Add compilation flag for HIDPI workaround

The HIDPI workaround is enabled by default. Expose a flag to be able to
disable it.

DEVELOP.md

@@ -268,3 +268,33 @@ For more details, go read the code!
 
 If you find a bug, or have an awesome idea to implement, please discuss and
 contribute ;-)
+
+
+### Debug the server
+
+The server is pushed to the device by the client on startup.
+
+To debug it, enable the server debugger during configuration:
+
+```bash
+meson x -Dserver_debugger=true
+# or, if x is already configured
+meson configure x -Dserver_debugger=true
+```
+
+Then recompile.
+
+When you start scrcpy, it will start a debugger on port 5005 on the device.
+Redirect that port to the computer:
+
+```bash
+adb forward tcp:5005 tcp:5005
+```
+
+In Android Studio, _Run_ > _Debug_ > _Edit configurations..._ On the left, click on
+`+`, _Remote_, and fill the form:
+
+ - Host: `localhost`
+ - Port: `5005`
+
+Then click on _Debug_.

app/meson.build

@@ -109,12 +109,15 @@ conf.set('DEFAULT_MAX_SIZE', '0')  # 0: unlimited
 # overridden by option --bit-rate
 conf.set('DEFAULT_BIT_RATE', '8000000')  # 8Mbps
 
-# enable High DPI support
-conf.set('HIDPI_SUPPORT', get_option('hidpi_support'))
-
 # disable console on Windows
 conf.set('WINDOWS_NOCONSOLE', get_option('windows_noconsole'))
 
+# run a server debugger and wait for a client to be attached
+conf.set('SERVER_DEBUGGER', get_option('server_debugger'))
+
+# enable a workaround for bug #15
+conf.set('HIDPI_WORKAROUND', get_option('hidpi_workaround'))
+
 configure_file(configuration: conf, output: 'config.h')
 
 src_dir = include_directories('src')

app/src/event_converter.c

@@ -5,7 +5,7 @@
 #define MAP(FROM, TO) case FROM: *to = TO; return true
 #define FAIL default: return false
 
-static bool
+bool
 convert_keycode_action(SDL_EventType from, enum android_keyevent_action *to) {
     switch (from) {
         MAP(SDL_KEYDOWN, AKEY_EVENT_ACTION_DOWN);
@@ -33,7 +33,7 @@ autocomplete_metastate(enum android_metastate metastate) {
     return metastate;
 }
 
-static enum android_metastate
+enum android_metastate
 convert_meta_state(SDL_Keymod mod) {
     enum android_metastate metastate = 0;
     if (mod & KMOD_LSHIFT) {
@@ -74,7 +74,7 @@ convert_meta_state(SDL_Keymod mod) {
     return autocomplete_metastate(metastate);
 }
 
-static bool
+bool
 convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod) {
     switch (from) {
         MAP(SDLK_RETURN,       AKEYCODE_ENTER);
@@ -128,7 +128,7 @@ convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod) {
     }
 }
 
-static enum android_motionevent_buttons
+enum android_motionevent_buttons
 convert_mouse_buttons(uint32_t state) {
     enum android_motionevent_buttons buttons = 0;
     if (state & SDL_BUTTON_LMASK) {
@@ -150,24 +150,6 @@ convert_mouse_buttons(uint32_t state) {
 }
 
 bool
-convert_input_key(const SDL_KeyboardEvent *from, struct control_msg *to) {
-    to->type = CONTROL_MSG_TYPE_INJECT_KEYCODE;
-
-    if (!convert_keycode_action(from->type, &to->inject_keycode.action)) {
-        return false;
-    }
-
-    uint16_t mod = from->keysym.mod;
-    if (!convert_keycode(from->keysym.sym, &to->inject_keycode.keycode, mod)) {
-        return false;
-    }
-
-    to->inject_keycode.metastate = convert_meta_state(mod);
-
-    return true;
-}
-
-static bool
 convert_mouse_action(SDL_EventType from, enum android_motionevent_action *to) {
     switch (from) {
         MAP(SDL_MOUSEBUTTONDOWN, AMOTION_EVENT_ACTION_DOWN);
@@ -177,41 +159,6 @@ convert_mouse_action(SDL_EventType from, enum android_motionevent_action *to) {
 }
 
