From ffad71bdc53f41946655be6a17e04dd7bc5c28c2 Mon Sep 17 00:00:00 2001 From: Alejandro Alonso Date: Fri, 11 Sep 2026 09:22:36 +0200 Subject: [PATCH] :bug: Hard-clip tile atlas blit to avoid seam hairlines (#11639) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit AA clip on the Current→atlas blit softens shared tile edges so the canvas background shows through as 1px lines at the 512px grid when tiles are composed with SrcOver. Closes #11638 --- render-wasm/src/render/surfaces.rs | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/render-wasm/src/render/surfaces.rs b/render-wasm/src/render/surfaces.rs index 36e5c02008..876cee8b0c 100644 --- a/render-wasm/src/render/surfaces.rs +++ b/render-wasm/src/render/surfaces.rs @@ -40,7 +40,9 @@ fn draw_surface_src_rect_to_dst( return; } to_canvas.save(); - to_canvas.clip_rect(dst, None, true); + // Hard clip: AA softens shared tile edges so the backbuffer background + // shows through as 1px seams when tiles are composed with SrcOver. + to_canvas.clip_rect(dst, None, false); let sx = dst.width() / src.width(); let sy = dst.height() / src.height(); to_canvas.translate((dst.left, dst.top));