C++ idPlane::Distance方法代码示例

/*
==================
BrushMostlyOnSide

==================
*/
int BrushMostlyOnSide( uBrush_t *brush, idPlane &plane )
{
	int			i, j;
	idWinding	*w;
	float		d, max = 0;
	int			side = PSIDE_FRONT;
	
	for( i = 0; i < brush->numsides; i++ )
	{
		w = brush->sides[i].winding;
		
		if( !w )
		{
			continue;
		}
		
		for( j = 0; j < w->GetNumPoints(); j++ )
		{
			d = plane.Distance( ( *w ) [j].ToVec3() );
			
			if( d > max )
			{
				max = d;
				side = PSIDE_FRONT;
			}
			
			if( -d > max )
			{
				max = -d;
				side = PSIDE_BACK;
			}
		}
	}
	return side;
}

/*
===================
Cull

cull points against given shadow frustum.
Return true of all points are outside the frustum.
===================
*/
bool shadowMapFrustum_t::Cull( const idVec3 points[8] ) const {

	bool outsidePlane[6];

	for (int i = 0; i < numPlanes; i++) {

		bool pointsCulled[8] = { true };
		const idPlane plane = planes[i];

		for (int j = 0; j < 8; j++) {
			const float distance = plane.Distance( points[j] );
			pointsCulled[j] = distance < 0;
		}

		outsidePlane[i] = true;
		for (int j = 0; j < 8; j++) {
			if (!pointsCulled[j]) {
				outsidePlane[i] = false;
			}
		}
	}

	for (int i = 0; i < numPlanes; i++) {
		if (outsidePlane[i])
			return true;
	}

	return false;
}

/*
================
R_CalcInteractionFacing

Determines which triangles of the surface are facing towards the light origin.

The facing array should be allocated with one extra index than
the number of surface triangles, which will be used to handle dangling
edge silhouettes.
================
*/
void R_CalcInteractionFacing( const idRenderEntityLocal *ent, const srfTriangles_t *tri, const idRenderLightLocal *light, srfCullInfo_t &cullInfo ) {
	SCOPED_PROFILE_EVENT( "R_CalcInteractionFacing" );

	if ( cullInfo.facing != NULL ) {
		return;
	}

	idVec3 localLightOrigin;
	R_GlobalPointToLocal( ent->modelMatrix, light->globalLightOrigin, localLightOrigin );

	const int numFaces = tri->numIndexes / 3;
	cullInfo.facing = (byte *) R_StaticAlloc( ( numFaces + 1 ) * sizeof( cullInfo.facing[0] ), TAG_RENDER_INTERACTION );

	// exact geometric cull against face
	for ( int i = 0, face = 0; i < tri->numIndexes; i += 3, face++ ) {
		const idDrawVert & v0 = tri->verts[tri->indexes[i + 0]];
		const idDrawVert & v1 = tri->verts[tri->indexes[i + 1]];
		const idDrawVert & v2 = tri->verts[tri->indexes[i + 2]];

		const idPlane plane( v0.xyz, v1.xyz, v2.xyz );
		const float d = plane.Distance( localLightOrigin );

		cullInfo.facing[face] = ( d >= 0.0f );
	}
	cullInfo.facing[numFaces] = 1;	// for dangling edges to reference
}

/*
============
idAASBuild::IsLedgeSide_r
============
*/
bool idAASBuild::IsLedgeSide_r( idBrushBSPNode *node, idFixedWinding *w, const idPlane &plane, const idVec3 &normal, const idVec3 &origin, const float radius ) {
	int res, i;
	idFixedWinding back;
	float dist;

	if ( !node ) {
		return false;
	}

	while ( node->GetChild(0) && node->GetChild(1) ) {
		dist = node->GetPlane().Distance( origin );
		if ( dist > radius ) {
			res = SIDE_FRONT;
		}
		else if ( dist < -radius ) {
			res = SIDE_BACK;
		}
		else {
			res = w->Split( &back, node->GetPlane(), LEDGE_EPSILON );
		}
		if ( res == SIDE_FRONT ) {
			node = node->GetChild(0);
		}
		else if ( res == SIDE_BACK ) {
			node = node->GetChild(1);
		}
		else if ( res == SIDE_ON ) {
			// continue with the side the winding faces
			if ( node->GetPlane().Normal() * normal > 0.0f ) {
				node = node->GetChild(0);
			}
			else {
				node = node->GetChild(1);
			}
		}
		else {
			if ( IsLedgeSide_r( node->GetChild(1), &back, plane, normal, origin, radius ) ) {
				return true;
			}
			node = node->GetChild(0);
		}
	}

