From ad235fad25ddb1e355c4843f732b9df0799db345 Mon Sep 17 00:00:00 2001
From: WerWolv <werwolv98@gmail.com>
Date: Sat, 29 Jun 2024 23:17:59 +0200
Subject: [PATCH] impr: Further try to improve window resize flickering on
 Windows

---
 main/gui/CMakeLists.txt                       |  2 +-
 main/gui/source/window/win_window.cpp         | 60 ++++++++++++++++++-
 main/gui/source/window/window.cpp             | 10 ++++
 .../source/content/window_decoration.cpp      |  2 +-
 4 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/main/gui/CMakeLists.txt b/main/gui/CMakeLists.txt
index bae7eaab7..c5a6e0362 100644
--- a/main/gui/CMakeLists.txt
+++ b/main/gui/CMakeLists.txt
@@ -60,7 +60,7 @@ target_compile_definitions(main PRIVATE IMHEX_PROJECT_NAME="${PROJECT_NAME}")
 
 target_link_libraries(main PRIVATE libromfs-imhex libimhex libwolv ${LIBBACKTRACE_LIBRARIES} LLVMDemangle)
 if (WIN32)
-    target_link_libraries(main PRIVATE usp10 wsock32 ws2_32 Dwmapi.lib)
+    target_link_libraries(main PRIVATE usp10 wsock32 ws2_32 Dwmapi.lib Winmm.lib)
 else ()
     target_link_libraries(main PRIVATE pthread)
 endif ()
diff --git a/main/gui/source/window/win_window.cpp b/main/gui/source/window/win_window.cpp
index c9e1cf379..81ca5e98f 100644
--- a/main/gui/source/window/win_window.cpp
+++ b/main/gui/source/window/win_window.cpp
@@ -5,7 +5,7 @@
 
     #include "messaging.hpp"
 
-#include <hex/helpers/utils.hpp>
+    #include <hex/helpers/utils.hpp>
     #include <hex/helpers/logger.hpp>
     #include <hex/helpers/default_paths.hpp>
 
@@ -24,6 +24,7 @@
     #include <wrl/client.h>
     #include <fcntl.h>
     #include <shellapi.h>
+    #include <timeapi.h>
 
     #include <cstdio>
 
@@ -160,7 +161,50 @@ namespace hex {
                     rect = client;
                 }
 
-                return 0;
+                // This code tries to avoid DWM flickering when resizing the window
+                // It's not perfect, but it's really the best we can do.
+
+                LARGE_INTEGER performanceFrequency = {};
+                QueryPerformanceFrequency(&performanceFrequency);
+                TIMECAPS tc = {};
+                timeGetDevCaps(&tc, sizeof(tc));
+
+                const auto granularity = tc.wPeriodMin;
+                timeBeginPeriod(tc.wPeriodMin);
+
+                DWM_TIMING_INFO dti = {};
+                dti.cbSize = sizeof(dti);
+                ::DwmGetCompositionTimingInfo(nullptr, &dti);
+
+                LARGE_INTEGER end = {};
+                QueryPerformanceCounter(&end);
+
+                const auto period = dti.qpcRefreshPeriod;
+                const i64 delta = dti.qpcVBlank - end.QuadPart;
+
+                i64 sleepTicks = 0;
+                i64 sleepMilliSeconds = 0;
+                if (delta >= 0) {
+                    sleepTicks = delta / period;
+                } else {
+
+                    sleepTicks = -1 + delta / period;
+                }
+
+                sleepMilliSeconds = delta - (period * sleepTicks);
+                const double sleepTime = (1000.0 * double(sleepMilliSeconds) / double(performanceFrequency.QuadPart));
+                Sleep(DWORD(std::round(sleepTime)));
+                timeEndPeriod(granularity);
+
+                return WVR_REDRAW;
+            }
+            case WM_ERASEBKGND:
+                return 1;
+            case WM_WINDOWPOSCHANGING: {
+                // Make sure that windows discards the entire client area when resizing to avoid flickering
+                const auto windowPos = reinterpret_cast<LPWINDOWPOS>(lParam);
+                windowPos->flags |= SWP_NOCOPYBITS;
+                break;
             }
             case WM_NCHITTEST: {
                 // Handle window resizing and moving
@@ -562,8 +606,20 @@ namespace hex {
             ImHexApi::System::impl::setMainWindowSize(width, height);
         });
 
+        DwmEnableMMCSS(TRUE);
+        
+        {
+            constexpr BOOL value = TRUE;
+            DwmSetWindowAttribute(hwnd, DWMWA_NCRENDERING_ENABLED, &value, sizeof(value));
+        }
+        {
+            constexpr DWMNCRENDERINGPOLICY value = DWMNCRP_ENABLED;
+            DwmSetWindowAttribute(hwnd, DWMWA_NCRENDERING_POLICY, &value, sizeof(value));
+        }
+
         glfwSetWindowRefreshCallback(m_window, [](GLFWwindow *window) {
             auto win = static_cast<Window *>(glfwGetWindowUserPointer(window));
+
             win->fullFrame();
             DwmFlush();
         });
diff --git a/main/gui/source/window/window.cpp b/main/gui/source/window/window.cpp
index c93026f2a..252d21d2e 100644
--- a/main/gui/source/window/window.cpp
+++ b/main/gui/source/window/window.cpp
@@ -194,6 +194,16 @@ namespace hex {
         while (!glfwWindowShouldClose(m_window)) {
             m_lastStartFrameTime = glfwGetTime();
 
+            {
+                int x = 0, y = 0;
+                int width = 0, height = 0;
+                glfwGetWindowPos(m_window, &x, &y);
+                glfwGetWindowSize(m_window, &width, &height);
+
+                ImHexApi::System::impl::setMainWindowPosition(x, y);
+                ImHexApi::System::impl::setMainWindowSize(width, height);
+            }
+
             // Determine if the application should be in long sleep mode
             bool shouldLongSleep = !m_unlockFrameRate;
 
diff --git a/plugins/builtin/source/content/window_decoration.cpp b/plugins/builtin/source/content/window_decoration.cpp
index cf390d900..a6ab17a1c 100644
--- a/plugins/builtin/source/content/window_decoration.cpp
+++ b/plugins/builtin/source/content/window_decoration.cpp
@@ -146,7 +146,7 @@ namespace hex::plugin::builtin {
             ImGui::PushStyleColor(ImGuiCol_ButtonActive, ImGui::GetColorU32(ImGuiCol_ScrollbarGrabActive));
             ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImGui::GetColorU32(ImGuiCol_ScrollbarGrabHovered));
 
-            const auto windowSize = ImHexApi::System::getMainWindowSize();
+            const auto windowSize = ImGui::GetWindowSize();
             auto searchBoxSize = ImVec2(s_showSearchBar ? windowSize.x / 2.5 : ImGui::CalcTextSize(s_windowTitle.c_str()).x, titleBarHeight);
             auto searchBoxPos = ImVec2((windowSize / 2 - searchBoxSize / 2).x, 0);
             auto titleBarButtonPosY = 0.0F;