7 files changed, 514 insertions, 235 deletions

diff --git a/win-resize-mt/build.sh b/win-resize-mt/build.sh
new file mode 100644
index 0000000..c7c4423
--- /dev/null
+++ b/win-resize-mt/build.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+mkdir -p bin
+cc -o bin/win-resize-mt -Wall -Wextra -Wpedantic -O0 -g ./win-resize-mt.c -ldwmapi -lgdi32
diff --git a/win-resize-mt/win-resize-mt.c b/win-resize-mt/win-resize-mt.c
new file mode 100644
index 0000000..2f9dd4e
--- /dev/null
+++ b/win-resize-mt/win-resize-mt.c
@@ -0,0 +1,277 @@
+// ================================================================================================
+// Example of how to draw while resizing / moving a window on Windows in C.
+//
+// This demo uses a dedicated render thread with basic synchronization with the event loop. There
+// is a single-threaded version called win-resize/ if that's more your style.
+//
+// Build (MSVC):
+//     > cl /W4 /Od /Zi win-resize-mt.c /Fe:win-resize-mt.exe
+// Build (GCC/clang):
+//     $ cc -o win-resize-mt.exe -Wall -Wextra -Wpedantic -O0 -g win-resize-mt.c -ldwmapi -lgdi32
+//
+// Changelog:
+//     XX/XX/XXXX: Initial release
+//
+// License:
+//     Copyright (c) 2026 Hunter Kvalevog
+//
+//     Permission to use, copy, modify, and/or distribute this software for any
+//     purpose with or without fee is hereby granted.
+//
+//     THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+//     WITH REGARD TO THIS SOFTWARE.
+// ================================================================================================
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <dwmapi.h>
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+
+#ifdef _MSC_VER
+#   pragma comment(lib, "dwmapi.lib")
+#   pragma comment(lib, "gdi32.lib")
+#   pragma comment(lib, "user32.lib")
+#endif
+
+#define UNUSED(Var) ((void)(Var))
+
+static void GfxInit(HWND wnd);
+static void GfxResize(UINT vpw, UINT vph);
+static void GfxDraw(void);
+
+#define THREAD_BIT_QUIT (1 << 0)
+#define THREAD_BIT_SIZE (1 << 1)
+#define THREAD_BIT_SYNC (1 << 2)
+
+typedef struct ThreadData ThreadData;
+struct ThreadData
+{
+    HWND          wnd;
+    HANDLE        init_sig;
+    HANDLE        sync_sig;
+    volatile LONG bits;
+    volatile LONG size_w;
+    volatile LONG size_h;
+};
+
+//
+static DWORD WINAPI RenderThread(LPVOID opaque)
+{
+    ThreadData *td = opaque;
+    GfxInit(td->wnd);
+    GfxDraw();
+
+    SetEvent(td->init_sig);
+
+    while (TRUE) {
+        const LONG bits = InterlockedOr(&td->bits, 0);
+
+        if (bits & THREAD_BIT_QUIT) {
+            break;
+        }
+
+        if (bits & THREAD_BIT_SIZE) {
+            const LONG size_w = InterlockedOr(&td->size_w, 0);
+            const LONG size_h = InterlockedOr(&td->size_h, 0);
+            GfxResize(size_w, size_h);
+            InterlockedAnd(&td->bits, ~THREAD_BIT_SIZE);
+        }
+
+        GfxDraw();
+
+        if (bits & THREAD_BIT_SYNC) {
+            SetEvent(td->sync_sig);
+            InterlockedAnd(&td->bits, ~THREAD_BIT_SYNC);
