This is the abstract base class that defines the interface needed to describe a terrain for rendering by SpeedTree. More...

#include "stTerrain.h"

Inheritance diagram for STTerrain:

Public Member Functions
virtual void	clear ()
	Resets the terrain to its initial, unloaded state. More...

virtual void	fill_vertices (GeomVertexData *data, PN_stdfloat start_x, PN_stdfloat start_y, PN_stdfloat size_xy, int num_xy) const
	After load_data() has been called, this will be called occasionally to populate the vertices for a terrain cell. More...

virtual TypeHandle	force_init_type ()

virtual PN_stdfloat	get_height (PN_stdfloat x, PN_stdfloat y) const =0
	After load_data() has been called, this should return the computed height value at point (x, y) of the terrain, where x and y are unbounded and may refer to any 2-d point in space. More...

PN_stdfloat	get_max_height () const
	Returns the largest height value that might be returned by get_height(). More...

PN_stdfloat	get_min_height () const
	Returns the smallest height value that might be returned by get_height(). More...

const Filename &	get_normal_map () const
	Returns the normal map that should be applied to the terrain. More...

int	get_num_splat_layers () const
	Returns the number of splat layers that are to be applied to the terrain. More...

virtual PN_stdfloat	get_slope (PN_stdfloat x, PN_stdfloat y) const
	After load_data() has been called, this should return the directionless slope at point (x, y) of the terrain, where 0.0 is flat and 1.0 is vertical. More...

virtual PN_stdfloat	get_smooth_height (PN_stdfloat x, PN_stdfloat y, PN_stdfloat radius) const
	After load_data() has been called, this should return the approximate average height value over a circle of the specified radius, centered at point (x, y) of the terrain. More...

const Filename &	get_splat_layer (int n) const
	Returns the nth splat layer that is to be applied to the terrain. More...

LColor	get_splat_layer_color (int n) const
	Returns the overall color of the nth splat layer. More...

PN_stdfloat	get_splat_layer_tiling (int n) const
	Returns the tiling value of the nth splat layer. More...

const Filename &	get_splat_map () const
	Returns the splat map that should be applied to the terrain. More...

const SpeedTree::SVertexAttribDesc *	get_st_vertex_format () const
	Returns a pointer to the SpeedTree array of vertex attribs that defines the vertex format for SpeedTree. More...

virtual TypeHandle	get_type () const

const GeomVertexFormat *	get_vertex_format ()
	Returns the vertex format of the vertex array that is supported by this terrain data. More...

bool	is_valid () const
	Returns true if the terrain data is well-defined and ready to use. More...

virtual void	load_data ()=0
	This will be called at some point after initialization. More...

virtual void	output (std::ostream &out) const

bool	placement_is_acceptable (PN_stdfloat x, PN_stdfloat y, PN_stdfloat height_min, PN_stdfloat height_max, PN_stdfloat slope_min, PN_stdfloat slope_max)
	Returns true if the elevation and slope of point (x, y) fall within the requested limits, false otherwise. More...

virtual void	write (std::ostream &out, int indent_level=0) const

Public Member Functions inherited from TypedReferenceCount
	TypedReferenceCount (const TypedReferenceCount &copy)

void	operator= (const TypedReferenceCount &copy)

Public Member Functions inherited from TypedObject
	TypedObject (const TypedObject &copy)=default

TypedObject *	as_typed_object ()
	Returns the object, upcast (if necessary) to a TypedObject pointer. More...

const TypedObject *	as_typed_object () const
	Returns the object, upcast (if necessary) to a TypedObject pointer. More...

int	get_best_parent_from_Set (const std::set< int > &) const

int	get_type_index () const
	Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. More...

bool	is_exact_type (TypeHandle handle) const
	Returns true if the current object is the indicated type exactly. More...

bool	is_of_type (TypeHandle handle) const
	Returns true if the current object is or derives from the indicated type. More...

TypedObject &	operator= (const TypedObject &copy)=default

Public Member Functions inherited from ReferenceCount
int	get_ref_count () const

WeakReferenceList *	get_weak_list () const
	Returns the WeakReferenceList associated with this ReferenceCount object. More...

bool	has_weak_list () const
	Returns true if this particular ReferenceCount object has a WeakReferenceList created, false otherwise. More...

void	local_object ()
	This function should be called, once, immediately after creating a new instance of some ReferenceCount-derived object on the stack. More...

void	ref () const
	Explicitly increments the reference count. More...

bool	ref_if_nonzero () const
	Atomically increases the reference count of this object if it is not zero. More...

bool	test_ref_count_integrity () const
	Does some easy checks to make sure that the reference count isn't completely bogus. More...

bool	test_ref_count_nonzero () const
	Does some easy checks to make sure that the reference count isn't zero, or completely bogus. More...

virtual bool	unref () const
	Explicitly decrements the reference count. More...

