Implemented an alternate collision-detection function, added namespace utils::math.

3 files changed, 152 insertions, 23 deletions

diff --git a/src/utils/fastsqrt.h b/src/utils/fastsqrt.h
deleted file mode 100644
index 8ba6f8ce..00000000
--- a/src/utils/fastsqrt.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* 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)

-{

-    float xhalf = 0.5f*x;

-    int i = *(int*)&x;

-    i = 0x5f375a86- (i>>1);

-    x = *(float*)&i;

-    x = x*(1.5f-xhalf*x*x);

-    return x;

-}

-

-float fastSqrt(float x)

-{

-    return 1.0f/fastInvSqrt(x);

-}

diff --git a/src/utils/mathutils.cpp b/src/utils/mathutils.cpp
new file mode 100644
index 00000000..0a46ff2c
--- /dev/null
+++ b/src/utils/mathutils.cpp
@@ -0,0 +1,106 @@
+/*

+ *  The Mana World Server

+ *  Copyright 2004 The Mana World Development Team

+ *

+ *  This file is part of The Mana World.

+ *

+ *  The Mana World  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.

+ *

+ *  The Mana  World 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 The Mana  World; if not, write to the  Free Software Foundation, Inc.,

+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

+ *

+ *  $Id: $

+ */

+

+#include "mathutils.h"

+

+#include <cmath>

+

+#define MATH_UTILS_MAX_ANGLE 360

+

+float sinList[MATH_UTILS_MAX_ANGLE];

+float cosList[MATH_UTILS_MAX_ANGLE];

+float tanList[MATH_UTILS_MAX_ANGLE];

+

+/**

+ * fastInvSqrt:

+ *

+ * A very fast function to calculate the approximate inverse square root of a

+ * floating point value. 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.

+ *

+ * TODO: - Make this function run on 64-bit architectures

+ *       - Find out and fix why this function fails when compiled with the -O2

+ *         optimization flag on

+ *         gcc version 4.0.2 20050808 (prerelease) (Ubuntu 4.0.1-4ubuntu9).

+ */

+float utils::math::fastInvSqrt(float x)

+{

+    float xhalf = 0.5f*x;

+    int i = *(int*)&x;

+    i = 0x5f375a86- (i>>1);

+    x = *(float*)&i;

+    x = x*(1.5f-xhalf*x*x);

+    return x;

+}

+

+/**

+ * fastSqrt:

+ *

+ * A helper function that uses the fastInvSqrt for getting the

+ * normal squareroot.

+ */

+float utils::math::fastSqrt(float x)

+{

+    return 1.0f/utils::math::fastInvSqrt(x);

+}

+

+void utils::math::init()

+{

+    // Constant for calculating an angle in radians out of an angle in degrees

+    const float radianAngleRatio = acos(0.0f) / 90.0f; // pi/2 / 90[deg]

+

+    for(int i = 0; i < MATH_UTILS_MAX_ANGLE; i++)

+    {

+        sinList[i] = sin(radianAngleRatio * (float)i);

+        cosList[i] = cos(radianAngleRatio * (float)i);

+

+        if (i == 90)

+        {

+            tanList[i] = 1.0E40f; //approximately infinity

+            continue;

+        }

+        if (i == 270)

+        {

+            tanList[i] = -1.0E40f; //approximately infinity

+            continue;

+        }

+        tanList[i] = tan(radianAngleRatio * (float)i);

+    }

+}

+

+float utils::math::cachedSin(int angle)

+{

+    return sinList[angle];

+}

+

+float utils::math::cachedCos(int angle)

+{

+    return cosList[angle];

+}

+

+float utils::math::cachedTan(int angle)

+{

+    return tanList[angle];

+}

diff --git a/src/utils/mathutils.h b/src/utils/mathutils.h
new file mode 100644
index 00000000..3d90b022
--- /dev/null
+++ b/src/utils/mathutils.h
@@ -0,0 +1,46 @@
+/*

+ *  The Mana World Server

+ *  Copyright 2004 The Mana World Development Team

+ *

+ *  This file is part of The Mana World.

+ *

+ *  The Mana World  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.

+ *

+ *  The Mana  World 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 The Mana  World; if not, write to the  Free Software Foundation, Inc.,

+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

+ *

+ *  $Id: $

+ */

+

+#ifndef _TMWSERV_MATHUTILS_H_

+#define _TMWSERV_MATHUTILS_H_

+

+namespace utils

+{

+    namespace math

+    {

+        float fastInvSqrt(float x);

+

+        float fastSqrt(float x);

+

+        float cachedSin(int angle);

+

+        float cachedCos(int angle);

+

+        float cachedTan(int angle);

+

+        void init();

+

+    } // namespace math

+

+} // namespace utils

+

+#endif