	if ( node->GetContents() & AREACONTENTS_SOLID ) {
		return false;
	}

	for ( i = 0; i < w->GetNumPoints(); i++ ) {
		if ( plane.Distance( (*w)[i].ToVec3() ) > 0.0f ) {
			return true;
		}
	}

	return false;
}

/*
================
idSphere::PlaneSide
================
*/
int idSphere::PlaneSide( const idPlane &plane, const float epsilon ) const {
	float d;

	d = plane.Distance( origin );
	if ( d > radius + epsilon ) {
		return PLANESIDE_FRONT;
	}
	if ( d < -radius - epsilon ) {
		return PLANESIDE_BACK;
	}
	return PLANESIDE_CROSS;
}

/*
================
idSphere::PlaneDistance
================
*/
float idSphere::PlaneDistance( const idPlane &plane ) const {
	float d;

	d = plane.Distance( origin );
	if ( d > radius ) {
		return d - radius;
	}
	if ( d < -radius ) {
		return d + radius;
	}
	return 0.0f;
}

/*
============
idAASLocal::FloorEdgeSplitPoint

  calculates either the closest or furthest point on the floor of the area which also lies on the pathPlane
  the point has to be on the front side of the frontPlane to be valid
============
*/
bool idAASLocal::FloorEdgeSplitPoint( idVec3 &bestSplit, int areaNum, const idPlane &pathPlane, const idPlane &frontPlane, bool closest ) const {
	int i, j, faceNum, edgeNum;
	const aasArea_t *area;
	const aasFace_t *face;
	idVec3 split;
	float dist, bestDist;

	if ( closest ) {
		bestDist = maxWalkPathDistance;
	} else {
		bestDist = -0.1f;
	}

	area = &file->GetArea( areaNum );

	for ( i = 0; i < area->numFaces; i++ ) {
		faceNum = file->GetFaceIndex( area->firstFace + i );
		face = &file->GetFace( abs(faceNum) );

		if ( !(face->flags & FACE_FLOOR ) ) {
			continue;
		}

		for ( j = 0; j < face->numEdges; j++ ) {
			edgeNum = file->GetEdgeIndex( face->firstEdge + j );

			if ( !EdgeSplitPoint( split, abs( edgeNum ), pathPlane ) ) {
				continue;
			}
			dist = frontPlane.Distance( split );
			if ( closest ) {
				if ( dist >= -0.1f && dist < bestDist ) {
					bestDist = dist;
					bestSplit = split;
				}
			} else {
				if ( dist > bestDist ) {
					bestDist = dist;
					bestSplit = split;
				}
			}
		}
	}

	if ( closest ) {
		return ( bestDist < maxWalkPathDistance );
	} else {
		return ( bestDist > -0.1f );
	}
}

/*
================
idBox::PlaneSide
================
*/
int idBox::PlaneSide( const idPlane &plane, const float epsilon ) const {
	float d1, d2;

	d1 = plane.Distance( center );
	d2 = idMath::Fabs( extents[0] * plane.Normal()[0] ) +
			idMath::Fabs( extents[1] * plane.Normal()[1] ) +
				idMath::Fabs( extents[2] * plane.Normal()[2] );

	if ( d1 - d2 > epsilon ) {
		return PLANESIDE_FRONT;
	}
	if ( d1 + d2 < -epsilon ) {
		return PLANESIDE_BACK;
	}
	return PLANESIDE_CROSS;
}

/*
================
idBox::PlaneDistance
================
*/
float idBox::PlaneDistance( const idPlane &plane ) const {
	float d1, d2;

	d1 = plane.Distance( center );
	d2 = idMath::Fabs( extents[0] * plane.Normal()[0] ) +
			idMath::Fabs( extents[1] * plane.Normal()[1] ) +
				idMath::Fabs( extents[2] * plane.Normal()[2] );

	if ( d1 - d2 > 0.0f ) {
		return d1 - d2;
	}
	if ( d1 + d2 < 0.0f ) {
		return d1 + d2;
	}
	return 0.0f;
}

/*
================
idBounds::PlaneSide
================
*/
int idBounds::PlaneSide( const idPlane &plane, const float epsilon ) const {
	idVec3 center;
	float d1, d2;

	center = ( b[0] + b[1] ) * 0.5f;

	d1 = plane.Distance( center );
	d2 = idMath::Fabs( ( b[1][0] - center[0] ) * plane.Normal()[0] ) +
			idMath::Fabs( ( b[1][1] - center[1] ) * plane.Normal()[1] ) +
				idMath::Fabs( ( b[1][2] - center[2] ) * plane.Normal()[2] );

	if ( d1 - d2 > epsilon ) {
		return PLANESIDE_FRONT;
	}
	if ( d1 + d2 < -epsilon ) {
		return PLANESIDE_BACK;
	}
	return PLANESIDE_CROSS;
}

