DirectX11程序初始化

//------------------------------------------------------------------------------------- // XNACollision.cpp // // An opimtized collision library based on XNAMath // // Microsoft XNA Developer Connection // Copyright (c) Microsoft Corporation. All rights reserved. //------------------------------------------------------------------------------------- //#include "DXUT.h" #include <Windows.h> #include <cfloat> #include "xnacollision.h" namespace XNA { static const XMVECTOR g_UnitQuaternionEpsilon = { 1.0e-4f, 1.0e-4f, 1.0e-4f, 1.0e-4f }; static const XMVECTOR g_UnitVectorEpsilon = { 1.0e-4f, 1.0e-4f, 1.0e-4f, 1.0e-4f }; static const XMVECTOR g_UnitPlaneEpsilon = { 1.0e-4f, 1.0e-4f, 1.0e-4f, 1.0e-4f }; //----------------------------------------------------------------------------- // Return TRUE if any of the elements of a 3 vector are equal to 0xffffffff. // Slightly more efficient than using XMVector3EqualInt. //----------------------------------------------------------------------------- static inline BOOL XMVector3AnyTrue( FXMVECTOR V ) { XMVECTOR C; // Duplicate the fourth element from the first element. C = XMVectorSwizzle( V, 0, 1, 2, 0 ); return XMComparisonAnyTrue( XMVector4EqualIntR( C, XMVectorTrueInt() ) ); } //----------------------------------------------------------------------------- // Return TRUE if all of the elements of a 3 vector are equal to 0xffffffff. // Slightly more efficient than using XMVector3EqualInt. //----------------------------------------------------------------------------- static inline BOOL XMVector3AllTrue( FXMVECTOR V ) { XMVECTOR C; // Duplicate the fourth element from the first element. C = XMVectorSwizzle( V, 0, 1, 2, 0 ); return XMComparisonAllTrue( XMVector4EqualIntR( C, XMVectorTrueInt() ) ); } //----------------------------------------------------------------------------- // Return TRUE if the vector is a unit vector (length == 1). //----------------------------------------------------------------------------- static inline BOOL XMVector3IsUnit( FXMVECTOR V ) { XMVECTOR Difference = XMVector3Length( V ) - XMVectorSplatOne(); return XMVector4Less( XMVectorAbs( Difference ), g_UnitVectorEpsilon ); } //----------------------------------------------------------------------------- // Return TRUE if the quaterion is a unit quaternion. //----------------------------------------------------------------------------- static inline BOOL XMQuaternionIsUnit( FXMVECTOR Q ) { XMVECTOR Difference = XMVector4Length( Q ) - XMVectorSplatOne(); return XMVector4Less( XMVectorAbs( Difference ), g_UnitQuaternionEpsilon ); } //----------------------------------------------------------------------------- // Return TRUE if the plane is a unit plane. //----------------------------------------------------------------------------- static inline BOOL XMPlaneIsUnit( FXMVECTOR Plane ) { XMVECTOR Difference = XMVector3Length( Plane ) - XMVectorSplatOne(); return XMVector4Less( XMVectorAbs( Difference ), g_UnitPlaneEpsilon ); } //----------------------------------------------------------------------------- // Transform a plane by a rotation and translation. //----------------------------------------------------------------------------- static inline XMVECTOR TransformPlane( FXMVECTOR Plane, FXMVECTOR Rotation, FXMVECTOR Translation ) { XMVECTOR Normal = XMVector3Rotate( Plane, Rotation ); XMVECTOR D = XMVectorSplatW( Plane ) - XMVector3Dot( Normal, Translation ); return XMVectorInsert( Normal, D, 0, 0, 0, 0, 1 ); } //----------------------------------------------------------------------------- // Return the point on the line segement (S1, S2) nearest the point P. //----------------------------------------------------------------------------- static inline XMVECTOR PointOnLineSegmentNearestPoint( FXMVECTOR S1, FXMVECTOR S2, FXMVECTOR P ) { XMVECTOR Dir = S2 - S1; XMVECTOR Projection = ( XMVector3Dot( P, Dir ) - XMVector3Dot( S1, Dir ) ); XMVECTOR LengthSq = XMVector3Dot( Dir, Dir ); XMVECTOR t = Projection * XMVectorReciprocal( LengthSq ); XMVECTOR Point = S1 + t * Dir; // t < 0 XMVECTOR SelectS1 = XMVectorLess( Projection, XMVectorZero() ); Point = XMVectorSelect( Point, S1, SelectS1 ); // t > 1 XMVECTOR SelectS2 = XMVectorGreater( Projection, LengthSq ); Point = XMVectorSelect( Point, S2, SelectS2 ); return Point; } //----------------------------------------------------------------------------- // Test if the point (P) on the plane of the triangle is inside the triangle // (V0, V1, V2). //----------------------------------------------------------------------------- static inline XMVECTOR PointOnPlaneInsideTriangle( FXMVECTOR P, FXMVECTOR V0, FXMVECTOR V1, CXMVECTOR V2 ) { // Compute the triangle normal. XMVECTOR N = XMVector3Cross( V2 - V0, V1 - V0 ); // Compute the cross products of the vector from the base of each edge to // the point with each edge vector. XMVECTOR C0 = XMVector3Cross( P - V0, V1 - V0 ); XMVECTOR C1 = XMVector3Cross( P - V1, V2 - V1 ); XMVECTOR C2 = XMVector3Cross( P - V2, V0 - V2 ); // If the cross product points in the same direction as the normal the the // point is inside the edge (it is zero if is on the edge). XMVECTOR Zero = XMVectorZero(); XMVECTOR Inside0 = XMVectorGreaterOrEqual( XMVector3Dot( C0, N ), Zero ); XMVECTOR Inside1 = XMVectorGreaterOrEqual( XMVector3Dot( C1, N ), Zero ); XMVECTOR Inside2 = XMVectorGreaterOrEqual( XMVector3Dot( C2, N ), Zero ); // If the point inside all of the edges it is inside. return XMVectorAndInt( XMVectorAndInt( Inside0, Inside1 ), Inside2 ); } //----------------------------------------------------------------------------- // Find the approximate smallest enclosing bounding sphere for a set of // points. Exact computation of the smallest enclosing bounding sphere is // possible but is slower and requires a more complex algorithm. // The algorithm is based on Jack Ritter, "An Efficient Bounding Sphere", // Graphics Gems. //----------------------------------------------------------------------------- VOID ComputeBoundingSphereFromPoints( Sphere* pOut, UINT Count, const XMFLOAT3* pPoints, UINT Stride ) { XMASSERT( pOut ); XMASSERT( Count > 0 ); XMASSERT( pPoints ); // Find the points with minimum and maximum x, y, and z XMVECTOR MinX, MaxX, MinY, MaxY, MinZ, MaxZ; MinX = MaxX = MinY = MaxY = MinZ = MaxZ = XMLoadFloat3( pPoints ); for( UINT i = 1; i < Count; i++ ) { XMVECTOR Point = XMLoadFloat3( ( XMFLOAT3* )( ( BYTE* )pPoints + i * Stride ) ); float px = XMVectorGetX( Point ); float py = XMVectorGetY( Point ); float pz = XMVectorGetZ( Point ); if( px < XMVectorGetX( MinX ) ) MinX = Point; if( px > XMVectorGetX( MaxX ) ) MaxX = Point; if( py < XMVectorGetY( MinY ) ) MinY = Point; if( py > XMVectorGetY( MaxY ) ) MaxY = Point; if( pz < XMVectorGetZ( MinZ ) ) MinZ = Point; if( pz > XMVectorGetZ( MaxZ ) ) MaxZ = Point; } // Use the min/max pair that are farthest apart to form the initial sphere. XMVECTOR DeltaX = MaxX - MinX; XMVECTOR DistX = XMVector3Length( DeltaX ); XMVECTOR DeltaY = MaxY - MinY; XMVECTOR DistY = XMVector3Length( DeltaY ); XMVECTOR DeltaZ = MaxZ - MinZ; XMVECTOR DistZ = XMVector3Length( DeltaZ ); XMVECTOR Center; XMVECTOR Radius; if( XMVector3Greater( DistX, DistY ) ) { if( XMVector3Greater( DistX, DistZ ) ) { // Use min/max x.