Mercator  0.4.0
Public Types | Public Member Functions | Static Public Attributes | List of all members
Mercator::Terrain Class Reference

Class storing centrally all data about an instance of some terrain. More...

#include <Terrain.h>

Public Types

typedef WFMath::AxisBox< 2 > Rect
 Bounding box.
 
typedef std::map< int, BasePointPointcolumn
 STL map to store sparse array of BasePoints.
 
typedef std::map< int, Segment * > Segmentcolumn
 STL map to store sparse array of Segment pointers.
 
typedef std::map< int, PointcolumnPointstore
 STL map to store sparse array of BasePoint columns.
 
typedef std::map< int, SegmentcolumnSegmentstore
 STL map to store sparse array of Segment pointer columns.
 
typedef std::map< int, const Shader * > Shaderstore
 STL map to store sparse array of Shader pointers.
 

Public Member Functions

 Terrain (unsigned int options=DEFAULT, unsigned int resolution=defaultResolution)
 Construct a new Terrain object with optional options and resolution. More...
 
 ~Terrain ()
 Destroy Terrain object, deleting contained objects. More...
 
float get (float x, float z) const
 Get the height value at a given coordinate x,z. More...
 
bool getHeight (float x, float z, float &) const
 
bool getHeightAndNormal (float x, float z, float &, WFMath::Vector< 3 > &) const
 Get an accurate height and normal vector at a given coordinate x,z. More...
 
bool getBasePoint (int x, int z, BasePoint &y) const
 Get the BasePoint at a given base point coordinate. More...
 
void setBasePoint (int x, int z, const BasePoint &y)
 Set the BasePoint value at a given base point coordinate. More...
 
void setBasePoint (int x, int y, float z)
 Set the height of the basepoint at x,y to z.
 
SegmentgetSegmentAtPos (float x, float z) const
 Get a pointer to the segment which contains the coord x,y. More...
 
SegmentgetSegmentAtIndex (int x, int z) const
 Get a pointer to the segment at index x,y. More...
 
int getResolution () const
 Accessor for base point resolution.
 
float getSpacing () const
 Accessor for base point spacing.
 
const SegmentstoregetTerrain () const
 Accessor for 2D sparse array of Segment pointers.
 
const PointstoregetPoints () const
 Accessor for 2D sparse array of BasePoint objects.
 
const ShaderstoregetShaders () const
 Accessor for list of Shader pointers.
 
void addShader (const Shader *t, int id)
 Add a new Shader to the list for this terrain. More...
 
void removeShader (const Shader *t, int id)
 remove a Shader from the list for this terrain. More...
 
Rect updateMod (long id, const TerrainMod *mod)
 Updates the terrain with a mod. More...
 
bool hasMod (long id) const
 Checks if a mod with the supplied id has been registered with the terrain. More...
 
const TerrainModgetMod (long id) const
 
void addArea (const Area *a)
 Add an area modifier to the terrain. More...
 
Rect updateArea (const Area *a)
 Updates the terrain affected by an area. More...
 
void removeArea (const Area *a)
 Remove an area modifier from the terrain. More...
 
bool hasArea (const Area *a) const
 Checks if the supplied area has been registered with the terrain. More...
 
int posToIndex (float pos) const
 Converts the supplied position into a segment index. More...
 
void processSegments (const WFMath::AxisBox< 2 > &area, const std::function< void(Segment &, int, int)> &func) const
 

Static Public Attributes

static const unsigned int DEFAULT = 0x0000
 value provided for no flags set.
 
static const unsigned int SHADED = 0x0001
 set if shaders are going to be used on this terrain.
 
static constexpr float defaultLevel = 8.f
 Height value used when no data is available.
 

Detailed Description

Class storing centrally all data about an instance of some terrain.

All the data includes:

Constructor & Destructor Documentation

Mercator::Terrain::Terrain ( unsigned int  options = DEFAULT,
unsigned int  resolution = defaultResolution 
)
explicit

Construct a new Terrain object with optional options and resolution.

Parameters
optionsa bitfield of option flags. Defaults to no flags set.
  • DEFAULT value provided for no flags set.
  • SHADED is set if shaders are going to be used on this terrain.
resolutionthe spacing between adjacent base points. Defaults to 64.
Mercator::Terrain::~Terrain ( )

Destroy Terrain object, deleting contained objects.

All Segment objects are deleted, but Shader objects are not yet deleted. Probably need to be fixed.

Member Function Documentation

void Mercator::Terrain::addArea ( const Area area)

Add an area modifier to the terrain.

Add a new Area object to the terrain, which defines a modification to the surface.

void Mercator::Terrain::addShader ( const Shader t,
int  id 
)

Add a new Shader to the list for this terrain.