WeakReferenceList *	weak_ref ()
	Adds the indicated PointerToVoid as a weak reference to this object. More...

void	weak_unref ()
	Removes the indicated PointerToVoid as a weak reference to this object. More...

Public Member Functions inherited from Namable
	Namable (const std::string &initial_name="")

void	clear_name ()
	Resets the Namable's name to empty. More...

const std::string &	get_name () const

bool	has_name () const
	Returns true if the Namable has a nonempty name set, false if the name is empty. More...

void	output (std::ostream &out) const
	Outputs the Namable. More...

void	set_name (const std::string &name)

Static Public Member Functions
static TypeHandle	get_class_type ()

static void	init_type ()

Static Public Member Functions inherited from TypedReferenceCount
static TypeHandle	get_class_type ()

static void	init_type ()

Static Public Member Functions inherited from TypedObject
static TypeHandle	get_class_type ()

static void	init_type ()
	This function is declared non-inline to work around a compiler bug in g++ 2.96. More...

Static Public Member Functions inherited from ReferenceCount
static TypeHandle	get_class_type ()

static void	init_type ()

Static Public Member Functions inherited from Namable
static TypeHandle	get_class_type ()

static void	init_type ()

Additional Inherited Members
Public Attributes inherited from TypedObject
	get_type

Public Attributes inherited from ReferenceCount
	get_ref_count
	Returns the current reference count. More...

Public Attributes inherited from Namable
	get_name

	set_name

Detailed Description

This is the abstract base class that defines the interface needed to describe a terrain for rendering by SpeedTree.

To use it, you must subclass and override the appropriate virtual methods. Or, consider just using STBasicTerrain.

A terrain is defined as a 2-d height function over all space: get_height(x, y) may be called for any point in space and it should return a reasonable value. A terrain also provides normal maps and splat maps, as rendered by SpeedTree's Terrain.hlsl shader file.

Definition at line 34 of file stTerrain.h.

Member Function Documentation

◆ clear()

void STTerrain::clear ( )

virtual

Resets the terrain to its initial, unloaded state.

Reimplemented in STBasicTerrain.

Definition at line 56 of file stTerrain.cxx.

Referenced by STBasicTerrain::clear().

◆ fill_vertices()

void STTerrain::fill_vertices	(	GeomVertexData *	data,
		PN_stdfloat	start_x,
		PN_stdfloat	start_y,
		PN_stdfloat	size_xy,
		int	num_xy
	)		const

virtual

After load_data() has been called, this will be called occasionally to populate the vertices for a terrain cell.

It will be passed a GeomVertexData whose format will match get_vertex_format(), and already allocated with num_xy * num_xy rows. This method should fill the rows of the data with the appropriate vertex data for the terrain, over the grid described by the corners (start_x, start_y) up to and including (start_x + size_x, start_y + size_xy)–a square of the terrain with num_xy vertices on a side, arranged in row-major order.

Reimplemented in STBasicTerrain.

Definition at line 143 of file stTerrain.cxx.

◆ get_height()

PN_stdfloat STTerrain::get_height	(	PN_stdfloat	x,
		PN_stdfloat	y
	)		const

pure virtual

After load_data() has been called, this should return the computed height value at point (x, y) of the terrain, where x and y are unbounded and may refer to any 2-d point in space.

Implemented in STBasicTerrain.

Definition at line 85 of file stTerrain.cxx.

Referenced by get_smooth_height(), and placement_is_acceptable().

◆ get_max_height()

PN_stdfloat STTerrain::get_max_height ( ) const

inline

Returns the largest height value that might be returned by get_height().

This is used as a culling optimization.

Definition at line 105 of file stTerrain.I.

◆ get_min_height()

PN_stdfloat STTerrain::get_min_height ( ) const

inline

Returns the smallest height value that might be returned by get_height().

This is used as a culling optimization.

Definition at line 96 of file stTerrain.I.

◆ get_normal_map()

const Filename & STTerrain::get_normal_map ( ) const

inline

Returns the normal map that should be applied to the terrain.

This will be loaded and supplied to the shader.

Definition at line 27 of file stTerrain.I.

◆ get_num_splat_layers()

int STTerrain::get_num_splat_layers ( ) const

inline

Returns the number of splat layers that are to be applied to the terrain.

