libtcoddocumentation

12.2. Splitting the tree

Splitting a node once

Once you have the root node, you can split it into two smaller non-overlapping nodes.

void TCODBsp::splitOnce(bool horizontal, int position)

void TCOD_bsp_split_once(TCOD_bsp_t *node, bool horizontal, int position)

bsp_split_once(node, horizontal, position)

void TCODBsp::splitOnce(bool horizontal, int position)

ParameterDescription
nodeIn the C version, the root node created with TCOD_bsp_new_with_size, or a node obtained by splitting.
horizontalIf true, the node will be splitted horizontally, else, vertically.
positionCoordinate of the splitting position.
If horizontal is true, x <= position < x+w
Else, y <= position < y+h
Example:

TCODBsp *myBSP = new TCODBsp(0,0,50,50);
myBSP->splitOnce(true,20);

TCOD_bsp_t *my_bsp=TCOD_bsp_new_with_size(0,0,50,50);
TCOD_bsp_split_once(my_bsp,false,20);

my_bsp=libtcod.bsp_new_with_size(0,0,50,50)
libtcod.bsp_split_once(my_bsp,False,20)


Recursively splitting a node

You can also recursively split the bsp. At each step, a random orientation (horizontal/vertical) and position are choosen :

void TCODBsp::splitRecursive(TCODRandom *randomizer, int nb, int minHSize, int minVSize, float maxHRatio, float maxVRatio);

void TCOD_bsp_split_recursive(TCOD_bsp_t *node, TCOD_random_t randomizer, int nb, int minHSize, int minVSize, float maxHRatio, float maxVRatio)

bsp_split_recursive(node, randomizer, nb, minHSize, minVSize, maxHRatio, maxVRatio)

void TCODBsp::splitRecursive(TCODRandom randomizer, int nb, int minHSize, int minVSize, float maxHRatio, float maxVRatio)

ParameterDescription
nodeIn the C version, the root node created with TCOD_bsp_new_with_size, or a node obtained by splitting.
randomizerThe random number generator to use. Use NULL for the default one.
nbNumber of recursion levels.
minHSize,minVSize minimum values of w and h for a node. A node is splitted only if the resulting sub-nodes are bigger than minHSize x minVSize
maxHRatio,maxVRation maximum values of w/h and h/w for a node. If a node does not conform, the splitting orientation is forced to reduce either the w/h or the h/w ratio. Use values near 1.0 to promote square nodes.
Example:

// Do a 4 levels BSP tree (the region is splitted into a maximum of 2*2*2*2 sub-regions).
TCODBsp *myBSP = new TCODBsp(0,0,50,50);
myBSP->splitRecursive(NULL,4,5,5,1.5f,1.5f);

TCOD_bsp_t *my_bsp=TCOD_bsp_new_with_size(0,0,50,50);
TCOD_bsp_split_recursive(my_bsp,NULL,4,5,5,1.5f,1.5f);

my_bsp=libtcod.bsp_new_with_size(0,0,50,50)
libtcod.bsp_split_recursive(my_bsp,0,4,5,5,1.5,1.5)