ON_ClippingRegion Class Reference

#include <opennurbs_xform.h>

Public Types
enum	{   max_clip_plane_count = 16, frustum_bitmask = 0x0000003F, near_plane_bitmask = 0x00000020, far_plane_bitmask = 0x00000010,   clip_plane_bitmask = 0x7FFFFFC0, negw_bitmask = 0x80000000 }

Public Member Functions
	ON_ClippingRegion ()
double	ClipPlaneTolerance () const
bool	GetLineClipPlaneParamters (ON_4dPoint P0, ON_4dPoint P1, double *t0, double *t1) const
	Calculate the interval for the segment of a line that is in the clip plane region. More...
int	InClipPlaneRegion (ON_3dPoint P) const
	The "clip plane region" is the convex hull of the planes in the m_clip_plane[] array. These functions determine if some portion of the convex hull of the test points is inside the clip plane region. More...
int	InClipPlaneRegion (const ON_BoundingBox &bbox) const
int	InClipPlaneRegion (int count, const ON_3fPoint *p) const
int	InClipPlaneRegion (int count, const ON_3dPoint *p) const
int	InClipPlaneRegion (int count, const ON_4dPoint *p) const
ON_Xform	InverseObjectToClipTransformation () const
int	InViewFrustum (ON_3dPoint P) const
	The "view frustum" is the frustum the m_xform transformation maps to clipping coordinate box (-1,+1)^3. These functions determine if some portion of the convex hull of the test points is inside the view frustum. More...
int	InViewFrustum (const ON_BoundingBox &bbox) const
int	InViewFrustum (int count, const ON_3fPoint *p) const
int	InViewFrustum (int count, const ON_3dPoint *p) const
int	InViewFrustum (int count, const ON_4dPoint *p) const
int	IsVisible (ON_3dPoint P) const
	The "visible area" is the intersection of the view frustum, defined by m_xform, and the clipping region, defined by the m_clip_plane[] array. These functions determing if some portion of the convex hull of the test points is visible. More...
int	IsVisible (const ON_BoundingBox &bbox) const
int	IsVisible (int count, const ON_3fPoint *p) const
int	IsVisible (int count, const ON_3dPoint *p) const
int	IsVisible (int count, const ON_4dPoint *p) const
ON_Xform	ObjectToClipTransformation () const
void	SetClipPlaneTolerance (double clip_plane_tolerance)
bool	SetObjectToClipTransformation (const class ON_Viewport &viewport)
	Sets the object to clip transformation to the viewport's workd to clip transformation. More...
bool	SetObjectToClipTransformation (const ON_Xform object_to_clip_transformation)
unsigned int	TransformPoint (const ON_4dPoint &P, ON_4dPoint &Q) const
	Transform a pont and return the clipping information. More...
unsigned int	TransformPoint (const ON_3dPoint &P, ON_3dPoint &Q) const
unsigned int	TransformPoint (const ON_3fPoint &P, ON_3dPoint &Q) const
int	TransformPoints (int count, ON_4dPoint *p) const
	Transform a list of 4d homogenous points while testing for visibility. More...
int	TransformPoints (int count, ON_4dPoint *p, unsigned int *pflags) const

Public Attributes
ON_PlaneEquation	m_clip_plane [max_clip_plane_count]
int	m_clip_plane_count

Member Enumeration Documentation

anonymous enum

anonymous enum

Enumerator
max_clip_plane_count
frustum_bitmask
near_plane_bitmask
far_plane_bitmask
clip_plane_bitmask
negw_bitmask

Constructor & Destructor Documentation

ON_ClippingRegion()

ON_ClippingRegion::ON_ClippingRegion

(

)

Member Function Documentation

ClipPlaneTolerance()

double ON_ClippingRegion::ClipPlaneTolerance

(

)

const

Returns

3d world coordinates tolerance to use when testing objects to see if the planes in m_clip_plane[] hide the objects.

The constructor sets this value to zero. Rhino uses values around 1e-5.

