From f756be3d22c1826b4504c17b0625075ba0fcc86c Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sun, 3 Apr 2022 19:32:01 +0900
Subject: [PATCH] internal/devicescale: bug fix: glfw.Monitor.GetContentScale
 might return 0

Retrying to call GetContentScale solved this.

Closes #2051
---
 internal/devicescale/impl_desktop.go | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/internal/devicescale/impl_desktop.go b/internal/devicescale/impl_desktop.go
index 8c7db22b0..6f26fe957 100644
--- a/internal/devicescale/impl_desktop.go
+++ b/internal/devicescale/impl_desktop.go
@@ -35,6 +35,13 @@ func monitorAt(x, y int) *glfw.Monitor {
 }
 
 func impl(x, y int) float64 {
-	sx, _ := monitorAt(x, y).GetContentScale()
-	return float64(sx)
+	// Keep calling GetContentScale until the returned scale is 0 (#2051).
+	// Retry this at most 5 times to avoid an inifinite loop.
+	for i := 0; i < 5; i++ {
+		sx, _ := monitorAt(x, y).GetContentScale()
+		if sx != 0 {
+			return float64(sx)
+		}
+	}
+	return 1
 }