C++ VMatrix::SetBasisVectors方法代码示例

//-----------------------------------------------------------------------------
// Computes the position of the canister
//-----------------------------------------------------------------------------
void CEnvHeadcrabCanisterShared::GetPositionAtTime( float flTime, Vector &vecPosition, QAngle &vecAngles )
{
	float flDeltaTime = flTime - m_flLaunchTime;
	if ( flDeltaTime > m_flFlightTime )
	{
		flDeltaTime = m_flFlightTime;
	}

	VMatrix initToWorld;
	if ( m_bLaunchedFromWithinWorld || m_bInSkybox )
	{
		VectorMA( m_vecStartPosition, flDeltaTime * m_flHorizSpeed, m_vecParabolaDirection, vecPosition );
		vecPosition.z += m_flInitialZSpeed * flDeltaTime + 0.5f * m_flZAcceleration * flDeltaTime * flDeltaTime;

		Vector vecLeft;
		CrossProduct( m_vecParabolaDirection, Vector( 0, 0, 1 ), vecLeft );

		Vector vecForward;
		VectorMultiply( m_vecParabolaDirection, -1.0f, vecForward );
		vecForward.z = -(m_flInitialZSpeed + m_flZAcceleration * flDeltaTime) / m_flHorizSpeed;	// This is -dz/dx.
		VectorNormalize( vecForward );

		Vector vecUp;
		CrossProduct( vecForward, vecLeft, vecUp );
 
		initToWorld.SetBasisVectors( vecForward, vecLeft, vecUp );
	}
	else
	{
		flDeltaTime -= m_flWorldEnterTime;
		Vector vecVelocity;
		VectorMultiply( m_vecDirection, m_flFlightSpeed, vecVelocity );
		VectorMA( m_vecEnterWorldPosition, flDeltaTime, vecVelocity, vecPosition );

		MatrixFromAngles( m_vecStartAngles.Get(), initToWorld );
	}

	VMatrix rotation;
	MatrixBuildRotationAboutAxis( rotation, Vector( 1, 0, 0 ), flDeltaTime * ROTATION_SPEED );

	VMatrix newAngles;
	MatrixMultiply( initToWorld, rotation, newAngles );
	MatrixToAngles( newAngles, vecAngles );
}

VMatrix VMatrix::NormalizeBasisVectors() const
{
	Vector vecs[3];
	VMatrix mRet;


	GetBasisVectors(vecs[0], vecs[1], vecs[2]);
	
	VectorNormalize( vecs[0] );
	VectorNormalize( vecs[1] );
	VectorNormalize( vecs[2] );

	mRet.SetBasisVectors(vecs[0], vecs[1], vecs[2]);
	
	// Set everything but basis vectors to identity.
	mRet.m[3][0] = mRet.m[3][1] = mRet.m[3][2] = 0.0f;
	mRet.m[3][3] = 1.0f;

	return mRet;
}

void EmitClipPortalGeometry( node_t *pHeadNode, portal_t *pPortal, int iSrcArea, dareaportal_t *dp )
{
	// Build a list of all the points in portals from the same original face.
	CUtlVector<portal_t*> portals;
	FindPortalsLeadingToArea_R( 
		pHeadNode, 
		iSrcArea, 
		dp->otherarea, 
		&pPortal->plane,
		portals );

	CUtlVector<Vector> points;
	for( int iPortal=0; iPortal < portals.Size(); iPortal++ )
	{
		portal_t *pPointPortal = portals[iPortal];
		winding_t *pWinding = pPointPortal->winding;
		for( int i=0; i < pWinding->numpoints; i++ )
		{
			points.AddToTail( pWinding->p[i] );
		}
	}

	// Get the 2D convex hull.

