From d9fe6977a6af691fb362002d9671d0c50e7ee631 Mon Sep 17 00:00:00 2001
From: jpark37 <jpark37@users.noreply.github.com>
Date: Fri, 21 Oct 2022 21:29:44 -0700
Subject: [PATCH] libobs-d3d11: Support advanced SDR window preview

Displays more than 8 bpc if monitor is configured to be higher.
---
 libobs-d3d11/d3d11-subsystem.cpp | 35 ++++++++++++++++++++++++--------
 libobs-d3d11/d3d11-subsystem.hpp | 12 ++++++++++-
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/libobs-d3d11/d3d11-subsystem.cpp b/libobs-d3d11/d3d11-subsystem.cpp
index ed4033a21..ecbebfc0f 100644
--- a/libobs-d3d11/d3d11-subsystem.cpp
+++ b/libobs-d3d11/d3d11-subsystem.cpp
@@ -66,7 +66,8 @@ gs_obj::~gs_obj()
 		next->prev_next = prev_next;
 }
 
-static bool screen_supports_hdr(gs_device_t *device, HMONITOR hMonitor)
+static gs_monitor_color_info get_monitor_color_info(gs_device_t *device,
+						    HMONITOR hMonitor)
 {
 	IDXGIFactory1 *factory1 = device->factory;
 	if (!factory1->IsCurrent()) {
@@ -75,7 +76,8 @@ static bool screen_supports_hdr(gs_device_t *device, HMONITOR hMonitor)
 		device->monitor_to_hdr.clear();
 	}
 
-	for (const std::pair<HMONITOR, bool> &pair : device->monitor_to_hdr) {
+	for (const std::pair<HMONITOR, gs_monitor_color_info> &pair :
+	     device->monitor_to_hdr) {
 		if (pair.first == hMonitor)
 			return pair.second;
 	}
@@ -96,15 +98,19 @@ static bool screen_supports_hdr(gs_device_t *device, HMONITOR hMonitor)
 					const bool hdr =
 						desc1.ColorSpace ==
 						DXGI_COLOR_SPACE_RGB_FULL_G2084_NONE_P2020;
-					device->monitor_to_hdr.emplace_back(
-						hMonitor, hdr);
-					return hdr;
+					return device->monitor_to_hdr
+						.emplace_back(
+							hMonitor,
+							gs_monitor_color_info(
+								hdr,
+								desc1.BitsPerColor))
+						.second;
 				}
 			}
 		}
 	}
 
-	return false;
+	return gs_monitor_color_info(false, 8);
 }
 
 static enum gs_color_space get_next_space(gs_device_t *device, HWND hwnd,
@@ -115,8 +121,12 @@ static enum gs_color_space get_next_space(gs_device_t *device, HWND hwnd,
 		const HMONITOR hMonitor =
 			MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
 		if (hMonitor) {
-			if (screen_supports_hdr(device, hMonitor))
+			const gs_monitor_color_info info =
+				get_monitor_color_info(device, hMonitor);
+			if (info.hdr)
 				next_space = GS_CS_709_SCRGB;
+			else if (info.bits_per_color > 8)
+				next_space = GS_CS_SRGB_16F;
 		}
 	}
 
@@ -126,7 +136,14 @@ static enum gs_color_space get_next_space(gs_device_t *device, HWND hwnd,
 static enum gs_color_format
 get_swap_format_from_space(gs_color_space space, gs_color_format sdr_format)
 {
-	return (space == GS_CS_709_SCRGB) ? GS_RGBA16F : sdr_format;
+	gs_color_format format = sdr_format;
+	switch (space) {
+	case GS_CS_SRGB_16F:
+	case GS_CS_709_SCRGB:
+		format = GS_RGBA16F;
+	}
+
+	return format;
 }
 
 static inline enum gs_color_space
@@ -3068,7 +3085,7 @@ extern "C" EXPORT bool device_p010_available(gs_device_t *device)
 extern "C" EXPORT bool device_is_monitor_hdr(gs_device_t *device, void *monitor)
 {
 	const HMONITOR hMonitor = static_cast<HMONITOR>(monitor);
-	return screen_supports_hdr(device, hMonitor);
+	return get_monitor_color_info(device, hMonitor).hdr;
 }
 
 extern "C" EXPORT void device_debug_marker_begin(gs_device_t *,
diff --git a/libobs-d3d11/d3d11-subsystem.hpp b/libobs-d3d11/d3d11-subsystem.hpp
index 0d4ff24a2..e1125da25 100644
--- a/libobs-d3d11/d3d11-subsystem.hpp
+++ b/libobs-d3d11/d3d11-subsystem.hpp
@@ -979,6 +979,16 @@ struct mat4float {
 	float mat[16];
 };
 
+struct gs_monitor_color_info {
+	bool hdr;
+	UINT bits_per_color;
+
+	gs_monitor_color_info(bool hdr, int bits_per_color)
+		: hdr(hdr), bits_per_color(bits_per_color)
+	{
+	}
+};
+
 struct gs_device {
 	ComPtr<IDXGIFactory1> factory;
 	ComPtr<IDXGIAdapter1> adapter;
@@ -1035,7 +1045,7 @@ struct gs_device {
 	vector<gs_device_loss> loss_callbacks;
 	gs_obj *first_obj = nullptr;
 
-	vector<std::pair<HMONITOR, bool>> monitor_to_hdr;
+	vector<std::pair<HMONITOR, gs_monitor_color_info>> monitor_to_hdr;
 
 	void InitCompiler();
 	void InitFactory();