From 9539d8871f474aff73beadfd10dfccec256eafa9 Mon Sep 17 00:00:00 2001
From: Raph Levien <raph.levien@gmail.com>
Date: Fri, 1 May 2020 09:06:10 -0700
Subject: [PATCH] Clear item ref on empty segments

---
 piet-gpu/shader/kernel2s.comp |   4 +++-
 piet-gpu/shader/kernel2s.spv  | Bin 17528 -> 17688 bytes
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/piet-gpu/shader/kernel2s.comp b/piet-gpu/shader/kernel2s.comp
index 8c60b5b..d6b1571 100644
--- a/piet-gpu/shader/kernel2s.comp
+++ b/piet-gpu/shader/kernel2s.comp
@@ -119,7 +119,9 @@ void main() {
 
                 start = end;
             }
-            if (chunk_n_segs > 0) {
+            if (chunk_n_segs == 0) {
+                ItemHeader_write(item_header, ItemHeader(SegChunkRef(0)));
+            } else {
                 SegChunk_write(seg_chunk_ref, SegChunk(chunk_n_segs, SegChunkRef(0)));
                 seg_chunk_ref.offset += SegChunk_size + Segment_size * chunk_n_segs;
             }
diff --git a/piet-gpu/shader/kernel2s.spv b/piet-gpu/shader/kernel2s.spv
index 4f249bbbe82be66b12983c07851eb737ee5e5c5d..f7c27f04f27c45e785ab91f33da2144f4b59923b 100644
GIT binary patch
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delta 832
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