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Diffstat (limited to 'src/utils/mathutils.cpp')
-rw-r--r-- | src/utils/mathutils.cpp | 58 |
1 files changed, 0 insertions, 58 deletions
diff --git a/src/utils/mathutils.cpp b/src/utils/mathutils.cpp deleted file mode 100644 index 7d50c68f..00000000 --- a/src/utils/mathutils.cpp +++ /dev/null @@ -1,58 +0,0 @@ -/* - * The Mana World - * Copyright (C) 2009 The Mana World Development Team - * - * This file is part of The Mana World. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -#include "utils/mathutils.h" - -/* A very fast function to calculate the approximate inverse square root of a - * floating point value and a helper function that uses it for getting the - * normal squareroot. For an explanation of the inverse squareroot function - * read: - * http://www.math.purdue.edu/~clomont/Math/Papers/2003/InvSqrt.pdf - * - * Unfortunately the original creator of this function seems to be unknown. - */ - -float fastInvSqrt(float x) -{ - union { int i; float x; } tmp; - float xhalf = 0.5f * x; - tmp.x = x; - tmp.i = 0x5f375a86 - (tmp.i >> 1); - x = tmp.x; - x = x * (1.5f - xhalf * x * x); - return x; -} - -float fastSqrt(float x) -{ - return 1.0f / fastInvSqrt(x); -} - -float weightedAverage(float n1, float n2, float w) -{ - if (w < 0.0f) - return n1; - - if (w > 1.0f) - return n2; - - return ((w * n2) + ((1.0f - w) * n1)); -} |