From 2d7ec208c42b6a354da33e8f4256d43cebbcdc1d Mon Sep 17 00:00:00 2001
From: Joshua Ashton <joshua@froggi.es>
Date: Thu, 12 Jan 2023 01:29:25 +0000
Subject: [PATCH] sdlwindow: Forward cursor in absolute mode to host compositor

---
 src/sdlwindow.cpp    | 59 ++++++++++++++++++++++++++++++++++++++++++++
 src/sdlwindow.hpp    |  1 +
 src/steamcompmgr.cpp | 20 +++++++++------
 src/steamcompmgr.hpp |  2 ++
 4 files changed, 75 insertions(+), 7 deletions(-)

diff --git a/src/sdlwindow.cpp b/src/sdlwindow.cpp
index a4e5083..b7df72d 100644
--- a/src/sdlwindow.cpp
+++ b/src/sdlwindow.cpp
@@ -34,6 +34,7 @@ enum UserEvents
 	USER_EVENT_TITLE,
 	USER_EVENT_VISIBLE,
 	USER_EVENT_GRAB,
+	USER_EVENT_CURSOR,
 
 	USER_EVENT_COUNT
 };
@@ -44,6 +45,15 @@ static std::mutex g_SDLWindowTitleLock;
 static std::string g_SDLWindowTitle;
 static bool g_bUpdateSDLWindowTitle = false;
 
+struct SDLPendingCursor
+{
+	uint32_t width, height, xhot, yhot;
+	std::vector<uint32_t> data;
+};
+static std::mutex g_SDLCursorLock;
+static SDLPendingCursor g_SDLPendingCursorData;
+static bool g_bUpdateSDLCursor = false;
+
 //-----------------------------------------------------------------------------
 // Purpose: Convert from the remote scancode to a Linux event keycode
 //-----------------------------------------------------------------------------
@@ -316,6 +326,24 @@ void inputSDLThreadRun( void )
 						bRelativeMouse = grab;
 					}
 				}
+				if ( event.type == g_unSDLUserEventID + USER_EVENT_CURSOR )
+				{
+					std::unique_lock lock(g_SDLCursorLock);
+					if ( g_bUpdateSDLCursor )
+					{
+						SDL_Surface *surface = SDL_CreateRGBSurfaceFrom(
+							g_SDLPendingCursorData.data.data(),
+							g_SDLPendingCursorData.width,
+							g_SDLPendingCursorData.height,
+							32,
+							g_SDLPendingCursorData.width * sizeof(uint32_t),
+							0x00FF0000, 0x0000FF00, 0x000000FF, 0xFF000000);
+
+						SDL_Cursor *cursor = SDL_CreateColorCursor( surface, g_SDLPendingCursorData.xhot, g_SDLPendingCursorData.yhot );
+						SDL_SetCursor( cursor );
+						g_bUpdateSDLCursor = false;
+					}
+				}
 				break;
 		}
 	}
@@ -372,8 +400,39 @@ void sdlwindow_grab( bool bGrab )
 	if ( g_bForceRelativeMouse )
 		return;
 
+	static bool s_bWasGrabbed = false;
+
+	if ( s_bWasGrabbed == bGrab )
+		return;
+
+	s_bWasGrabbed = bGrab;
+
 	SDL_Event event;
 	event.type = g_unSDLUserEventID + USER_EVENT_GRAB;
 	event.user.code = bGrab ? 1 : 0;
 	SDL_PushEvent( &event );
 }
+
+void sdlwindow_cursor(void* pixels, uint32_t width, uint32_t height, uint32_t xhot, uint32_t yhot)
+{
+	if ( !BIsNested() )
+		return;
+
+	if ( g_bForceRelativeMouse )
+		return;
+
+	{
+		std::unique_lock lock( g_SDLCursorLock );
+		g_SDLPendingCursorData.width = width;
+		g_SDLPendingCursorData.height = height;
+		g_SDLPendingCursorData.xhot = xhot;
+		g_SDLPendingCursorData.yhot = yhot;
+		g_SDLPendingCursorData.data.resize( width * height );
+		memcpy(g_SDLPendingCursorData.data.data(), pixels, width * height * sizeof(uint32_t));
+		g_bUpdateSDLCursor = true;
+	}
+
+	SDL_Event event;
+	event.type = g_unSDLUserEventID + USER_EVENT_CURSOR;
+	SDL_PushEvent( &event );
+}
diff --git a/src/sdlwindow.hpp b/src/sdlwindow.hpp
index 5bfce11..5ddf878 100644
--- a/src/sdlwindow.hpp
+++ b/src/sdlwindow.hpp
@@ -13,5 +13,6 @@ void sdlwindow_title( const char* title );
 // called from other threads with interesting things have happened with clients that might warrant updating the nested window
 void sdlwindow_visible( bool bVisible );
 void sdlwindow_grab( bool bGrab );
+void sdlwindow_cursor(void* pixels, uint32_t width, uint32_t height, uint32_t xhot, uint32_t yhot);
 
 extern SDL_Window *g_SDLWindow;
diff --git a/src/steamcompmgr.cpp b/src/steamcompmgr.cpp
index 2b7f15f..7d8bf0d 100644
--- a/src/steamcompmgr.cpp
+++ b/src/steamcompmgr.cpp
@@ -1364,14 +1364,12 @@ bool MouseCursor::getTexture()
 		}
 	}
 
-	if (bNoCursor != m_imageEmpty) {
-		m_imageEmpty = bNoCursor;
+	m_imageEmpty = bNoCursor;
 
-		if ( !g_bForceRelativeMouse )
-		{
-			sdlwindow_grab( m_imageEmpty );
-			bSteamCompMgrGrab = BIsNested() && m_imageEmpty;
-		}
+	if ( !g_bForceRelativeMouse )
+	{
+		sdlwindow_grab( m_imageEmpty );
+		bSteamCompMgrGrab = BIsNested() && m_imageEmpty;
 	}
 
 	m_dirty = false;
@@ -1391,6 +1389,7 @@ bool MouseCursor::getTexture()
 	}
 
 	m_texture = vulkan_create_texture_from_bits(surfaceWidth, surfaceHeight, image->width, image->height, DRM_FORMAT_ARGB8888, texCreateFlags, cursorBuffer.data());
+	sdlwindow_cursor(cursorBuffer.data(), image->width, image->height, image->xhot, image->yhot);
 	assert(m_texture);
 	XFree(image);
 
@@ -1910,6 +1909,13 @@ paint_all(bool async)
 		}
 	}
 
+	if (input)
+	{
+		// Make sure to un-dirty the texture before we do any painting logic.
+		// We determine whether we are grabbed etc this way.
+		global_focus.cursor->undirty();
+	}
+
 	bool bForceHideCursor = BIsNested() && !bSteamCompMgrGrab;
 
 	bool bDrewCursor = false;
diff --git a/src/steamcompmgr.hpp b/src/steamcompmgr.hpp
index e824c60..4d15164 100644
--- a/src/steamcompmgr.hpp
+++ b/src/steamcompmgr.hpp
@@ -71,6 +71,8 @@ public:
 		m_y = y;
 	}
 
+	void undirty() { getTexture(); }
+
 private:
 	void warp(int x, int y);
 	void checkSuspension();