cube Class Reference

The fundemental building block of the octree world, representing a 3D cube. More...

#include <octa.h>

Public Member Functions
bool	isempty () const
	returns if the cube is empty (face 0 does not exist)
bool	issolid () const
	returns if the cube passed is entirely solid (no distortions)
void	setmat (ushort mat, ushort matmask, ushort filtermat, ushort filtermask, int filtergeom)
	Sets a cube's materials, given a material & filter to use.
void	discardchildren (bool fixtex=false, int depth=0)
	discards children
void	calcmerges ()
	Merges adjacent faces that can be losslessly merged.
bool	isvalidcube () const
	Returns whether the cube is valid.

Public Attributes
std::array< cube, 8 > *	children
cubeext *	ext
union {
uchar   edges [12]
uint   faces [3]
};
ushort	texture [6]
ushort	material
uchar	merged
union {
uchar   escaped
uchar   visible
};
bool	valid

Friends
bool	operator== (const cfkey &x, const cfkey &y)

Detailed Description

The fundemental building block of the octree world, representing a 3D cube.

The main rendered object in the world is an octree (8-leaf tree) comprising of objects of this type. Each cube object has its own deformation information, texture information, and a handful of utility functions as well as pointing to up to eight children in a fractal manner.

Cube objects are the game-facing abstraction which the renderer itself does not use; they are converted to vertex arrays by the engine which requires calculation by itself. However, the octree structure is capable of a relatively simple and effective representation of detail over several orders of magnitude.

The integer indices for the textures are shown below.

+z
 |  /+x
 | /
 |/___+y
    ______
   /.    /|
  / . 5 / |
 /__.__/  |
 |  ...|3./
 | .0  | /
 |.    |/
 .-----/
    ______
   /|    .|
  / |  1. |
 /..|...  |
 |2 |-----/
 | /   . /
 |/   4./
 .-----/

The integer indices of the 8 children are shown below.

       ^ +z
       |
     __________
    /  4 /  5 /
   /____/____/.
  /  6 /  7 / .
 /____/____/  .
.    _____.___.
.   /  0 /. 1 /     +x
.  /____/_.__/    ->
. /  2 / 3. /
./____/___./
 
 
    / +y
   |/

The integer indices of the 12 edges are shown below.

         ^ +z
         |
         |
       _____2____
      /         /
   5 /.8      7/.
    / .       / .
   /_____3___/  .9
  . . ._____.___.
10.   /  0  .   /     +x
  . 4/    11.  /    ->
  . /       . /6
  ./________./
       1
 
      / +y
     |/

Member Function Documentation

calcmerges()

void cube::calcmerges

(

)

Merges adjacent faces that can be losslessly merged.

Merges adjacent faces, provided that the resulting cube created is no larger than the maxmerge gridpower size. Faces resulting from the merge process are always lossless; therefore the previously existing cubes must be coplanar prior to the merge request.

Applies to all children of this cube, and also all adjacent cubes at the same level as this cube. This function is assumed to be called from the first element of an octree (eight element) array and will fail ungracefully if this condition is not satisfied.

discardchildren()

void cube::discardchildren	(	bool	fixtex = false,
		int	depth = 0 )

discards children

Parameters

fixtex	toggles fixing the texture of the resulting cube
depth	at which to stop discarding

isempty()

bool cube::isempty ( ) const

inline

returns if the cube is empty (face 0 does not exist)

note that a non-empty (but distorted) cube missing faces for an axis is impossible unless there are no faces at all (impossible to construct a 3d cube otherwise)

isvalidcube()

bool cube::isvalidcube

(

)

const

Returns whether the cube is valid.

If the cube is not convex, this function returns true, otherwise it returns false.

setmat()

void cube::setmat	(	ushort	mat,
		ushort	matmask,
		ushort	filtermat,
		ushort	filtermask,
		int	filtergeom )

Sets a cube's materials, given a material & filter to use.

Modifies the material properties of a cube object, given the various filtering parameters.

Parameters

c	the cube object to use
mat	material index to apply
matmask	material mask
filtermat	if nonzero, determines what existing mats to apply to
filtermask	filter material mask
filtergeom	type of geometry inside the cube (empty, solid, partially solid)

Member Data Documentation

children

std::array<cube, 8>* cube::children

points to 8 cube structures which are its children, or nullptr. -Z first, then -Y, -X. If children[0] == nullptr, assume there are no children.

edges

uchar cube::edges[12]

edges of the cube, each uchar is 2 4bit values denoting the range. see documentation jpgs for more info.

escaped

uchar cube::escaped

mask of which children have escaped merges

ext

cubeext* cube::ext

extended info for the cube

faces

uint cube::faces[3]

4 edges of each dimension together representing 2 perpendicular faces

material

ushort cube::material

empty-space material, bitmask created from available mats

merged

uchar cube::merged

merged faces of the cube

texture

ushort cube::texture[6]

one for each face. same order as orient.

valid

bool cube::valid

status of the cube:

visible

uchar cube::visible

visibility info for faces

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

• /github/workspace/src/libprimis-headers/octa.h