A ProjectionScreen implements a simple system for projective texturing. More...

#include "projectionScreen.h"

Inheritance diagram for ProjectionScreen:

Public Member Functions
	ProjectionScreen (const string &name="")
void	clear_undist_lut ()
	Removes the distortion lookup table from the projector, if specified.
virtual bool	cull_callback (CullTraverser *trav, CullTraverserData &data)
	This function will be called during the cull traversal to perform any additional operations that should be performed at cull time.
virtual TypeHandle	force_init_type ()
bool	get_auto_recompute () const
	Returns the auto_recompute flag.
const LColor &	get_frame_color () const
	Returns the color the screen will be painted at the portions outside of the lens' frustum.
bool	get_invert_uvs () const
	Returns whether this screen is compensating for a graphics driver inverting the framebuffer image.
const UpdateSeq &	get_last_screen () const
	Returns an UpdateSeq corresponding to the last time a screen mesh was generated for the ProjectionScreen.
const NodePath &	get_projector () const
	Returns the NodePath to the LensNode that is to serve as the projector for this screen, or empty if no projector is associated.
bool	get_texcoord_3d () const
	See set_texcoord_3d().
string	get_texcoord_name () const
	Returns the name of the texture coordinates that will be generated by this particular ProjectionScreen, as set by set_texcoord_name().
virtual TypeHandle	get_type () const
const PfmFile &	get_undist_lut () const
	Returns the distortion lookup table provided via set_undist_lut(), if any.
const LColor &	get_vignette_color () const
	Returns the color the screen will be painted at the portions outside of the lens' frustum.
bool	get_vignette_on () const
	Returns true if vertex-based vignetting is on, false otherwise.
bool	has_undist_lut () const
	Returns true if a valid distortion lookup table was provided via set_undist_lut(), false otherwise.
virtual PandaNode *	make_copy () const
	Returns a newly-allocated Node that is a shallow copy of this one.
	PT (GeomNode) generate_screen(const NodePath &projector
	PT (PandaNode) make_flat_mesh(const NodePath &this_np
void	recompute ()
	Recomputes all the UV's for geometry below the ProjectionScreen node, as if the texture were projected from the associated projector.
bool	recompute_if_stale ()
	Calls recompute() only if the relative transform between the ProjectionScreen and the projector has changed, or if any other relevant property has changed.
bool	recompute_if_stale (const NodePath &this_np)
	Calls recompute() only if the relative transform between the ProjectionScreen and the projector has changed, or if any other relevant property has changed.
void	regenerate_screen (const NodePath &projector, const string &screen_name, int num_x_verts, int num_y_verts, PN_stdfloat distance, PN_stdfloat fill_ratio)
	Removes all the children from the ProjectionScreen node, and adds the newly generated child returned by generate_screen().
void	set_auto_recompute (bool auto_recompute)
	Sets the auto_recompute flag.
void	set_frame_color (const LColor &frame_color)
	Specifies the color the screen will be painted at the portions outside of the lens' frustum; i.e.
void	set_invert_uvs (bool invert_uvs)
	Some OpenGL graphics drivers are known to invert the framebuffer image when they copy it to texture.
void	set_projector (const NodePath &projector)
	Specifies the LensNode that is to serve as the projector for this screen.
void	set_texcoord_3d (bool texcoord_3d)
	Set this true to force 3-D texture coordinates to be created for the geometry.
void	set_texcoord_name (const string &texcoord_name)
	Specifies the name of the texture coordinates that are generated by this particular ProjectionScreen.
void	set_undist_lut (const PfmFile &undist_lut)
	Applies a distortion lookup table to the projector.
void	set_vignette_color (const LColor &vignette_color)
	Specifies the color the screen will be painted at the portions outside of the lens' frustum; i.e.
void	set_vignette_on (bool vignette_on)
	Specifies whether vertex-based vignetting should be on.
Static Public Member Functions
static TypeHandle	get_class_type ()
static void	init_type ()
Public Attributes
const NodePath &	camera
const string int int PN_stdfloat	distance
const string int int PN_stdfloat PN_stdfloat	fill_ratio
const string int	num_x_verts
const string int int	num_y_verts
const string &	screen_name
Protected Member Functions
	ProjectionScreen (const ProjectionScreen &copy)

Detailed Description

A ProjectionScreen implements a simple system for projective texturing.

The ProjectionScreen node is the parent of a hierarchy of geometry that is considered a "screen"; the ProjectionScreen will automatically recompute all the UV's (for a particular texture stage) on its subordinate geometry according to the relative position and lens parameters of the indicated LensNode.

All this does is recompute UV's; the caller is responsible for applying the appropriate texture(s) to the geometry.

