From 5743da3d56f9073cc2c8d366541d51b1f53d2eb0 Mon Sep 17 00:00:00 2001
From: Ian Chamberlain <ian.h.chamberlain@gmail.com>
Date: Wed, 11 May 2022 23:50:09 -0400
Subject: [PATCH] Initial attempt at build script compilation

---
 citro3d/build.rs                     | 39 ++++++++++++++++++++++++++++
 citro3d/examples/assets/vshader.pica |  2 --
 citro3d/examples/triangle.rs         | 21 +++++----------
 3 files changed, 46 insertions(+), 16 deletions(-)
 create mode 100644 citro3d/build.rs

diff --git a/citro3d/build.rs b/citro3d/build.rs
new file mode 100644
index 0000000..b6935f0
--- /dev/null
+++ b/citro3d/build.rs
@@ -0,0 +1,39 @@
+use std::ffi::OsStr;
+use std::path::PathBuf;
+use std::process::Command;
+
+fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=examples/assets");
+
+    let mut asset_dir = PathBuf::from(std::env::var_os("CARGO_MANIFEST_DIR").unwrap());
+    asset_dir.push("examples");
+    asset_dir.push("assets");
+
+    println!("Checking dir {:?}", asset_dir.display());
+
+    for entry in asset_dir.read_dir().unwrap().flatten() {
+        println!("Checking {:?}", entry.path().display());
+        if let Some("pica") = entry.path().extension().and_then(OsStr::to_str) {
+            println!("cargo:rerun-if-changed={}", entry.path().display());
+
+            let mut out_path = PathBuf::from(std::env::var_os("OUT_DIR").unwrap());
+            out_path.push("examples");
+            out_path.push("assets");
+            out_path.push(entry.path().with_extension("shbin").file_name().unwrap());
+
+            std::fs::create_dir_all(out_path.parent().unwrap()).unwrap();
+
+            println!("Compiling {:?}", out_path.display());
+
+            let mut cmd = Command::new("picasso");
+            cmd.arg(entry.path()).arg("--out").arg(out_path);
+
+            let status = cmd.spawn().unwrap().wait().unwrap();
+            assert!(
+                status.success(),
+                "Command {cmd:#?} failed with code {status:?}"
+            );
+        }
+    }
+}
diff --git a/citro3d/examples/assets/vshader.pica b/citro3d/examples/assets/vshader.pica
index 79077d1..27ce6bf 100644
--- a/citro3d/examples/assets/vshader.pica
+++ b/citro3d/examples/assets/vshader.pica
@@ -5,8 +5,6 @@
 
 ; Constants
 .constf myconst(0.0, 1.0, -1.0, 0.1)
-.constf myconst2(0.3, 0.0, 0.0, 0.0)
-.alias  zeros myconst.xxxx ; Vector full of zeros
 .alias  ones  myconst.yyyy ; Vector full of ones
 
 ; Outputs
diff --git a/citro3d/examples/triangle.rs b/citro3d/examples/triangle.rs
index 20d4c25..266d165 100644
--- a/citro3d/examples/triangle.rs
+++ b/citro3d/examples/triangle.rs
@@ -91,25 +91,18 @@ impl Vertex {
     }
 }
 
+static SHBIN_BYTES: &[u8] =
+    include_bytes!(concat!(env!("OUT_DIR"), "/examples/assets/vshader.shbin"));
+
 fn scene_init() -> (shaderProgram_s, i8, C3D_Mtx, *mut libc::c_void, *mut DVLB_s) {
     // Load the vertex shader, create a shader program and bind it
     unsafe {
-        // To compile the shader:
-        // ```sh
-        // picasso assets/vshader.v.pica -o assets/vshader.shbin
-        // ```
-        // TODO: can we do this in a build script?
-
-        // boo, this way we have to specify the length. Alternative seems to be allocating a
-        // slice first, then copying into it with a transmute...
-        const SHBIN_BYTES: &[u8; 280] = include_bytes!("assets/vshader.shbin");
-        // Assume the data is aligned properly...
-        let mut shbin_data: [u32; SHBIN_BYTES.len() / 4] = std::mem::transmute_copy(SHBIN_BYTES);
+        let mut shader_bytes = SHBIN_BYTES.to_owned();
 
+        // Assume the data is aligned properly...
         let vshader_dvlb = citro3d_sys::DVLB_ParseFile(
-            shbin_data.as_mut_ptr(),
-            shbin_data
-                .len()
+            shader_bytes.as_mut_ptr() as _,
+            (shader_bytes.len() / 4)
                 .try_into()
                 .expect("shader len fits in a u32"),
         );