GDI + мерцание

Поэтому я пытаюсь сделать дешевую копию Gyazo (инструмент скриншотов)

Проблема в том, что координаты курсора мерцают, как я могу предотвратить это? Я уже пробовала WM_ERASEBKGND но это ничего не помогает

Также есть что-то еще не так с моим кодом? Какие-нибудь плохие практики / техники?

#include <Windows.h>
#include <string>
#include <gdiplus.h>
#pragma comment (lib, "Gdiplus.lib")

// Store the "screenshot" when first launching the program
HBITMAP hbm;

// This draws the cursor coordinates close to the cursor
void DrawCursorCoords(Gdiplus::Graphics &graphics, Gdiplus::Bitmap &bitmap, Gdiplus::Color c)
{
POINT cursorPos;
GetCursorPos(&cursorPos);

std::wstring x = std::to_wstring(cursorPos.x);
std::wstring y = std::to_wstring(cursorPos.y);

graphics.DrawString(x.c_str(), x.length(), &Gdiplus::Font(L"Consolas", 16), Gdiplus::PointF(cursorPos.x, cursorPos.y), &Gdiplus::SolidBrush(c));
graphics.DrawString(y.c_str(), y.length(), &Gdiplus::Font(L"Consolas", 16), Gdiplus::PointF(cursorPos.x, cursorPos.y + 16), &Gdiplus::SolidBrush(c));
}

// Paint our stuff
void Paint(HDC &hdc)
{
Gdiplus::Graphics * gfx = new Gdiplus::Graphics(hdc);
Gdiplus::Bitmap * bmap = new Gdiplus::Bitmap(hbm, (HPALETTE)0);

gfx->DrawImage(bmap, 0, 0, GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN));

if (GetAsyncKeyState(VK_LBUTTON))
DrawCursorCoords(*gfx, *bmap, Gdiplus::Color::Red);
else
DrawCursorCoords(*gfx, *bmap, Gdiplus::Color::Green);

delete gfx;
delete bmap;
}

LRESULT APIENTRY WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
PAINTSTRUCT ps;
HDC hdc;

switch (message)
{
case WM_PAINT:
{
hdc = BeginPaint(hwnd, &ps);

Paint(hdc);

EndPaint(hwnd, &ps);
break;
}

case WM_TIMER:
{
InvalidateRect(hwnd, NULL, NULL);
break;
}

case WM_CLOSE:
{
DestroyWindow(hwnd);
break;
}

case WM_RBUTTONUP:
case WM_KEYDOWN:
case WM_DESTROY:
{
PostQuitMessage(0);
break;
}

case WM_ERASEBKGND: return TRUE;

default: return DefWindowProc(hwnd, message, wParam, lParam);

}

return 0L;
}

BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
char className[] = "_className";
HWND hwnd = NULL;

WNDCLASS wc;
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = NULL;
wc.hCursor = LoadCursor(NULL, IDC_CROSS);
wc.hbrBackground = (HBRUSH)(0);
wc.lpszMenuName = NULL;
wc.lpszClassName = className;

if (RegisterClass(&wc))
{
hwnd = CreateWindowEx(
WS_EX_TRANSPARENT | WS_EX_TOPMOST,
className, NULL,
WS_POPUP | WS_VISIBLE,
0, 0, GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN),
NULL, NULL, hInstance, NULL);
}

if (!hwnd) return FALSE;

ShowWindow(hwnd, SW_SHOW);
UpdateWindow(hwnd);

SetTimer(hwnd, 1, 1, NULL);

return TRUE;
}

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
// Take a screenshot and store it to 'hbm'
HWND hwndDesktop = GetDesktopWindow();
HDC hdcDesktop = GetDC(hwndDesktop);
HDC hdcCapture = CreateCompatibleDC(hdcDesktop);
hbm = CreateCompatibleBitmap(hdcDesktop, GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN));
SelectObject(hdcCapture, hbm);
BitBlt(hdcCapture, 0, 0, GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN),
hdcDesktop, 0, 0, SRCCOPY | CAPTUREBLT);

// Start GDI+
Gdiplus::GdiplusStartupInput gdiplusStartupInput;
ULONG_PTR gdiplusToken;
Gdiplus::GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);

MSG msg;

InitInstance(hInstance, nCmdShow);

while (GetMessage(&msg, NULL, 0, 0) > 0)
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}

Gdiplus::GdiplusShutdown(gdiplusToken);
DeleteObject(hbm);
ReleaseDC(hwndDesktop, hdcDesktop);
DeleteDC(hdcDesktop);
DeleteDC(hdcCapture);

return msg.wParam;
}