+        }
+    }
+
+    return 0;
+}
+
+//
+static LRESULT CALLBACK WndProc(HWND wnd, UINT msg, WPARAM wparam, LPARAM lparam)
+{
+    ThreadData *td = (ThreadData *)GetWindowLongPtrW(wnd, GWLP_USERDATA);
+    switch (msg)
+    {
+        case WM_DESTROY:
+            PostQuitMessage(0);
+            return 0;
+        case WM_SIZE:
+            // Resize
+            InterlockedExchange(&td->size_w, LOWORD(lparam));
+            InterlockedExchange(&td->size_h, HIWORD(lparam));
+            InterlockedOr(&td->bits, THREAD_BIT_SIZE);
+
+            // Sync
+            InterlockedOr(&td->bits, THREAD_BIT_SYNC);
+            WaitForSingleObject(td->sync_sig, INFINITE);
+            ResetEvent(td->sync_sig);
+            break;
+    }
+    return DefWindowProcW(wnd, msg, wparam, lparam);
+}
+
+//
+int WinMain(HINSTANCE instance, HINSTANCE previnstance, LPSTR cmdline, int cmdshow)
+{
+    UNUSED(previnstance); UNUSED(cmdline);
+
+    // Register window class
+    WNDCLASSEXW wc = { 0 };
+    wc.cbSize        = sizeof(wc);
+    wc.hCursor       = LoadCursor(0, IDC_ARROW);
+    wc.hInstance     = instance;
+    wc.lpfnWndProc   = WndProc;
+    wc.lpszClassName = L"win-resize-mt";
+
+    ATOM atom = RegisterClassExW(&wc);
+    assert(atom && "Failed to register window class");
+
+    // Create window
+    HWND wnd = CreateWindowExW(WS_EX_APPWINDOW, wc.lpszClassName, wc.lpszClassName,
+                               WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 
+                               CW_USEDEFAULT, 0, 0, wc.hInstance, 0);
+    assert(wnd && "Failed to create window");
+
+    //
+    ThreadData td = { 0 };
+    td.wnd      = wnd;
+    td.init_sig = CreateEvent(0, TRUE, FALSE, 0);
+    td.sync_sig = CreateEvent(0, TRUE, FALSE, 0);
+
+    //
+    HANDLE th = CreateThread(0, 0, RenderThread, &td, 0, 0);
+    assert(th && "Failed to create render thread");
+
+    //
+    SetWindowLongPtrW(wnd, GWLP_USERDATA, (LONG_PTR)&td);
+    WaitForSingleObject(td.init_sig, INFINITE);
+
+    //
+    ShowWindow(wnd, cmdshow);
+
+    //
+    MSG msg;
+    while (GetMessageW(&msg, 0, 0, 0) > 0) {
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+    }
+
+    //
+    InterlockedOr(&td.bits, THREAD_BIT_QUIT);
+    WaitForSingleObject(th, INFINITE);
+
+    return 0;
+}
+
+// ================================================================================================
+
+static UINT    g_vpw       = 0;
+static UINT    g_vph       = 0;
+static HDC     g_hdc       = 0;
+static HDC     g_hdc_back  = 0;
+static HBITMAP g_bmp       = 0;
+static HBRUSH  g_bgbr      = 0;
+static HBRUSH  g_fgbr      = 0;
+static HPEN    g_pen       = 0;
+
+static void GfxInit(HWND wnd)
+{
+    g_hdc       = GetDC(wnd);
+    g_hdc_back  = CreateCompatibleDC(g_hdc);
+    g_bgbr      = CreateSolidBrush(RGB(0x00, 0x20, 0x20));
+    g_fgbr      = CreateSolidBrush(RGB(0xE0, 0xE0, 0xE0));
+    g_pen       = CreatePen(PS_SOLID, 2, RGB(0xFF, 0x10, 0x10));
+
+    RECT rc;
+    GetClientRect(wnd, &rc);
