//	VirtualDub - Video processing and capture application
//	System library component
//	Copyright (C) 1998-2004 Avery Lee, All Rights Reserved.
//
//	Beginning with 1.6.0, the VirtualDub system library is licensed
//	differently than the remainder of VirtualDub.  This particular file is
//	thus licensed as follows (the "zlib" license):
//
//	This software is provided 'as-is', without any express or implied
//	warranty.  In no event will the authors be held liable for any
//	damages arising from the use of this software.
//
//	Permission is granted to anyone to use this software for any purpose,
//	including commercial applications, and to alter it and redistribute it
//	freely, subject to the following restrictions:
//
//	1.	The origin of this software must not be misrepresented; you must
//		not claim that you wrote the original software. If you use this
//		software in a product, an acknowledgment in the product
//		documentation would be appreciated but is not required.
//	2.	Altered source versions must be plainly marked as such, and must
//		not be misrepresented as being the original software.
//	3.	This notice may not be removed or altered from any source
//		distribution.

#ifndef f_VD2_SYSTEM_MATH_H
#define f_VD2_SYSTEM_MATH_H

#include <math.h>
#include <vd2/system/vdtypes.h>

// Constants
namespace nsVDMath {
	static const float	kfPi = 3.1415926535897932384626433832795f;
	static const float	krPi = 3.1415926535897932384626433832795;
	static const double	kfTwoPi = 6.283185307179586476925286766559f;
	static const double	krTwoPi = 6.283185307179586476925286766559;
	static const float	kfLn2 = 0.69314718055994530941723212145818f;
	static const double	krLn2 = 0.69314718055994530941723212145818;
	static const float	kfLn10 = 2.3025850929940456840179914546844f;
	static const double	krLn10 = 2.3025850929940456840179914546844;
	static const float	kfOneOverLn10 = 0.43429448190325182765112891891661f;
	static const double	krOneOverLn10 = 0.43429448190325182765112891891661;
};

///////////////////////////////////////////////////////////////////////////
// Integer clamping functions
//
#ifdef _M_IX86
	inline uint32 VDClampToUint32(sint64 v) {
		union U {
			__int64 v64;
			struct {
				unsigned lo;
				int hi;
			} v32;
		};

		return ((U *)&v)->v32.hi ? ~(((U *)&v)->v32.hi >> 31) : ((U *)&v)->v32.lo;
	}
#else
	inline uint32 VDClampToUint32(sint64 v) {
		uint32 r = (uint32)v;
		return r == v ? r : (uint32)~(sint32)(v>>63);
	}
#endif

inline sint32 VDClampToSint32(sint64 v) {
	sint32 r = (sint32)v;
	return r == v ? r : (sint32)(v >> 63) ^ 0x7FFFFFFF;
}

///////////////////////////////////////////////////////////////////////////
// Absolute value functions
inline sint64 VDAbs64(sint64 v) {
	return v<0 ? -v : v;
}

inline ptrdiff_t VDAbsPtrdiff(ptrdiff_t v) {
	return v<0 ? -v : v;
}

// Rounding functions
//
// Round a double to an int or a long.  Behavior is not specified at
// int(y)+0.5, if x is NaN or Inf, or if x is out of range.

int VDRoundToInt(double x);
long VDRoundToLong(double x);
sint32 VDRoundToInt32(double x);
sint64 VDRoundToInt64(double x);

inline sint32 VDRoundToIntFast(float x) {
	union {
		float f;
		sint32 i;
	} u = {x + 12582912.0f};		// 2^22+2^23

	return (sint32)u.i - 0x4B400000;
}

inline sint32 VDRoundToIntFastFullRange(double x) {
	union {
		double f;
		sint32 i[2];
	} u = {x + 6755399441055744.0f};		// 2^51+2^52

	return (sint32)u.i[0];
}

#ifdef _M_AMD64
	inline sint32 VDFloorToInt(double x) {
		return (sint32)floor(x);
	}

	inline sint64 VDFloorToInt64(double x) {
		return (sint64)floor(x);
	}
#else
	#pragma warning(push)
	#pragma warning(disable: 4035)		// warning C4035: 'VDFloorToInt' : no return value
	inline sint32 VDFloorToInt(double x) {
		sint32 temp;

		__asm {
			fld x
			fist temp
			fild temp
			mov eax, temp
			fsub
			fstp temp
			cmp	temp, 80000001h
			adc eax, -1
		}
	}
	inline sint64 VDFloorToInt64(double x) {
		sint64 temp;
		sint32 temp2;

		__asm {
			fld x
			fld st(0)
			fistp qword ptr temp
			fild qword ptr temp
			mov eax, dword ptr temp
			mov edx, dword ptr temp+4
			fsub
			fstp dword ptr temp2
			cmp	dword ptr temp2, 80000001h
			adc eax, -1
			adc edx, -1
		}
	}
	#pragma warning(pop)
#endif

#ifdef _M_AMD64
	inline sint32 VDCeilToInt(double x) {
		return (sint32)ceil(x);
	}

	inline sint64 VDCeilToInt64(double x) {
		return (sint64)ceil(x);
	}
#else
	#pragma warning(push)
	#pragma warning(disable: 4035)		// warning C4035: 'VDCeilToInt' : no return value
	inline sint32 VDCeilToInt(double x) {
		sint32 temp;

		__asm {
			fld x
			fist temp
			fild temp
			mov eax, temp
			fsubr
			fstp temp
			cmp	temp, 80000001h
			sbb eax, -1
		}
	}

	inline sint32 VDCeilToInt64(double x) {
		sint64 temp;
		sint32 temp2;

		__asm {
			fld x
			fld st(0)
			fistp temp
			fild temp
			mov eax, dword ptr temp
			mov edx, dword ptr temp+4
			fsubr
			fstp temp2
			cmp	temp2, 80000001h
			sbb eax, -1
			sbb edx, -1
		}
	}
	#pragma warning(pop)
#endif

///////////////////////////////////////////////////////////////////////////
inline sint16 VDClampedRoundFixedToInt16Fast(float x) {
	union {
		float f;
		sint32 i;
	} u = {x + 384.0f};		// 2^7+2^8

	sint32 v = (sint32)u.i - 0x43BF8000;

	if ((uint32)v >= 0x10000)
		v = ~v >> 31;

	return (sint16)(v - 0x8000);
}

inline uint8 VDClampedRoundFixedToUint8Fast(float x) {
	union {
		float f;
		sint32 i;
	} u = {x * 255.0f + 12582912.0f};		// 2^22+2^23

	sint32 v = (sint32)u.i - 0x4B400000;

	if ((uint32)v >= 0xFF)
		v = ~v >> 31;

	return (uint8)v;
}

///////////////////////////////////////////////////////////////////////////

#ifdef _M_IX86
	sint64 __stdcall VDFractionScale64(uint64 a, uint32 b, uint32 c, uint32& remainder);
	uint64 __stdcall VDUMulDiv64x32(uint64 a, uint32 b, uint32 c);
#else
	extern "C" sint64 VDFractionScale64(uint64 a, uint64 b, uint64 c, uint32& remainder);
	extern "C" uint64 VDUMulDiv64x32(uint64 a, uint32 b, uint32 c);
#endif

sint64 VDMulDiv64(sint64 a, sint64 b, sint64 c);

#endif