As each shader is added, surfaces are added to all existing segments to store the result of the shader.

float Mercator::Terrain::get ( float  x,
float  z 
) const

Get the height value at a given coordinate x,z.

This is a convenience function provided to quickly get a height value at a given point. It always succeeds, as if no height data is available it just returns the default value. If a Segment does exist in the right place and is populated, the coords within that Segment are determined, and the heightfield queried. This function does not cause any data to be populated, and does not attempt to do any interpolation to get an accurate height figure. For more accurate results see Terrain::getHeightAndNormal.

bool Mercator::Terrain::getBasePoint ( int  x,
int  z,
BasePoint y 
) const

Get the BasePoint at a given base point coordinate.

Get the BasePoint value for the given coordinate on the base point grid.

Parameters
xcoordinate on the base point grid.
zcoordinate on the base point grid.
yreference to variable which will be used to store the BasePoint data.
Returns
true if a BasePoint is defined at the given coordinate, false otherwise.
bool Mercator::Terrain::getHeightAndNormal ( float  x,
float  z,
float &  h,
WFMath::Vector< 3 > &  n 
) const

Get an accurate height and normal vector at a given coordinate x,z.

This is a more expensive function that Terrain::get() for getting an accurate height value and surface normal at a given point. The main body of functionality is in the Segment::getHeightAndNormal() function called from here. The height and normal are interpolated based on a model where each tile of the heightfield comprises two triangles. If no heightfield data is available for the given location, this function returns false, and no data is returned.

Parameters
xcoordinate of point to be returned.
zcoordinate of point to be returned.
hreference to variable which will be used to store the resulting height value.
nreference to variable which will be used to store the resulting normal value.
Returns
true if heightdata was available, false otherwise.
Segment * Mercator::Terrain::getSegmentAtIndex ( int  x,
int  z 
) const

Get a pointer to the segment at index x,y.

Get the Segment at a given index.

Returns
Null if no segment is defined at that location, or a pointer to a Segment otherwise.

Get the Segment pointer for the given coordinate on the base point grid. The Segment in question may not have been populated with heightfield or surface data.

Parameters
xcoordinate on the base point grid.
zcoordinate on the base point grid.
Returns
a valid pointer if a Segment is defined at the given coordinate, zero otherwise.
Segment * Mercator::Terrain::getSegmentAtPos ( float  x,
float  z 
) const
inline

Get a pointer to the segment which contains the coord x,y.

Returns
Null if no segment is defined at that location, or a pointer to a Segment otherwise.
bool Mercator::Terrain::hasArea ( const Area a) const

Checks if the supplied area has been registered with the terrain.

Parameters
aThe area to check for.
Returns
True if the area is added to the terrain.
bool Mercator::Terrain::hasMod ( long  id) const

Checks if a mod with the supplied id has been registered with the terrain.

Parameters
idThe id of the mod to check for.
Returns
True if the mod is added to the terrain.
int Mercator::Terrain::posToIndex ( float  pos) const
inline

Converts the supplied position into a segment index.

Parameters
posA position, either x or y.
Returns
The index
void Mercator::Terrain::processSegments ( const WFMath::AxisBox< 2 > &  area,
const std::function< void(Segment &, int, int)> &  func 
) const

Processes all segments within the supplied area.

Parameters
areaAn area.
funcFunction called for each segment. X and Y index are submitted as second and third arguments.
void Mercator::Terrain::removeArea ( const Area area)

Remove an area modifier from the terrain.

Remove an existing Area object from the terrain, and mark all the affected terrain surfaces as invalid.

void Mercator::Terrain::removeShader ( const Shader t,
int  id 
)

remove a Shader from the list for this terrain.

As each shader is removed, surfaces are removed from existing segments

void Mercator::Terrain::setBasePoint ( int  x,
int  z,
const BasePoint y 
)

Set the BasePoint value at a given base point coordinate.

Set the BasePoint value for the given coordinate on the base point grid. If inserting this BasePoint completes the set of points required to define one or more Segment objects which were not yet defined, new Segment objects are created. If this replaces a point for one or more Segment objects that were already defined, the contents of those Segment objects are invalidated.

Parameters
xcoordinate on the base point grid.
zcoordinate on the base point grid.
yBasePoint value to be used at the given coordinate.
Terrain::Rect Mercator::Terrain::updateArea ( const Area a)

Updates the terrain affected by an area.

Apply changes to an area modifier to the terrain.

Call this when an already added terrain area has changed.

Parameters
aThe terrain area which has changed.
Returns
The area affected by the terrain area before it was updated.
Terrain::Rect Mercator::Terrain::updateMod ( long  id,
const TerrainMod mod 
)

Updates the terrain with a mod.

Parameters
idThe id of the mod, which is also used for ordering.
modThe terrain mod, or null if the entry for the id should be removed.
Returns
The area affected by the terrain mod before it was updated.

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