Apply resizing workaround on size changed

The "resized" event is called on user resizing only, while "size
changed" is called on any resize, including at every step of a
progressive resize animation.

app/src/input_manager.c

@@ -7,6 +7,33 @@
 #include "util/lock.h"
 #include "util/log.h"
 
+// Convert window coordinates (as provided by SDL_GetMouseState() to renderer
+// coordinates (as provided in SDL mouse events)
+//
+// See my question:
+// <https://stackoverflow.com/questions/49111054/how-to-get-mouse-position-on-mouse-wheel-event>
+static void
+convert_to_renderer_coordinates(SDL_Renderer *renderer, int *x, int *y) {
+    SDL_Rect viewport;
+    float scale_x, scale_y;
+    SDL_RenderGetViewport(renderer, &viewport);
+    SDL_RenderGetScale(renderer, &scale_x, &scale_y);
+    *x = (int) (*x / scale_x) - viewport.x;
+    *y = (int) (*y / scale_y) - viewport.y;
+}
+
+static struct point
+get_mouse_point(struct screen *screen) {
+    int x;
+    int y;
+    SDL_GetMouseState(&x, &y);
+    convert_to_renderer_coordinates(screen->renderer, &x, &y);
+    return (struct point) {
+        .x = x,
+        .y = y,
+    };
+}
+
 static const int ACTION_DOWN = 1;
 static const int ACTION_UP = 1 << 1;
 
@@ -460,17 +487,11 @@ convert_touch(const SDL_TouchFingerEvent *from, struct screen *screen,
 
     to->inject_touch_event.pointer_id = from->fingerId;
     to->inject_touch_event.position.screen_size = screen->frame_size;
-
-    int ww;
-    int wh;
-    SDL_GL_GetDrawableSize(screen->window, &ww, &wh);
-
     // SDL touch event coordinates are normalized in the range [0; 1]
-    int32_t x = from->x * ww;
+    float x = from->x * screen->content_size.width;
-    int32_t y = from->y * wh;
+    float y = from->y * screen->content_size.height;
     to->inject_touch_event.position.point =
         screen_convert_to_frame_coords(screen, x, y);
-
     to->inject_touch_event.pressure = from->pressure;
     to->inject_touch_event.buttons = 0;
     return true;
@@ -487,6 +508,13 @@ input_manager_process_touch(struct input_manager *im,
     }
 }
 
+static bool
+is_outside_device_screen(struct input_manager *im, int x, int y)
+{
+    return x < 0 || x >= im->screen->content_size.width ||
+           y < 0 || y >= im->screen->content_size.height;
+}
+
 static bool
 convert_mouse_button(const SDL_MouseButtonEvent *from, struct screen *screen,
                      struct control_msg *to) {
@@ -524,15 +552,10 @@ input_manager_process_mouse_button(struct input_manager *im,
             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) {
-            int32_t x = event->x;
+            bool outside =
-            int32_t y = event->y;
+                is_outside_device_screen(im, event->x, event->y);
-            screen_hidpi_scale_coords(im->screen, &x, &y);
-            SDL_Rect *r = &im->screen->rect;
-            bool outside = x < r->x || x >= r->x + r->w
-                        || y < r->y || y >= r->y + r->h;
             if (outside) {
                 screen_resize_to_fit(im->screen);
                 return;
@@ -556,15 +579,9 @@ input_manager_process_mouse_button(struct input_manager *im,
 static bool
 convert_mouse_wheel(const SDL_MouseWheelEvent *from, struct screen *screen,
                     struct control_msg *to) {
-
-    // mouse_x and mouse_y are expressed in pixels relative to the window
-    int mouse_x;
-    int mouse_y;
-    SDL_GetMouseState(&mouse_x, &mouse_y);
-
     struct position position = {
         .screen_size = screen->frame_size,
-        .point = screen_convert_to_frame_coords(screen, mouse_x, mouse_y),
+        .point = get_mouse_point(screen),
     };
 
     to->type = CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT;

app/src/scrcpy.c

@@ -133,10 +133,10 @@ static int
 event_watcher(void *data, SDL_Event *event) {
     (void) data;
     if (event->type == SDL_WINDOWEVENT
-            && event->window.event == SDL_WINDOWEVENT_RESIZED) {
+            && event->window.event == SDL_WINDOWEVENT_SIZE_CHANGED) {
         // In practice, it seems to always be called from the same thread in
         // that specific case. Anyway, it's just a workaround.
-        screen_render(&screen, true);
+        screen_render(&screen);
     }
     return 0;
 }

app/src/screen.c

@@ -68,16 +68,6 @@ get_preferred_display_bounds(struct size *bounds) {
     return true;
 }
 
