Merge pull request #47 from wowemulation-dev/fix/issue-35-texture-combiner-combos-flag

fix(m2): use USE_TEXTURE_COMBINERS flag for texture_combiner_combos

Author: danielsreichenbach

file-formats/graphics/wow-m2/src/header.rs

@@ -343,7 +343,8 @@ impl M2Header {
             None
         };
 
-        let texture_combiner_combos = if m2_version >= M2Version::Cataclysm {
+        // Texture combiner combos (when USE_TEXTURE_COMBINERS flag is set)
+        let texture_combiner_combos = if flags.contains(M2ModelFlags::USE_TEXTURE_COMBINERS) {
             Some(M2Array::parse(reader)?)
         } else {
             None
@@ -523,11 +524,7 @@ impl M2Header {
     pub fn new(version: M2Version) -> Self {
         let version_num = version.to_header_version();
 
-        let texture_combiner_combos = if version >= M2Version::Cataclysm {
-            Some(M2Array::new(0, 0))
-        } else {
-            None
-        };
+        let texture_combiner_combos = None;
 
         let texture_transforms = if version >= M2Version::Legion {
             Some(M2Array::new(0, 0))
@@ -653,10 +650,12 @@ impl M2Header {
             new_header.texture_flipbooks = Some(M2Array::new(0, 0));
         }
 
-        // Handle texture_combiner_combos (added in Cataclysm)
-        if target_version >= M2Version::Cataclysm && source_version < M2Version::Cataclysm {
+        // Handle texture_combiner_combos (controlled by USE_TEXTURE_COMBINERS flag)
+        // The flag determines presence of this field, not version
+        let source_has_combos = self.flags.contains(M2ModelFlags::USE_TEXTURE_COMBINERS);
+        if target_version >= M2Version::Cataclysm && source_has_combos {
             new_header.texture_combiner_combos = Some(M2Array::new(0, 0));
-        } else if target_version < M2Version::Cataclysm && source_version >= M2Version::Cataclysm {
+        } else {
             new_header.texture_combiner_combos = None;
         }
 
@@ -677,7 +676,7 @@ mod tests {
     use std::io::Cursor;
 
     // Helper function to create a basic test header
-    fn create_test_header(version: M2Version) -> Vec<u8> {
+    fn create_test_header(version: M2Version, flags: M2ModelFlags) -> Vec<u8> {
         let mut data = Vec::new();
 
         // Magic "MD20"
@@ -691,7 +690,7 @@ mod tests {
         data.extend_from_slice(&0u32.to_le_bytes()); // offset = 0
 
         // Flags
-        data.extend_from_slice(&0u32.to_le_bytes());
+        data.extend_from_slice(&flags.bits().to_le_bytes());
 
         // Global sequences
         data.extend_from_slice(&0u32.to_le_bytes()); // count = 0
@@ -710,7 +709,7 @@ mod tests {
 
     #[test]
     fn test_header_parse_classic() {
-        let data = create_test_header(M2Version::Vanilla);
+        let data = create_test_header(M2Version::Vanilla, M2ModelFlags::empty());
         let mut cursor = Cursor::new(data);
 
         let header = M2Header::parse(&mut cursor).unwrap();
@@ -723,7 +722,7 @@ mod tests {
 
     #[test]
     fn test_header_parse_cataclysm() {
-        let data = create_test_header(M2Version::Cataclysm);
+        let data = create_test_header(M2Version::Cataclysm, M2ModelFlags::USE_TEXTURE_COMBINERS);
         let mut cursor = Cursor::new(data);
 
         let header = M2Header::parse(&mut cursor).unwrap();
@@ -736,7 +735,7 @@ mod tests {
 
     #[test]
     fn test_header_parse_legion() {
-        let data = create_test_header(M2Version::Legion);
+        let data = create_test_header(M2Version::Legion, M2ModelFlags::USE_TEXTURE_COMBINERS);
         let mut cursor = Cursor::new(data);
 
         let header = M2Header::parse(&mut cursor).unwrap();
@@ -749,7 +748,9 @@ mod tests {
 
     #[test]
     fn test_header_conversion() {
-        let classic_header = M2Header::new(M2Version::Vanilla);
+        let mut classic_header = M2Header::new(M2Version::Vanilla);
+        // Set USE_TEXTURE_COMBINERS flag for test
+        classic_header.flags = M2ModelFlags::USE_TEXTURE_COMBINERS;
 
         // Convert Classic to Cataclysm
         let cataclysm_header = classic_header.convert(M2Version::Cataclysm).unwrap();

file-formats/graphics/wow-m2/src/model.rs

@@ -3207,7 +3207,7 @@ impl M2Model {
             None
         };
 
-        let texture_combiner_combos = if m2_version >= M2Version::Cataclysm {
+        let texture_combiner_combos = if flags.contains(M2ModelFlags::USE_TEXTURE_COMBINERS) {
             Some(M2Array::parse(chunk_inner)?)
         } else {
             None