# Self-made port
## Compatibility with RISC architectures
### Unaligned access
Unaligned access on **i386** causes only performance penalty, but on **RISC** it can cause unstable work.
For HLSDK at least you need such patches in util.cpp:
- https://github.com/FWGS/halflife/commit/7bfefe86e35d67867ae7af830ac1fc38f2908360
- https://github.com/FWGS/hlsdk-portable/commit/617d75545f2ecb9b2d46cc30728dc37c9eb6d35e
### Signed chars
`char` type defined as **signed** for **x86** and as **unsigned** for **arm** .
And sometimes such difference can break logic.
As a solution you can use `signed char` type in code directly or use `-fsigned-char` option for gcc/clang compilers.
For HLSDK at least you need such [fix ](https://github.com/FWGS/hlsdk-portable/commit/1ca34fcb4381682bd517612b530db22a1354a795 ) in nodes.cpp/.h.
## Compatibility with 64bit architectures
You need list of patches for Studio Model Render, MAKE_STRING macro and nodes:
- https://github.com/FWGS/hlsdk-portable/commit/d287ed446332e615ab5fb25ca81b99fa14d18a73
- https://github.com/FWGS/hlsdk-portable/commit/3bce17e3a04f8af10a927a07ceb8ab0f09152ec4
- https://github.com/FWGS/hlsdk-portable/commit/9ebfc981773ec4c7a89ffe52d9c249e1fbef9634
- https://github.com/FWGS/hlsdk-portable/commit/00833188dab87ef5746286479ba5aeb9d83b4a0c
- https://github.com/FWGS/hlsdk-portable/commit/4661b5c1a5245b27a5532745c11e44b5540e4172
- https://github.com/FWGS/hlsdk-portable/commit/2b61380146b1d58a8c465f0e312c061b12bda115
- https://github.com/FWGS/hlsdk-portable/commit/8ef6cb2427ee16a763103bd3f315f38e2f01cfe2
## Mobility API
Xash3D FWGS has special extended interface in `mobility_int.h` which adds some new features like vibration on mobile platforms.
## Porting server-side code
Original valve's server code was compatible with linux and gcc 2.x.
Newer gcc versions have restriction which breaks build.
Now, to make it building with gcc 4.x+ or clang, you need to do following:
* Go to cbase.h and redefine macros as following
```
#define SetThink( a ) m_pfnThink = static_cast <void (CBaseEntity::*)(void)> (&a)
#define SetTouch( a ) m_pfnTouch = static_cast <void (CBaseEntity::*)(CBaseEntity *)> (&a)
#define SetUse( a ) m_pfnUse = static_cast <void (CBaseEntity::*)( CBaseEntity *pActivator, CBaseEntity *pCaller, USE_TYPE useType, float value )> (&a)
#define SetBlocked( a ) m_pfnBlocked = static_cast <void (CBaseEntity::*)(CBaseEntity *)> (&a)
#define ResetThink( ) m_pfnThink = static_cast <void (CBaseEntity::*)(void)> (NULL)
#define ResetTouch( ) m_pfnTouch = static_cast <void (CBaseEntity::*)(CBaseEntity *)> (NULL)
#define ResetUse( ) m_pfnUse = static_cast <void (CBaseEntity::*)( CBaseEntity *pActivator, CBaseEntity *pCaller, USE_TYPE useType, float value )> (NULL)
#define ResetBlocked( ) m_pfnBlocked = static_cast <void (CBaseEntity::*)(CBaseEntity *)> (NULL)
...
#define SetMoveDone( a ) m_pfnCallWhenMoveDone = static_cast <void (CBaseToggle::*)(void)> (&a)
```
* Replace all SetThink(NULL), SetTouch(NULL), setUse(NULL) and SetBlocked(NULL) by ResetThink(), ResetTouch(), ResetUse() and ResetBlocked()
* Sometimes you may need to add #include < ctype.h > if functions tolower or isspace are missing
## Porting client-side code
* Redefine all DLLEXPORT defines as empty field (Place it under _WIN32 macro if you want to keep windows compatibility).
* Remove hud_servers.cpp and Servers_Init/Servers_Shutdown from hud.cpp.
* Fix CAPS filenames in includes (like STDIO.H, replace by stdio.h).
* Replace broken macros as DECLARE_MESSAGE, DECLARE_COMMAND by fixed examples from our hlsdk-portable port (cl_util.h).
* Add ctype.h where is needed (tolower, isspace functions).
* Add string.h where is needed (memcpy, strcpy, etc).
* Use in_defs.h from hlsdk-portable.
* Add input_xash3d.cpp from hlsdk-portable project to fix input.
Now your client should be able to build and work correctly.
# Porting mod to hlsdk-portable
Look at changes which was made.
If there are not too much changes (for example, only some weapons was added), add these changes in hlsdk-portable.
You can use diff with original HLSDK and apply it as patch to hlsdk-portable.
```
NOTE: Many an old mods was made on HLSDK 2.0-2.1 and some rare mods on HLSDK 1.0.
So you need to have different versions of HLSDK to make diffs.
Plus different Spirit of Half-Life versions if mod was made on it.
Also, weapons in old HLSDK versions does not use client weapon prediction system and you may be need to port standart half-life weapons to server side.
```
Files must have same line endings (use dos2unix on all files).
We recommend to enable ignoring space changes in diff.
Move all new files to separate directories.
# Possible replacements for non-portable external dependencies
1. If mod uses **fmod.dll** or **base.dll** to play mp3/ogg on client-side or to precache sounds on server-side, you can replace it with:
- [pfnPrimeMusicStream ](https://github.com/FWGS/hlsdk-portable/blob/master/engine/cdll_int.h#L293= ) engine callback;
- [miniaudio ](https://github.com/mackron/miniaudio );
- [phonon ](https://community.kde.org/Phonon ).
2. If mod uses **OpenGL** , porting code to Xash3D render interface is recommended.
3. If mod uses **cg.dll** , you can try to port code to [NVFX ](https://github.com/tlorach/nvFX ).
4. If mod uses detours, comment code or try to find replacement somehow by yourself.
# Additional recommendations
1. If mod uses STL, you can replace it with [MiniUTL ](https://github.com/FWGS/MiniUTL ).
2. Avoid to use dynamic casts to make small size binaries.
3. Avoid to use exceptions to make small size binaries.
# Writing build scripts
Use wscript/CMakeLists.txt files from hlsdk-portable as build scripts example.
Get .c and .cpp file lists from Visual Studio project.
Add missing include dirs.