 bool
-convert_mouse_button(const SDL_MouseButtonEvent *from, struct size screen_size,
-                     struct control_msg *to) {
-    to->type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT;
-
-    if (!convert_mouse_action(from->type, &to->inject_touch_event.action)) {
-        return false;
-    }
-
-    to->inject_touch_event.pointer_id = POINTER_ID_MOUSE;
-    to->inject_touch_event.position.screen_size = screen_size;
-    to->inject_touch_event.position.point.x = from->x;
-    to->inject_touch_event.position.point.y = from->y;
-    to->inject_touch_event.pressure = 1.f;
-    to->inject_touch_event.buttons =
-        convert_mouse_buttons(SDL_BUTTON(from->button));
-
-    return true;
-}
-
-bool
-convert_mouse_motion(const SDL_MouseMotionEvent *from, struct size screen_size,
-                     struct control_msg *to) {
-    to->type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT;
-    to->inject_touch_event.action = AMOTION_EVENT_ACTION_MOVE;
-    to->inject_touch_event.pointer_id = POINTER_ID_MOUSE;
-    to->inject_touch_event.position.screen_size = screen_size;
-    to->inject_touch_event.position.point.x = from->x;
-    to->inject_touch_event.position.point.y = from->y;
-    to->inject_touch_event.pressure = 1.f;
-    to->inject_touch_event.buttons = convert_mouse_buttons(from->state);
-
-    return true;
-}
-
-static bool
 convert_touch_action(SDL_EventType from, enum android_motionevent_action *to) {
     switch (from) {
         MAP(SDL_FINGERMOTION, AMOTION_EVENT_ACTION_MOVE);
@@ -220,39 +167,3 @@ convert_touch_action(SDL_EventType from, enum android_motionevent_action *to) {
         FAIL;
     }
 }
-
-bool
-convert_touch(const SDL_TouchFingerEvent *from, struct size screen_size,
-              struct control_msg *to) {
-    to->type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT;
-
-    if (!convert_touch_action(from->type, &to->inject_touch_event.action)) {
-        return false;
-    }
-
-    to->inject_touch_event.pointer_id = from->fingerId;
-    to->inject_touch_event.position.screen_size = screen_size;
-    // SDL touch event coordinates are normalized in the range [0; 1]
-    to->inject_touch_event.position.point.x = from->x * screen_size.width;
-    to->inject_touch_event.position.point.y = from->y * screen_size.height;
-    to->inject_touch_event.pressure = from->pressure;
-    to->inject_touch_event.buttons = 0;
-    return true;
-}
-
-bool
-convert_mouse_wheel(const SDL_MouseWheelEvent *from, struct position position,
-                    struct control_msg *to) {
-    to->type = CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT;
-
-    to->inject_scroll_event.position = position;
-
-    int mul = from->direction == SDL_MOUSEWHEEL_NORMAL ? 1 : -1;
-    // SDL behavior seems inconsistent between horizontal and vertical scrolling
-    // so reverse the horizontal
-    // <https://wiki.libsdl.org/SDL_MouseWheelEvent#Remarks>
-    to->inject_scroll_event.hscroll = -mul * from->x;
-    to->inject_scroll_event.vscroll = mul * from->y;
-
-    return true;
-}

app/src/event_converter.h

@@ -7,36 +7,22 @@
 #include "config.h"
 #include "control_msg.h"
 
-struct complete_mouse_motion_event {
-    SDL_MouseMotionEvent *mouse_motion_event;
-    struct size screen_size;
-};
+bool
+convert_keycode_action(SDL_EventType from, enum android_keyevent_action *to);
 