This must be consistent with c_nNumTerrainSplatLayers in SpeedTree's TerrainRI.h.

Definition at line 48 of file stTerrain.I.

◆ get_slope()

PN_stdfloat STTerrain::get_slope	(	PN_stdfloat	x,
		PN_stdfloat	y
	)		const

virtual

After load_data() has been called, this should return the directionless slope at point (x, y) of the terrain, where 0.0 is flat and 1.0 is vertical.

This is used for determining the legal points to place trees and grass.

Reimplemented in STBasicTerrain.

Definition at line 106 of file stTerrain.cxx.

Referenced by placement_is_acceptable().

◆ get_smooth_height()

PN_stdfloat STTerrain::get_smooth_height	(	PN_stdfloat	x,
		PN_stdfloat	y,
		PN_stdfloat	radius
	)		const

virtual

After load_data() has been called, this should return the approximate average height value over a circle of the specified radius, centered at point (x, y) of the terrain.

Reimplemented in STBasicTerrain.

Definition at line 95 of file stTerrain.cxx.

References get_height().

◆ get_splat_layer()

const Filename & STTerrain::get_splat_layer ( int n ) const

inline

Returns the nth splat layer that is to be applied to the terrain.

Definition at line 56 of file stTerrain.I.

◆ get_splat_layer_color()

LColor STTerrain::get_splat_layer_color ( int n ) const

inline

Returns the overall color of the nth splat layer.

This is used just to match the color of the grass to its terrain.

Definition at line 76 of file stTerrain.I.

◆ get_splat_layer_tiling()

PN_stdfloat STTerrain::get_splat_layer_tiling ( int n ) const

inline

Returns the tiling value of the nth splat layer.

This is an arbitrary UV scale that is applied to each layer individually, by the terrain shader.

Definition at line 66 of file stTerrain.I.

◆ get_splat_map()

const Filename & STTerrain::get_splat_map ( ) const

inline

Returns the splat map that should be applied to the terrain.

This will be loaded and supplied to the shader. Presumably, the shader will use the channels of this map to determine which of the splat layers are to be rendered at any given point.

Definition at line 38 of file stTerrain.I.

◆ get_st_vertex_format()

const SpeedTree::SVertexAttribDesc * STTerrain::get_st_vertex_format ( ) const

Returns a pointer to the SpeedTree array of vertex attribs that defines the vertex format for SpeedTree.

Definition at line 170 of file stTerrain.cxx.

◆ get_vertex_format()

const GeomVertexFormat * STTerrain::get_vertex_format ( )

inline

Returns the vertex format of the vertex array that is supported by this terrain data.

A GeomVertexData of the requested format will be passed to fill_vertices().

Definition at line 87 of file stTerrain.I.

◆ is_valid()

bool STTerrain::is_valid ( ) const

inline

Returns true if the terrain data is well-defined and ready to use.

Definition at line 18 of file stTerrain.I.

Referenced by SpeedTreeNode::set_terrain().

◆ load_data()

void STTerrain::load_data ( )

pure virtual

This will be called at some point after initialization.

It should be overridden by a derived class to load up the terrain data from its source and fill in the data members of this class appropriately, especially _is_valid. After this call, if _is_valid is true, then get_height() etc. will be called to query the terrain's data.

Implemented in STBasicTerrain.

Definition at line 76 of file stTerrain.cxx.

Referenced by SpeedTreeNode::set_terrain().

◆ placement_is_acceptable()

bool STTerrain::placement_is_acceptable	(	PN_stdfloat	x,
		PN_stdfloat	y,
		PN_stdfloat	height_min,
		PN_stdfloat	height_max,
		PN_stdfloat	slope_min,
		PN_stdfloat	slope_max
	)

Returns true if the elevation and slope of point (x, y) fall within the requested limits, false otherwise.

Definition at line 115 of file stTerrain.cxx.

References get_height(), and get_slope().

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

panda/src/speedtree/stTerrain.h
panda/src/speedtree/stTerrain.cxx
panda/src/speedtree/stTerrain.I

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ clear()

◆ fill_vertices()

◆ get_height()

◆ get_max_height()

◆ get_min_height()

◆ get_normal_map()

◆ get_num_splat_layers()

◆ get_slope()

◆ get_smooth_height()

◆ get_splat_layer()

◆ get_splat_layer_color()

◆ get_splat_layer_tiling()

◆ get_splat_map()

◆ get_st_vertex_format()

◆ get_vertex_format()

◆ is_valid()

◆ load_data()

◆ placement_is_acceptable()