Add runtime data parsing and demo accurate timer

[eim64]

Adds 2 hw.dll hooks:

• ValidStuffText
• CL_ReadDemoMessage_OLD

That are used to read the //BXTD0 commands and corresponding runtime data each frame. These have only been tested on latest steam version of Half-Life.

Conversion back to a vector was implemented by adding a decrypt filter and load template.
demo_data_visitor is then applied to the recovered data and should contain logic such as updating timer/health. This could arguably be part of the load template, but imo it's better for parse logic to be separate.

I currently set HwDll::executing to true whenever a demo frame is read, to make the timer resume after save/loads. This is scuffed, and the Cbuf_Execute hook should be fixed to resume in demos instead, but I dont know how to.

Can be used to resolve #294

[chinese-soup]

Good stuff.

Please add Linux hooks as well:

diff --git a/BunnymodXT/modules/HwDLL.cpp b/BunnymodXT/modules/HwDLL.cpp
index 852c73f..f683a01 100644
--- a/BunnymodXT/modules/HwDLL.cpp
+++ b/BunnymodXT/modules/HwDLL.cpp
@@ -317,6 +317,16 @@ extern "C" qboolean __cdecl CL_CheckGameDirectory(char *gamedir)
 {
 	return HwDLL::HOOKED_CL_CheckGameDirectory(gamedir);
 }
+
+extern "C" int __cdecl ValidStuffText(char *buf)
+{
+	return HwDLL::HOOKED_ValidStuffText(buf);
+}
+
+extern "C" qboolean __cdecl CL_ReadDemoMessage_OLD()
+{
+	return HwDLL::HOOKED_CL_ReadDemoMessage_OLD();
+}
 #endif
 
 void HwDLL::Hook(const std::wstring& moduleName, void* moduleHandle, void* moduleBase, size_t moduleLength, bool needToIntercept)
@@ -1021,6 +1031,18 @@ void HwDLL::FindStuff()
 		else
 			EngineDevWarning("[hw dll] Could not find CL_CheckGameDirectory.\n");
 
+		ORIG_ValidStuffText = reinterpret_cast<_ValidStuffText>(MemUtils::GetSymbolAddress(m_Handle, "ValidStuffText"));
+		if (ORIG_ValidStuffText)
+			EngineDevMsg("[hw dll] Found ValidStuffText at %p.\n", ORIG_ValidStuffText);
+		else
+			EngineDevWarning("[hw dll] Could not find ValidStuffText.\n");
+
+		ORIG_CL_ReadDemoMessage_OLD = reinterpret_cast<_CL_ReadDemoMessage_OLD>(MemUtils::GetSymbolAddress(m_Handle, "CL_ReadDemoMessage_OLD"));
+		if (ORIG_CL_ReadDemoMessage_OLD)
+			EngineDevMsg("[hw dll] Found CL_ReadDemoMessage_OLD at %p.\n", ORIG_CL_ReadDemoMessage_OLD);
+		else
+			EngineDevWarning("[hw dll] Could not find CL_ReadDemoMessage_OLD.\n");
+
 		if (!cls || !psv || !svs || !svmove || !ppmove || !host_client || !sv_player || !sv_areanodes || !cmd_text || !cmd_alias || !host_frametime || !cvar_vars || !movevars || !ORIG_SV_AddLinksToPM || !ORIG_SV_SetMoveVars)
 			ORIG_Cbuf_Execute = nullptr;

[YaLTeR]

Hey! Sorry for taking so long to look at this, I'm just completely buried in finishing TAS editor 2.

This is indeed a valuable feature to have, and it mostly matches how I would implement it. I just have a few comments, and we need to decide what to do about executing.