add plugin system

app/meson.build

@@ -2,6 +2,7 @@ src = [
     'src/main.c',
     'src/adb.c',
     'src/cli.c',
+    'src/plugin.c',
     'src/compat.c',
     'src/control_msg.c',
     'src/controller.c',

app/src/plugin.c

@@ -0,0 +1,49 @@
+#include "plugin.h"
+#include "scrcpy.h"
+#include <stdio.h>
+#include <string.h>
+#include <SDL2/SDL.h>
+
+#ifdef _WIN32
+// not needed here, but winsock2.h must never be included AFTER windows.h
+# include <winsock2.h>
+# include <windows.h>
+#endif
+
+#ifdef _WIN32
+
+#define WM_PLUGIN_BASE WM_USER 
+void on_window_message(void *userdata, void *hWnd, unsigned int message, Uint64 wParam, int64_t lParam){
+    (void)(userdata);
+    (void)(hWnd);
+    if (message >= WM_PLUGIN_BASE ){
+        message -= WM_PLUGIN_BASE;
+        switch (message)
+        {
+        case SDL_FINGERDOWN:
+        case SDL_FINGERUP:
+        case SDL_FINGERMOTION:
+            {
+                SDL_Event sdlevent;
+                sdlevent.type = message;
+                sdlevent.tfinger.fingerId = 0;
+                sdlevent.tfinger.pressure = 0.8;
+                sdlevent.tfinger.x  = (double)(wParam) / (1000*1000);
+                sdlevent.tfinger.y  = (double)(lParam) / (1000*1000);
+                SDL_PushEvent(&sdlevent);
+            }
+            break;
+        default:
+            break;
+        }
+        
+    }
+}
+#endif
+
+
+void plugin_init(){
+#ifdef _WIN32
+    SDL_SetWindowsMessageHook(on_window_message,NULL);
+#endif
+}

app/src/plugin.h

@@ -0,0 +1,5 @@
+#ifndef __PLUGIN_H__
+#define __PLUGIN_H__
+
+void plugin_init();
+#endif

app/src/scrcpy.c

@@ -1,5 +1,5 @@
 #include "scrcpy.h"
-
+#include "plugin.h"
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -115,6 +115,7 @@ sdl_init_and_configure(bool display, const char *render_driver,
         SDL_EnableScreenSaver();
     }
 
+    plugin_init();
     return true;
 }