From acf76d6cffca9b57dd1c96c934a4f7e87685420f Mon Sep 17 00:00:00 2001
From: Joshua Ashton <joshua@froggi.es>
Date: Tue, 20 Dec 2022 16:22:08 +0000
Subject: [PATCH] steamcompmgr: Add GAMESCOPE_HDR_OUTPUT_FEEDBACK

Exposes whether HDR output is currently enabled.
---
 src/steamcompmgr.cpp | 12 ++++++++++++
 src/xwayland_ctx.hpp |  1 +
 2 files changed, 13 insertions(+)

diff --git a/src/steamcompmgr.cpp b/src/steamcompmgr.cpp
index be2d513..9d7f04d 100644
--- a/src/steamcompmgr.cpp
+++ b/src/steamcompmgr.cpp
@@ -5395,6 +5395,7 @@ void init_xwayland_ctx(gamescope_xwayland_server_t *xwayland_server)
 	ctx->atoms.gamescopeDisplayHDREnabled = XInternAtom( ctx->dpy, "GAMESCOPE_DISPLAY_HDR_ENABLED", false );
 	ctx->atoms.gamescopeDisplayHDRForceWideGammutForSDR = XInternAtom( ctx->dpy, "GAMESCOPE_DISPLAY_HDR_FORCE_WIDE_GAMMUT_FOR_SDR", false );
 	ctx->atoms.gamescopeDebugForceHDR10OutputSupport = XInternAtom( ctx->dpy, "GAMESCOPE_DEBUG_FORCE_HDR10_OUTPUT_SUPPORT", false );
+	ctx->atoms.gamescopeHDROutputFeedback = XInternAtom( ctx->dpy, "GAMESCOPE_HDR_OUTPUT_FEEDBACK", false );
 
 	ctx->atoms.wineHwndStyle = XInternAtom( ctx->dpy, "_WINE_HWND_STYLE", false );
 	ctx->atoms.wineHwndStyleEx = XInternAtom( ctx->dpy, "_WINE_HWND_EXSTYLE", false );
@@ -5825,6 +5826,17 @@ steamcompmgr_main(int argc, char **argv)
 				vulkan_remake_output_images();
 			}
 
+
+			{
+				gamescope_xwayland_server_t *server = NULL;
+				for (size_t i = 0; (server = wlserver_get_xwayland_server(i)); i++)
+				{
+					uint32_t hdr_value = g_bOutputHDREnabled ? 1 : 0;
+					XChangeProperty(root_ctx->dpy, root_ctx->root, root_ctx->atoms.gamescopeHDROutputFeedback, XA_CARDINAL, 32, PropModeReplace,
+						(unsigned char *)&hdr_value, 1 );
+				}
+			}
+
 			currentOutputWidth = g_nOutputWidth;
 			currentOutputHeight = g_nOutputHeight;
 			currentHDROutput = g_bOutputHDREnabled;
diff --git a/src/xwayland_ctx.hpp b/src/xwayland_ctx.hpp
index 5048f9a..89a29aa 100644
--- a/src/xwayland_ctx.hpp
+++ b/src/xwayland_ctx.hpp
@@ -172,6 +172,7 @@ struct xwayland_ctx_t
 		Atom gamescopeDisplayHDREnabled;
 		Atom gamescopeDisplayHDRForceWideGammutForSDR;
 		Atom gamescopeDebugForceHDR10OutputSupport;
+		Atom gamescopeHDROutputFeedback;
 
 		Atom wineHwndStyle;
 		Atom wineHwndStyleEx;