-static bool
-is_optimal_size(struct size current_size, struct size content_size) {
-    // The size is optimal if we can recompute one dimension of the current
-    // size from the other
-    return current_size.height == current_size.width * content_size.height
-                                                     / content_size.width
-        || current_size.width == current_size.height * content_size.width
-                                                     / content_size.height;
-}
-
 // return the optimal size of the window, with the following constraints:
 //  - it attempts to keep at least one dimension of the current_size (i.e. it
 //    crops the black borders)
@@ -90,36 +80,40 @@ get_optimal_size(struct size current_size, struct size content_size) {
         return current_size;
     }
 
-    struct size window_size;
-
     struct size display_size;
+    // 32 bits because we need to multiply two 16 bits values
+    uint32_t w;
+    uint32_t h;
+
     if (!get_preferred_display_bounds(&display_size)) {
         // could not get display bounds, do not constraint the size
-        window_size.width = current_size.width;
+        w = current_size.width;
-        window_size.height = current_size.height;
+        h = current_size.height;
     } else {
-        window_size.width = MIN(current_size.width, display_size.width);
+        w = MIN(current_size.width, display_size.width);
-        window_size.height = MIN(current_size.height, display_size.height);
+        h = MIN(current_size.height, display_size.height);
     }
 
-    if (is_optimal_size(window_size, content_size)) {
+    if (h == w * content_size.height / content_size.width
-        return window_size;
+     || w == h * content_size.width / content_size.height) {
+        // The size is already optimal, if we ignore rounding errors due to
+        // integer window dimensions
+        return (struct size) {w, h};
     }
 
-    bool keep_width = content_size.width * window_size.height
+    bool keep_width = content_size.width * h > content_size.height * w;
-                    > content_size.height * window_size.width;
     if (keep_width) {
         // remove black borders on top and bottom
-        window_size.height = content_size.height * window_size.width
+        h = content_size.height * w / content_size.width;
-                           / content_size.width;
     } else {
         // remove black borders on left and right (or none at all if it already
         // fits)
-        window_size.width = content_size.width * window_size.height
+        w = content_size.width * h / content_size.height;
-                          / content_size.height;
     }
 
-    return window_size;
+    // w and h must fit into 16 bits
+    assert(w < 0x10000 && h < 0x10000);
+    return (struct size) {w, h};
 }
 
 // same as get_optimal_size(), but read the current size from the window
@@ -156,51 +150,6 @@ get_initial_optimal_size(struct size content_size, uint16_t req_width,
     return window_size;
 }
 
-static void
-screen_update_content_rect(struct screen *screen) {
-    int dw;
-    int dh;
-    SDL_GL_GetDrawableSize(screen->window, &dw, &dh);
-
-    int ww, wh;
-    SDL_GetWindowSize(screen->window, &ww, &wh);
-
-    struct size content_size = screen->content_size;
-    // The drawable size is the window size * the HiDPI scale
-    struct size drawable_size = {dw, dh};
-
-    LOGI("update_content_rect: window=%dx%d, drawable=%dx%d content=%ux%u", ww, wh, dw, dh, content_size.width, content_size.height);
-
-    SDL_Rect *rect = &screen->rect;
-
-    if (is_optimal_size(drawable_size, content_size)) {
-        rect->x = 0;
-        rect->y = 0;
-        rect->w = drawable_size.width;
-        rect->h = drawable_size.height;
-        LOGI("  --> (optimal) rect (%d, %d) %dx%d", rect->x, rect->y, rect->w, rect->h);
-        return;
-    }
-
-    bool keep_width = content_size.width * drawable_size.height
-                    > content_size.height * drawable_size.width;
-    if (keep_width) {
-        rect->x = 0;
-        rect->w = drawable_size.width;
-        rect->h = drawable_size.width * content_size.height
-                                      / content_size.width;
-        rect->y = (drawable_size.height - rect->h) / 2;
-    } else {
-        rect->y = 0;
-        rect->h = drawable_size.height;
-        rect->w = drawable_size.height * content_size.width
-                                       / content_size.height;
-        rect->x = (drawable_size.width - rect->w) / 2;
-    }
-
-    LOGI("  --> rect (%d, %d) %dx%d", rect->x, rect->y, rect->w, rect->h);
-}
-
 void
 screen_init(struct screen *screen) {
     *screen = (struct screen) SCREEN_INITIALIZER;
@@ -290,6 +239,13 @@ screen_init_rendering(struct screen *screen, const char *window_title,
     const char *renderer_name = r ? NULL : renderer_info.name;
     LOGI("Renderer: %s", renderer_name ? renderer_name : "(unknown)");
 
