From be0cf257fe5ba68afb1ef328ab47527a060adad7 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Fri, 12 Aug 2022 18:13:42 -0700
Subject: [PATCH] Only force the resize event in the DPI changed case
OpenGL windows don't actually get the WM_WINDOWPOSCHANGED event in the SetWindowPos() call in WIN_SetWindowFullscreen(), so setting the window size to zero never gets reset and we're stuck with a zero sized window.
Instead, just force the resize event in WM_DPICHANGED handling, where we know we need it. If we end up needing to force it in WIN_SetWindowFullscreen(), just set a flag in the window data and respond to that in WM_WINDOWPOSCHANGED, but that's a fairly risky behavior change as suddenly all applications would start getting SDL_WINDOWEVENT_SIZE_CHANGED when going fullscreen, and they may respond to that in expensive and potentially disruptive ways.
For later we'll probably create a DPI changed event and respond to that in the renderer instead of this window size changed hack.
This fixes https://github.com/libsdl-org/SDL/issues/6033 @ericwa
---
src/video/windows/SDL_windowsevents.c | 9 ++++++++-
src/video/windows/SDL_windowswindow.c | 5 -----
2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/src/video/windows/SDL_windowsevents.c b/src/video/windows/SDL_windowsevents.c
index aa29da1579f..e2b95ad4ec6 100644
--- a/src/video/windows/SDL_windowsevents.c
+++ b/src/video/windows/SDL_windowsevents.c
@@ -1548,7 +1548,14 @@ WIN_WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
data->scaling_dpi = newDPI;
/* Send a SDL_WINDOWEVENT_SIZE_CHANGED saying that the client size (in dpi-scaled points) is unchanged.
- Renderers need to get this to know that the framebuffer size changed. */
+ Renderers need to get this to know that the framebuffer size changed.
+
+ We clear the window size to force the event to be delivered, but what we really
+ want for SDL3 is a new event to notify that the DPI changed and then watch for
+ that in the renderer directly.
+ */
+ data->window->w = 0;
+ data->window->h = 0;
SDL_SendWindowEvent(data->window, SDL_WINDOWEVENT_SIZE_CHANGED, data->window->w, data->window->h);
}
diff --git a/src/video/windows/SDL_windowswindow.c b/src/video/windows/SDL_windowswindow.c
index 58f7b980927..eb536bbe469 100644
--- a/src/video/windows/SDL_windowswindow.c
+++ b/src/video/windows/SDL_windowswindow.c
@@ -932,11 +932,6 @@ WIN_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display,
SDL_Log("WIN_SetWindowFullscreen: %d", (int)fullscreen);
#endif
- /* Clear the window size, to force SDL_SendWindowEvent to send a SDL_WINDOWEVENT_RESIZED
- event in WM_WINDOWPOSCHANGED. */
- data->window->w = 0;
- data->window->h = 0;
-
if (SDL_ShouldAllowTopmost() && (window->flags & SDL_WINDOW_ALWAYS_ON_TOP)) {
top = HWND_TOPMOST;
} else {