/*
================
idBounds::PlaneDistance
================
*/
float idBounds::PlaneDistance( const idPlane &plane ) const {
	idVec3 center;
	float d1, d2;

	center = ( b[0] + b[1] ) * 0.5f;

	d1 = plane.Distance( center );
	d2 = idMath::Fabs( ( b[1][0] - center[0] ) * plane.Normal()[0] ) +
			idMath::Fabs( ( b[1][1] - center[1] ) * plane.Normal()[1] ) +
				idMath::Fabs( ( b[1][2] - center[2] ) * plane.Normal()[2] );

	if ( d1 - d2 > 0.0f ) {
		return d1 - d2;
	}
	if ( d1 + d2 < 0.0f ) {
		return d1 + d2;
	}
	return 0.0f;
}

/*
=============
R_ChopWinding

Clips a triangle from one buffer to another, setting edge flags
The returned buffer may be the same as inNum if no clipping is done
If entirely clipped away, clipTris[returned].numVerts == 0

I have some worries about edge flag cases when polygons are clipped
multiple times near the epsilon.
=============
*/
static int R_ChopWinding( clipTri_t clipTris[2], int inNum, const idPlane &plane ) {
	clipTri_t	*in, *out;
	float	dists[MAX_CLIPPED_POINTS];
	int		sides[MAX_CLIPPED_POINTS];
	int		counts[3];
	float	dot;
	int		i, j;
	idVec3	*p1, *p2;
	idVec3	mid;

	in = &clipTris[inNum];
	out = &clipTris[inNum^1];
	counts[0] = counts[1] = counts[2] = 0;

	// determine sides for each point
	for ( i = 0 ; i < in->numVerts ; i++ ) {
		dot = plane.Distance( in->verts[i] );
		dists[i] = dot;
		if ( dot < -LIGHT_CLIP_EPSILON ) {
			sides[i] = SIDE_BACK;
		} else if ( dot > LIGHT_CLIP_EPSILON ) {
			sides[i] = SIDE_FRONT;
		} else {
			sides[i] = SIDE_ON;
		}
		counts[sides[i]]++;
	}

	// if none in front, it is completely clipped away
	if ( !counts[SIDE_FRONT] ) {
		in->numVerts = 0;
		return inNum;
	}
	if ( !counts[SIDE_BACK] ) {
		return inNum;		// inout stays the same
	}

	// avoid wrapping checks by duplicating first value to end
	sides[i] = sides[0];
	dists[i] = dists[0];
	in->verts[in->numVerts] = in->verts[0];
	in->edgeFlags[in->numVerts] = in->edgeFlags[0];

	out->numVerts = 0;
	for ( i = 0 ; i < in->numVerts ; i++ ) {
		p1 = &in->verts[i];

		if ( sides[i] != SIDE_BACK ) {
			out->verts[out->numVerts] = *p1;
			if ( sides[i] == SIDE_ON && sides[i+1] == SIDE_BACK ) {
				out->edgeFlags[out->numVerts] = 1;
			} else {
				out->edgeFlags[out->numVerts] = in->edgeFlags[i];
			}
			out->numVerts++;
		}

		if ( (sides[i] == SIDE_FRONT && sides[i+1] == SIDE_BACK)
			|| (sides[i] == SIDE_BACK && sides[i+1] == SIDE_FRONT) ) {
			// generate a split point
			p2 = &in->verts[i+1];
			
			dot = dists[i] / (dists[i]-dists[i+1]);
			for ( j=0 ; j<3 ; j++ ) {
				mid[j] = (*p1)[j] + dot*((*p2)[j]-(*p1)[j]);
			}
				
			out->verts[out->numVerts] = mid;

