cc = (_oglNdc ? 2.0f : 1.0f) / (_far - _near);
+		const float dd = (_left + _right )/(_left   - _right);
+		const float ee = (_top  + _bottom)/(_bottom - _top  );
+		const float ff = _oglNdc
+			? (_near + _far)/(_near - _far)
+			:  _near        /(_near - _far)
+			;
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = aa;
+		_result[ 5] = bb;
+		_result[10] = (Handness::Right == HandnessT) ? -cc : cc;
+		_result[12] = dd + _offset;
+		_result[13] = ee;
+		_result[14] = ff;
+		_result[15] = 1.0f;
+	}
+
+	void mtxOrtho(float* _result, float _left, float _right, float _bottom, float _top, float _near, float _far, float _offset, bool _oglNdc)
+	{
+		mtxOrthoImpl<Handness::Left>(_result, _left, _right, _bottom, _top, _near, _far, _offset, _oglNdc);
+	}
+
+	void mtxOrthoLh(float* _result, float _left, float _right, float _bottom, float _top, float _near, float _far, float _offset, bool _oglNdc)
+	{
+		mtxOrthoImpl<Handness::Left>(_result, _left, _right, _bottom, _top, _near, _far, _offset, _oglNdc);
+	}
+
+	void mtxOrthoRh(float* _result, float _left, float _right, float _bottom, float _top, float _near, float _far, float _offset, bool _oglNdc)
+	{
+		mtxOrthoImpl<Handness::Right>(_result, _left, _right, _bottom, _top, _near, _far, _offset, _oglNdc);
+	}
+
+	void mtxRotateX(float* _result, float _ax)
+	{
+		const float sx = fsin(_ax);
+		const float cx = fcos(_ax);
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = 1.0f;
+		_result[ 5] = cx;
+		_result[ 6] = -sx;
+		_result[ 9] = sx;
+		_result[10] = cx;
+		_result[15] = 1.0f;
+	}
+
+	void mtxRotateY(float* _result, float _ay)
+	{
+		const float sy = fsin(_ay);
+		const float cy = fcos(_ay);
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = cy;
+		_result[ 2] = sy;
+		_result[ 5] = 1.0f;
+		_result[ 8] = -sy;
+		_result[10] = cy;
+		_result[15] = 1.0f;
+	}
+
+	void mtxRotateZ(float* _result, float _az)
+	{
+		const float sz = fsin(_az);
+		const float cz = fcos(_az);
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = cz;
+		_result[ 1] = -sz;
+		_result[ 4] = sz;
+		_result[ 5] = cz;
+		_result[10] = 1.0f;
+		_result[15] = 1.0f;
+	}
+
+	void mtxRotateXY(float* _result, float _ax, float _ay)
+	{
+		const float sx = fsin(_ax);
+		const float cx = fcos(_ax);
+		const float sy = fsin(_ay);
+		const float cy = fcos(_ay);
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = cy;
+		_result[ 2] = sy;
+		_result[ 4] = sx*sy;
+		_result[ 5] = cx;
+		_result[ 6] = -sx*cy;
+		_result[ 8] = -cx*sy;
+		_result[ 9] = sx;
+		_result[10] = cx*cy;
+		_result[15] = 1.0f;
+	}
+
+	void mtxRotateXYZ(float* _result, float _ax, float _ay, float _az)
+	{
+		const float sx = fsin(_ax);
+		const float cx = fcos(_ax);
+		const float sy = fsin(_ay);
