From 157ac02dc661f2ddb23b615545ed825626eae9de Mon Sep 17 00:00:00 2001 From: Martijn Sneijders Date: Thu, 29 Dec 2022 10:58:26 +0100 Subject: [PATCH] _Matrix memory optimized using stack --- .../Input/GestureRecognizers/VelocityTracker.cs | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/src/Avalonia.Base/Input/GestureRecognizers/VelocityTracker.cs b/src/Avalonia.Base/Input/GestureRecognizers/VelocityTracker.cs index f72ac61c4b..206a73f436 100644 --- a/src/Avalonia.Base/Input/GestureRecognizers/VelocityTracker.cs +++ b/src/Avalonia.Base/Input/GestureRecognizers/VelocityTracker.cs @@ -236,7 +236,7 @@ namespace Avalonia.Input.GestureRecognizers int n = degree + 1; // Expand the X vector to a matrix A, pre-multiplied by the weights. - _Matrix a = new _Matrix(n, m); + _Matrix a = new _Matrix(m, stackalloc double[n * m]); for (int h = 0; h < m; h += 1) { a[0, h] = w[h]; @@ -249,9 +249,9 @@ namespace Avalonia.Input.GestureRecognizers // Apply the Gram-Schmidt process to A to obtain its QR decomposition. // Orthonormal basis, column-major order Vector. - _Matrix q = new _Matrix(n, m); + _Matrix q = new _Matrix(m, stackalloc double[n * m]); // Upper triangular matrix, row-major order. - _Matrix r = new _Matrix(n, n); + _Matrix r = new _Matrix(n, stackalloc double[n * n]); for (int j = 0; j < n; j += 1) { for (int h = 0; h < m; h += 1) @@ -352,15 +352,15 @@ namespace Avalonia.Input.GestureRecognizers return Math.Sqrt(Multiply(v, v)); } - private readonly struct _Matrix + private readonly ref struct _Matrix { private readonly int _columns; - private readonly double[] _elements; + private readonly Span _elements; - internal _Matrix(int rows, int cols) + internal _Matrix(int cols, Span elements) { _columns = cols; - _elements = new double[rows * cols]; + _elements = elements;// new double[rows * cols]; } public double this[int row, int col] @@ -369,7 +369,7 @@ namespace Avalonia.Input.GestureRecognizers set => _elements[row * _columns + col] = value; } - public Span GetRow(int row) => _elements.AsSpan(row * _columns, _columns); + public Span GetRow(int row) => _elements.Slice(row * _columns, _columns); } } }