+
+    GfxResize(rc.right, rc.bottom);
+}
+
+static void GfxResize(UINT vpw, UINT vph)
+{
+    if (g_bmp)
+    {
+        DeleteObject(g_bmp);
+        g_bmp = 0;
+    }
+
+    if (vpw > 0 && vph > 0)
+    {
+        g_bmp = CreateCompatibleBitmap(g_hdc, vpw, vph);
+        SelectObject(g_hdc_back, g_bmp);
+    }
+
+    g_vpw = vpw;
+    g_vph = vph;
+}
+
+static void GfxDraw(void)
+{
+    static UINT frame = 0;
+    ++frame;
+
+    if (g_bmp && g_vpw > 0 && g_vph > 0)
+    {
+        HDC hdc = g_hdc_back;
+
+        // Clear
+        {
+            RECT rc = { 0, 0, g_vpw, g_vph };
+            FillRect(hdc, &rc, g_bgbr);
+        }
+
+        // Draw X
+        {
+            SelectObject(hdc, g_pen);
+            MoveToEx(hdc, 0, 0, 0);
+            LineTo(hdc, g_vpw, g_vph);
+            MoveToEx(hdc, 0, g_vph, 0);
+            LineTo(hdc, g_vpw, 0);
+        }
+
+        // Draw rotating triangle
+        {
+            int cx = g_vpw / 2;
+            int cy = g_vph / 2;
+            int r = (g_vpw < g_vph ? g_vpw : g_vph) / 3;
+
+            POINT verts[3];
+            for (int i = 0; i < 3; ++i)
+            {
+                float ang = ((float)frame / 100.0f) + (float)i * (2.0f * 3.14159265f / 3.0f);
+                verts[i].x = cx + (int)(cosf(ang) * r);
+                verts[i].y = cy + (int)(sinf(ang) * r);
+            }
+
+            SelectObject(hdc, g_pen);
+            SelectObject(hdc, g_fgbr);
+            Polygon(hdc, verts, ARRAYSIZE(verts));
+        }
+
+        // Draw text
+        {
+            WCHAR txtbuf[256];
+            _snwprintf_s(txtbuf, ARRAYSIZE(txtbuf), _TRUNCATE, L"win-resize-mt (frame %u)", frame);
+
+            SIZE sz;
+            GetTextExtentPoint32W(hdc, txtbuf, (int)wcslen(txtbuf), &sz);
+
+            SetBkMode(hdc, TRANSPARENT);
+            SetTextColor(hdc, RGB(0xE0, 0xE0, 0xE0));
+            TextOutW(hdc, (g_vpw - sz.cx) / 2, 19, txtbuf, (int)wcslen(txtbuf));
+        }
+
+        // Present
+        BitBlt(g_hdc, 0, 0, g_vpw, g_vph, g_hdc_back, 0, 0, SRCCOPY);
+
+        // Wait for dwm to display a frame
+        DwmFlush();
+    }
+}
+
diff --git a/win-resize-st/build.bat b/win-resize-st/build.bat
new file mode 100644
index 0000000..8568ca2
--- /dev/null
+++ b/win-resize-st/build.bat
@@ -0,0 +1,3 @@
+@echo off
+if not exist bin mkdir bin
+cl /W4 /Od /Zi /Fe:bin\win-resize-st.exe win-resize-st.c /Fd:bin\ /Fo:bin\
diff --git a/win-resize-st/build.sh b/win-resize-st/build.sh
new file mode 100644
index 0000000..d644837
--- /dev/null
+++ b/win-resize-st/build.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+mkdir -p bin
+cc -o bin/win-resize-st -Wall -Wextra -Wpedantic -O0 -g ./win-resize-st.c -ldwmapi -lgdi32
diff --git a/win-resize/win-resize.c b/win-resize-st/win-resize-st.c
index 275760e..5aace81 100644
--- a/win-resize/win-resize.c
+++ b/win-resize-st/win-resize-st.c
@@ -1,229 +1,228 @@
-// ================================================================================================