+		const float cy = fcos(_ay);
+		const float sz = fsin(_az);
+		const float cz = fcos(_az);
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = cy*cz;
+		_result[ 1] = -cy*sz;
+		_result[ 2] = sy;
+		_result[ 4] = cz*sx*sy + cx*sz;
+		_result[ 5] = cx*cz - sx*sy*sz;
+		_result[ 6] = -cy*sx;
+		_result[ 8] = -cx*cz*sy + sx*sz;
+		_result[ 9] = cz*sx + cx*sy*sz;
+		_result[10] = cx*cy;
+		_result[15] = 1.0f;
+	}
+
+	void mtxRotateZYX(float* _result, float _ax, float _ay, float _az)
+	{
+		const float sx = fsin(_ax);
+		const float cx = fcos(_ax);
+		const float sy = fsin(_ay);
+		const float cy = fcos(_ay);
+		const float sz = fsin(_az);
+		const float cz = fcos(_az);
+
+		memSet(_result, 0, sizeof(float)*16);
+		_result[ 0] = cy*cz;
+		_result[ 1] = cz*sx*sy-cx*sz;
+		_result[ 2] = cx*cz*sy+sx*sz;
+		_result[ 4] = cy*sz;
+		_result[ 5] = cx*cz + sx*sy*sz;
+		_result[ 6] = -cz*sx + cx*sy*sz;
+		_result[ 8] = -sy;
+		_result[ 9] = cy*sx;
+		_result[10] = cx*cy;
+		_result[15] = 1.0f;
+	};
+
+	void mtxSRT(float* _result, float _sx, float _sy, float _sz, float _ax, float _ay, float _az, float _tx, float _ty, float _tz)
+	{
+		const float sx = fsin(_ax);
+		const float cx = fcos(_ax);
+		const float sy = fsin(_ay);
+		const float cy = fcos(_ay);
+		const float sz = fsin(_az);
+		const float cz = fcos(_az);
+
+		const float sxsz = sx*sz;
+		const float cycz = cy*cz;
+
+		_result[ 0] = _sx * (cycz - sxsz*sy);
+		_result[ 1] = _sx * -cx*sz;
+		_result[ 2] = _sx * (cz*sy + cy*sxsz);
+		_result[ 3] = 0.0f;
+
+		_result[ 4] = _sy * (cz*sx*sy + cy*sz);
+		_result[ 5] = _sy * cx*cz;
+		_result[ 6] = _sy * (sy*sz -cycz*sx);
+		_result[ 7] = 0.0f;
+
+		_result[ 8] = _sz * -cx*sy;
+		_result[ 9] = _sz * sx;
+		_result[10] = _sz * cx*cy;
+		_result[11] = 0.0f;
+
+		_result[12] = _tx;
+		_result[13] = _ty;
+		_result[14] = _tz;
+		_result[15] = 1.0f;
+	}
+
 	void mtx3Inverse(float* _result, const float* _a)
 	{
 		float xx = _a[0];
@@ -165,4 +620,123 @@ namespace bx
 		_result[15] = +(xx*(yy*zz - zy*yz) - xy*(yx*zz - zx*yz) + xz*(yx*zy - zx*yy) ) * invDet;
 	}
 
+	void calcLinearFit2D(float _result[2], const void* _points, uint32_t _stride, uint32_t _numPoints)
+	{
+		float sumX  = 0.0f;
+		float sumY  = 0.0f;
+		float sumXX = 0.0f;
+		float sumXY = 0.0f;
+
+		const uint8_t* ptr = (const uint8_t*)_points;
+		for (uint32_t ii = 0; ii < _numPoints; ++ii, ptr += _stride)
+		{
+			const float* point = (const float*)ptr;
+			float xx = point[0];
+			float yy = point[1];
+			sumX  += xx;
+			sumY  += yy;
+			sumXX += xx*xx;
+			sumXY += xx*yy;
+		}
+
+		// [ sum(x^2) sum(x)    ] [ A ] = [ sum(x*y) ]
+		// [ sum(x)   numPoints ] [ B ]   [ sum(y)   ]
+
+		float det = (sumXX*_numPoints - sumX*sumX);