	//// First transform them into a plane.
	QAngle vAngles;
	Vector vecs[3];

	VectorAngles( pPortal->plane.normal, vAngles );
	AngleVectors( vAngles, &vecs[0], &vecs[1], &vecs[2] );
	VMatrix mTransform;
	mTransform.Identity();
	mTransform.SetBasisVectors( vecs[0], vecs[1], vecs[2] );
	VMatrix mInvTransform = mTransform.Transpose();

	int i;
	CUtlVector<Vector2D> points2D;
	for( i=0; i < points.Size(); i++ )
	{
		Vector vTest = mTransform * points[i];
		points2D.AddToTail( Vector2D( vTest.y, vTest.z ) );
	}

	// Build the hull.
	int indices[512];
	int nIndices = Convex2D( points2D.Base(), points2D.Size(), indices, 512 );

	// Output the hull.
	dp->m_FirstClipPortalVert = g_nClipPortalVerts;
	dp->m_nClipPortalVerts = nIndices;

	if ( nIndices >= 32 )
	{
		Warning( "Warning: area portal has %d verts. Could be a vbsp bug.\n", nIndices );
	}

	if( dp->m_FirstClipPortalVert + dp->m_nClipPortalVerts >= MAX_MAP_PORTALVERTS )
	{
		Vector *p = pPortal->winding->p;
		Error( "MAX_MAP_PORTALVERTS (probably a broken areaportal near %.1f %.1f %.1f ", p->x, p->y, p->z );
	}
	
	for( i=0; i < nIndices; i++ )
	{
		g_ClipPortalVerts[g_nClipPortalVerts] = points[ indices[i] ];
		++g_nClipPortalVerts;
	}
}

static void PlaceDetail( DetailModel_t const& model, const Vector& pt, const Vector& normal )
{
	// But only place it on the surface if it meets the angle constraints...
	float cosAngle = normal.z;

	// Never emit if the angle's too steep
	if (cosAngle < model.m_MaxCosAngle)
		return;

	// If it's between min + max, flip a coin...
	if (cosAngle < model.m_MinCosAngle)
	{
		float probability = (cosAngle - model.m_MaxCosAngle) / 
			(model.m_MinCosAngle - model.m_MaxCosAngle);

		float t = rand() / (float)RAND_MAX;
		if (t > probability)
			return;
	}

	// Compute the orientation of the detail
	QAngle angles;
	if (model.m_Flags & MODELFLAG_UPRIGHT)
	{
		// If it's upright, we just select a random yaw
		angles.Init( 0, 360.0f * rand() / (float)RAND_MAX, 0.0f );
	}
	else
	{
		// It's not upright, so it must conform to the ground. Choose
		// a random orientation based on the surface normal

		Vector zaxis;
		VectorCopy( normal, zaxis );

		// Choose any two arbitrary axes which are perpendicular to the normal
		Vector xaxis( 1, 0, 0 );
		if (fabs(xaxis.Dot(zaxis)) - 1.0 > -1e-3)
			xaxis.Init( 0, 1, 0 );
		Vector yaxis;
		CrossProduct( zaxis, xaxis, yaxis );
		CrossProduct( yaxis, zaxis, xaxis );
		VMatrix matrix;
		matrix.SetBasisVectors( xaxis, yaxis, zaxis );

		float rotAngle = 360.0f * rand() / (float)RAND_MAX;
		VMatrix rot = SetupMatrixAxisRot( Vector( 0, 0, 1 ), rotAngle );
		matrix = matrix * rot;

		MatrixToAngles( matrix, angles );
	}

	// FIXME: We may also want a purely random rotation too

	// Insert an element into the object dictionary if it aint there...
	switch ( model.m_Type )
	{
	case DETAIL_PROP_TYPE_MODEL:
		AddDetailToLump( model.m_ModelName.String(), pt, angles, model.m_Orientation );
		break;

	case DETAIL_PROP_TYPE_SPRITE:
		{
			float flScale = 1.0f;
			if ( model.m_flRandomScaleStdDev != 0.0f ) 
			{
				flScale = fabs( RandomGaussianFloat( 1.0f, model.m_flRandomScaleStdDev ) );
			}

			AddDetailSpriteToLump( pt, angles, model.m_Orientation, model.m_Pos, model.m_Tex, flScale );
		}
		break;
	}
}