-// Example of how to draw while resizing / moving a window on Windows in C.

-//

-// Window contents are rendered via GDI, but the behavior is the same no matter what graphics API

-// you use. The original version of this demo (on old-20260427 branch) used D3D11.

-//

-// Pretty much all modern Direct3D Windows apps use a render thread and therefore don't have to

-// deal with this problem. That strategy doesn't work with APIs that have weird thread affinity

-// issues (OpenGL), so this is one way of doing it without multithreading.

-//

-// Build (MSVC):

-//     > cl /W4 /Od /Zi win-resize.c /Fe:win-resize.exe

-// Build (GCC/clang):

-//     $ cc -o win-resize.exe -Wall -Wextra -Wpedantic -O0 -g win-resize.c -ldwmapi -lgdi32

-//

-// Changelog:

-//     5/15/2026: Initial release

-//

-// License:

-//     SPDX-License-Identifier: 0BSD

-//     Copyright (c) 2026 Hunter Kvalevog

-//

-//     Permission to use, copy, modify, and/or distribute this software for any

-//     purpose with or without fee is hereby granted.

-//

-//     THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

-//     WITH REGARD TO THIS SOFTWARE.

-// ================================================================================================

-

-#define WIN32_LEAN_AND_MEAN

-#include <windows.h>

-#include <dwmapi.h>

-

-#include <assert.h>

-#include <math.h>

-#include <stdio.h>

-

-#ifdef _MSC_VER

-#   pragma comment(lib, "dwmapi.lib")

-#   pragma comment(lib, "gdi32.lib")

-#   pragma comment(lib, "user32.lib")

-#endif

-

-#define UNUSED(Var) ((void)(Var))

-

-static void GfxInit(HWND wnd);

-static void GfxResize(UINT vpw, UINT vph);

-static void GfxDraw(void);

-

-//

-static LRESULT CALLBACK WndProc(HWND wnd, UINT msg, WPARAM wparam, LPARAM lparam)

-{

-    switch (msg)

-    {

-        case WM_DESTROY:

-            PostQuitMessage(0);

-            return 0;

-        case WM_SIZE:

-            GfxResize(LOWORD(lparam), HIWORD(lparam));

-            GfxDraw();

-            break;

-        case WM_ENTERSIZEMOVE:

-            SetTimer(wnd, 1, USER_TIMER_MINIMUM, 0);

-            break;

-        case WM_EXITSIZEMOVE:

-            KillTimer(wnd, 1);

-            break;

-        case WM_TIMER:

-            GfxDraw();

-            break;

-    }

-    return DefWindowProcW(wnd, msg, wparam, lparam);

-}

-

-//

-int WinMain(HINSTANCE instance, HINSTANCE previnstance, LPSTR cmdline, int cmdshow)

-{

-    UNUSED(previnstance); UNUSED(cmdline);

-

-    // Register window class

-    WNDCLASSEXW wc = { };

-    wc.cbSize        = sizeof(wc);

-    wc.hCursor       = LoadCursor(0, IDC_ARROW);

-    wc.hInstance     = instance;

-    wc.lpfnWndProc   = WndProc;

-    wc.lpszClassName = L"win-resize";

-

-    ATOM atom = RegisterClassExW(&wc);

-    assert(atom && "Failed to register window class");

-

-    // Create window

-    HWND wnd = CreateWindowExW(WS_EX_APPWINDOW, wc.lpszClassName, wc.lpszClassName,

-                               WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 

-                               CW_USEDEFAULT, 0, 0, wc.hInstance, 0);

-    assert(wnd && "Failed to create window");

-

-    //

-    GfxInit(wnd);

-

-    //

-    ShowWindow(wnd, cmdshow);

-

-    // Run a typical D3D-style window loop

-    BOOL quit = FALSE;

-    while (!quit)

-    {

-        // Pump the message loop

-        MSG msg;

-        while (PeekMessageW(&msg, 0, 0, 0, PM_REMOVE))

-        {

-            quit |= (msg.message == WM_QUIT);

-            TranslateMessage(&msg);

-            DispatchMessageW(&msg);

-        }

-

-        // Update the screen

-        GfxDraw();

-    }

-

-    return 0;

-}

-

-// ================================================================================================

-

-static UINT    g_vpw       = 0;

-static UINT    g_vph       = 0;

-static HDC     g_hdc       = 0;

-static HDC     g_hdc_back  = 0;

-static HBITMAP g_bmp       = 0;

-static HBRUSH  g_bgbr      = 0;

-static HBRUSH  g_fgbr      = 0;

-static HPEN    g_pen       = 0;

-

-static void GfxInit(HWND wnd)

