此库提供挂钩虚拟方法表（VMT）的功能。

它通过复制原始VMT然后将其与修改后的版本交换来实现。

安装

将以下内容添加到您的 Cargo.toml

[dependencies]
vmt-hook = { version = "0.2.0" }

示例

• 挂钩DirectX 9中的'Present'方法。

use vmt_hook::VTableHook;

use windows::{
    core::HRESULT,
    Win32::{
        Foundation::{HWND, RECT},
        Graphics::{
            Direct3D9::IDirect3DDevice9,
            Gdi::RGNDATA,
        },
    },
};

type FnPresent = extern "stdcall" fn(
    IDirect3DDevice9,
    *const RECT,
    *const RECT,
    HWND,
    *const RGNDATA,
) -> HRESULT;

static mut ORIGINAL_PRESENT: Option<FnPresent> = None;

extern "stdcall" fn hk_present(
    device: IDirect3DDevice9,
    source_rect: *const RECT,
    dest_rect: *const RECT,
    dest_window_override: HWND,
    dirty_region: *const RGNDATA,
) -> HRESULT {
    // Your code.

    unsafe {
        let original_present = ORIGINAL_PRESENT.unwrap();
        original_present(device, source_rect, dest_rect, dest_window_override, dirty_region)
    }
}

unsafe fn instal_d3d9_hook() {
    let device: IDirect3DDevice9 = /* Your ptr. */;

    // Creating a hook with automatic detection of the number of methods in its VMT.
    // let hook = VTableHook::new(device);

    // If you know the number of methods in the table, you can specify it manually.
    let hook = VTableHook::with_count(device, 119);

    // Getting the original method.
    ORIGINAL_PRESENT = Some(std::mem::transmute(hook.get_original_method(17)));

    // Replacing the method at index 17 in the VMT with our function.
    hook.replace_method(17, hk_present as usize);
}