Windhawk mod: Remove Windows 11 Window Border

a.wh.cpp

// ==WindhawkMod==
// @id              remove-window-border
// @name            Remove Windows 11 Window Border
// @description     Hides the 1-pixel border from all windows without changing dimensions or layout.
// @version         0.1.0
// @author          Jaid
// @github          https://github.com/jaid
// @include         *
// @compilerOptions -ldwmapi
// ==/WindhawkMod==

#include <windows.h>
#include <dwmapi.h>

#ifndef DWMWA_BORDER_COLOR
#define DWMWA_BORDER_COLOR 34
#endif

#ifndef DWMWA_COLOR_NONE
#define DWMWA_COLOR_NONE 0xFFFFFFFE
#endif

void ApplyNoBorder(HWND hWnd) {
  if (!IsWindow(hWnd)) {
    return;
  }
  LONG_PTR style = GetWindowLongPtr(hWnd, GWL_STYLE);
  if (style & WS_CHILD) {
    return;
  }
  COLORREF color = DWMWA_COLOR_NONE;
  HRESULT hr = DwmSetWindowAttribute(hWnd, DWMWA_BORDER_COLOR, &color, sizeof(color));
}

using CreateWindowExW_t = decltype(&CreateWindowExW);
CreateWindowExW_t pOriginalCreateWindowExW;

HWND WINAPI CreateWindowExW_Hook(DWORD dwExStyle, LPCWSTR lpClassName, LPCWSTR lpWindowName, DWORD dwStyle, int X, int Y, int nWidth, int nHeight, HWND hWndParent, HMENU hMenu, HINSTANCE hInstance, LPVOID lpParam) {
  HWND hWnd = pOriginalCreateWindowExW(dwExStyle, lpClassName, lpWindowName, dwStyle, X, Y, nWidth, nHeight, hWndParent, hMenu, hInstance, lpParam);
  if (hWnd && !(dwStyle & WS_CHILD)) {
    ApplyNoBorder(hWnd);
  }
  return hWnd;
}

BOOL CALLBACK InitEnumWindowsProc(HWND hWnd, LPARAM lParam) {
  DWORD pid = 0;
  GetWindowThreadProcessId(hWnd, &pid);
  if (pid == GetCurrentProcessId()) {
    ApplyNoBorder(hWnd);
  }
  return TRUE;
}

BOOL Wh_ModInit() {
  Wh_SetFunctionHook((void*) CreateWindowExW, (void*) CreateWindowExW_Hook, (void**) &pOriginalCreateWindowExW);
  EnumWindows(InitEnumWindowsProc, 0);
  return TRUE;
}