Add bitmap font rendering via PNG tilesheet

Replace egui text rendering with a BitmapFont system:
- Glyph.tile: u32 replaces ch: char; top-left pixel of PNG is background sentinel
- BitmapFont loads/preprocesses PNG to opaque-white + transparent, tinted at render time
- Default font: assets/vga-font-8x16.png (CP437, 8×16 tiles); placeholder generated if missing
- Boards can specify a per-board font via [font] in their .toml file
- Editor Board tab: "Font…" button opens font dialog (rfd file picker, tile dims, tilesheet preview)
- Glyph picker: tile grid from active font replaces hardcoded ASCII char grid
- map_file: TileIndex untagged enum accepts char or integer in palette entries

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
2026-05-19 00:07:04 -05:00
parent 12ebe77932
commit 212297ecf9
14 changed files with 1174 additions and 260 deletions
+75 -41
View File
@@ -1,7 +1,7 @@
use std::collections::HashMap;
use serde::Deserialize;
use crate::game::{Archetype, Board, FontSpec, Glyph, ObjectDef, Player, PortalDef};
use eframe::egui::Color32;
use crate::game::{Archetype, Board, Glyph, ObjectDef, Player, PortalDef};
use serde::Deserialize;
use std::collections::HashMap;
/// The top-level deserialization type for a `.toml` map file.
///
@@ -15,11 +15,12 @@ pub struct MapFile {
/// The `[map]` section: name, dimensions, player start position.
pub map: MapHeader,
/// The `[palette]` section: maps single-character keys to tile definitions.
/// Each entry defines both the visual ([`Glyph`]) and the [`Archetype`]
/// for all cells that use that character in the grid.
pub palette: HashMap<String, PaletteEntry>,
/// The `[grid]` section: the multi-line string that defines cell layout.
pub grid: GridData,
/// Optional `[font]` section specifying a bitmap font for this board.
#[serde(default)]
pub font: Option<FontHeader>,
/// Any `[[objects]]` entries. Optional; defaults to empty.
#[serde(default)]
pub objects: Vec<ObjectDef>,
@@ -32,40 +33,68 @@ pub struct MapFile {
#[derive(Deserialize)]
pub struct MapHeader {
/// Human-readable name for this board, e.g. `"Opening Room"`.
/// Not yet displayed anywhere at runtime.
#[allow(dead_code)]
pub name: String,
/// Width of the board in cells. Must match the length of every row in
/// `[grid] content`.
/// Width of the board in cells. Must match the length of every row in `[grid] content`.
pub width: usize,
/// Height of the board in cells. Must match the number of rows in
/// `[grid] content`.
/// Height of the board in cells. Must match the number of rows in `[grid] content`.
pub height: usize,
/// Starting position of the player as `[x, y]` (0-indexed, origin
/// top-left). This field will become optional once the player is a
/// scripted object rather than a hardcoded entity.
/// Starting position of the player as `[x, y]` (0-indexed, origin top-left).
pub player_start: [i32; 2],
}
/// The `[font]` section of a map file, specifying a bitmap font for this board.
///
/// When absent, the app's default embedded CP437 font is used.
#[derive(Deserialize)]
pub struct FontHeader {
/// Path to the PNG font image, relative to the working directory.
pub path: String,
/// Width of each tile in the font image, in pixels.
pub tile_w: u32,
/// Height of each tile in the font image, in pixels.
pub tile_h: u32,
}
/// A tile index in a palette entry: either a plain integer or a character literal.
///
/// Accepting both forms lets map files use `tile = 32` for new files or
/// `tile = " "` for convenience (the char is converted to its Unicode scalar).
/// This means existing maps that used `ch = "#"` can be migrated by renaming
/// the key to `tile`; the char form keeps working.
#[derive(Deserialize)]
#[serde(untagged)]
enum TileIndex {
/// A direct tile index (e.g. `tile = 35`).
Num(u32),
/// A single-character shorthand (e.g. `tile = "#"`); converted to its Unicode scalar.
Chr(char),
}
impl TileIndex {
fn into_u32(self) -> u32 {
match self {
TileIndex::Num(n) => n,
TileIndex::Chr(c) => c as u32,
}
}
}
/// One entry in the `[palette]` table.
///
/// Each palette entry is keyed by a single character (e.g. `"#"` or `" "`).
/// Each entry is keyed by a single character (e.g. `"#"` or `" "`).
/// That character is used in the `[grid]` content string to place tiles.
/// The entry defines both how the tile looks (`ch`, `fg`, `bg`) and which
/// The entry defines both how the tile looks (`tile`, `fg`, `bg`) and which
/// [`Archetype`] it uses for behavior.
