add readme

3 files changed, 86 insertions, 4 deletions

diff --git a/README.md b/README.md
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+<!--
+.. File: README.md
+.. Location: https://bgstack15.ddns.net/cgit/srb_lib
+.. Author: bgstack15
+.. SPDX-License-Identifier: GPL-3.0-only
+.. Startdate: 2024-03-20-4 10:14
+.. Title: Readme for savegame editor for Snoopy vs. the Red Baron
+.. Project: srb_lib
+.. Purpose: Read it.
+.. Usage: Read it.
+.. Reference: See heading References
+.. Improve:
+.. Documentation: Read it.
+-->
+
+# README for Savegame Editor for Snoopy vs. the Red Baron
+Modify an existing savegame file for the PC game [Snoopy vs. the Red Baron (2006)](https://en.wikipedia.org/wiki/Snoopy_vs._the_Red_Baron_(video_game).
+
+# tl;dr
+
+    ./srb.py --profile 1 --unlock-everything --buy-everything ~/"Documents/Snoopy vs. the Red Baron/Profile 1/Profile 1.sav"
+
+## Upstream
+This project's upstream is at <https://bgstack15.ddns.net/cgit/srb_lib/>.
+
+## Alternatives
+None found.
+
+## Reason for existence
+The author was unable to find any trainer or savegame editor for this game, and I wanted to be able to reset certain elements or cheat and give myself everything. Mostly I wanted "Octo-gun" and I was concerned I wasn't good enough to beat every level (mostly boss levels) with rank General. I did actually beat the game with 100% completion before I finished this tool.
+
+## Using
+Most capabilities have "set" and "get" parameters. Some have "set" and "add/remove" parameters. To see a full list of commands, run `./srb.py --help`.
+
+Some common examples.
+
+    ./srb.py --profile 1 --set-name "newname" --file "Profile 1.sav"
+    ./srb.py --profile 1 --set-money 10000 --file "Profile 1.sav"
+    ./srb.py --profile 1 --set-level 5,done --file "Profile 1.sav"
+    ./srb.py --profile 1 --set-health 4 --file "Profile 1.sav"
+
+Note that `--set-level 5,done` operates three separate parameters that could be done individually:
+
+    --set-level-status 5,general
+    --set-level-balloons 5,all
+    --set-level-letters 5,all
+
+Individual letter/balloon control is not implemented at this time.
+
+## Dependencies
+Just python3.
+
+## Building
+N/A
+
+## Design notes
+The checksum used is this crc32:
+
+    crc width=32 poly=0x4c11db7 init=0x0 xorout=0x235b4b9c refin=false refout=false out_endian=little
+
+Which I only learned through the reverse-engineering efforts of <https://github.com/8051Enthusiast/delsum>.
+
+Before I learned this, none of this savegame editing was possible.
+
+The binary contents are stored in little-endian, which makes visual inspection of the file in a hexeditor slower.
+
+## References
+
+1. <https://bgstack15.ddns.net/blog/posts/2024/03/22/initial-research-for-hacking-savegame-files-for-snoopy-vs-the-red-baron/>
+2. <https://bgstack15.ddns.net/blog/posts/2024/03/26/the-checksum-for-the-savegame-file-for-snoopy-vs-the-red-baron>
+3. <https://github.com/8051Enthusiast/delsum>
+4. <https://gist.github.com/Lauszus/6c787a3bc26fea6e842dfb8296ebd630>
+5. <https://stackoverflow.com/questions/46109815/reversing-the-byte-order-of-a-string-containing-hexadecimal-characters>
+6. [Walkthrough for Snoopy vs. the Red Baron](https://gamefaqs.gamespot.com/pc/930591-snoopy-vs-the-red-baron/faqs/46161)
diff --git a/srb.py b/srb.py
index 8fe12bf..4b72330 100755
--- a/srb.py
+++ b/srb.py
@@ -1,15 +1,21 @@
 #!/usr/bin/env python3
+# File: srb.py
+# Location: https://bgstack15.ddns.net/cgit/srb_lib
+# Author: bgstack15
+# SPDX-License-Identifier: GPL-3.0-only
 # Startdate: 2024-03-08-6 15:28
-# File: srb_lib.py
+# Title: Frontend for savegame editor for Snoopy vs. the Red Baron
+# Project: srb_lib
 # Purpose: frontend for srb_lib
 # History:
 # Usage:
 #    tl;dr: ./srb.py --profile 1 --unlock-everything --buy-everything "Profile 1.sav"
 # Reference:
-#    blog posts 2024-03
-#    delsum from github
 #    bgconf.py
-# WORKHERE: still some confusion around the --unlock-everything --lock-everything and the levelset available levels.
+# Improve:
+#    still some confusion around the --unlock-everything --lock-everything and the levelset available levels.
+# Documentation: README.md
+# Dependencies:
 
 import srb_lib, argparse, sys
 from srb_lib import ferror, debuglev
diff --git a/srb_lib.py b/srb_lib.py
index 874c287..a361c16 100644
--- a/srb_lib.py
+++ b/srb_lib.py
@@ -19,6 +19,8 @@
 #    Fuctions that worked: <https://gist.github.com/Lauszus/6c787a3bc26fea6e842dfb8296ebd630> Author: Lauszus
 #    <https://stackoverflow.com/questions/46109815/reversing-the-byte-order-of-a-string-containing-hexadecimal-characters>
 #    <https://gamefaqs.gamespot.com/pc/930591-snoopy-vs-the-red-baron/faqs/46161>
+# Improve:
+#    test all functions after trying '<1I' for unsigned int
 # Documentation:
 #    winetricks vd=1024x768
 #    winetricks vd=off