1 files changed, 200 insertions, 0 deletions

diff --git a/src/common/math_util.h b/src/common/math_util.h
new file mode 100644
index 000000000..4410c5e01
--- /dev/null
+++ b/src/common/math_util.h
@@ -0,0 +1,200 @@
+// Copyright 2013 Dolphin Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+
+#ifndef _MATH_UTIL_H_
+#define _MATH_UTIL_H_
+
+#include "common.h"
+
+#include <vector>
+
+namespace MathUtil
+{
+
+static const u64 DOUBLE_SIGN = 0x8000000000000000ULL,
+    DOUBLE_EXP  = 0x7FF0000000000000ULL,
+    DOUBLE_FRAC = 0x000FFFFFFFFFFFFFULL,
+    DOUBLE_ZERO = 0x0000000000000000ULL;
+
+static const u32 FLOAT_SIGN = 0x80000000,
+    FLOAT_EXP  = 0x7F800000,
+    FLOAT_FRAC = 0x007FFFFF,
+    FLOAT_ZERO = 0x00000000;
+
+union IntDouble {
+    double d;
+    u64 i;
+};
+union IntFloat {
+    float f;
+    u32 i;
+};
+
+inline bool IsNAN(double d)
+{
+    IntDouble x; x.d = d;
+    return ( ((x.i & DOUBLE_EXP) == DOUBLE_EXP) &&
+             ((x.i & DOUBLE_FRAC) != DOUBLE_ZERO) );
+}
+
+inline bool IsQNAN(double d)
+{
+    IntDouble x; x.d = d;
+    return ( ((x.i & DOUBLE_EXP) == DOUBLE_EXP) &&
+             ((x.i & 0x0007fffffffffffULL) == 0x000000000000000ULL) &&
+             ((x.i & 0x000800000000000ULL) == 0x000800000000000ULL) );
+}
+
+inline bool IsSNAN(double d)
+{
+    IntDouble x; x.d = d;
+    return( ((x.i & DOUBLE_EXP) == DOUBLE_EXP) &&
+            ((x.i & DOUBLE_FRAC) != DOUBLE_ZERO) &&
+            ((x.i & 0x0008000000000000ULL) == DOUBLE_ZERO) );
+}
+
+inline float FlushToZero(float f)
+{
+    IntFloat x; x.f = f;
+    if ((x.i & FLOAT_EXP) == 0)
+        x.i &= FLOAT_SIGN;  // turn into signed zero
+    return x.f;
+}
+
+inline double FlushToZeroAsFloat(double d)
+{
+    IntDouble x; x.d = d;
+    if ((x.i & DOUBLE_EXP) < 0x3800000000000000ULL)
+        x.i &= DOUBLE_SIGN;  // turn into signed zero
+    return x.d;
+}
+
+enum PPCFpClass
+{
+    PPC_FPCLASS_QNAN = 0x11,
+    PPC_FPCLASS_NINF = 0x9,
+    PPC_FPCLASS_NN   = 0x8,
+    PPC_FPCLASS_ND   = 0x18,
+    PPC_FPCLASS_NZ   = 0x12,
+    PPC_FPCLASS_PZ   = 0x2,
+    PPC_FPCLASS_PD   = 0x14,
+    PPC_FPCLASS_PN   = 0x4,
+    PPC_FPCLASS_PINF = 0x5,
+};
+
+// Uses PowerPC conventions for the return value, so it can be easily
+// used directly in CPU emulation.
+u32 ClassifyDouble(double dvalue);
+// More efficient float version.
+u32 ClassifyFloat(float fvalue);
+
+template<class T>
+struct Rectangle
+{
+    T left;
+    T top;
+    T right;
+    T bottom;
+
+    Rectangle()
+    { }
+
+    Rectangle(T theLeft, T theTop, T theRight, T theBottom)
+        : left(theLeft), top(theTop), right(theRight), bottom(theBottom)
+    { }
+    
+    bool operator==(const Rectangle& r) { return left==r.left && top==r.top && right==r.right && bottom==r.bottom; }
+
+    T GetWidth() const { return abs(right - left); }
+    T GetHeight() const { return abs(bottom - top); }
+
+    // If the rectangle is in a coordinate system with a lower-left origin, use
+    // this Clamp.
+    void ClampLL(T x1, T y1, T x2, T y2)
+    {
+        if (left < x1) left = x1;
+        if (right > x2) right = x2;
+        if (top > y1) top = y1;
+        if (bottom < y2) bottom = y2;
+    }
+
+    // If the rectangle is in a coordinate system with an upper-left origin,
+    // use this Clamp.
+    void ClampUL(T x1, T y1, T x2, T y2) 
+    {
+        if (left < x1) left = x1;
+        if (right > x2) right = x2;
+        if (top < y1) top = y1;
+        if (bottom > y2) bottom = y2;
+    }
+};
+
+}  // namespace MathUtil
+
+inline float pow2f(float x) {return x * x;}
+inline double pow2(double x) {return x * x;}
+
+float MathFloatVectorSum(const std::vector<float>&);
+
+#define ROUND_UP(x, a)        (((x) + (a) - 1) & ~((a) - 1))
+#define ROUND_DOWN(x, a)    ((x) & ~((a) - 1))
+
+// Rounds down. 0 -> undefined
+inline u64 Log2(u64 val)
+{
+#if defined(__GNUC__)
+    return 63 - __builtin_clzll(val);
+
+#elif defined(_MSC_VER) && defined(_M_X64)
+    unsigned long result = -1;
+    _BitScanReverse64(&result, val);
+    return result;
+
+#else
+    u64 result = -1;
+    while (val != 0)
+    {
+        val >>= 1;
+        ++result;
+    }
+    return result;
+#endif
+}
+
+// Tiny matrix/vector library.
+// Used for things like Free-Look in the gfx backend.
+
+class Matrix33
+{
+public:
+    static void LoadIdentity(Matrix33 &mtx);
+
+    // set mtx to be a rotation matrix around the x axis
+    static void RotateX(Matrix33 &mtx, float rad);
+    // set mtx to be a rotation matrix around the y axis
+    static void RotateY(Matrix33 &mtx, float rad);
+
+    // set result = a x b
+    static void Multiply(const Matrix33 &a, const Matrix33 &b, Matrix33 &result);
+    static void Multiply(const Matrix33 &a, const float vec[3], float result[3]);
+
+    float data[9];
+};
+
+class Matrix44
+{
+public:
+    static void LoadIdentity(Matrix44 &mtx);
+    static void LoadMatrix33(Matrix44 &mtx, const Matrix33 &m33);
+    static void Set(Matrix44 &mtx, const float mtxArray[16]);
+
+    static void Translate(Matrix44 &mtx, const float vec[3]);
+
+    static void Multiply(const Matrix44 &a, const Matrix44 &b, Matrix44 &result);
+
+    float data[16];
+};
+
+#endif // _MATH_UTIL_H_