			// set the edge flag
			if ( sides[i+1] != SIDE_FRONT ) {
				out->edgeFlags[out->numVerts] = 1;
			} else {
				out->edgeFlags[out->numVerts] = in->edgeFlags[i];
			}

			out->numVerts++;
		}
	}

	return inNum ^ 1;
}

/*
=================
idSurface::Split
=================
*/
int idSurface::Split( const idPlane &plane, const float epsilon, idSurface **front, idSurface **back, int *frontOnPlaneEdges, int *backOnPlaneEdges ) const {
	float *			dists;
	float			f;
	byte *			sides;
	int				counts[3];
	int *			edgeSplitVertex;
	int				numEdgeSplitVertexes;
	int *			vertexRemap[2];
	int				vertexIndexNum[2][2];
	int *			vertexCopyIndex[2];
	int *			indexPtr[2];
	int				indexNum[2];
	int *			index;
	int *			onPlaneEdges[2];
	int				numOnPlaneEdges[2];
	int				maxOnPlaneEdges;
	int				i;
	idSurface *		surface[2];
	idDrawVert		v;

	dists = (float *) _alloca( verts.Num() * sizeof( float ) );
	sides = (byte *) _alloca( verts.Num() * sizeof( byte ) );

	counts[0] = counts[1] = counts[2] = 0;

	// determine side for each vertex
	for ( i = 0; i < verts.Num(); i++ ) {
		dists[i] = f = plane.Distance( verts[i].xyz );
		if ( f > epsilon ) {
			sides[i] = SIDE_FRONT;
		} else if ( f < -epsilon ) {
			sides[i] = SIDE_BACK;
		} else {
			sides[i] = SIDE_ON;
		}
		counts[sides[i]]++;
	}

	*front = *back = NULL;

	// if coplanar, put on the front side if the normals match
	if ( !counts[SIDE_FRONT] && !counts[SIDE_BACK] ) {

		f = ( verts[indexes[1]].xyz - verts[indexes[0]].xyz ).Cross( verts[indexes[0]].xyz - verts[indexes[2]].xyz ) * plane.Normal();
		if ( FLOATSIGNBITSET( f ) ) {
			*back = new idSurface( *this );
			return SIDE_BACK;
		} else {
			*front = new idSurface( *this );
			return SIDE_FRONT;
		}
	}
	// if nothing at the front of the clipping plane
	if ( !counts[SIDE_FRONT] ) {
		*back = new idSurface( *this );
		return SIDE_BACK;
	}
	// if nothing at the back of the clipping plane
	if ( !counts[SIDE_BACK] ) {
		*front = new idSurface( *this );
		return SIDE_FRONT;
	}

	// allocate front and back surface
	*front = surface[0] = new idSurface();
	*back = surface[1] = new idSurface();

	edgeSplitVertex = (int *) _alloca( edges.Num() * sizeof( int ) );
	numEdgeSplitVertexes = 0;

	maxOnPlaneEdges = 4 * counts[SIDE_ON];
	counts[SIDE_FRONT] = counts[SIDE_BACK] = counts[SIDE_ON] = 0;

	// split edges
	for ( i = 0; i < edges.Num(); i++ ) {
		int v0 = edges[i].verts[0];
		int v1 = edges[i].verts[1];
		int sidesOr = ( sides[v0] | sides[v1] );

		// if both vertexes are on the same side or one is on the clipping plane
		if ( !( sides[v0] ^ sides[v1] ) || ( sidesOr & SIDE_ON ) ) {
			edgeSplitVertex[i] = -1;
			counts[sidesOr & SIDE_BACK]++;
			counts[SIDE_ON] += ( sidesOr & SIDE_ON ) >> 1;
		} else {

/*
============
idBrush::Split
============
*/
int idBrush::Split( const idPlane& plane, int planeNum, idBrush** front, idBrush** back ) const
{
	int res, i, j;
	idBrushSide* side, *frontSide, *backSide;
	float dist, maxBack, maxFront, *maxBackWinding, *maxFrontWinding;
	idWinding* w, *mid;
	
	assert( windingsValid );
	
	if( front )
	{
		*front = NULL;
	}
	if( back )
	{
		*back = NULL;
	}
	
	res = bounds.PlaneSide( plane, -BRUSH_EPSILON );
	if( res == PLANESIDE_FRONT )
	{
		if( front )
		{
			*front = Copy();
		}
		return res;
	}
	if( res == PLANESIDE_BACK )
	{
		if( back )
		{
			*back = Copy();
		}
		return res;
	}
	
	maxBackWinding = ( float* ) _alloca16( sides.Num() * sizeof( float ) );
	maxFrontWinding = ( float* ) _alloca16( sides.Num() * sizeof( float ) );
	
	maxFront = maxBack = 0.0f;
	for( i = 0; i < sides.Num(); i++ )
	{
		side = sides[i];
		
		w = side->winding;
		
		if( !w )
		{
			continue;
		}
		
		maxBackWinding[i] = 10.0f;
		maxFrontWinding[i] = -10.0f;
		