///
/// Note that `ch` (the display character) does not have to match the palette
/// key. The key is just a label for the grid; `ch` is what actually gets
/// rendered. This allows, for example, using `"W"` as the palette key for a
/// wall tile that displays as `#`.
/// `tile` accepts either an integer (`tile = 35`) or a char (`tile = "#"`).
#[derive(Deserialize)]
pub struct PaletteEntry {
/// The archetype name for this tile, e.g. `"wall"` or `"empty"`.
/// Parsed via [`Archetype::try_from`]; unknown names produce an
/// [`Archetype::ErrorBlock`] cell and a logged warning.
pub archetype: String,
/// The character displayed in this cell.
pub ch: char,
/// The tile index into the board's bitmap font.
/// Accepts either an integer or a single-character string.
tile: TileIndex,
/// Foreground color as an `"#RRGGBB"` hex string.
pub fg: String,
/// Background color as an `"#RRGGBB"` hex string.
@@ -76,9 +105,7 @@ pub struct PaletteEntry {
///
/// `content` is a TOML multi-line string. Each line is one row of the board;
/// each character in a line is looked up in the palette to determine the
/// tile for that cell. TOML automatically strips the newline immediately
/// following the opening `"""`, so no special handling is needed for a
/// leading blank line.
/// tile for that cell.
#[derive(Deserialize)]
pub struct GridData {
/// The raw grid content. Split by [`str::lines`] during loading.
@@ -104,13 +131,11 @@ fn parse_color(hex: &str) -> Color32 {
///
/// 1. **Palette pass** — each entry is parsed into a `(Glyph, Archetype)` pair
/// and stored in a temporary `HashMap` keyed by the palette character.
/// Unknown archetype names produce an [`Archetype::ErrorBlock`] and a
/// logged warning so malformed maps are visible in-game.
/// Unknown archetype names produce an [`Archetype::ErrorBlock`] and a logged
/// warning so malformed maps are visible in-game.
///
/// 2. **Grid pass** — `grid.content` is split into lines; each character
/// is looked up in the palette map and pushed directly into `cells`.
/// Unknown characters are silently skipped, so a malformed grid will
/// result in a `cells` vec shorter than `width * height`.
/// 2. **Grid pass** — `grid.content` is split into lines; each character is
/// looked up in the palette map and pushed directly into `cells`.
impl From<MapFile> for Board {
fn from(mf: MapFile) -> Self {
let w = mf.map.width;
@@ -119,19 +144,24 @@ impl From<MapFile> for Board {
// Pass 1: build a char → (Glyph, Archetype) lookup from the palette.
let mut palette: HashMap<char, (Glyph, Archetype)> = HashMap::new();
for (key, entry) in &mf.palette {
for (key, entry) in mf.palette {
let key_char = key.chars().next().unwrap_or(' ');
// Unknown archetype names fall back to ErrorBlock so the error is
// visible in-game rather than silently producing empty tiles.
let tile = entry.tile.into_u32();
match Archetype::try_from(entry.archetype.as_str()) {
Ok(archetype) => {
let glyph = Glyph { ch: entry.ch, fg: parse_color(&entry.fg), bg: parse_color(&entry.bg) };
let glyph = Glyph {
tile,
fg: parse_color(&entry.fg),
bg: parse_color(&entry.bg),
};
palette.insert(key_char, (glyph, archetype));
}
Err(e) => {
// Be sure to log and ignore the default glyph for an unknown archetype
eprintln!("{e}");
palette.insert(key_char, (Archetype::ErrorBlock.default_glyph(), Archetype::ErrorBlock));
palette.insert(
key_char,
(Archetype::ErrorBlock.default_glyph(), Archetype::ErrorBlock),
);
}
}
}
@@ -146,6 +176,12 @@ impl From<MapFile> for Board {
}
}
let font = mf.font.map(|f| FontSpec {
path: f.path,
tile_w: f.tile_w,
tile_h: f.tile_h,
});
Board {
width: w,
height: h,
@@ -156,6 +192,7 @@ impl From<MapFile> for Board {
},
objects: mf.objects,
portals: mf.portals,
font,
}
}
}
@@ -165,9 +202,6 @@ impl From<MapFile> for Board {
/// Reads the file at `path`, deserializes it as TOML into a [`MapFile`],
/// then converts it via [`From<MapFile>`]. Propagates both I/O errors and
/// TOML parse errors through the `Box<dyn Error>` return.
///
/// Called from `main()` before the window is created so that board
/// dimensions are available for window sizing.
pub fn load(path: &str) -> Result<Board, Box<dyn std::error::Error>> {
let content = std::fs::read_to_string(path)?;
let map_file: MapFile = toml::from_str(&content)?;