[Proc Gen] BSP.to_heightmap and BSPMap class #206

New issue

Open

opened 2026-01-12 00:10:08 +00:00 by john · 0 comments

john commented

2026-01-12 00:10:08 +00:00

Owner

Parent Issue: #192
Depends On: #193 (HeightMap core), #202 (BSP core), #203 (BSPNode), #204 (BSP iteration)

Overview

Add method to convert BSP node selection to a HeightMap, and implement the BSPMap subclass.

Specification

BSP.to_heightmap

def to_heightmap(self,
                 size: tuple[int, int] = None,
                 select: str = "leaves",
                 nodes: list[BSPNode] = None,
                 shrink: int = 0,
                 value: float = 1.0) -> BSPMap

Parameter	Type	Description
`size`	`(int, int)`	Output size. Default: bounds size.
`select`	`str`	`"leaves"`, `"all"`, or `"internal"`. Default: `"leaves"`.
`nodes`	`list[BSPNode]`	Override: specific nodes only.
`shrink`	`int`	Pixels to shrink from each node's bounds. Default: 0.
`value`	`float`	Value inside selected regions. Default: 1.0.

BSPMap Class

BSPMap extends HeightMap with BSP-specific context and operations.

Properties

Property	Type	Description
`bsp`	`BSP`	Read-only. The tree that created this map.
`nodes`	`tuple[BSPNode, ...]`	Read-only. Nodes represented in this map.
`shrink`	`int`	Read-only. Margin applied from bounds.

Methods

def inverse(self) -> BSPMap

Return a new BSPMap with walls instead of rooms.

def expand(self, amount: int = 1) -> BSPMap
def contract(self, amount: int = 1) -> BSPMap

Return new BSPMap with adjusted bounds.

def with_nodes(self, nodes: list[BSPNode]) -> BSPMap
def with_shrink(self, shrink: int) -> BSPMap

Return new BSPMap with different parameters.

Example

bsp = mcrfpy.BSP(bounds=((0, 0), (80, 50)))
bsp.split_recursive(depth=4, min_size=(8, 8))

# Get room mask with 1-tile margin for walls
rooms = bsp.to_heightmap(select="leaves", shrink=1)

# Apply to grid
grid.apply_threshold(rooms, range=(0.5, 1.0), walkable=True)

Implementation Notes

BSPMap inherits all HeightMap methods
inverse() fills BSP bounds with 1.0, then subtracts rooms
shrink creates margin from node edges (for wall thickness)
Selected regions get value, unselected get 0.0

Acceptance Criteria

to_heightmap creates correct BSPMap
shrink parameter reduces room sizes correctly
inverse() produces wall layout
BSPMap works with all HeightMap operations
Visual demo showing room/wall masks

**Parent Issue:** #192 **Depends On:** #193 (HeightMap core), #202 (BSP core), #203 (BSPNode), #204 (BSP iteration) ## Overview Add method to convert BSP node selection to a HeightMap, and implement the BSPMap subclass. ## Specification ### BSP.to_heightmap ```python def to_heightmap(self, size: tuple[int, int] = None, select: str = "leaves", nodes: list[BSPNode] = None, shrink: int = 0, value: float = 1.0) -> BSPMap ``` | Parameter | Type | Description | |-----------|------|-------------| | `size` | `(int, int)` | Output size. Default: bounds size. | | `select` | `str` | `"leaves"`, `"all"`, or `"internal"`. Default: `"leaves"`. | | `nodes` | `list[BSPNode]` | Override: specific nodes only. | | `shrink` | `int` | Pixels to shrink from each node's bounds. Default: 0. | | `value` | `float` | Value inside selected regions. Default: 1.0. | ### BSPMap Class BSPMap extends HeightMap with BSP-specific context and operations. #### Properties | Property | Type | Description | |----------|------|-------------| | `bsp` | `BSP` | Read-only. The tree that created this map. | | `nodes` | `tuple[BSPNode, ...]` | Read-only. Nodes represented in this map. | | `shrink` | `int` | Read-only. Margin applied from bounds. | #### Methods ```python def inverse(self) -> BSPMap ``` Return a new BSPMap with walls instead of rooms. ```python def expand(self, amount: int = 1) -> BSPMap def contract(self, amount: int = 1) -> BSPMap ``` Return new BSPMap with adjusted bounds. ```python def with_nodes(self, nodes: list[BSPNode]) -> BSPMap def with_shrink(self, shrink: int) -> BSPMap ``` Return new BSPMap with different parameters. ### Example ```python bsp = mcrfpy.BSP(bounds=((0, 0), (80, 50))) bsp.split_recursive(depth=4, min_size=(8, 8)) # Get room mask with 1-tile margin for walls rooms = bsp.to_heightmap(select="leaves", shrink=1) # Apply to grid grid.apply_threshold(rooms, range=(0.5, 1.0), walkable=True) ``` ## Implementation Notes - BSPMap inherits all HeightMap methods - `inverse()` fills BSP bounds with 1.0, then subtracts rooms - `shrink` creates margin from node edges (for wall thickness) - Selected regions get `value`, unselected get 0.0 ## Acceptance Criteria - [ ] `to_heightmap` creates correct BSPMap - [ ] `shrink` parameter reduces room sizes correctly - [ ] `inverse()` produces wall layout - [ ] BSPMap works with all HeightMap operations - [ ] Visual demo showing room/wall masks