Add shim for Rust noise library, exposing 2d Perlin noise functions (t…

…gstation#28) Provides an interface to get 2d Perlin noise generated by the Rust [noise] library. rustg_noise_get_at_coordinates(seed, x, y) takes an integer seed and floating-point coordinates, and returns a floating-point value in the range [0,1]. [noise]: https://docs.rs/noise/0.6.0/noise/
ParadiseSS13 · May 6, 2020 · 552dff4 · 552dff4
1 parent 4120da8
commit 552dff4
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Showing 7 changed files with 189 additions and 4 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -21,6 +21,7 @@ hex = { version = "0.3", optional = true }
 percent-encoding = { version = "1.0", optional = true }
 png = { version = "0.11.0", optional = true }
 git2 = { version = "0.7.1", optional = true, default-features = false }
+noise = { version = "0.6.0", optional = true}
 reqwest = { version = "0.9", optional = true, default-features = false, features = ["rustls-tls"] }
 serde = { version = "1.0", optional = true }
 serde_json = { version = "1.0", optional = true }

diff --git a/README.md b/README.md
@@ -89,6 +89,7 @@ cargo build --release --features dmi,file,log,url,http
 * hash: Faster replacement for `md5`, support for SHA-1, SHA-256, and SHA-512. Requires OpenSSL on Linux.
 * **log** (default): Faster log output.
 * url: Faster replacements for `url_encode` and `url_decode`.
+* 2d-noise: 2d perlin noise.
 * http: HTTP client to allow `GET`, `POST`, `PUT`, `PATCH`, `DELETE` and `HEAD`. 
 
 ## Installing

diff --git a/build.rs b/build.rs
@@ -29,6 +29,13 @@ fn main() {
 "#).unwrap();
     }
 
+    // module: noise
+    if enabled!("NOISE") {
+        write!(f, r#"
+#define rustg_noise_get_at_coordinates(seed, x, y) call(RUST_G, "noise_get_at_coordinates")(seed, x, y)
+"#).unwrap()
+    }
+
     // module: file
     if enabled!("FILE") {
         write!(f, r#"
@@ -102,5 +109,5 @@ fn main() {
 #define rustg_http_request_async(method, url, body, headers) call(RUST_G, "http_request_async")(method, url, body, headers)
 #define rustg_http_check_request(req_id) call(RUST_G, "http_check_request")(req_id)
 "#).unwrap();
-    }    
+    }
 }
diff --git a/src/error.rs b/src/error.rs
@@ -1,7 +1,7 @@
 use std::io;
 use std::result;
 use std::str::Utf8Error;
-use std::num::ParseIntError;
+use std::num::{ParseIntError, ParseFloatError};
 
 #[cfg(feature="png")]
 use png::{DecodingError, EncodingError};
@@ -26,9 +26,10 @@ pub enum Error {
     #[cfg(feature="png")]
     #[fail(display = "{}", _0)]
     ImageEncoding(#[cause] EncodingError),
-    #[cfg(feature="png")]
     #[fail(display = "{}", _0)]
     ParseIntError(#[cause] ParseIntError),
+    #[fail(display = "{}", _0)]
+    ParseFloatError(#[cause] ParseFloatError),
     #[cfg(feature="png")]
     #[fail(display = "Invalid png data.")]
     InvalidPngDataError,
@@ -66,13 +67,17 @@ impl From<EncodingError> for Error {
     }
 }
 
-#[cfg(feature="png")]
 impl From<ParseIntError> for Error {
     fn from(error: ParseIntError) -> Error {
         Error::ParseIntError(error)
     }
 }
 
+impl From<ParseFloatError> for Error {
+    fn from(error: ParseFloatError) -> Error {
+        Error::ParseFloatError(error)
+    }
+}
 #[cfg(feature="http")]
 impl From<reqwest::Error> for Error {
     fn from(error: reqwest::Error) -> Error {

diff --git a/src/lib.rs b/src/lib.rs
@@ -13,6 +13,8 @@ extern crate hex;
 extern crate percent_encoding;
 #[cfg(feature="png")]
 extern crate png;
+#[cfg(feature="noise")]
+extern crate noise;
 #[cfg(feature="http")]
 extern crate reqwest;
 #[cfg(feature="http")]
@@ -42,5 +44,7 @@ pub mod hash;
 pub mod log;
 #[cfg(feature="url")]
 pub mod url;
+#[cfg(feature="2d-noise")]
+pub mod noise_gen;
 #[cfg(feature="http")]
 pub mod http;
diff --git a/src/noise_gen.rs b/src/noise_gen.rs
@@ -0,0 +1,36 @@
+use noise::{NoiseFn, Perlin, Seedable};
+use std::cell::RefCell;
+use std::collections::HashMap;
+use std::collections::hash_map::Entry;
+
+use crate::error::Result;
+
+thread_local! {
+    static GENERATORS: RefCell<HashMap<String,  Perlin>> = RefCell::new(HashMap::new());
+}
+
+byond_fn! { noise_get_at_coordinates(seed, x, y) {
+    get_at_coordinates(seed, x, y).ok()
+} }
+
+//note that this will be 0 at integer x & y, scaling is left up to the caller
+fn get_at_coordinates(seed_as_str: &str, x_as_str: &str, y_as_str: &str) -> Result<String> {
+    let x = x_as_str.parse::<f64>()?;
+    let y = y_as_str.parse::<f64>()?;
+    GENERATORS.with(|cell| {
+        let mut generators = cell.borrow_mut();
+        let mut entry = generators.entry(seed_as_str.to_string());
+        let generator = match entry {
+            Entry::Occupied(ref mut occ) => occ.get_mut(),
+            Entry::Vacant(vac) => {
+                let seed = seed_as_str.parse::<u32>()?;
+                let perlin = Perlin::new().set_seed(seed);
+                vac.insert(perlin)
+            }
+        };
+        //perlin noise produces a result in [-sqrt(0.5), sqrt(0.5)] which we scale to [0, 1] for simplicity
+        let unscaled = generator.get([x, y]);
+        let scaled_from_0_to_1 = (unscaled * 2.0_f64.sqrt() + 1.0) / 2.0;
+        Ok(scaled_from_0_to_1.to_string())
+    })
+}