-{

-    g_hdc       = GetDC(wnd);

-    g_hdc_back  = CreateCompatibleDC(g_hdc);

-    g_bgbr      = CreateSolidBrush(RGB(0x00, 0x20, 0x20));

-    g_fgbr      = CreateSolidBrush(RGB(0xE0, 0xE0, 0xE0));

-    g_pen       = CreatePen(PS_SOLID, 2, RGB(0xFF, 0x10, 0x10));

-

-    RECT rc;

-    GetClientRect(wnd, &rc);

-

-    GfxResize(rc.right, rc.bottom);

-}

-

-static void GfxResize(UINT vpw, UINT vph)

-{

-    if (g_bmp)

-    {

-        DeleteObject(g_bmp);

-        g_bmp = 0;

-    }

-

-    if (vpw > 0 && vph > 0)

-    {

-        g_bmp = CreateCompatibleBitmap(g_hdc, vpw, vph);

-        SelectObject(g_hdc_back, g_bmp);

-    }

-

-    g_vpw = vpw;

-    g_vph = vph;

-}

-

-static void GfxDraw(void)

-{

-    static UINT frame = 0;

-    ++frame;

-

-    if (g_bmp && g_vpw > 0 && g_vph > 0)

-    {

-        HDC hdc = g_hdc_back;

-

-        // Clear

-        {

-            RECT rc = { 0, 0, g_vpw, g_vph };

-            FillRect(hdc, &rc, g_bgbr);

-        }

-

-        // Draw X

-        {

-            SelectObject(hdc, g_pen);

-            MoveToEx(hdc, 0, 0, 0);

-            LineTo(hdc, g_vpw, g_vph);

-            MoveToEx(hdc, 0, g_vph, 0);

-            LineTo(hdc, g_vpw, 0);

-        }

-

-        // Draw rotating triangle

-        {

-            int cx = g_vpw / 2;

-            int cy = g_vph / 2;

-            int r = (g_vpw < g_vph ? g_vpw : g_vph) / 3;

-

-            POINT verts[3];

-            for (int i = 0; i < 3; ++i)

-            {

-                float ang = ((float)frame / 100.0f) + (float)i * (2.0f * 3.14159265f / 3.0f);

-                verts[i].x = cx + (int)(cosf(ang) * r);

-                verts[i].y = cy + (int)(sinf(ang) * r);

-            }

-

-            SelectObject(hdc, g_pen);

-            SelectObject(hdc, g_fgbr);

-            Polygon(hdc, verts, ARRAYSIZE(verts));

-        }

-

-        // Draw text

-        {

-            WCHAR txtbuf[256];

-            _snwprintf_s(txtbuf, ARRAYSIZE(txtbuf), _TRUNCATE, L"win-resize (frame %u)", frame);

-

-            SIZE sz;

-            GetTextExtentPoint32W(hdc, txtbuf, (int)wcslen(txtbuf), &sz);

-

-            SetBkMode(hdc, TRANSPARENT);

-            SetTextColor(hdc, RGB(0xE0, 0xE0, 0xE0));

-            TextOutW(hdc, (g_vpw - sz.cx) / 2, 19, txtbuf, (int)wcslen(txtbuf));

-        }

-

-        // Present

-        BitBlt(g_hdc, 0, 0, g_vpw, g_vph, g_hdc_back, 0, 0, SRCCOPY);

-

-        // Wait for dwm to display a frame

-        DwmFlush();