This does not take advantage of any hardware-assisted projective texturing; all of the UV's are computed in the CPU. (Use NodePath::project_texture() to enable hardware-assisted projective texturing.) However, the ProjectionScreen interface does support any kind of lens, linear or nonlinear, that might be defined using the Lens interface, including fisheye and cylindrical lenses.

Definition at line 55 of file projectionScreen.h.

Member Function Documentation

void ProjectionScreen::clear_undist_lut ( ) [inline]

Removes the distortion lookup table from the projector, if specified.

Definition at line 36 of file projectionScreen.I.

bool ProjectionScreen::cull_callback	(	CullTraverser *	trav,
		CullTraverserData &	data
	)		`[virtual]`

This function will be called during the cull traversal to perform any additional operations that should be performed at cull time.

This may include additional manipulation of render state or additional visible/invisible decisions, or any other arbitrary operation.

Note that this function will *not* be called unless set_cull_callback() is called in the constructor of the derived class. It is necessary to call set_cull_callback() to indicated that we require cull_callback() to be called.

By the time this function is called, the node has already passed the bounding-volume test for the viewing frustum, and the node's transform and state have already been applied to the indicated CullTraverserData object.

The return value is true if this node should be visible, or false if it should be culled.

Reimplemented from PandaNode.

Definition at line 121 of file projectionScreen.cxx.

References WorkingNodePath::get_node_path(), and recompute_if_stale().

bool ProjectionScreen::get_auto_recompute ( ) const [inline]

Returns the auto_recompute flag.

When this is true, the ProjectionScreen will always be recomputed if necessary before the frame is drawn; when it is false, an explicit call to recompute_if_stale() may be required.

Definition at line 279 of file projectionScreen.I.

const LColor & ProjectionScreen::get_frame_color ( ) const [inline]

Returns the color the screen will be painted at the portions outside of the lens' frustum.

See set_frame_color().

Definition at line 250 of file projectionScreen.I.

bool ProjectionScreen::get_invert_uvs ( ) const [inline]

Returns whether this screen is compensating for a graphics driver inverting the framebuffer image.

See set_invert_uvs().

Definition at line 137 of file projectionScreen.I.

const UpdateSeq & ProjectionScreen::get_last_screen ( ) const [inline]

Returns an UpdateSeq corresponding to the last time a screen mesh was generated for the ProjectionScreen.

Each time generate_screen() is called, this number is incremented; this allows other objects (like NonlinearImager) to know when they need to recompute themselves.

Definition at line 295 of file projectionScreen.I.

const NodePath & ProjectionScreen::get_projector ( ) const [inline]

Returns the NodePath to the LensNode that is to serve as the projector for this screen, or empty if no projector is associated.

Definition at line 25 of file projectionScreen.I.

bool ProjectionScreen::get_texcoord_3d ( ) const [inline]

See set_texcoord_3d().

Definition at line 164 of file projectionScreen.I.

string ProjectionScreen::get_texcoord_name ( ) const [inline]

Returns the name of the texture coordinates that will be generated by this particular ProjectionScreen, as set by set_texcoord_name().

Definition at line 104 of file projectionScreen.I.

Referenced by set_texcoord_name().

const PfmFile & ProjectionScreen::get_undist_lut ( ) const [inline]

Returns the distortion lookup table provided via set_undist_lut(), if any.

Definition at line 77 of file projectionScreen.I.

const LColor & ProjectionScreen::get_vignette_color ( ) const [inline]

Returns the color the screen will be painted at the portions outside of the lens' frustum.

See set_vignette_color().

Definition at line 223 of file projectionScreen.I.

bool ProjectionScreen::get_vignette_on ( ) const [inline]

Returns true if vertex-based vignetting is on, false otherwise.

See set_vignette_on().

Definition at line 196 of file projectionScreen.I.

bool ProjectionScreen::has_undist_lut ( ) const [inline]

Returns true if a valid distortion lookup table was provided via set_undist_lut(), false otherwise.

Definition at line 66 of file projectionScreen.I.

PandaNode * ProjectionScreen::make_copy ( ) const [virtual]

Returns a newly-allocated Node that is a shallow copy of this one.

It will be a different Node pointer, but its internal data may or may not be shared with that of the original Node.

Reimplemented from PandaNode.

Definition at line 91 of file projectionScreen.cxx.

void ProjectionScreen::recompute ( )

Recomputes all the UV's for geometry below the ProjectionScreen node, as if the texture were projected from the associated projector.

This function is normally called automatically whenever the relevant properties change, so it should not normally need to be called directly by the user. However, it does no harm to call this if there is any doubt.

Definition at line 339 of file projectionScreen.cxx.

References NodePath::any_path().

Referenced by recompute_if_stale().

bool ProjectionScreen::recompute_if_stale ( )

Calls recompute() only if the relative transform between the ProjectionScreen and the projector has changed, or if any other relevant property has changed.