GetLineClipPlaneParamters()

bool ON_ClippingRegion::GetLineClipPlaneParamters	(	ON_4dPoint	P0,
		ON_4dPoint	P1,
		double *	t0,
		double *	t1
	)		const

Calculate the interval for the segment of a line that is in the clip plane region.

Parameters

P0	[in] start point
P1	[in] end point
t0	[out] start parameter
t1	[out] end parameter

Returns

True if some portion of the line is visible and 0.0 <= *t0 <= *t1 <= 1.0.

InClipPlaneRegion() [1/5]

int ON_ClippingRegion::InClipPlaneRegion

(

ON_3dPoint

P

)

const

The "clip plane region" is the convex hull of the planes in the m_clip_plane[] array. These functions determine if some portion of the convex hull of the test points is inside the clip plane region.

Parameters

P	[in] point
box	[in] bounding box
count	[in] number of points
p	[in] array of points
bEnableClippingPlanes	[in] If true, then the additional clipping planes are tested. If false, then the additional clipping planes are ignored.

Returns

0 = No part of the of the convex hull of the tested points is in the clip plane region. 1 = A portion of the convex hull of the tested points may be in the clip plane region. 2 = The entire convex hull of the tested points is in the clip plane region.

InClipPlaneRegion() [2/5]

int ON_ClippingRegion::InClipPlaneRegion

(

const ON_BoundingBox &

bbox

)

const

InClipPlaneRegion() [3/5]

int ON_ClippingRegion::InClipPlaneRegion	(	int	count,
		const ON_3fPoint *	p
	)		const

InClipPlaneRegion() [4/5]

int ON_ClippingRegion::InClipPlaneRegion	(	int	count,
		const ON_3dPoint *	p
	)		const

InClipPlaneRegion() [5/5]

int ON_ClippingRegion::InClipPlaneRegion	(	int	count,
		const ON_4dPoint *	p
	)		const

InverseObjectToClipTransformation()

ON_Xform ON_ClippingRegion::InverseObjectToClipTransformation

(

)

const

InViewFrustum() [1/5]

int ON_ClippingRegion::InViewFrustum

(

ON_3dPoint

P

)

const

The "view frustum" is the frustum the m_xform transformation maps to clipping coordinate box (-1,+1)^3. These functions determine if some portion of the convex hull of the test points is inside the view frustum.

Parameters

P	[in] point
box	[in] bounding box
count	[in] number of points
p	[in] array of points
bEnableClippingPlanes	[in] If true, then the additional clipping planes are tested. If false, then the additional clipping planes are ignored.

Returns

0 = No part of the of the convex hull of the tested points is in the view frustum. 1 = A portion of the convex hull of the otested points may be in the view frustum. 2 = The entire convex hull of the tested points is in the view frustum.

InViewFrustum() [2/5]

int ON_ClippingRegion::InViewFrustum

(

const ON_BoundingBox &

bbox

)

const

InViewFrustum() [3/5]

int ON_ClippingRegion::InViewFrustum	(	int	count,
		const ON_3fPoint *	p
	)		const

InViewFrustum() [4/5]

int ON_ClippingRegion::InViewFrustum	(	int	count,
		const ON_3dPoint *	p
	)		const

InViewFrustum() [5/5]

int ON_ClippingRegion::InViewFrustum	(	int	count,
		const ON_4dPoint *	p
	)		const

IsVisible() [1/5]

int ON_ClippingRegion::IsVisible

(

ON_3dPoint

P

)

const

The "visible area" is the intersection of the view frustum, defined by m_xform, and the clipping region, defined by the m_clip_plane[] array. These functions determing if some portion of the convex hull of the test points is visible.