-    }

-}

-

+// ================================================================================================
+// Example of how to draw while resizing / moving a window on Windows in C.
+//
+// Window contents are rendered via GDI, but the behavior is the same no matter what graphics API
+// you use. The original version of this demo (on old-20260427 branch) used D3D11.
+//
+// Pretty much all modern Direct3D Windows apps use a render thread and therefore don't have to
+// deal with this problem. That strategy doesn't work with APIs that have weird thread affinity
+// issues (OpenGL), so this is one way of doing it without multithreading.
+//
+// Build (MSVC):
+//     > cl /W4 /Od /Zi win-resize-st.c /Fe:win-resize-st.exe
+// Build (GCC/clang):
+//     $ cc -o win-resize-st.exe -Wall -Wextra -Wpedantic -O0 -g win-resize-st.c -ldwmapi -lgdi32
+//
+// Changelog:
+//     5/15/2026: Initial release
+//
+// License:
+//     Copyright (c) 2026 Hunter Kvalevog
+//
+//     Permission to use, copy, modify, and/or distribute this software for any
+//     purpose with or without fee is hereby granted.
+//
+//     THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+//     WITH REGARD TO THIS SOFTWARE.
+// ================================================================================================
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <dwmapi.h>
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+
+#ifdef _MSC_VER
+#   pragma comment(lib, "dwmapi.lib")
+#   pragma comment(lib, "gdi32.lib")
+#   pragma comment(lib, "user32.lib")
+#endif
+
+#define UNUSED(Var) ((void)(Var))
+
+static void GfxInit(HWND wnd);
+static void GfxResize(UINT vpw, UINT vph);
+static void GfxDraw(void);
+
+//
+static LRESULT CALLBACK WndProc(HWND wnd, UINT msg, WPARAM wparam, LPARAM lparam)
+{
+    switch (msg)
+    {
+        case WM_DESTROY:
+            PostQuitMessage(0);
+            return 0;
+        case WM_SIZE:
+            GfxResize(LOWORD(lparam), HIWORD(lparam));
+            GfxDraw();
+            break;
+        case WM_ENTERSIZEMOVE:
+            SetTimer(wnd, 1, USER_TIMER_MINIMUM, 0);
+            break;
+        case WM_EXITSIZEMOVE:
+            KillTimer(wnd, 1);
+            break;
+        case WM_TIMER:
+            GfxDraw();
+            break;
+    }
+    return DefWindowProcW(wnd, msg, wparam, lparam);
+}
+
+//
+int WinMain(HINSTANCE instance, HINSTANCE previnstance, LPSTR cmdline, int cmdshow)
+{
+    UNUSED(previnstance); UNUSED(cmdline);
+
+    // Register window class
+    WNDCLASSEXW wc = { 0 };
+    wc.cbSize        = sizeof(wc);
+    wc.hCursor       = LoadCursor(0, IDC_ARROW);
+    wc.hInstance     = instance;
+    wc.lpfnWndProc   = WndProc;
+    wc.lpszClassName = L"win-resize-st";
+
+    ATOM atom = RegisterClassExW(&wc);
+    assert(atom && "Failed to register window class");
+
+    // Create window
+    HWND wnd = CreateWindowExW(WS_EX_APPWINDOW, wc.lpszClassName, wc.lpszClassName,
+                               WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 
+                               CW_USEDEFAULT, 0, 0, wc.hInstance, 0);
+    assert(wnd && "Failed to create window");
+
+    //
+    GfxInit(wnd);
+
+    //
+    ShowWindow(wnd, cmdshow);
+
+    // Run a typical D3D-style window loop
+    BOOL quit = FALSE;
+    while (!quit)
+    {
+        // Pump the message loop
+        MSG msg;
+        while (PeekMessageW(&msg, 0, 0, 0, PM_REMOVE))
+        {
+            quit |= (msg.message == WM_QUIT);
+            TranslateMessage(&msg);
