From a5e8fc21b236c14fa3dcf64323586c826a173fca Mon Sep 17 00:00:00 2001
From: hwsmm <9151706+hwsmm@users.noreply.github.com>
Date: Tue, 12 Nov 2024 22:56:32 +0900
Subject: [PATCH] Add SDL_androidpen

---
 src/video/android/SDL_androidpen.c | 96 ++++++++++++++++++++++++++++++
 src/video/android/SDL_androidpen.h | 25 ++++++++
 2 files changed, 121 insertions(+)
 create mode 100644 src/video/android/SDL_androidpen.c
 create mode 100644 src/video/android/SDL_androidpen.h

diff --git a/src/video/android/SDL_androidpen.c b/src/video/android/SDL_androidpen.c
new file mode 100644
index 0000000000..65730bd75d
--- /dev/null
+++ b/src/video/android/SDL_androidpen.c
@@ -0,0 +1,96 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#ifdef SDL_VIDEO_DRIVER_ANDROID
+
+#include "SDL_androidpen.h"
+#include "../../events/SDL_pen_c.h"
+#include "../../core/android/SDL_android.h"
+
+#define ACTION_DOWN 0
+#define ACTION_UP   1
+#define ACTION_POINTER_DOWN   5
+#define ACTION_POINTER_UP     6
+#define ACTION_HOVER_EXIT     10
+
+void Android_OnPen(SDL_Window *window, int pen_id_in, int button, int action, float x, float y, float p)
+{
+    if (!window) {
+        return;
+    }
+
+    // pointer index starts from zero.
+    pen_id_in++;
+
+    SDL_PenID pen = SDL_FindPenByHandle((void *) (size_t) pen_id_in);
+    if (!pen) {
+        // TODO: Query JNI for pen device info
+        SDL_PenInfo peninfo;
+        SDL_zero(peninfo);
+        peninfo.capabilities = SDL_PEN_CAPABILITY_PRESSURE | SDL_PEN_CAPABILITY_ERASER;
+        peninfo.num_buttons = 2;
+        peninfo.subtype = SDL_PEN_TYPE_PEN;
+        pen = SDL_AddPenDevice(0, NULL, &peninfo, (void *) (size_t) pen_id_in);
+        if (!pen) {
+            SDL_Log("error: can't add a pen device %d", pen_id_in);
+            return;
+        }
+    }
+
+    if (action == ACTION_HOVER_EXIT) {
+        SDL_RemovePenDevice(0, pen);
+        return;
+    }
+
+    SDL_SendPenMotion(0, pen, window, x, y);
+    SDL_SendPenAxis(0, pen, window, SDL_PEN_AXIS_PRESSURE, p);
+    // TODO: add more axis
+
+    SDL_PenInputFlags current = SDL_GetPenStatus(pen, NULL, 0);
+    int diff = current ^ button;
+    if (diff != 0) {
+        // Android only exposes BUTTON_STYLUS_PRIMARY and BUTTON_STYLUS_SECONDARY
+        if (diff & SDL_PEN_INPUT_BUTTON_1)
+            SDL_SendPenButton(0, pen, window, 1, (button & SDL_PEN_INPUT_BUTTON_1) != 0);
+
+        if (diff & SDL_PEN_INPUT_BUTTON_2)
+            SDL_SendPenButton(0, pen, window, 2, (button & SDL_PEN_INPUT_BUTTON_2) != 0);
+    }
+
+    // button contains DOWN/ERASER_TIP on DOWN/UP regardless of pressed state, use action to distinguish
+    switch (action) {
+    case ACTION_DOWN:
+    case ACTION_POINTER_DOWN:
+        SDL_SendPenTouch(0, pen, window, (button & SDL_PEN_INPUT_ERASER_TIP) != 0, true);
+        break;
+
+    case ACTION_UP:
+    case ACTION_POINTER_UP:
+        SDL_SendPenTouch(0, pen, window, (button & SDL_PEN_INPUT_ERASER_TIP) != 0, false);
+        break;
+
+    default:
+        break;
+    }
+}
+
+#endif // SDL_VIDEO_DRIVER_ANDROID
diff --git a/src/video/android/SDL_androidpen.h b/src/video/android/SDL_androidpen.h
new file mode 100644
index 0000000000..15c2256361
--- /dev/null
+++ b/src/video/android/SDL_androidpen.h
@@ -0,0 +1,25 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#include "SDL_androidvideo.h"
+
+extern void Android_OnPen(SDL_Window *window, int pen_id_in, int button, int action, float x, float y, float p);