Parameters

P	[in] point
box	[in] bounding box
count	[in] number of points
p	[in] array of points

Returns

0 = no part of the object is in the region. 1 = a portion of the object is in the region 2 = entire object is in clipping region

IsVisible() [2/5]

int ON_ClippingRegion::IsVisible

(

const ON_BoundingBox &

bbox

)

const

IsVisible() [3/5]

int ON_ClippingRegion::IsVisible	(	int	count,
		const ON_3fPoint *	p
	)		const

IsVisible() [4/5]

int ON_ClippingRegion::IsVisible	(	int	count,
		const ON_3dPoint *	p
	)		const

IsVisible() [5/5]

int ON_ClippingRegion::IsVisible	(	int	count,
		const ON_4dPoint *	p
	)		const

ObjectToClipTransformation()

ON_Xform ON_ClippingRegion::ObjectToClipTransformation

(

)

const

SetClipPlaneTolerance()

void ON_ClippingRegion::SetClipPlaneTolerance

(

double

clip_plane_tolerance

)

Parameters

clip_plane_tolerance

[in] 3d world coordinates tolerance to use when testing objects to see if the planes in m_clip_plane[] hide the objects.

The constructor sets this value to zero. Rhino uses values around 1e-5.

SetObjectToClipTransformation() [1/2]

bool ON_ClippingRegion::SetObjectToClipTransformation

(

const class ON_Viewport &

viewport

)

Sets the object to clip transformation to the viewport's workd to clip transformation.

SetObjectToClipTransformation() [2/2]

bool ON_ClippingRegion::SetObjectToClipTransformation

(

const ON_Xform

object_to_clip_transformation

)

TransformPoint() [1/3]

unsigned int ON_ClippingRegion::TransformPoint	(	const ON_4dPoint &	P,
		ON_4dPoint &	Q
	)		const

Transform a pont and return the clipping information.

Parameters

P	[in] point ot transform
Q	[out] transformed point

Returns

0 when the point is in the visible region. Otherwise the bits are set to indicate which planes clip the intput point. 0x01 left of the view frusturm 0x02 right of the view frustum 0x04 below the view frustum 0x08 above the view frustum 0x10 behind the view frustum (too far) 0x20 in front of the view frustum (too near)

0x10 below m_clip_plane[0] 0x20 below m_clip_plane[1] ... 0x40000000 below m_clip_plane[24]

0x80000000 transformation created a non-positive weight

TransformPoint() [2/3]

unsigned int ON_ClippingRegion::TransformPoint	(	const ON_3dPoint &	P,
		ON_3dPoint &	Q
	)		const

TransformPoint() [3/3]

unsigned int ON_ClippingRegion::TransformPoint	(	const ON_3fPoint &	P,
		ON_3dPoint &	Q
	)		const

TransformPoints() [1/2]

int ON_ClippingRegion::TransformPoints	(	int	count,
		ON_4dPoint *	p
	)		const

Transform a list of 4d homogenous points while testing for visibility.

Parameters

count	[in] number of points
p	[in/out] array of points to test and transform If 0 is returned, some of the points may not be transformed. In all other cases, the output points are transformed by m_xform.
pflags	[out] 0 when the point is in the visible region. Otherwise the bits are set to indicate which planes clip the intput point. 0x01 left of the view frusturm 0x02 right of the view frustum 0x04 below the view frustum 0x08 above the view frustum 0x10 behind the view frustum (too far) 0x20 in front of the view frustum (too near)

0x10 below m_clip_plane[0] 0x20 below m_clip_plane[1] ... 0x40000000 below m_clip_plane[24]

0x80000000 transformation created a non-positive weight

Returns

0 = convex hull of the points is not in the region. The m_cull_bits field reports which plane or planes culled the point set. 1 = a portion of the convex hull is in the region. The m_cull_bits field reports which plane or planes culled the point set. 2 = all points are in the region. The m_cull_bits field will be zero.

TransformPoints() [2/2]

int ON_ClippingRegion::TransformPoints	(	int	count,
		ON_4dPoint *	p,
		unsigned int *	pflags
	)		const

Member Data Documentation

m_clip_plane

ON_PlaneEquation ON_ClippingRegion::m_clip_plane[max_clip_plane_count]

m_clip_plane_count

int ON_ClippingRegion::m_clip_plane_count