From a1f40e8463a4a4fadbef0b2b55b36f87d3dee177 Mon Sep 17 00:00:00 2001
From: justnullname <51329027+justnullname@users.noreply.github.com>
Date: Fri, 27 Mar 2026 11:38:14 +0000
Subject: [PATCH] Fix: Preserve zoom and pan states when switching color spaces
 or RAW mode

When right-clicking to switch color spaces, toggle soft proofing, or
enable/disable RAW rendering, the image is re-decoded and re-uploaded
to the GPU, causing the `AdjustWindowToImage` system to reset the user's
current zoom scale and pan offsets to default (Fit Window).

This patch introduces a dedicated global flag (`g_preserveViewStateOnNextLoad`)
and a storage struct (`g_preservedViewState`) to seamlessly persist the
`g_viewState` across these specific user-initiated asynchronous image reloads.

Once the new image resource completes decoding and reaches `ProcessEngineEvents`,
the original zoom and pan are cleanly restored to the hardware
composition engine matrix immediately before the `SyncDCompState` update.
---
 QuickView/main.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/QuickView/main.cpp b/QuickView/main.cpp
index ad60691..9d3e920 100644
--- a/QuickView/main.cpp
+++ b/QuickView/main.cpp
@@ -236,6 +236,8 @@ static EditState g_editState;
 AppConfig g_config;
 RuntimeConfig g_runtime;
 ViewState g_viewState;  // Non-static for extern access from UIRenderer
+bool g_preserveViewStateOnNextLoad = false;
+ViewState g_preservedViewState;
 static int g_renderExifOrientation = 1; // Exif orientation baked into the bitmap surface
 FileNavigator g_navigator; // New Navigator (Non-static for extern access from SettingsOverlay)
 static ThumbnailManager g_thumbMgr;
@@ -8586,6 +8588,8 @@ SKIP_EDGE_NAV:;
                          g_imageEngine->UpdateConfig(g_runtime); // [Fix] Push config to engine
                          g_imageEngine->SetForceRefresh(true);
                      }
+                     g_preservedViewState = g_viewState;
+                     g_preserveViewStateOnNextLoad = true;
                      ReleaseImageResources();
                      LoadImageAsync(hwnd, contextPath.c_str()); 
                  }
@@ -8613,6 +8617,8 @@ SKIP_EDGE_NAV:;
                      g_imageEngine->UpdateConfig(g_runtime);
                      g_imageEngine->SetForceRefresh(true);
                  }
+                 g_preservedViewState = g_viewState;
+                 g_preserveViewStateOnNextLoad = true;
                  ReleaseImageResources();
                  LoadImageAsync(hwnd, g_imagePath, false, QuickView::BrowseDirection::IDLE);
              }
@@ -9211,6 +9217,15 @@ void ProcessEngineEvents(HWND hwnd) {
                         ApplyFullScreenZoomMode(hwnd);
                     }
 
+                    // [Fix] Restore View State if it was saved prior to reloading (e.g. Color Space switch)
+                    // Do this before SyncDCompState so it receives the correct zoom and pan
+                    if (g_preserveViewStateOnNextLoad) {
+                        g_viewState.Zoom = g_preservedViewState.Zoom;
+                        g_viewState.PanX = g_preservedViewState.PanX;
+                        g_viewState.PanY = g_preservedViewState.PanY;
+                        g_preserveViewStateOnNextLoad = false; // Consume it
+                    }
+
                     // [Fix] Explicitly Sync DComp State immediately after Window Adjustment
                     // This covers the case where the Window Size DOES NOT CHANGE (e.g. Locked or Maximized),
                     // so WM_SIZE is never fired, leaving the DComp Transform Matrix stale (using old image AR).