-struct complete_mouse_wheel_event {
-    SDL_MouseWheelEvent *mouse_wheel_event;
-    struct point position;
-};
+enum android_metastate
+convert_meta_state(SDL_Keymod mod);
 
 bool
-convert_input_key(const SDL_KeyboardEvent *from, struct control_msg *to);
+convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod);
+
+enum android_motionevent_buttons
+convert_mouse_buttons(uint32_t state);
 
 bool
-convert_mouse_button(const SDL_MouseButtonEvent *from, struct size screen_size,
-                     struct control_msg *to);
-
-// the video size may be different from the real device size, so we need the
-// size to which the absolute position apply, to scale it accordingly
-bool
-convert_mouse_motion(const SDL_MouseMotionEvent *from, struct size screen_size,
-                     struct control_msg *to);
+convert_mouse_action(SDL_EventType from, enum android_motionevent_action *to);
 
 bool
-convert_touch(const SDL_TouchFingerEvent *from, struct size screen_size,
-              struct control_msg *to);
-
-// on Android, a scroll event requires the current mouse position
-bool
-convert_mouse_wheel(const SDL_MouseWheelEvent *from, struct position position,
-                    struct control_msg *to);
+convert_touch_action(SDL_EventType from, enum android_motionevent_action *to);
 
 #endif

app/src/input_manager.c

@@ -212,7 +212,7 @@ clipboard_paste(struct controller *controller) {
 }
 
 void
-input_manager_process_text_input(struct input_manager *input_manager,
+input_manager_process_text_input(struct input_manager *im,
                                  const SDL_TextInputEvent *event) {
     char c = event->text[0];
     if (isalpha(c) || c == ' ') {
@@ -227,14 +227,32 @@ input_manager_process_text_input(struct input_manager *input_manager,
         LOGW("Could not strdup input text");
         return;
     }
-    if (!controller_push_msg(input_manager->controller, &msg)) {
+    if (!controller_push_msg(im->controller, &msg)) {
         SDL_free(msg.inject_text.text);
         LOGW("Could not request 'inject text'");
     }
 }
 
+static bool
+convert_input_key(const SDL_KeyboardEvent *from, struct control_msg *to) {
+    to->type = CONTROL_MSG_TYPE_INJECT_KEYCODE;
+
+    if (!convert_keycode_action(from->type, &to->inject_keycode.action)) {
+        return false;
+    }
+
+    uint16_t mod = from->keysym.mod;
+    if (!convert_keycode(from->keysym.sym, &to->inject_keycode.keycode, mod)) {
+        return false;
+    }
+
+    to->inject_keycode.metastate = convert_meta_state(mod);
+
+    return true;
+}
+
 void
-input_manager_process_key(struct input_manager *input_manager,
+input_manager_process_key(struct input_manager *im,
                           const SDL_KeyboardEvent *event,
                           bool control) {
     // control: indicates the state of the command-line option --no-control
@@ -261,7 +279,7 @@ input_manager_process_key(struct input_manager *input_manager,
         return;
     }
 
-    struct controller *controller = input_manager->controller;
+    struct controller *controller = im->controller;
 
     // capture all Ctrl events
     if (ctrl || cmd) {
@@ -336,23 +354,23 @@ input_manager_process_key(struct input_manager *input_manager,
                 return;
             case SDLK_f:
                 if (!shift && cmd && !repeat && down) {
-                    screen_switch_fullscreen(input_manager->screen);
+                    screen_switch_fullscreen(im->screen);
                 }
                 return;
             case SDLK_x:
                 if (!shift && cmd && !repeat && down) {
-                    screen_resize_to_fit(input_manager->screen);
+                    screen_resize_to_fit(im->screen);
                 }
                 return;
             case SDLK_g:
                 if (!shift && cmd && !repeat && down) {
-                    screen_resize_to_pixel_perfect(input_manager->screen);
+                    screen_resize_to_pixel_perfect(im->screen);
                 }
                 return;
             case SDLK_i:
                 if (!shift && cmd && !repeat && down) {
                     struct fps_counter *fps_counter =
-                        input_manager->video_buffer->fps_counter;
+                        im->video_buffer->fps_counter;
                     switch_fps_counter_state(fps_counter);
                 }
                 return;
@@ -382,8 +400,23 @@ input_manager_process_key(struct input_manager *input_manager,
     }
 }
 
