From 66be33b3a72aceaf1e7227de66138fc21afcec1f Mon Sep 17 00:00:00 2001
From: Paul Nodet <5941125+pnodet@users.noreply.github.com>
Date: Sat, 4 Jul 2026 01:12:04 +0200
Subject: [PATCH] fix: stream points instead of buffering the whole cloud in
 memory

The las Writer clears the header it receives and recomputes point
counts, per-return counts, and bounds itself on write/close, so the
manual header.add_point pass was dead work and the Vec buffer only
existed to support it. Stream read->write in one pass for constant
memory usage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 src/main.rs | 27 ++++++---------------------
 1 file changed, 6 insertions(+), 21 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index a20c675..d046736 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,6 @@
 use anyhow::{Context, Result};
 use clap::Parser;
-use las::{Builder, Read, Reader, Write, Writer};
+use las::{Read, Reader, Write, Writer};
 
 #[derive(Parser)]
 #[command(author, version, about, long_about = None)]
@@ -15,32 +15,17 @@ struct Args {
 fn main() -> Result<()> {
     let args = Args::parse();
 
-    let mut reader = Reader::from_path(args.path).context("Failed to open las file")?;
-
-    let original_header = reader.header().clone();
-
-    let mut header = Builder::from(original_header).into_header()?;
-
-    let mut las_points: Vec<las::Point> = Vec::new();
+    let mut reader = Reader::from_path(&args.path).context("Failed to open las file")?;
+    let header = reader.header().clone();
+    let mut writer = Writer::from_path(&args.output, header).context("Failed to create las writer")?;
 
     for point in reader.points() {
         match point {
-            Ok(point) => {
-                header.add_point(&point);
-                las_points.push(point);
-            }
-            Err(_) => {
-                continue;
-            }
+            Ok(point) => writer.write(point).context("Failed to write point")?,
+            Err(_) => continue,
         }
     }
 
-    let mut writer = Writer::from_path(args.output, header).context("Failed to get las writer")?;
-
-    for point in las_points {
-        writer.write(point).context("Unable to write:")?;
-    }
-
     writer.close().context("Failed to close las writer")?;
 
     Ok(())