From f8014e0d01e9a48a94e5f7e5e38f33f4c873653b Mon Sep 17 00:00:00 2001
From: AndrewDanial <110853278+AndrewDanial@users.noreply.github.com>
Date: Tue, 18 Jun 2024 23:23:02 -0400
Subject: [PATCH] Shader code paths (#13908)

# Objective

Add extra metadata for the shader examples that contains the location of
their associated shader file(s). This is to be used for the bevy website
shader examples so that the shader code is underneath the rust code.

## Solution

Parse the example rust files for mentions of `.wgsl`, `.frag`, and
`.vert`, then append the found paths to a field called
`shader_code_paths` in the generated `index.md`s for each shader
example.
---
 tools/example-showcase/Cargo.toml  |  1 +
 tools/example-showcase/src/main.rs | 21 +++++++++++++++++++--
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/tools/example-showcase/Cargo.toml b/tools/example-showcase/Cargo.toml
index 262df1e44b..83ac5ef592 100644
--- a/tools/example-showcase/Cargo.toml
+++ b/tools/example-showcase/Cargo.toml
@@ -13,6 +13,7 @@ toml_edit = { version = "0.22.7", default-features = false, features = [
   "parse",
 ] }
 pbr = "1.1"
+regex = "1.10.5"
 
 [lints]
 workspace = true
diff --git a/tools/example-showcase/src/main.rs b/tools/example-showcase/src/main.rs
index dbdbbec64d..484cbe4a6f 100644
--- a/tools/example-showcase/src/main.rs
+++ b/tools/example-showcase/src/main.rs
@@ -1,7 +1,7 @@
 //! Tool to run all examples or generate a showcase page for the Bevy website.
 
 use std::{
-    collections::{hash_map::DefaultHasher, HashMap},
+    collections::{hash_map::DefaultHasher, HashMap, HashSet},
     fmt::Display,
     fs::{self, File},
     hash::{Hash, Hasher},
@@ -14,6 +14,7 @@ use std::{
 
 use clap::{error::ErrorKind, CommandFactory, Parser, ValueEnum};
 use pbr::ProgressBar;
+use regex::Regex;
 use toml_edit::DocumentMut;
 use xshell::{cmd, Shell};
 
@@ -546,6 +547,7 @@ technical_name = \"{}\"
 link = \"/examples{}/{}/{}\"
 image = \"../static/screenshots/{}/{}.png\"
 code_path = \"content/examples{}/{}\"
+shader_code_paths = {:?}
 github_code_path = \"{}\"
 header_message = \"Examples ({})\"
 +++",
@@ -580,6 +582,7 @@ header_message = \"Examples ({})\"
                                 .skip(1)
                                 .collect::<PathBuf>()
                                 .display(),
+                            to_show.shader_paths,
                             &to_show.path,
                             match api {
                                 WebApi::Webgpu => "WebGPU",
@@ -723,6 +726,18 @@ fn parse_examples() -> Vec<Example> {
         .flat_map(|val| {
             let technical_name = val.get("name").unwrap().as_str().unwrap().to_string();
 
+            let source_code = fs::read_to_string(val["path"].as_str().unwrap()).unwrap();
+            let shader_regex =
+                Regex::new(r"(shaders\/\w+\.wgsl)|(shaders\/\w+\.frag)|(shaders\/\w+\.vert)")
+                    .unwrap();
+
+            // Find all instances of references to shader files, collect into set to avoid duplicates, then convert to vec of strings.
+            let shader_paths = Vec::from_iter(
+                shader_regex
+                    .find_iter(&source_code)
+                    .map(|matches| matches.as_str().to_owned())
+                    .collect::<HashSet<String>>(),
+            );
             if metadatas
                 .get(&technical_name)
                 .and_then(|metadata| metadata.get("hidden"))
@@ -736,6 +751,7 @@ fn parse_examples() -> Vec<Example> {
             metadatas.get(&technical_name).map(|metadata| Example {
                 technical_name,
                 path: val["path"].as_str().unwrap().to_string(),
+                shader_paths,
                 name: metadata["name"].as_str().unwrap().to_string(),
                 description: metadata["description"].as_str().unwrap().to_string(),
                 category: metadata["category"].as_str().unwrap().to_string(),
@@ -780,9 +796,10 @@ struct Example {
     technical_name: String,
     /// Path to the example file
     path: String,
+    /// Path to the associated wgsl file if it exists
+    shader_paths: Vec<String>,
     /// List of non default required features
     required_features: Vec<String>,
-
     // From the example metadata
     /// Pretty name, used for display
     name: String,