Vanilla Bug with Multiple Fire Hardpoint Weapons

IrateRedKite

I’ve run up against a vanilla bug with weapons that have multiple HPFire hardpoints: They don’t properly decrement ammo as you’d expect!

The ammo goes down properly in the weapons window tracker in the bottom right, for instance a weapon with 2 HpFires will lower its ammo count by 2 every time you fire. However if you check your ship’s actual cargo or if you try to buy ammunition from a dock after, you’ll notice that the ammo only seems to be going down by 1 each time, no matter how many projectiles are being fired simultaneously each time.

Has anyone formulated a fix for this? The behaviour seems to be consistent between MP and SP, suggesting this is something in server.dll not firing quite right. @Laz and @Aingar have already taken a peek at this and unfortunately haven’t managed to get anywhere with it. Hoping that perhaps @adoxa or @BC46 might have some insight here that we’ve missed?

IrateRedKite

Update: I’ve isolated the cause of this! It seems @Venemon 's patch to fix the multiple HPFire sound bug causes this behaviour! The patch is as follows in Common.dll:

PatchM(0x039F77, 0x83, 0xFA, 0xFF, 0xBA, 0xFF, 0xFF, 0xFF, 0xFF, 0xC3)

Tagging @Aingar and @Laz for interest

IrateRedKite

The eventual fix for this, courtesy of @BC46 and @Aingar turned out to be a bit more complicated. Posting it here for visibility:

struct SrvGun
{
    void* vtable;
    CELauncher* launcher;
};

DWORD server;
UINT projectilesPerFire;

typedef bool (__fastcall HandlePlayerLauncherFire)(SrvGun *srvGun, PVOID _edx, Vector *vector);

bool __fastcall HandlePlayerLauncherFire_Hook(SrvGun *srvGun, PVOID _edx, Vector *vector)
{
    projectilesPerFire = srvGun->launcher->GetProjectilesPerFire();
    return ((HandlePlayerLauncherFire*) (server + 0xD840))(srvGun, _edx, vector);
}

__declspec(naked) void SetProjectilesPerFire()
{
    __asm {
        push 0x3F800000
        push [projectilesPerFire]
        mov eax, [server]
        add eax, 0xD91A
        jmp eax
    }
}

server = (DWORD) GetModuleHandleA("server.dll");
Hook(server + 0xD9A9, (DWORD) HandlePlayerLauncherFire_Hook, 5);
Hook(server + 0xDC09, (DWORD) HandlePlayerLauncherFire_Hook, 5);
Hook(server + 0xE009, (DWORD) HandlePlayerLauncherFire_Hook, 5);
Hook(server + 0xD913, (DWORD) SetProjectilesPerFire, 5, true);

This also fixes some serverside issues with ammo counts saving incorrectly on client reconnect,