summaryrefslogtreecommitdiff
path: root/win-resize-mt/win-resize-mt.c
diff options
context:
space:
mode:
Diffstat (limited to 'win-resize-mt/win-resize-mt.c')
-rw-r--r--win-resize-mt/win-resize-mt.c276
1 files changed, 0 insertions, 276 deletions
diff --git a/win-resize-mt/win-resize-mt.c b/win-resize-mt/win-resize-mt.c
deleted file mode 100644
index 06fb5d0..0000000
--- a/win-resize-mt/win-resize-mt.c
+++ /dev/null
@@ -1,276 +0,0 @@
-// ================================================================================================
-// 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.
-//
-// This demo uses a multiple threads. There's a multi threaded version called win-resize-mt 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:
-// 6/2/2026: Fixed potential race condition during resize
-// 5/21/2026: 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);
-
-#define THREAD_BIT_QUIT (1 << 0)
-#define THREAD_BIT_SYNC (1 << 1)
-
-typedef struct ThreadData ThreadData;
-struct ThreadData
-{
- HWND wnd;
- HANDLE init_sig;
- HANDLE sync_sig;
- volatile LONG bits;
- volatile LONG size;
-};
-
-//
-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;
- }
-
- const LONG size = InterlockedOr(&td->size, 0);
- if (size > 0) {
- GfxResize(LOWORD(size), HIWORD(size));
- InterlockedExchange(&td->size, 0);
- }
-
- 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, lparam);
-
- // 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();
- }
-}
-
generated by cgit v1.2.3 (git 2.46.0) at 2026-10-12 11:33:04 +0000