adds rustg_dmi_icon_states (#140)

Cargo.toml

@@ -56,6 +56,7 @@ rayon = { version = "1.7", optional = true }
 dbpnoise = { version = "0.1.2", optional = true }
 pathfinding = { version = "4.2.1", optional = true }
 num = { version = "0.4.0", optional = true }
+dmi = { version = "0.3.0", optional = true }
 
 [features]
 default = [
@@ -77,7 +78,7 @@ default = [
 # default features
 acreplace = ["aho-corasick"]
 cellularnoise = ["rand", "rayon"]
-dmi = ["png", "image"]
+dmi = ["png", "image", "dep:dmi"]
 file = []
 git = ["git2", "chrono"]
 http = ["reqwest", "serde", "serde_json", "once_cell", "jobs"]

README.md

@@ -89,8 +89,8 @@ To get additional features, pass a list to `--features`, for example `--features
 The default features are:
 * acreplace: Aho-Corasick string matching and replacement.
 * cellularnoise: Function to generate cellular automata-based noise.
-* dmi: DMI manipulations which are impossible from within BYOND.
-  Used by the asset cache subsystem to improve load times.
+* dmi: DMI manipulations which are impossible or degraded from within BYOND.
+  Mostly used by the asset cache subsystem to improve load times.
 * file: Faster replacements for `file2text` and `text2file`, as well as reading or checking if files exist.
 * git: Functions for robustly checking the current git revision.
 * http: Asynchronous HTTP(s) client supporting most standard methods.

dmsrc/dmi.dm

@@ -1,3 +1,9 @@
 #define rustg_dmi_strip_metadata(fname) RUSTG_CALL(RUST_G, "dmi_strip_metadata")(fname)
 #define rustg_dmi_create_png(path, width, height, data) RUSTG_CALL(RUST_G, "dmi_create_png")(path, width, height, data)
 #define rustg_dmi_resize_png(path, width, height, resizetype) RUSTG_CALL(RUST_G, "dmi_resize_png")(path, width, height, resizetype)
+/**
+ * input: must be a path, not an /icon; you have to do your own handling if it is one, as icon objects can't be directly passed to rustg.
+ *
+ * output: json_encode'd list. json_decode to get a flat list with icon states in the order they're in inside the .dmi
+ */
+#define rustg_dmi_icon_states(fname) RUSTG_CALL(RUST_G, "dmi_icon_states")(fname)

src/dmi.rs

@@ -1,7 +1,9 @@
 use crate::error::{Error, Result};
+use dmi::icon::Icon;
 use png::{Decoder, Encoder, OutputInfo, Reader};
 use std::{
     fs::{create_dir_all, File},
+    io::BufReader,
     path::Path,
 };
 
@@ -25,6 +27,10 @@ byond_fn!(fn dmi_resize_png(path, width, height, resizetype) {
     resize_png(path, width, height, resizetype).err()
 });
 
+byond_fn!(fn dmi_icon_states(path) {
+    read_states(path).ok()
+});
+
 fn strip_metadata(path: &str) -> Result<()> {
     let (reader, frame_info, image) = read_png(path)?;
     write_png(path, &reader, &frame_info, &image, true)
@@ -112,3 +118,21 @@ fn resize_png<P: AsRef<Path>>(
 
     Ok(newimg.save_with_format(path.as_ref(), image::ImageFormat::Png)?)
 }
+
+/// Output is a JSON string for reading within BYOND
+///
+/// Erroring at any point will produce an empty string
+fn read_states(path: &str) -> Result<String> {
+    let reader = BufReader::new(File::open(path)?);
+    let icon = Icon::load(reader).ok();
+    if icon.is_none() {
+        return Err(Error::InvalidPngData);
+    }
+    let states: Vec<_> = icon
+        .unwrap()
+        .states
+        .iter()
+        .map(|s| s.name.clone())
+        .collect();
+    Ok(serde_json::to_string(&states)?)
+}