grid + dir utilities

Author: MrPicklePinosaur

Cargo.lock

@@ -11,6 +11,8 @@ repository = "https://github.com/HalfPixelStudios/bevy_bobs"
 [dependencies]
 bevy = { version = "0.7" }
 rand = { version = "0.8.5" }
+anyhow = "1.0.58"
+thiserror = "1"
 
 ron = "0.7.1"
 serde = { version = "1", features = ["derive"] }
@@ -20,7 +22,7 @@ bevy_kira_audio = { version = "0.10.0", default-features = false, features = [ "
 
 [features]
 default = ["all"]
-all = ["prefab", "physics_2d", "spawn_wave", "attack_pattern", "health_bar", "sfx", "cursor"]
+all = ["prefab", "physics_2d", "spawn_wave", "attack_pattern", "health_bar", "sfx", "cursor", "grid"]
 
 prefab = []
 physics_2d = []
@@ -29,6 +31,7 @@ attack_pattern = []
 health_bar = []
 sfx = ["dep:bevy_kira_audio"]
 cursor = []
+grid = []
 
 egui = ["dep:bevy-inspector-egui"]
 serde = []

Cargo.toml

@@ -8,9 +8,13 @@ Bits and Bobs for [Bevy](https://bevyengine.org/) Projects
 
 ## Included utilities
 
-- **attack_pattern** - utilities to generate attack patterns (straight, shotgun, around)
-- **health_bar** - health bar ui component
-- **physics_2d** - dead simple 2d components
-- **prefab** - utilities for loading prefabs from ron files
+general
 - **spawn_wave** - spawn wave system
+- **prefab** - utilities for loading prefabs from ron files
+- **physics_2d** - dead simple 2d components
+- **sfx** sound player
 
+ui
+- **attack_pattern** - utilities to generate attack patterns (straight, shotgun, around)
+- **health_bar** - health bar ui component
+- **cursor** - in game coords of mouse cursor

README.md

@@ -0,0 +1,95 @@
+//! Grid related utilities
+
+use anyhow::{anyhow, Result};
+use bevy::prelude::*;
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum GridError {
+    #[error("tried to access position outside of grid {0}")]
+    OutOfBounds(IVec2),
+}
+
+/// Collection of grid positions that can be queried and manipulated
+///
+/// The grid is a read-only structure. It is not a source of truth. GridPositions are the actual
+/// source of truth. The grid is just a visual representation of where all the GridPosition objects
+/// are relative to each other.
+pub struct Grid<T: PartialEq> {
+    width: i32,
+    height: i32,
+    grid: Vec<Vec<T>>,
+}
+
+impl<T: PartialEq> Grid<T> {
+    /// Construct a new grid
+    pub fn new(width: i32, height: i32) -> Self {
+        // TODO this is sorta stupid lol (maybe just force T to derive Clone)
+        let grid_vec = (0..width * height).into_iter().map(|_| vec![]).collect();
+
+        Grid {
+            width,
+            height,
+            grid: grid_vec,
+        }
+    }
+
+    /// Check if position is within the grid
+    pub fn bounds_check(&self, pos: &IVec2) -> bool {
+        0 <= pos.x && pos.x < self.width && 0 <= pos.y && pos.y < self.height
+    }
+
+    pub fn pos_to_index(&self, pos: &IVec2) -> Result<usize> {
+        if self.bounds_check(pos) {
+            Ok((pos.y * self.width + pos.x) as usize)
+        } else {
+            Err(anyhow!(GridError::OutOfBounds(pos.to_owned())))
+        }
+    }
+
+    /// Get reference to cell at position
+    pub fn get_cell(&self, pos: &IVec2) -> Result<&Vec<T>> {
+        let ind = self.pos_to_index(pos)?;
+        // shouldn't panic (since already bounds checked)?
+        Ok(self.grid.get(ind).unwrap())
+    }
+
+    /// Get mutable reference to cell at position
+    pub fn get_cell_mut(&mut self, pos: &IVec2) -> Result<&mut Vec<T>> {
+        let ind = self.pos_to_index(pos)?;
+        Ok(self.grid.get_mut(ind).unwrap())
+    }
+
+    /// Insert a cell entity at position
+    pub fn insert_at(&mut self, pos: &IVec2, val: T) -> Result<()> {
+        self.get_cell_mut(pos)?.push(val);
+        Ok(())
+    }
+
+    /// Query if cell contains a given entity
+    pub fn contains_at(&self, pos: &IVec2, val: T) -> Result<bool> {
+        Ok(self.get_cell(pos)?.contains(&val))
+    }
+
+    /// Query if a cell at position is empty
+    pub fn empty_at(&self, pos: &IVec2) -> Result<bool> {
+        Ok(self.get_cell(pos)?.is_empty())
+    }
+
+    /// Wipe the entire map
+    pub fn clear(&mut self) {
+        for cell in self.grid.iter_mut() {
+            cell.clear();
+        }
+    }
+
+    /// Get grid width
+    pub fn width(&self) -> i32 {
+        self.width
+    }
+
+    /// Get grid height
+    pub fn height(&self) -> i32 {
+        self.height
+    }
+}

src/grid.rs

@@ -17,6 +17,8 @@ pub mod attack_pattern;
 pub mod component;
 #[cfg(feature = "cursor")]
 pub mod cursor;
+#[cfg(feature = "grid")]
+pub mod grid;
 #[cfg(feature = "health_bar")]
 pub mod health_bar;
 pub mod misc;

src/lib.rs

@@ -0,0 +1,67 @@
+/// 2d enum for directions
+use bevy::prelude::*;
+
+#[derive(Debug, Copy, Clone)]
+pub enum Dir {
+    None,
+
+    North,
+    East,
+    South,
+    West,
+}
+
+impl From<IVec2> for Dir {
+    fn from(v: IVec2) -> Self {
+        let clamped = v.clamp(-IVec2::ONE, IVec2::ONE);
+
+        // TODO can match directly in bevy 0.8
+        match clamped.to_array() {
+            [0, 1] => Dir::North,
+            [1, 0] => Dir::East,
+            [0, -1] => Dir::South,
+            [-1, 0] => Dir::West,
+            _ => Dir::None,
+        }
+    }
+}
+
+impl From<Dir> for IVec2 {
+    fn from(d: Dir) -> Self {
+        match d {
+            Dir::North => IVec2::new(0, 1),
+            Dir::East => IVec2::new(1, 0),
+            Dir::South => IVec2::new(0, -1),
+            Dir::West => IVec2::new(-1, 0),
+            Dir::None => IVec2::new(0, 0),
+        }
+    }
+}
+
+impl From<String> for Dir {
+    fn from(s: String) -> Self {
+        match s.to_lowercase().as_str() {
+            "north" => Dir::North,
+            "south" => Dir::South,
+            "east" => Dir::East,
+            "west" => Dir::West,
+            _ => Dir::None,
+        }
+    }
+}
+
+pub fn to_rotation(dir: Dir) -> f32 {
+    use std::f32::consts::PI;
+
+    match dir {
+        Dir::East => 0.,
+        Dir::North => PI / 2.,
+        Dir::West => PI,
+        Dir::South => 3. * PI / 2.,
+        _ => unreachable!(),
+    }
+}
+
+pub fn cardinal_dirs() -> Vec<Dir> {
+    vec![Dir::North, Dir::South, Dir::East, Dir::West]
+}

src/misc/dir.rs

@@ -1,3 +1,4 @@
 //! Miscellenous utilities
 
+pub mod dir;
 pub mod displacement;