+            DispatchMessageW(&msg);
+        }
+
+        // Update the screen
+        GfxDraw();
+    }
+
+    return 0;
+}
+
+// ================================================================================================
+
+static UINT    g_vpw       = 0;
+static UINT    g_vph       = 0;
+static HDC     g_hdc       = 0;
+static HDC     g_hdc_back  = 0;
+static HBITMAP g_bmp       = 0;
+static HBRUSH  g_bgbr      = 0;
+static HBRUSH  g_fgbr      = 0;
+static HPEN    g_pen       = 0;
+
+static void GfxInit(HWND wnd)
+{
+    g_hdc       = GetDC(wnd);
+    g_hdc_back  = CreateCompatibleDC(g_hdc);
+    g_bgbr      = CreateSolidBrush(RGB(0x00, 0x20, 0x20));
+    g_fgbr      = CreateSolidBrush(RGB(0xE0, 0xE0, 0xE0));
+    g_pen       = CreatePen(PS_SOLID, 2, RGB(0xFF, 0x10, 0x10));
+
+    RECT rc;
+    GetClientRect(wnd, &rc);
+
+    GfxResize(rc.right, rc.bottom);
+}
+
+static void GfxResize(UINT vpw, UINT vph)
+{
+    if (g_bmp)
+    {
+        DeleteObject(g_bmp);
+        g_bmp = 0;
+    }
+
+    if (vpw > 0 && vph > 0)
+    {
+        g_bmp = CreateCompatibleBitmap(g_hdc, vpw, vph);
+        SelectObject(g_hdc_back, g_bmp);
+    }
+
+    g_vpw = vpw;
+    g_vph = vph;
+}
+
+static void GfxDraw(void)
+{
+    static UINT frame = 0;
+    ++frame;
+
+    if (g_bmp && g_vpw > 0 && g_vph > 0)
+    {
+        HDC hdc = g_hdc_back;
+
+        // Clear
+        {
+            RECT rc = { 0, 0, g_vpw, g_vph };
+            FillRect(hdc, &rc, g_bgbr);
+        }
+
+        // Draw X
+        {
+            SelectObject(hdc, g_pen);
+            MoveToEx(hdc, 0, 0, 0);
+            LineTo(hdc, g_vpw, g_vph);
+            MoveToEx(hdc, 0, g_vph, 0);
+            LineTo(hdc, g_vpw, 0);
+        }
+
+        // Draw rotating triangle
+        {
+            int cx = g_vpw / 2;
+            int cy = g_vph / 2;
+            int r = (g_vpw < g_vph ? g_vpw : g_vph) / 3;
+
+            POINT verts[3];
+            for (int i = 0; i < 3; ++i)
+            {
+                float ang = ((float)frame / 100.0f) + (float)i * (2.0f * 3.14159265f / 3.0f);
+                verts[i].x = cx + (int)(cosf(ang) * r);
+                verts[i].y = cy + (int)(sinf(ang) * r);
+            }
+
+            SelectObject(hdc, g_pen);
+            SelectObject(hdc, g_fgbr);
+            Polygon(hdc, verts, ARRAYSIZE(verts));
+        }
+
+        // Draw text
+        {
+            WCHAR txtbuf[256];
+            _snwprintf_s(txtbuf, ARRAYSIZE(txtbuf), _TRUNCATE, L"win-resize-st (frame %u)", frame);
+
+            SIZE sz;
+            GetTextExtentPoint32W(hdc, txtbuf, (int)wcslen(txtbuf), &sz);
+
+            SetBkMode(hdc, TRANSPARENT);
+            SetTextColor(hdc, RGB(0xE0, 0xE0, 0xE0));
+            TextOutW(hdc, (g_vpw - sz.cx) / 2, 19, txtbuf, (int)wcslen(txtbuf));
+        }
+
+        // Present
+        BitBlt(g_hdc, 0, 0, g_vpw, g_vph, g_hdc_back, 0, 0, SRCCOPY);
+
+        // Wait for dwm to display a frame
+        DwmFlush();
+    }
+}
+
diff --git a/win-resize/build.bat b/win-resize/build.bat
deleted file mode 100644
index 14ca49c..0000000
--- a/win-resize/build.bat
+++ /dev/null
@@ -1,3 +0,0 @@
-@echo off
-if not exist bin mkdir bin
-cl /W4 /Od /Zi /Fe:bin\win-resize.exe win-resize.c /Fd:bin\ /Fo:bin\
diff --git a/win-resize/build.sh b/win-resize/build.sh
deleted file mode 100755
index 4d3a4ab..0000000
--- a/win-resize/build.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/bash
-mkdir -p bin
-cc -o bin/win-resize -Wall -Wextra -Wpedantic -O0 -g ./win-resize.c -ldwmapi -lgdi32