world: hide unknown block/biome type warnings by default

While using MinedMap with modded Minecraft version is not officially
supported, it should still work reasonably well if you're okay with
custom block types being invisible and custom biomes using default
grass/color/foliage colors.

Avoid spamming the log with messages for each section in this case
without --verbose, and instead just print a single warning at the end of
processing.

src/core/region_processor.rs

@@ -1,6 +1,14 @@
 //! The [RegionProcessor] and related functions
 
-use std::{ffi::OsStr, path::PathBuf, sync::mpsc, time::SystemTime};
+use std::{
+	ffi::OsStr,
+	path::PathBuf,
+	sync::{
+		atomic::{AtomicBool, Ordering},
+		mpsc,
+	},
+	time::SystemTime,
+};
 
 use anyhow::{Context, Result};
 use rayon::prelude::*;
@@ -32,6 +40,8 @@ fn parse_region_filename(file_name: &OsStr) -> Option<TileCoords> {
 enum RegionProcessorStatus {
 	/// Region was processed
 	Ok,
+	/// Region was processed, unknown blocks or biomes were encountered
+	OkWithUnknown,
 	/// Region was unchanged and skipped
 	Skipped,
 	/// Reading the region failed, previous processed data is reused
@@ -68,6 +78,8 @@ struct SingleRegionProcessor<'a> {
 	processed_region: ProcessedRegion,
 	/// Lightmap intermediate data
 	lightmap: image::GrayAlphaImage,
+	/// True if any unknown block or biome types were encountered during processing
+	has_unknown: bool,
 }
 
 impl<'a> SingleRegionProcessor<'a> {
@@ -104,6 +116,7 @@ impl<'a> SingleRegionProcessor<'a> {
 			lightmap_needed,
 			processed_region,
 			lightmap,
+			has_unknown: false,
 		})
 	}
 
@@ -162,8 +175,10 @@ impl<'a> SingleRegionProcessor<'a> {
 
 	/// Processes a single chunk
 	fn process_chunk(&mut self, chunk_coords: ChunkCoords, data: world::de::Chunk) -> Result<()> {
-		let chunk = world::chunk::Chunk::new(&data, self.block_types, self.biome_types)
-			.with_context(|| format!("Failed to decode chunk {:?}", chunk_coords))?;
+		let (chunk, has_unknown) =
+			world::chunk::Chunk::new(&data, self.block_types, self.biome_types)
+				.with_context(|| format!("Failed to decode chunk {:?}", chunk_coords))?;
+		self.has_unknown |= has_unknown;
 		let Some(layer::LayerData {
 			blocks,
 			biomes,
@@ -231,7 +246,11 @@ impl<'a> SingleRegionProcessor<'a> {
 		self.save_region()?;
 		self.save_lightmap()?;
 
-		Ok(RegionProcessorStatus::Ok)
+		Ok(if self.has_unknown {
+			RegionProcessorStatus::OkWithUnknown
+		} else {
+			RegionProcessorStatus::Ok
+		})
 	}
 }
 
@@ -300,6 +319,8 @@ impl<'a> RegionProcessor<'a> {
 		let (processed_send, processed_recv) = mpsc::channel();
 		let (error_send, error_recv) = mpsc::channel();
 
+		let has_unknown = AtomicBool::new(false);
+
 		self.collect_regions()?.par_iter().try_for_each(|&coords| {
 			let ret = self
 				.process_region(coords)
@@ -311,6 +332,10 @@ impl<'a> RegionProcessor<'a> {
 
 			match ret {
 				RegionProcessorStatus::Ok => processed_send.send(()).unwrap(),
+				RegionProcessorStatus::OkWithUnknown => {
+					has_unknown.store(true, Ordering::Relaxed);
+					processed_send.send(()).unwrap();
+				}
 				RegionProcessorStatus::Skipped => {}
 				RegionProcessorStatus::ErrorOk | RegionProcessorStatus::ErrorMissing => {
 					error_send.send(()).unwrap()
@@ -335,6 +360,16 @@ impl<'a> RegionProcessor<'a> {
 			errors,
 		);
 
+		if has_unknown.into_inner() {
+			warn!("Unknown block or biome types found during processing");
+			eprint!(concat!(
+				"\n",
+				"  If you're encountering this issue with an unmodified Minecraft version supported by MinedMap,\n",
+				"  please file a bug report including the output with the --verbose flag.\n",
+				"\n",
+			));
+		}
+
 		// Sort regions in a zig-zag pattern to optimize cache usage
 		regions.sort_unstable_by_key(|&TileCoords { x, z }| (x, if x % 2 == 0 { z } else { -z }));