From c1237b53dd7e646127140d2a0287b2699dec4215 Mon Sep 17 00:00:00 2001
From: rsn8887 <rsn8887@users.noreply.github.com>
Date: Mon, 22 Jul 2019 12:16:40 -0500
Subject: [PATCH] Correctly handle window size and docking/undocking on Switch

---
 CMakeLists.txt                      |  2 ++
 SourceX/miniwin/misc_msg.cpp        |  9 ++++++
 SourceX/platform/switch/docking.cpp | 49 +++++++++++++++++++++++++++++
 SourceX/platform/switch/docking.h   |  7 +++++
 4 files changed, 67 insertions(+)
 create mode 100644 SourceX/platform/switch/docking.cpp
 create mode 100644 SourceX/platform/switch/docking.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e435830f8..fd947e1ba 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -282,6 +282,8 @@ endif()
 set(BIN_TARGET devilutionx)
 
 if(SWITCH)
+  list(APPEND devilutionx_SRCS
+    SourceX/platform/switch/docking.cpp)
   set(BIN_TARGET devilutionx.elf)
 endif()
 
diff --git a/SourceX/miniwin/misc_msg.cpp b/SourceX/miniwin/misc_msg.cpp
index d391f9c5c..472145773 100644
--- a/SourceX/miniwin/misc_msg.cpp
+++ b/SourceX/miniwin/misc_msg.cpp
@@ -11,6 +11,11 @@
 #include "controls/touch.h"
 #include "miniwin/ddraw.h"
 
+#ifdef __SWITCH__
+#include "platform/switch/docking.h"
+#include <switch.h>
+#endif
+
 /** @file
  * *
  * Windows message handling and keyboard event conversion for SDL.
@@ -322,6 +327,10 @@ void BlurInventory()
 
 WINBOOL PeekMessageA(LPMSG lpMsg, HWND hWnd, UINT wMsgFilterMin, UINT wMsgFilterMax, UINT wRemoveMsg)
 {
+#ifdef __SWITCH__
+	HandleDocking();
+#endif
+
 	if (wMsgFilterMin != 0)
 		UNIMPLEMENTED();
 	if (wMsgFilterMax != 0)
diff --git a/SourceX/platform/switch/docking.cpp b/SourceX/platform/switch/docking.cpp
new file mode 100644
index 000000000..631c65743
--- /dev/null
+++ b/SourceX/platform/switch/docking.cpp
@@ -0,0 +1,49 @@
+#include <switch.h>
+#include <SDL.h>
+#include "miniwin/ddraw.h"
+#include "platform/switch/docking.h"
+
+namespace dvl {
+
+static int currently_docked = -1; // keep track of docked or handheld mode
+
+/**
+ * @brief Do a manual window resize when docking/undocking the Switch
+ */
+void HandleDocking()
+{
+	int docked;
+	switch (appletGetOperationMode()) {
+		case AppletOperationMode_Handheld:
+			docked = 0;
+			break;
+		case AppletOperationMode_Docked:
+			docked = 1;
+			break;
+		default:
+			docked = 0;
+	}
+
+	int display_width;
+	int display_height;
+	if ((currently_docked == -1) || (docked && !currently_docked) || (!docked && currently_docked)) {
+		// docked mode has changed, update window size
+		if (docked) {
+			display_width = 1920;
+			display_height = 1080;
+			currently_docked = 1;
+		} else {
+			display_width = 1280;
+			display_height = 720;
+			currently_docked = 0;
+		}
+		// remove leftover-garbage on screen
+		for (int i = 0; i < 3; i++) {
+			SDL_RenderClear(renderer);
+			SDL_RenderPresent(renderer);
+		}
+		SDL_SetWindowSize(window, display_width, display_height);
+	}
+}
+
+} // namespace dvl
diff --git a/SourceX/platform/switch/docking.h b/SourceX/platform/switch/docking.h
new file mode 100644
index 000000000..5a81a1e24
--- /dev/null
+++ b/SourceX/platform/switch/docking.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace dvl {
+
+void HandleDocking();
+
+} // namespace dvl