Returns true if recomputed, false otherwise.

Definition at line 354 of file projectionScreen.cxx.

References NodePath::any_path().

Referenced by cull_callback().

bool ProjectionScreen::recompute_if_stale ( const NodePath & this_np )

Calls recompute() only if the relative transform between the ProjectionScreen and the projector has changed, or if any other relevant property has changed.

Returns true if recomputed, false otherwise.

Definition at line 369 of file projectionScreen.cxx.

References LMatrix4f::almost_equal(), NodePath::get_transform(), NodePath::is_empty(), NodePath::node(), and recompute().

void ProjectionScreen::regenerate_screen	(	const NodePath &	projector,
		const string &	screen_name,
		int	num_x_verts,
		int	num_y_verts,
		PN_stdfloat	distance,
		PN_stdfloat	fill_ratio
	)

Removes all the children from the ProjectionScreen node, and adds the newly generated child returned by generate_screen().

Definition at line 272 of file projectionScreen.cxx.

void ProjectionScreen::set_auto_recompute ( bool auto_recompute ) [inline]

Sets the auto_recompute flag.

When this is true, the ProjectionScreen will always be recomputed if necessary before the frame is drawn; when it is false, an explicit call to recompute_if_stale() may be required.

Definition at line 264 of file projectionScreen.I.

void ProjectionScreen::set_frame_color ( const LColor & frame_color ) [inline]

Specifies the color the screen will be painted at the portions outside of the lens' frustum; i.e.

where the lens can't see it or illuminate it. This color is only used if the vignette_on flag is true; see set_vignette_on().

Definition at line 237 of file projectionScreen.I.

void ProjectionScreen::set_invert_uvs ( bool invert_uvs ) [inline]

Some OpenGL graphics drivers are known to invert the framebuffer image when they copy it to texture.

(This is arguably a problem with the OpenGL spec, which seems to be unclear about the proper ordering of pixels in this operation.)

In any case, set this true to compensate for this effect by inverting the UV's of the projection screen. The default is taken from the Configrc variable project-invert-uvs.

Definition at line 123 of file projectionScreen.I.

void ProjectionScreen::set_projector ( const NodePath & projector )

Specifies the LensNode that is to serve as the projector for this screen.

The relative position of the LensNode to the ProjectionScreen, as well as the properties of the lens associated with the LensNode, determines the UV's that will be assigned to the geometry within the ProjectionScreen.

The NodePath must refer to a LensNode (or a Camera).

Definition at line 141 of file projectionScreen.cxx.

References NodePath::is_empty(), TypedObject::is_of_type(), and NodePath::node().

void ProjectionScreen::set_texcoord_3d ( bool texcoord_3d ) [inline]

Set this true to force 3-D texture coordinates to be created for the geometry.

When this is true and the geometry has only 2-D texture coordinates, those texture coordinates are dumped in favor of 3-D coordinates. When this is false, whatever texture coordinates already exist are preserved as-is.

Definition at line 152 of file projectionScreen.I.

void ProjectionScreen::set_texcoord_name ( const string & texcoord_name ) [inline]

Specifies the name of the texture coordinates that are generated by this particular ProjectionScreen.

This can be used in the presence of multitexturing to compute the UV's for just a subset of all of the active stages of the multitexture pipeline.

Definition at line 91 of file projectionScreen.I.

References get_texcoord_name().

void ProjectionScreen::set_undist_lut ( const PfmFile & undist_lut ) [inline]

Applies a distortion lookup table to the projector.

This mapping warps the lens effect by passing each ray through an indirection table: the point (u,v) in the indicated lookup table stores the actual (u,v) that the lens produces.

This does not affect the operation of generate_screen().

Definition at line 54 of file projectionScreen.I.

void ProjectionScreen::set_vignette_color ( const LColor & vignette_color ) [inline]

Specifies the color the screen will be painted at the portions outside of the lens' frustum; i.e.

where the lens can't see it or illuminate it. This color is only used if the vignette_on flag is true; see set_vignette_on().

Definition at line 210 of file projectionScreen.I.

void ProjectionScreen::set_vignette_on ( bool vignette_on ) [inline]

Specifies whether vertex-based vignetting should be on.

When this is enabled, vertex color will be set on the screen vertices to color the screen two distinct colors, usually white and black, for the parts of the screen in front of and outside the lens' frustum, respectively. When this is not enabled, the screen color will be left alone.

This effect generally looks terrible, but it does at least make the boundaries of the lens clear.

Definition at line 183 of file projectionScreen.I.

The documentation for this class was generated from the following files:

panda/src/distort/projectionScreen.h
panda/src/distort/projectionScreen.cxx
panda/src/distort/projectionScreen.I

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Member Functions

Detailed Description

Member Function Documentation