From 8865c6ae3ba5570be95d0c1aae3e9bc68d029c1f Mon Sep 17 00:00:00 2001
From: Maxim <maxim@smspower.org>
Date: Sat, 16 Nov 2024 23:33:07 +0000
Subject: [PATCH] Add a comment describing the format

---
 compressors/gfxcomp_wbmw.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/compressors/gfxcomp_wbmw.cpp b/compressors/gfxcomp_wbmw.cpp
index dbb7622..861deec 100644
--- a/compressors/gfxcomp_wbmw.cpp
+++ b/compressors/gfxcomp_wbmw.cpp
@@ -5,6 +5,13 @@
 #include "utils.h"
 #include "rle.h"
 
+// Compression format:
+// - Data is processed one bitplane at a time
+// - For each bitplane:
+//   - %0nnnnnnn = RLE run of n bytes, 1<=n<=127
+//   - %1nnnnnnn = raw run of n bytes (byte is negated count), 1<=n<=128
+//   - %00000000 = end of bitplane
+
 void compressPlane(
     std::vector<uint8_t>& destination,
     const std::vector<uint8_t>::const_iterator& source,