From d736a8cff7ac040308db1b58495f9c2e99de881e Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 23 Sep 2023 17:27:57 +0900
Subject: [PATCH] internal/ui: bug fix: GetVideoMode must not be called from
 othere threads

Now setInitMonitor can be called from any other threads than the main
thread. Do not call this.

This change fixes the issue by using *Monitor instead of *glfw.Monitor.
---
 internal/ui/ui_glfw.go     | 28 ++++++++++++++--------------
 internal/ui/window_glfw.go |  2 +-
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/internal/ui/ui_glfw.go b/internal/ui/ui_glfw.go
index baf014545..e51c4e5e4 100644
--- a/internal/ui/ui_glfw.go
+++ b/internal/ui/ui_glfw.go
@@ -79,7 +79,7 @@ type userInterfaceImpl struct {
 
 	// These values are not changed after initialized.
 	// TODO: the fullscreen size should be updated when the initial window position is changed?
-	initMonitor               *glfw.Monitor
+	initMonitor               *Monitor
 	initDeviceScaleFactor     float64
 	initFullscreenWidthInDIP  int
 	initFullscreenHeightInDIP int
@@ -187,7 +187,7 @@ func initialize() error {
 		return errors.New("ui: no monitor was found at initialize")
 	}
 
-	theUI.setInitMonitor(m)
+	theUI.setInitMonitor(theMonitors.monitorFromGLFWMonitor(m))
 
 	// Create system cursors. These cursors are destroyed at glfw.Terminate().
 	glfwSystemCursors[CursorShapeDefault] = nil
@@ -204,17 +204,17 @@ func initialize() error {
 	return nil
 }
 
-func (u *userInterfaceImpl) setInitMonitor(m *glfw.Monitor) {
+func (u *userInterfaceImpl) setInitMonitor(m *Monitor) {
 	u.m.Lock()
 	defer u.m.Unlock()
 
 	u.initMonitor = m
-	u.initDeviceScaleFactor = u.deviceScaleFactor(m)
-	// GetVideoMode must be called from the main thread, then call this here and record
-	// initFullscreen{Width,Height}InDIP.
-	v := m.GetVideoMode()
-	u.initFullscreenWidthInDIP = int(u.dipFromGLFWMonitorPixel(float64(v.Width), m))
-	u.initFullscreenHeightInDIP = int(u.dipFromGLFWMonitorPixel(float64(v.Height), m))
+
+	// TODO: Remove these members. These can be calculated anytime from initMonitor.
+	u.initDeviceScaleFactor = u.deviceScaleFactor(m.m)
+	v := m.vm
+	u.initFullscreenWidthInDIP = int(u.dipFromGLFWMonitorPixel(float64(v.Width), m.m))
+	u.initFullscreenHeightInDIP = int(u.dipFromGLFWMonitorPixel(float64(v.Height), m.m))
 }
 
 // AppendMonitors appends the current monitors to the passed in mons slice and returns it.
@@ -990,9 +990,9 @@ func (u *userInterfaceImpl) initOnMainThread(options *RunOptions) error {
 	}
 
 	ww, wh := u.getInitWindowSizeInDIP()
-	initW := int(u.dipToGLFWPixel(float64(ww), u.initMonitor))
-	initH := int(u.dipToGLFWPixel(float64(wh), u.initMonitor))
-	if err := u.createWindow(initW, initH, u.initMonitor); err != nil {
+	initW := int(u.dipToGLFWPixel(float64(ww), u.initMonitor.m))
+	initH := int(u.dipToGLFWPixel(float64(wh), u.initMonitor.m))
+	if err := u.createWindow(initW, initH, u.initMonitor.m); err != nil {
 		return err
 	}
 
@@ -1013,7 +1013,7 @@ func (u *userInterfaceImpl) initOnMainThread(options *RunOptions) error {
 	if max := u.initFullscreenHeightInDIP - wh; wy >= max {
 		wy = max
 	}
-	u.setWindowPositionInDIP(wx, wy, u.initMonitor)
+	u.setWindowPositionInDIP(wx, wy, u.initMonitor.m)
 	u.setWindowSizeInDIP(ww, wh, true)
 
 	// Maximizing a window requires a proper size and position. Call Maximize here (#1117).
@@ -1508,7 +1508,7 @@ func (u *userInterfaceImpl) updateVsyncOnRenderThread() {
 // currentMonitor must be called on the main thread.
 func (u *userInterfaceImpl) currentMonitor() *glfw.Monitor {
 	if u.window == nil {
-		return u.initMonitor
+		return u.initMonitor.m
 	}
 	if m := monitorFromWindow(u.window); m != nil {
 		return m
diff --git a/internal/ui/window_glfw.go b/internal/ui/window_glfw.go
index c2799ca41..d6bb8d0d7 100644
--- a/internal/ui/window_glfw.go
+++ b/internal/ui/window_glfw.go
@@ -234,7 +234,7 @@ func (w *glfwWindow) SetMonitor(monitor *Monitor) {
 		return
 	}
 	if !w.ui.isRunning() {
-		w.ui.setInitMonitor(monitor.m)
+		w.ui.setInitMonitor(monitor)
 		return
 	}
 	w.ui.mainThread.Call(func() {