From 6e2514cd0d78bdb23e8f1aba133d5c4fd0e8444c Mon Sep 17 00:00:00 2001
From: Matt <m.moninger.h@gmail.com>
Date: Tue, 11 Dec 2018 03:05:57 +0100
Subject: [PATCH] Refactor sprite_checksum, returns rct_sprite_checksum now.

---
 src/openrct2/network/Network.cpp | 11 +++++-----
 src/openrct2/world/Sprite.cpp    | 35 ++++++++++++++++++++------------
 src/openrct2/world/Sprite.h      |  9 +++++++-
 3 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/src/openrct2/network/Network.cpp b/src/openrct2/network/Network.cpp
index fe9a10dd15..51c65597e3 100644
--- a/src/openrct2/network/Network.cpp
+++ b/src/openrct2/network/Network.cpp
@@ -941,14 +941,14 @@ bool Network::CheckSRAND(uint32_t tick, uint32_t srand0)
     {
         server_srand0_tick = 0;
         // Check that the server and client sprite hashes match
-        const char* client_sprite_hash = sprite_checksum();
-        const bool sprites_mismatch = server_sprite_hash[0] != '\0'
-            && strcmp(client_sprite_hash, server_sprite_hash.c_str()) != 0;
+        rct_sprite_checksum checksum = sprite_checksum();
+        std::string client_sprite_hash = checksum.ToString();
+        const bool sprites_mismatch = server_sprite_hash[0] != '\0' && client_sprite_hash != server_sprite_hash;
         // Check PRNG values and sprite hashes, if exist
         if ((srand0 != server_srand0) || sprites_mismatch)
         {
 #    ifdef DEBUG_DESYNC
-            dbg_report_desync(tick, srand0, server_srand0, client_sprite_hash, server_sprite_hash.c_str());
+            dbg_report_desync(tick, srand0, server_srand0, client_sprite_hash.c_str(), server_sprite_hash.c_str());
 #    endif
             return false;
         }
@@ -1613,7 +1613,8 @@ void Network::Server_Send_TICK()
     *packet << flags;
     if (flags & NETWORK_TICK_FLAG_CHECKSUMS)
     {
-        packet->WriteString(sprite_checksum());
+        rct_sprite_checksum checksum = sprite_checksum();
+        packet->WriteString(checksum.ToString().c_str());
     }
     SendPacketToClients(*packet);
 }
diff --git a/src/openrct2/world/Sprite.cpp b/src/openrct2/world/Sprite.cpp
index 507e4732d4..09e64c05a3 100644
--- a/src/openrct2/world/Sprite.cpp
+++ b/src/openrct2/world/Sprite.cpp
@@ -53,6 +53,22 @@ static LocationXYZ16 _spritelocations2[MAX_SPRITES];
 
 static size_t GetSpatialIndexOffset(int32_t x, int32_t y);
 
+std::string rct_sprite_checksum::ToString() const
+{
+    std::string result;
+
+    result.clear();
+    result.reserve(raw.size() * 2);
+    for (auto b : raw)
+    {
+        char buf[3];
+        snprintf(buf, 3, "%02x", b);
+        result.append(buf);
+    }
+
+    return result;
+}
+
 rct_sprite* try_get_sprite(size_t spriteIndex)
 {
     rct_sprite* sprite = nullptr;
@@ -207,14 +223,15 @@ static size_t GetSpatialIndexOffset(int32_t x, int32_t y)
 
 #ifndef DISABLE_NETWORK
 
-const char* sprite_checksum()
+rct_sprite_checksum sprite_checksum()
 {
     using namespace Crypt;
 
     // TODO Remove statics, should be one of these per sprite manager / OpenRCT2 context.
     //      Alternatively, make a new class for this functionality.
     static std::unique_ptr<HashAlgorithm<20>> _spriteHashAlg;
-    static std::string result;
+
+    rct_sprite_checksum checksum;
 
     try
     {
@@ -245,23 +262,15 @@ const char* sprite_checksum()
             }
         }
 
-        auto hash = _spriteHashAlg->Finish();
-
-        result.clear();
-        result.reserve(hash.size() * 2);
-        for (auto b : hash)
-        {
-            char buf[3];
-            snprintf(buf, 3, "%02x", b);
-            result.append(buf);
-        }
-        return result.c_str();
+        checksum.raw = std::move(_spriteHashAlg->Finish());
     }
     catch (std::exception& e)
     {
         log_error("sprite_checksum failed: %s", e.what());
         throw;
     }
+
+    return checksum;
 }
 #else
 
diff --git a/src/openrct2/world/Sprite.h b/src/openrct2/world/Sprite.h
index eed4bf90de..8b6cfd6ec4 100644
--- a/src/openrct2/world/Sprite.h
+++ b/src/openrct2/world/Sprite.h
@@ -201,6 +201,13 @@ union rct_sprite
 };
 assert_struct_size(rct_sprite, 0x100);
 
+struct rct_sprite_checksum
+{
+    std::array<uint8_t, 20> raw;
+
+    std::string ToString() const;
+};
+
 #pragma pack(pop)
 
 enum
@@ -305,7 +312,7 @@ void crashed_vehicle_particle_update(rct_crashed_vehicle_particle* particle);
 void crash_splash_create(int32_t x, int32_t y, int32_t z);
 void crash_splash_update(rct_crash_splash* splash);
 
-const char* sprite_checksum();
+rct_sprite_checksum sprite_checksum();
 
 void sprite_set_flashing(rct_sprite* sprite, bool flashing);
 bool sprite_get_flashing(rct_sprite* sprite);