From c58d5b690a83872b3a32c3c1ee6a92b7dcbcb7b3 Mon Sep 17 00:00:00 2001
From: kichikuou <KichikuouChrome@gmail.com>
Date: Sat, 14 Aug 2021 13:18:42 +0900
Subject: [PATCH] Fix mouse cursor movement in fullscreen mode

Ported from kichikuou/xsystem35-sdl2@91d30c9.
---
 src/sys/ags.h          |  1 +
 src/sys/ags_cursor.cpp | 28 ++++++++++++++++++++++++++++
 src/sys/nact_input.cpp |  2 +-
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/sys/ags.h b/src/sys/ags.h
index 43785b0..3f4a41b 100644
--- a/src/sys/ags.h
+++ b/src/sys/ags.h
@@ -137,6 +137,7 @@ public:
 
 	void load_cursor(int page);
 	void select_cursor();
+	void translate_mouse_coords(int* x, int* y);
 
 	void save_screenshot(const char* path);
 
diff --git a/src/sys/ags_cursor.cpp b/src/sys/ags_cursor.cpp
index dced7b3..9f3625a 100644
--- a/src/sys/ags_cursor.cpp
+++ b/src/sys/ags_cursor.cpp
@@ -7,6 +7,8 @@
 #include "ags.h"
 #include <string.h>
 
+extern SDL_Window* g_window;
+
 void AGS::load_cursor(int page)
 {
 	// カーソルCGをロードする
@@ -91,3 +93,29 @@ void AGS::select_cursor()
 	}
 }
 
+void AGS::translate_mouse_coords(int* x, int* y)
+{
+	// scale mouse x and y
+	float scalex, scaley;
+	SDL_RenderGetScale(sdlRenderer, &scalex, &scaley);
+	*x *= scalex;
+	*y *= scaley;
+
+	// calculate window borders
+	int logw, logh;
+	SDL_RenderGetLogicalSize(sdlRenderer, &logw, &logh);
+
+	float scalew, scaleh;
+	scalew = logw * scalex;
+	scaleh = logh * scaley;
+
+	int winw, winh;
+	SDL_GetWindowSize(g_window, &winw, &winh);
+
+	float border_left = (winw - scalew) / 2;
+	float border_top  = (winh - scaleh) / 2;
+
+	// offset x and y by window borders
+	*x += border_left;
+	*y += border_top;
+}
diff --git a/src/sys/nact_input.cpp b/src/sys/nact_input.cpp
index c663299..5a4ce3d 100644
--- a/src/sys/nact_input.cpp
+++ b/src/sys/nact_input.cpp
@@ -105,6 +105,6 @@ void NACT::get_cursor(int* x, int* y)
 
 void NACT::set_cursor(int x, int y)
 {
+	ags->translate_mouse_coords(&x, &y);
 	SDL_WarpMouseInWindow(g_window, x, y);
 }
-