www.pudn.com > Balls.rar > Utility.cpp, change:2007-05-09,size:2300b

#include "stdafx.h" 
#include "Utility.h" 
 
#define new VNEW 
 
 
D3DXVECTOR3 Vec3Mutiply( const D3DXVECTOR3 &v1, const D3DXVECTOR3 &v2 ) 
{ 
	D3DXVECTOR3 vResult; 
	vResult.x = v1.x * v2.x; 
	vResult.y = v1.y * v2.y; 
	vResult.z = v1.z * v2.z; 
	return vResult; 
} 
 
 
void Vec3Perpendicular( D3DXVECTOR3 &out, const D3DXVECTOR3 &src ) 
{ 
	static D3DXVECTOR3 UNIT_X(1.f, 0.f, 0.f); 
	static D3DXVECTOR3 UNIT_Y(0.f, 1.f, 0.f); 
 
	static const float fSquareZero = static_cast<float>(1e-06 * 1e-06); 
 
	D3DXVECTOR3 perp; 
	D3DXVec3Cross( &perp, &src, &UNIT_X ); 
 
	// Check length 
	if( D3DXVec3LengthSq(&perp)  fSquareZero ) 
	{ 
		/* This vector is the Y axis multiplied by a scalar, so we have  
		to use another axis. 
		*/ 
		D3DXVec3Cross( &perp, &src, &UNIT_Y ); 
	} 
 
	out = perp; 
} 
 
void RandomDeviant( D3DXVECTOR3 &result, const D3DXVECTOR3 &dir, float fAngle ) 
{ 
	D3DXVECTOR3 up; 
	Vec3Perpendicular( up, dir ); 
 
	D3DXMATRIX m; 
	D3DXMatrixRotationAxis( &m, &dir, UnitRandom() * D3DX_PI*2.f ); 
	D3DXVec3TransformNormal( &up, &up, &m ); 
 
	D3DXMatrixRotationAxis( &m, &up, fAngle ); 
	D3DXVec3TransformNormal( &result, &dir, &m ); 
} 
 
 
 
 
// returns a random number 
FORCEINLINE float asm_rand() 
{ 
 
#if _MSC_VER == 1300 
 
	static unsigned __int64 q = time( NULL ); 
 
	_asm { 
		movq mm0, q 
 
			// do the magic MMX thing 
			pshufw mm1, mm0, 0x1E 
			paddd mm0, mm1 
 
			// move to integer memory location and free MMX 
			movq q, mm0 
			emms 
	} 
 
	return float( q ); 
#else 
	// VC6 does not support pshufw 
	return float( rand() ); 
#endif 
} 
 
// returns the maximum random number 
FORCEINLINE float asm_rand_max() 
{ 
 
#if _MSC_VER == 1300 
 
	//	return std::numeric_limits unsigned __int64 >::max(); 
	return 9223372036854775807.0f; 
#else 
	// VC6 does not support unsigned __int64 
	return float( RAND_MAX ); 
#endif 
 
} 
 
float UnitRandom() 
{ 
	return asm_rand() / asm_rand_max(); 
} 
 
float RangeRandom(float fLow, float fHigh) 
{ 
	return (fHigh-fLow)*UnitRandom() + fLow; 
} 
 
float SymmetricRandom() 
{ 
	return 2.f * UnitRandom() - 1.f; 
} 
 
void ChangeFileNameToDDS( string &name ) 
{ 
	basic_string <char>::size_type indexChar = name.find_last_of( '.' ); 
	if( indexChar != -1 ) 
	{ 
		name = name.substr( 0, indexChar ) + ".dds"; 
	} 
}