+static bool
+convert_mouse_motion(const SDL_MouseMotionEvent *from, struct screen *screen,
+                     struct control_msg *to) {
+    to->type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT;
+    to->inject_touch_event.action = AMOTION_EVENT_ACTION_MOVE;
+    to->inject_touch_event.pointer_id = POINTER_ID_MOUSE;
+    to->inject_touch_event.position.screen_size = screen->frame_size;
+    to->inject_touch_event.position.point.x = from->x;
+    to->inject_touch_event.position.point.y = from->y;
+    to->inject_touch_event.pressure = 1.f;
+    to->inject_touch_event.buttons = convert_mouse_buttons(from->state);
+
+    return true;
+}
+
 void
-input_manager_process_mouse_motion(struct input_manager *input_manager,
+input_manager_process_mouse_motion(struct input_manager *im,
                                    const SDL_MouseMotionEvent *event) {
     if (!event->state) {
         // do not send motion events when no button is pressed
@@ -394,33 +427,74 @@ input_manager_process_mouse_motion(struct input_manager *input_manager,
         return;
     }
     struct control_msg msg;
-    if (convert_mouse_motion(event, input_manager->screen->frame_size, &msg)) {
-        if (!controller_push_msg(input_manager->controller, &msg)) {
+    if (convert_mouse_motion(event, im->screen, &msg)) {
+        if (!controller_push_msg(im->controller, &msg)) {
             LOGW("Could not request 'inject mouse motion event'");
         }
     }
 }
 
+static bool
+convert_touch(const SDL_TouchFingerEvent *from, struct screen *screen,
+              struct control_msg *to) {
+    to->type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT;
+
+    if (!convert_touch_action(from->type, &to->inject_touch_event.action)) {
+        return false;
+    }
+
+    struct size frame_size = screen->frame_size;
+
+    to->inject_touch_event.pointer_id = from->fingerId;
+    to->inject_touch_event.position.screen_size = frame_size;
+    // SDL touch event coordinates are normalized in the range [0; 1]
+    to->inject_touch_event.position.point.x = from->x * frame_size.width;
+    to->inject_touch_event.position.point.y = from->y * frame_size.height;
+    to->inject_touch_event.pressure = from->pressure;
+    to->inject_touch_event.buttons = 0;
+    return true;
+}
+
 void
-input_manager_process_touch(struct input_manager *input_manager,
+input_manager_process_touch(struct input_manager *im,
                             const SDL_TouchFingerEvent *event) {
     struct control_msg msg;
-    if (convert_touch(event, input_manager->screen->frame_size, &msg)) {
-        if (!controller_push_msg(input_manager->controller, &msg)) {
+    if (convert_touch(event, im->screen, &msg)) {
+        if (!controller_push_msg(im->controller, &msg)) {
             LOGW("Could not request 'inject touch event'");
         }
     }
 }
 
 static bool
-is_outside_device_screen(struct input_manager *input_manager, int x, int y)
+is_outside_device_screen(struct input_manager *im, int x, int y)
 {
-    return x < 0 || x >= input_manager->screen->frame_size.width ||
-           y < 0 || y >= input_manager->screen->frame_size.height;
+    return x < 0 || x >= im->screen->frame_size.width ||
+           y < 0 || y >= im->screen->frame_size.height;
+}
+
+static bool
+convert_mouse_button(const SDL_MouseButtonEvent *from, struct screen *screen,
+                     struct control_msg *to) {
+    to->type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT;
+
+    if (!convert_mouse_action(from->type, &to->inject_touch_event.action)) {
+        return false;
+    }
+
+    to->inject_touch_event.pointer_id = POINTER_ID_MOUSE;
+    to->inject_touch_event.position.screen_size = screen->frame_size;
+    to->inject_touch_event.position.point.x = from->x;
+    to->inject_touch_event.position.point.y = from->y;
+    to->inject_touch_event.pressure = 1.f;
+    to->inject_touch_event.buttons =
+        convert_mouse_buttons(SDL_BUTTON(from->button));
+
+    return true;
 }
 
 void
-input_manager_process_mouse_button(struct input_manager *input_manager,
+input_manager_process_mouse_button(struct input_manager *im,
                                    const SDL_MouseButtonEvent *event,
                                    bool control) {
     if (event->which == SDL_TOUCH_MOUSEID) {
@@ -429,19 +503,19 @@ input_manager_process_mouse_button(struct input_manager *input_manager,
     }
     if (event->type == SDL_MOUSEBUTTONDOWN) {
         if (control && event->button == SDL_BUTTON_RIGHT) {
-            press_back_or_turn_screen_on(input_manager->controller);
+            press_back_or_turn_screen_on(im->controller);
             return;
         }
         if (control && event->button == SDL_BUTTON_MIDDLE) {
-            action_home(input_manager->controller, ACTION_DOWN | ACTION_UP);
+            action_home(im->controller, ACTION_DOWN | ACTION_UP);
             return;
         }
         // double-click on black borders resize to fit the device screen
         if (event->button == SDL_BUTTON_LEFT && event->clicks == 2) {
             bool outside =
-                is_outside_device_screen(input_manager, event->x, event->y);
+                is_outside_device_screen(im, event->x, event->y);
             if (outside) {
-                screen_resize_to_fit(input_manager->screen);
+                screen_resize_to_fit(im->screen);
                 return;
             }
         }
@@ -453,23 +527,41 @@ input_manager_process_mouse_button(struct input_manager *input_manager,
     }
 
