From cc729e38d86d54110f616b2c126e3aa3d53405fe Mon Sep 17 00:00:00 2001
From: Joshua Goins <josh@redstrate.com>
Date: Sun, 21 Apr 2024 10:04:35 -0400
Subject: [PATCH] Add crc method to SHPK for calculating it's value, add test
 for selector

---
 Cargo.toml  |  7 ++++---
 src/shpk.rs | 40 +++++++++++++++++++++++++++++++++++-----
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index e6df754..9a66afc 100755
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,8 +29,6 @@ hmac-sha512 = "1"
 # used while rust doesn't have native benchmarking capability
 brunch = { version = "0.5.3", default-features = false }
 
-# used for testing our jamcrc implementation
-crc = "3"
 
 [features]
 default = ["visual_data"]
@@ -67,4 +65,7 @@ half = { version = "2", optional = true }
 bitflags = { version = "1.3", optional = true }
 
 # needed for dxt/bc decompression
-texture2ddecoder = { version = "0.0.5", optional = true }
\ No newline at end of file
+texture2ddecoder = { version = "0.0.5", optional = true }
+
+# used for testing our jamcrc implementation and currently SHPK
+crc = "3"
\ No newline at end of file
diff --git a/src/shpk.rs b/src/shpk.rs
index ece5b24..8d0db6b 100644
--- a/src/shpk.rs
+++ b/src/shpk.rs
@@ -5,6 +5,7 @@ use std::io::{Cursor, SeekFrom};
 
 use crate::ByteSpan;
 use binrw::{binread, BinRead};
+use crc::{Algorithm, Crc};
 
 #[binread]
 #[br(little, import {
@@ -68,11 +69,12 @@ pub struct MaterialParameter {
 }
 
 #[binread]
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
+#[repr(C)]
 #[allow(unused)]
 pub struct Key {
-    id: u32,
-    default_value: u32,
+    pub id: u32,
+    pub default_value: u32,
 }
 
 #[binread]
@@ -171,7 +173,7 @@ pub struct ShaderPackage {
     #[br(count = scene_key_count)]
     scene_keys: Vec<Key>,
     #[br(count = material_key_count)]
-    material_keys: Vec<Key>,
+    pub material_keys: Vec<Key>,
 
     sub_view_key1_default: u32,
     sub_view_key2_default: u32,
@@ -186,6 +188,12 @@ pub struct ShaderPackage {
     node_aliases: Vec<NodeAlias>,
 }
 
+const SELECTOR_MULTIPLER: u32 = 31;
+
+// TODO: replace use of crc crate here
+const CRC_32_TEST: Algorithm<u32> = Algorithm { width: 32, poly: 0x04c11db7, init: 0x00000000, refin: true, refout: true, xorout: 0x00000000, check: 0x765e7680, residue: 0xc704dd7b };
+const JAMCR: Crc<u32> = Crc::<u32>::new(&CRC_32_TEST);
+
 impl ShaderPackage {
     /// Reads an existing SHPK file
     pub fn from_existing(buffer: ByteSpan) -> Option<ShaderPackage> {
@@ -241,17 +249,22 @@ impl ShaderPackage {
 
         for key in keys {
             selector = selector.wrapping_add(key.wrapping_mul(multiplier));
-            multiplier = multiplier.wrapping_mul(31);
+            multiplier = multiplier.wrapping_mul(SELECTOR_MULTIPLER);
         }
 
         selector
     }
+
+    pub fn crc(str: &str) -> u32 {
+        return JAMCR.checksum(str.as_bytes());
+    }
 }
 
 #[cfg(test)]
 mod tests {
     use std::fs::read;
     use std::path::PathBuf;
+    use crate::repository::Category::Shader;
 
     use super::*;
 
@@ -264,4 +277,21 @@ mod tests {
         // Feeding it invalid data should not panic
         ShaderPackage::from_existing(&read(d).unwrap());
     }
+
+    #[test]
+    fn test_crc() {
+        assert_eq!(ShaderPackage::crc("PASS_0"), 0xC5A5389C);
+        assert_eq!(ShaderPackage::crc("DecodeDepthBuffer"), 0x2C6C023C);
+    }
+
+    #[test]
+    fn test_selector() {
+        let selector = ShaderPackage::build_selector_from_all_keys(
+            &[],
+            &[ShaderPackage::crc("TransformViewSkin"), ShaderPackage::crc("GetAmbientLight_SH"), ShaderPackage::crc("GetReflectColor_Texture"), ShaderPackage::crc("GetAmbientOcclusion_None"), ShaderPackage::crc("ApplyDitherClipOff")],
+            &[3756477356, 1556481461, 1111668802, 428675533],
+            &[ShaderPackage::crc("Default"), ShaderPackage::crc("SUB_VIEW_MAIN")]);
+
+        assert_eq!(selector, 0x1075AE91);
+    }
 }