From c93fca94f7fb2cbbc01e4b75ef048aa4fae55080 Mon Sep 17 00:00:00 2001
From: Taylor Richards <taylor@icculus.org>
Date: Fri, 17 Jun 2016 01:22:56 -0400
Subject: [PATCH] fix some mouse handling issues

 - relative mouse mode for fullscreen to fix offscreen cursor
 - grab cursor properly when using mouse to fly
 - ungrab cursor when necessary
 - make sure Int3() will release & reset cursor during debugging
---
 include/mouse.h     |  1 +
 src/io/mouse.cpp    | 52 ++++++++++++++++++++++++++++++++++-----------
 src/osapi/osapi.cpp | 15 +++++++++++++
 3 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/include/mouse.h b/include/mouse.h
index 147ee73..9f5ae54 100644
--- a/include/mouse.h
+++ b/include/mouse.h
@@ -125,6 +125,7 @@ int mouse_down(int btn);			// returns 1 if mouse button btn is down, 0 otherwise
 float mouse_down_time(int btn);	// returns the fraction of time btn has been down since last call
 int mouse_is_visible();				// returns 1 if mouse is visible, 0 otherwise
 
+void mouse_grab(int grab);
 void mouse_eval_deltas();
 void mouse_get_delta(int *dx = NULL, int *dy = NULL, int *dz = NULL);
 
diff --git a/src/io/mouse.cpp b/src/io/mouse.cpp
index 6747b60..8a9aa4c 100644
--- a/src/io/mouse.cpp
+++ b/src/io/mouse.cpp
@@ -424,10 +424,38 @@ void mouse_force_pos(int x, int y)
 {
 	if (os_foreground()) {  // only mess with windows's mouse if we are in control of it
 		SDL_WarpMouseInWindow(os_get_window(), x, y);
+		Mouse_x = x;
+		Mouse_y = y;
 	}
 }
 
 static bool Mouse_grabbed = false;
+
+void mouse_grab(int grab)
+{
+	if (grab) {
+		// never grab when fullscreen
+		if (gr_screen.fullscreen) {
+			return;
+		}
+
+		if ( !Mouse_grabbed ) {
+			SDL_SetWindowGrab(os_get_window(), SDL_TRUE);
+			SDL_SetRelativeMouseMode(SDL_TRUE);
+
+			Mouse_grabbed = true;
+		}
+	} else if (Mouse_grabbed) {
+		SDL_SetWindowGrab(os_get_window(), SDL_FALSE);
+
+		if ( !gr_screen.fullscreen ) {
+			SDL_SetRelativeMouseMode(SDL_FALSE);
+		}
+
+		Mouse_grabbed = false;
+	}
+}
+
 void mouse_eval_deltas()
 {
 	Mouse_dx = Mouse_dx_inc;
@@ -437,17 +465,9 @@ void mouse_eval_deltas()
 
 	// make sure mouse is bound to window if we're flying with it
 	if (Keep_mouse_centered && Mouse_hidden) {
-		if ( !Mouse_grabbed ) {
-			SDL_SetRelativeMouseMode(SDL_TRUE);
-			SDL_SetWindowGrab(os_get_window(), SDL_TRUE);
-			Mouse_grabbed = true;
-		}
+		mouse_grab(1);
 	} else {
-		if (Mouse_grabbed) {
-			SDL_SetRelativeMouseMode(SDL_FALSE);
-			SDL_SetWindowGrab(os_get_window(), SDL_FALSE);
-			Mouse_grabbed = false;
-		}
+		mouse_grab(0);
 	}
 }
 
@@ -496,8 +516,16 @@ void mouse_set_pos(int xpos, int ypos)
 
 void mouse_update_pos(int x, int y, int dx, int dy)
 {
-	Mouse_x = x;
-	Mouse_y = y;
+	if (gr_screen.fullscreen) {
+		Mouse_x += dx;
+		Mouse_y += dy;
+
+		CAP(Mouse_x, 0, gr_screen.max_w-1);
+		CAP(Mouse_y, 0, gr_screen.max_h-1);
+	} else {
+		Mouse_x = x;
+		Mouse_y = y;
+	}
 
 	Mouse_dx_inc += dx;
 	Mouse_dy_inc += dy;
diff --git a/src/osapi/osapi.cpp b/src/osapi/osapi.cpp
index cd244d5..f887f87 100644
--- a/src/osapi/osapi.cpp
+++ b/src/osapi/osapi.cpp
@@ -433,9 +433,12 @@ void os_poll()
 				switch (e.window.event) {
 					case SDL_WINDOWEVENT_RESIZED:
 						gr_set_viewport(e.window.data1, e.window.data2);
+						// ungrab mouse, it will be grabbed again if needed
+						mouse_grab(0);
 						break;
 
 					case SDL_WINDOWEVENT_FOCUS_LOST:
+						mouse_grab(0);
 						joy_unacquire_ff();
 						break;
 
@@ -443,6 +446,10 @@ void os_poll()
 						joy_reacquire_ff();
 						break;
 
+					case SDL_WINDOWEVENT_MINIMIZED:
+						mouse_grab(0);
+						break;
+
 					case SDL_WINDOWEVENT_CLOSE:
 					//	gameseq_post_event(GS_EVENT_QUIT_GAME);
 						break;
@@ -463,5 +470,13 @@ void os_poll()
 
 void debug_int3()
 {
+	SDL_bool mode = SDL_GetRelativeMouseMode();
+	SDL_SetRelativeMouseMode(SDL_FALSE);
+	SDL_bool grab = SDL_GetWindowGrab(Os_window);
+	SDL_SetWindowGrab(Os_window, SDL_FALSE);
+
 	SDL_TriggerBreakpoint();
+
+	SDL_SetRelativeMouseMode(mode);
+	SDL_SetWindowGrab(Os_window, grab);
 }
-- 
2.39.2