     struct control_msg msg;
-    if (convert_mouse_button(event, input_manager->screen->frame_size, &msg)) {
-        if (!controller_push_msg(input_manager->controller, &msg)) {
+    if (convert_mouse_button(event, im->screen, &msg)) {
+        if (!controller_push_msg(im->controller, &msg)) {
             LOGW("Could not request 'inject mouse button event'");
         }
     }
 }
 
-void
-input_manager_process_mouse_wheel(struct input_manager *input_manager,
-                                  const SDL_MouseWheelEvent *event) {
+static bool
+convert_mouse_wheel(const SDL_MouseWheelEvent *from, struct screen *screen,
+                    struct control_msg *to) {
     struct position position = {
-        .screen_size = input_manager->screen->frame_size,
-        .point = get_mouse_point(input_manager->screen),
+        .screen_size = screen->frame_size,
+        .point = get_mouse_point(screen),
     };
+
+    to->type = CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT;
+
+    to->inject_scroll_event.position = position;
+
+    int mul = from->direction == SDL_MOUSEWHEEL_NORMAL ? 1 : -1;
+    // SDL behavior seems inconsistent between horizontal and vertical scrolling
+    // so reverse the horizontal
+    // <https://wiki.libsdl.org/SDL_MouseWheelEvent#Remarks>
+    to->inject_scroll_event.hscroll = -mul * from->x;
+    to->inject_scroll_event.vscroll = mul * from->y;
+
+    return true;
+}
+
+void
+input_manager_process_mouse_wheel(struct input_manager *im,
+                                  const SDL_MouseWheelEvent *event) {
     struct control_msg msg;
-    if (convert_mouse_wheel(event, position, &msg)) {
-        if (!controller_push_msg(input_manager->controller, &msg)) {
+    if (convert_mouse_wheel(event, im->screen, &msg)) {
+        if (!controller_push_msg(im->controller, &msg)) {
             LOGW("Could not request 'inject mouse wheel event'");
         }
     }

app/src/input_manager.h

@@ -17,29 +17,29 @@ struct input_manager {
 };
 
 void
-input_manager_process_text_input(struct input_manager *input_manager,
+input_manager_process_text_input(struct input_manager *im,
                                  const SDL_TextInputEvent *event);
 
 void
-input_manager_process_key(struct input_manager *input_manager,
+input_manager_process_key(struct input_manager *im,
                           const SDL_KeyboardEvent *event,
                           bool control);
 
 void
-input_manager_process_mouse_motion(struct input_manager *input_manager,
+input_manager_process_mouse_motion(struct input_manager *im,
                                    const SDL_MouseMotionEvent *event);
 
 void
-input_manager_process_touch(struct input_manager *input_manager,
+input_manager_process_touch(struct input_manager *im,
                             const SDL_TouchFingerEvent *event);
 
 void
-input_manager_process_mouse_button(struct input_manager *input_manager,
+input_manager_process_mouse_button(struct input_manager *im,
                                    const SDL_MouseButtonEvent *event,
                                    bool control);
 
 void
-input_manager_process_mouse_wheel(struct input_manager *input_manager,
+input_manager_process_mouse_wheel(struct input_manager *im,
                                   const SDL_MouseWheelEvent *event);
 