		for( j = 0; j < w->GetNumPoints(); j++ )
		{
		
			dist = plane.Distance( ( *w )[j].ToVec3() );
			if( dist > maxFrontWinding[i] )
			{
				maxFrontWinding[i] = dist;
			}
			if( dist < maxBackWinding[i] )
			{
				maxBackWinding[i] = dist;
			}
		}
		
		if( maxFrontWinding[i] > maxFront )
		{
			maxFront = maxFrontWinding[i];
		}
		if( maxBackWinding[i] < maxBack )
		{
			maxBack = maxBackWinding[i];
		}
	}
	
	if( maxFront < BRUSH_EPSILON )
	{
		if( back )
		{
			*back = Copy();
		}
		return PLANESIDE_BACK;
	}
	
	if( maxBack > -BRUSH_EPSILON )
	{
		if( front )
		{
			*front = Copy();
		}
		return PLANESIDE_FRONT;
	}
//.........这里部分代码省略.........

/*
============
idAASLocal::FloorEdgeSplitPoint

  calculates either the closest or furthest point on the floor of the area which also lies on the pathPlane
  the point has to be on the front side of the frontPlane to be valid
============
*/
bool idAASLocal::FloorEdgeSplitPoint( idVec3 &bestSplit, int areaNum, const idPlane &pathPlane, const idPlane &frontPlane, bool closest ) const {
	int i, j, faceNum, edgeNum;
	const aasArea_t *area;
	const aasFace_t *face;
	idVec3 split;
	float dist, bestDist;
	const aasEdge_t *edge;
	idVec3 v1, v2;
	float d1, d2;

	area = &file->GetArea( areaNum );
	if ( closest ) {
		bestDist = maxWalkPathDistance;

		for ( i = area->numFaces-1; i >= 0; i-- ) {
			faceNum = file->GetFaceIndex( area->firstFace + i );
			face = &file->GetFace( abs(faceNum) );

			if ( !(face->flags & FACE_FLOOR ) ) {
				continue;
			}

			for ( j = face->numEdges-1; j >= 0; j-- ) {
				edgeNum = file->GetEdgeIndex( face->firstEdge + j );

				edge = &file->GetEdge( abs( edgeNum ) );
				v1 = file->GetVertex( edge->vertexNum[0] );
				v2 = file->GetVertex( edge->vertexNum[1] );
				d1 = v1 * pathPlane.Normal() - pathPlane.Dist();
				d2 = v2 * pathPlane.Normal() - pathPlane.Dist();

				//if ( (d1 < CM_CLIP_EPSILON && d2 < CM_CLIP_EPSILON) || (d1 > -CM_CLIP_EPSILON && d2 > -CM_CLIP_EPSILON) ) {
				if ( FLOATSIGNBITSET( d1 ) == FLOATSIGNBITSET( d2 ) ) {
					continue;
				}

				split = v1 + (d1 / (d1 - d2)) * (v2 - v1);
				dist = frontPlane.Distance( split );
				if ( dist >= -0.1f && dist < bestDist ) {
					bestDist = dist;
					bestSplit = split;
				}
			}
		}

		return ( bestDist < maxWalkPathDistance );

	} else {
		bestDist = -0.1f;

		for ( i = area->numFaces-1; i >= 0; i-- ) {
			faceNum = file->GetFaceIndex( area->firstFace + i );
			face = &file->GetFace( abs(faceNum) );

			if ( !(face->flags & FACE_FLOOR ) ) {
				continue;
			}

			for ( j = face->numEdges-1; j >= 0; j-- ) {
				edgeNum = file->GetEdgeIndex( face->firstEdge + j );

				edge = &file->GetEdge( abs( edgeNum ) );
				v1 = file->GetVertex( edge->vertexNum[0] );
				v2 = file->GetVertex( edge->vertexNum[1] );
				d1 = v1 * pathPlane.Normal() - pathPlane.Dist();
				d2 = v2 * pathPlane.Normal() - pathPlane.Dist();

				//if ( (d1 < CM_CLIP_EPSILON && d2 < CM_CLIP_EPSILON) || (d1 > -CM_CLIP_EPSILON && d2 > -CM_CLIP_EPSILON) ) {
				if ( FLOATSIGNBITSET( d1 ) == FLOATSIGNBITSET( d2 ) ) {
					continue;
				}

				split = v1 + (d1 / (d1 - d2)) * (v2 - v1);
				dist = frontPlane.Distance( split );
				if ( dist > bestDist ) {
					bestDist = dist;
					bestSplit = split;
				}
			}
		}

		return ( bestDist > -0.1f );
	}
}