feat(exporters): scaffold PngExporter

crates/exporters/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2024"
 
 [dependencies]
 lib = { path = "../lib" }
+image = { version = "0.25", default-features = false, features = ["png"] }
 fastnbt = "2.6.1"
 flate2 = "1.1.9"
 anyhow = { workspace = true }

crates/exporters/src/image_export.rs

@@ -0,0 +1,22 @@
+use lib::{BlockPalette, StructureExporter, VoxelGrid, VoxelType};
+
+pub struct PngExporter {
+    palette: BlockPalette,
+    cell_size: u32,
+}
+
+impl PngExporter {
+    pub fn new(palette: &BlockPalette, cell_size: u32) -> Self {
+        Self { palette: palette.clone(), cell_size }
+    }
+}
+
+impl StructureExporter for PngExporter {
+    fn export(&self, _grid: &VoxelGrid) -> anyhow::Result<Vec<u8>> {
+        todo!("png export not yet implemented")
+    }
+
+    fn file_extension(&self) -> &'static str {
+        "png"
+    }
+}

crates/exporters/src/lib.rs

@@ -1,8 +1,10 @@
+mod image_export;
 mod litematica;
 mod mcfunction;
 
 use lib::{BlockPalette, StructureExporter};
 
+pub use image_export::PngExporter;
 pub use litematica::LitematicaExporter;
 pub use mcfunction::McFunctionExporter;
 
@@ -11,12 +13,17 @@ type ExporterFactory = fn(&BlockPalette) -> Box<dyn StructureExporter>;
 const REGISTRY: &[(&str, ExporterFactory)] = &[
     ("mcfunction", |p| Box::new(McFunctionExporter::new(p))),
     ("litematica", |p| Box::new(LitematicaExporter::new(p))),
+    ("png", |p| Box::new(PngExporter::new(p, 16))),
 ];
 
 pub fn available_names() -> Vec<&'static str> {
     REGISTRY.iter().map(|(name, _)| *name).collect()
 }
 
+pub fn build_png(palette: &BlockPalette, cell_size: u32) -> Box<dyn StructureExporter> {
+    Box::new(PngExporter::new(palette, cell_size))
+}
+
 pub fn build(name: &str, palette: &BlockPalette) -> Option<Box<dyn StructureExporter>> {
     REGISTRY.iter()
         .find(|(n, _)| *n == name)

crates/lib/src/lib.rs

@@ -13,6 +13,7 @@ pub use fonts::ttf_font::TtfFont;
 pub use grid::VoxelGrid;
 pub use models::VoxelType;
 pub use palette::BlockPalette;
+pub use palette::PaletteMappings;
 
 pub trait StructureExporter {
     fn export(&self, grid: &VoxelGrid) -> anyhow::Result<Vec<u8>>;