 #endif

app/src/scrcpy.c

@@ -145,9 +145,11 @@ handle_event(SDL_Event *event, bool control) {
         case SDL_WINDOWEVENT:
             switch (event->window.event) {
                 case SDL_WINDOWEVENT_EXPOSED:
-                case SDL_WINDOWEVENT_SIZE_CHANGED:
                     screen_render(&screen);
                     break;
+                case SDL_WINDOWEVENT_SIZE_CHANGED:
+                    screen_window_resized(&screen);
+                    break;
             }
             break;
         case SDL_TEXTINPUT:

app/src/screen.c

@@ -134,16 +134,57 @@ create_texture(SDL_Renderer *renderer, struct size frame_size) {
                              frame_size.width, frame_size.height);
 }
 
+#ifdef HIDPI_WORKAROUND
+static void
+screen_get_sizes(struct screen *screen, struct screen_sizes *out) {
+    int ww, wh, dw, dh;
+    SDL_GetWindowSize(screen->window, &ww, &wh);
+    SDL_GL_GetDrawableSize(screen->window, &dw, &dh);
+    out->window.width = ww;
+    out->window.height = wh;
+    out->window.width = dw;
+    out->window.height = dh;
+}
+#endif
+
+// This may be called more than once to work around SDL bugs
+static bool
+screen_init_renderer_and_texture(struct screen *screen) {
+    screen->renderer = SDL_CreateRenderer(screen->window, -1,
+                                          SDL_RENDERER_ACCELERATED);
+    if (!screen->renderer) {
+        LOGC("Could not create renderer: %s", SDL_GetError());
+        return false;
+    }
+
+    if (SDL_RenderSetLogicalSize(screen->renderer, screen->frame_size.width,
+                                 screen->frame_size.height)) {
+        LOGE("Could not set renderer logical size: %s", SDL_GetError());
+        return false;
+    }
+
+    screen->texture = create_texture(screen->renderer, screen->frame_size);
+    if (!screen->texture) {
+        LOGC("Could not create texture: %s", SDL_GetError());
+        return false;
+    }
+
+#ifdef HIDPI_WORKAROUND
+    screen_get_sizes(screen, &screen->sizes);
+#endif
+
+    return true;
+}
+
 bool
 screen_init_rendering(struct screen *screen, const char *window_title,
                       struct size frame_size, bool always_on_top) {
     screen->frame_size = frame_size;
 
     struct size window_size = get_initial_optimal_size(frame_size);
-    uint32_t window_flags = SDL_WINDOW_HIDDEN | SDL_WINDOW_RESIZABLE;
-#ifdef HIDPI_SUPPORT
-    window_flags |= SDL_WINDOW_ALLOW_HIGHDPI;
-#endif
+    uint32_t window_flags = SDL_WINDOW_HIDDEN
+                          | SDL_WINDOW_RESIZABLE
+                          | SDL_WINDOW_ALLOW_HIGHDPI;
     if (always_on_top) {
 #ifdef SCRCPY_SDL_HAS_WINDOW_ALWAYS_ON_TOP
         window_flags |= SDL_WINDOW_ALWAYS_ON_TOP;
@@ -162,21 +203,6 @@ screen_init_rendering(struct screen *screen, const char *window_title,
         return false;
     }
 
-    screen->renderer = SDL_CreateRenderer(screen->window, -1,
-                                          SDL_RENDERER_ACCELERATED);
-    if (!screen->renderer) {
-        LOGC("Could not create renderer: %s", SDL_GetError());
-        screen_destroy(screen);
-        return false;
-    }
-
-    if (SDL_RenderSetLogicalSize(screen->renderer, frame_size.width,
-                                 frame_size.height)) {
-        LOGE("Could not set renderer logical size: %s", SDL_GetError());
-        screen_destroy(screen);
-        return false;
-    }
-
     SDL_Surface *icon = read_xpm(icon_xpm);
     if (icon) {
         SDL_SetWindowIcon(screen->window, icon);
@@ -187,9 +213,7 @@ screen_init_rendering(struct screen *screen, const char *window_title,
 
     LOGI("Initial texture: %" PRIu16 "x%" PRIu16, frame_size.width,
                                                   frame_size.height);
-    screen->texture = create_texture(screen->renderer, frame_size);
-    if (!screen->texture) {
-        LOGC("Could not create texture: %s", SDL_GetError());
+    if (!screen_init_renderer_and_texture(screen)) {
         screen_destroy(screen);
         return false;
     }
@@ -278,6 +302,43 @@ screen_update_frame(struct screen *screen, struct video_buffer *vb) {
     return true;
 }
 