+		float invDet = 1.0f/det;
+
+		_result[0] = (-sumX * sumY + _numPoints * sumXY) * invDet;
+		_result[1] = (sumXX * sumY - sumX       * sumXY) * invDet;
+	}
+
+	void calcLinearFit3D(float _result[3], const void* _points, uint32_t _stride, uint32_t _numPoints)
+	{
+		float sumX  = 0.0f;
+		float sumY  = 0.0f;
+		float sumZ  = 0.0f;
+		float sumXX = 0.0f;
+		float sumXY = 0.0f;
+		float sumXZ = 0.0f;
+		float sumYY = 0.0f;
+		float sumYZ = 0.0f;
+
+		const uint8_t* ptr = (const uint8_t*)_points;
+		for (uint32_t ii = 0; ii < _numPoints; ++ii, ptr += _stride)
+		{
+			const float* point = (const float*)ptr;
+			float xx = point[0];
+			float yy = point[1];
+			float zz = point[2];
+
+			sumX  += xx;
+			sumY  += yy;
+			sumZ  += zz;
+			sumXX += xx*xx;
+			sumXY += xx*yy;
+			sumXZ += xx*zz;
+			sumYY += yy*yy;
+			sumYZ += yy*zz;
+		}
+
+		// [ sum(x^2) sum(x*y) sum(x)    ] [ A ]   [ sum(x*z) ]
+		// [ sum(x*y) sum(y^2) sum(y)    ] [ B ] = [ sum(y*z) ]
+		// [ sum(x)   sum(y)   numPoints ] [ C ]   [ sum(z)   ]
+
+		float mtx[9] =
+		{
+			sumXX, sumXY, sumX,
+			sumXY, sumYY, sumY,
+			sumX,  sumY,  float(_numPoints),
+		};
+		float invMtx[9];
+		mtx3Inverse(invMtx, mtx);
+
+		_result[0] = invMtx[0]*sumXZ + invMtx[1]*sumYZ + invMtx[2]*sumZ;
+		_result[1] = invMtx[3]*sumXZ + invMtx[4]*sumYZ + invMtx[5]*sumZ;
+		_result[2] = invMtx[6]*sumXZ + invMtx[7]*sumYZ + invMtx[8]*sumZ;
+	}
+
+	void rgbToHsv(float _hsv[3], const float _rgb[3])
+	{
+		const float rr = _rgb[0];
+		const float gg = _rgb[1];
+		const float bb = _rgb[2];
+
+		const float s0 = fstep(bb, gg);
+
+		const float px = flerp(bb,        gg,         s0);
+		const float py = flerp(gg,        bb,         s0);
+		const float pz = flerp(-1.0f,     0.0f,       s0);
+		const float pw = flerp(2.0f/3.0f, -1.0f/3.0f, s0);
+
+		const float s1 = fstep(px, rr);
+
+		const float qx = flerp(px, rr, s1);
+		const float qy = py;
+		const float qz = flerp(pw, pz, s1);
+		const float qw = flerp(rr, px, s1);
+
+		const float dd = qx - fmin(qw, qy);
+		const float ee = 1.0e-10f;
+
+		_hsv[0] = fabsolute(qz + (qw - qy) / (6.0f * dd + ee) );
+		_hsv[1] = dd / (qx + ee);
+		_hsv[2] = qx;
+	}
+
+	void hsvToRgb(float _rgb[3], const float _hsv[3])
+	{
+		const float hh = _hsv[0];
+		const float ss = _hsv[1];
+		const float vv = _hsv[2];
+
+		const float px = fabsolute(ffract(hh + 1.0f     ) * 6.0f - 3.0f);
+		const float py = fabsolute(ffract(hh + 2.0f/3.0f) * 6.0f - 3.0f);
+		const float pz = fabsolute(ffract(hh + 1.0f/3.0f) * 6.0f - 3.0f);
+
+		_rgb[0] = vv * flerp(1.0f, fsaturate(px - 1.0f), ss);
+		_rgb[1] = vv * flerp(1.0f, fsaturate(py - 1.0f), ss);
+		_rgb[2] = vv * flerp(1.0f, fsaturate(pz - 1.0f), ss);
+	}
+
 } // namespace bx