From 7c640bfeaf2a0fbc8c3550b4c19790a800a7f6a2 Mon Sep 17 00:00:00 2001
From: Dylan <boss@tehbox.org>
Date: Wed, 26 Aug 2026 23:58:16 +1200
Subject: feat: Added a bunch of stuff

Added derive macro for byte encode
Added start for PNG reading
Added BMP writing
---
 byte_encode_derive/src/lib.rs | 128 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 byte_encode_derive/src/lib.rs

(limited to 'byte_encode_derive/src')

diff --git a/byte_encode_derive/src/lib.rs b/byte_encode_derive/src/lib.rs
new file mode 100644
index 0000000..5970c66
--- /dev/null
+++ b/byte_encode_derive/src/lib.rs
@@ -0,0 +1,128 @@
+// Code mostly made by gemini somehow
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, Data, DeriveInput, Fields};
+
+#[proc_macro_derive(ByteEncode)]
+pub fn derive_byte_encode(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+    let name = input.ident;
+
+    // We only support structs with named fields for this example
+    let fields = match input.data {
+        Data::Struct(data) => match data.fields {
+            Fields::Named(fields) => fields.named,
+            _ => panic!("Only named fields are supported"),
+        },
+        _ => panic!("Only structs are supported"),
+    };
+
+    // --- 1. Generate from_le_bytes parsing logic ---
+    let mut current_offset = quote! { 0 };
+    let from_le_bytes_initializers = fields.iter().map(|f| {
+        let field_name = &f.ident;
+        let field_type = &f.ty;
+
+        // Calculate start and end bounds for the current field slice
+        let start = quote! { #current_offset };
+        let end = quote! { #start + <#field_type>::SIZE };
+        
+        // Update the offset tracking for the next iteration loop
+        current_offset = quote! { #end };
+
+        quote! {
+            #field_name: <#field_type as ByteEncode<{<#field_type>::SIZE}>>::from_le_bytes(
+                buffer[#start..#end].try_into().unwrap()
+            )
+        }
+    });
+	let mut current_offset = quote! { 0 };
+    let from_be_bytes_initializers = fields.iter().map(|f| {
+        let field_name = &f.ident;
+        let field_type = &f.ty;
+
+        // Calculate start and end bounds for the current field slice
+        let start = quote! { #current_offset };
+        let end = quote! { #start + <#field_type>::SIZE };
+        
+        // Update the offset tracking for the next iteration loop
+        current_offset = quote! { #end };
+
+        quote! {
+            #field_name: <#field_type as ByteEncode<{<#field_type>::SIZE}>>::from_be_bytes(
+                &mut buffer[#start..#end].try_into().unwrap()
+            )
+        }
+    });
+
+	
+    // --- 2. Generate to_le_bytes serialization logic ---
+    let mut current_offset = quote! { 0 };
+    let to_le_bytes_writers = fields.iter().map(|f| {
+        let field_name = &f.ident;
+        let field_type = &f.ty;
+
+        let start = quote! { #current_offset };
+        let end = quote! { #start + <#field_type>::SIZE };
+        
+        current_offset = quote! { #end };
+
+        quote! {
+            res[#start..#end].copy_from_slice(&self.#field_name.to_le_bytes());
+        }
+    });
+	let mut current_offset = quote! { 0 };
+    let to_be_bytes_writers = fields.iter().map(|f| {
+        let field_name = &f.ident;
+        let field_type = &f.ty;
+
+        let start = quote! { #current_offset };
+        let end = quote! { #start + <#field_type>::SIZE };
+        
+        current_offset = quote! { #end };
+
+        quote! {
+            res[#start..#end].copy_from_slice(&self.#field_name.to_be_bytes());
+        }
+    });
+	
+
+    // --- 3. Construct final token stream ---
+    // This dynamically sums up sizes like: 0 + Field1::SIZE + Field2::SIZE ...
+    let total_size_expr = fields.iter().fold(quote! { 0 }, |acc, f| {
+        let field_type = &f.ty;
+        quote! { #acc + <#field_type>::SIZE }
+    });
+
+    let expanded = quote! {
+        impl ByteEncode<{ #total_size_expr }> for #name {
+            fn from_le_bytes(buffer: &[u8; { #total_size_expr }]) -> Self {
+                Self {
+                    #( #from_le_bytes_initializers, )*
+                }
+            }
+
+            fn to_le_bytes(&self) -> [u8; { #total_size_expr }] {
+                let mut res = [0u8; { #total_size_expr }];
+                #( #to_le_bytes_writers )*
+                res
+            }
+
+			
+            fn from_be_bytes(buffer: &mut [u8; { #total_size_expr }]) -> Self {
+                Self {
+                    #( #from_be_bytes_initializers, )*
+                }
+            }
+
+            fn to_be_bytes(&self) -> [u8; { #total_size_expr }] {
+                let mut res = [0u8; { #total_size_expr }];
+                #( #to_be_bytes_writers )*
+                res
+            }
+        }
+    };
+
+    TokenStream::from(expanded)
+}
-- 
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