+#ifdef HIDPI_WORKAROUND
+// workaround for <https://github.com/Genymobile/scrcpy/issues/15>
+static inline bool
+screen_fix_hidpi(struct screen *screen) {
+    struct screen_sizes cur;
+    screen_get_sizes(screen, &cur);
+
+    struct screen_sizes *prev = &screen->sizes;
+
+    bool width_ratio_changed = cur.window.width * prev->drawable.width !=
+                               cur.drawable.width * prev->window.width;
+    bool height_ratio_changed = cur.window.height * prev->drawable.height !=
+                                cur.drawable.height * prev->window.height;
+    if (width_ratio_changed || height_ratio_changed) {
+        SDL_DestroyTexture(screen->texture);
+        SDL_DestroyRenderer(screen->renderer);
+        if (!screen_init_renderer_and_texture(screen)) {
+            screen->texture = NULL;
+            screen->renderer = NULL;
+            return false;
+        }
+
+        LOGI("Renderer reset after hidpi scaling changed");
+    }
+
+    return true;
+}
+#endif
+
+void
+screen_window_resized(struct screen *screen) {
+#ifdef HIDPI_WORKAROUND
+    screen_fix_hidpi(screen);
+#endif
+    screen_render(screen);
+}
+
 void
 screen_render(struct screen *screen) {
     SDL_RenderClear(screen->renderer);

app/src/screen.h

@@ -20,6 +20,12 @@ struct screen {
     bool has_frame;
     bool fullscreen;
     bool no_window;
+#ifdef HIDPI_WORKAROUND
+    struct screen_sizes {
+        struct size window;
+        struct size drawable;
+    } sizes;
+#endif
 };
 
 #define SCREEN_INITIALIZER {  \
@@ -60,6 +66,10 @@ screen_destroy(struct screen *screen);
 bool
 screen_update_frame(struct screen *screen, struct video_buffer *vb);
 
+// update content after window resizing
+void
+screen_window_resized(struct screen *screen);
+
 // render the texture to the renderer
 void
 screen_render(struct screen *screen);

app/src/server.c

@@ -124,6 +124,11 @@ execute_server(struct server *server, const struct server_params *params) {
         "shell",
         "CLASSPATH=/data/local/tmp/" SERVER_FILENAME,
         "app_process",
+#ifdef SERVER_DEBUGGER
+# define SERVER_DEBUGGER_PORT "5005"
+        "-agentlib:jdwp=transport=dt_socket,suspend=y,server=y,address="
+            SERVER_DEBUGGER_PORT,
+#endif
         "/", // unused
         "com.genymobile.scrcpy.Server",
         max_size_string,
@@ -133,6 +138,17 @@ execute_server(struct server *server, const struct server_params *params) {
         "true", // always send frame meta (packet boundaries + timestamp)
         params->control ? "true" : "false",
     };
+#ifdef SERVER_DEBUGGER
+    LOGI("Server debugger waiting for a client on device port "
+         SERVER_DEBUGGER_PORT "...");
+    // From the computer, run
+    //     adb forward tcp:5005 tcp:5005
+    // Then, from Android Studio: Run > Debug > Edit configurations...
+    // On the left, click on '+', "Remote", with:
+    //     Host: localhost
+    //     Port: 5005
+    // Then click on "Debug"
+#endif
     return adb_execute(server->serial, cmd, sizeof(cmd) / sizeof(cmd[0]));
 }
 

meson_options.txt

@@ -4,4 +4,5 @@ option('crossbuild_windows', type: 'boolean', value: false, description: 'Build
 option('windows_noconsole', type: 'boolean', value: false, description: 'Disable console on Windows (pass -mwindows flag)')
 option('prebuilt_server', type: 'string', description: 'Path of the prebuilt server')
 option('portable', type: 'boolean', value: false, description: 'Use scrcpy-server from the same directory as the scrcpy executable')
-option('hidpi_support', type: 'boolean', value: true, description: 'Enable High DPI support')
+option('server_debugger', type: 'boolean', value: false, description: 'Run a server debugger and wait for a client to be attached')
+option('hidpi_workaround', type: 'boolean', value: true, description: 'Enable a workaround for bug #15')