+    if (SDL_RenderSetLogicalSize(screen->renderer, content_size.width,
+                                 content_size.height)) {
+        LOGE("Could not set renderer logical size: %s", SDL_GetError());
+        screen_destroy(screen);
+        return false;
+    }
+
     // starts with "opengl"
     screen->use_opengl = renderer_name && !strncmp(renderer_name, "opengl", 6);
     if (screen->use_opengl) {
@@ -333,10 +289,6 @@ screen_init_rendering(struct screen *screen, const char *window_title,
         return false;
     }
 
-    SDL_SetWindowSize(screen->window, window_size.width, window_size.height);
-
-    screen_update_content_rect(screen);
-
     return true;
 }
 
@@ -407,12 +359,18 @@ screen_set_rotation(struct screen *screen, unsigned rotation) {
     struct size new_content_size =
         get_rotated_size(screen->frame_size, rotation);
 
-    set_content_size(screen, new_content_size);
+    if (SDL_RenderSetLogicalSize(screen->renderer,
+                                 new_content_size.width,
+                                 new_content_size.height)) {
+        LOGE("Could not set renderer logical size: %s", SDL_GetError());
+        return;
+    }
 
+    set_content_size(screen, new_content_size);
     screen->rotation = rotation;
     LOGI("Display rotation set to %u", rotation);
 
-    screen_render(screen, true);
+    screen_render(screen);
 }
 
 // recreate the texture and resize the window if the frame size has changed
@@ -420,16 +378,20 @@ static bool
 prepare_for_frame(struct screen *screen, struct size new_frame_size) {
     if (screen->frame_size.width != new_frame_size.width
             || screen->frame_size.height != new_frame_size.height) {
+        struct size new_content_size =
+            get_rotated_size(new_frame_size, screen->rotation);
+        if (SDL_RenderSetLogicalSize(screen->renderer,
+                                     new_content_size.width,
+                                     new_content_size.height)) {
+            LOGE("Could not set renderer logical size: %s", SDL_GetError());
+            return false;
+        }
+
         // frame dimension changed, destroy texture
         SDL_DestroyTexture(screen->texture);
 
-        screen->frame_size = new_frame_size;
-
-        struct size new_content_size =
-            get_rotated_size(new_frame_size, screen->rotation);
         set_content_size(screen, new_content_size);
-
+        screen->frame_size = new_frame_size;
-        screen_update_content_rect(screen);
 
         LOGI("New texture: %" PRIu16 "x%" PRIu16,
                      screen->frame_size.width, screen->frame_size.height);
@@ -471,19 +433,15 @@ screen_update_frame(struct screen *screen, struct video_buffer *vb) {
     update_texture(screen, frame);
     mutex_unlock(vb->mutex);
 
-    screen_render(screen, false);
+    screen_render(screen);
     return true;
 }
 
 void
-screen_render(struct screen *screen, bool update_content_rect) {
+screen_render(struct screen *screen) {
-    if (update_content_rect) {
-        screen_update_content_rect(screen);
-    }
-
     SDL_RenderClear(screen->renderer);
     if (screen->rotation == 0) {
-        SDL_RenderCopy(screen->renderer, screen->texture, NULL, &screen->rect);
+        SDL_RenderCopy(screen->renderer, screen->texture, NULL, NULL);
     } else {
         // rotation in RenderCopyEx() is clockwise, while screen->rotation is
         // counterclockwise (to be consistent with --lock-video-orientation)
@@ -493,14 +451,12 @@ screen_render(struct screen *screen, bool update_content_rect) {
         SDL_Rect *dstrect = NULL;
         SDL_Rect rect;
         if (screen->rotation & 1) {
-            rect.x = screen->rect.x + (screen->rect.w - screen->rect.h) / 2;
+            struct size size = screen->content_size;
-            rect.y = screen->rect.y + (screen->rect.h - screen->rect.w) / 2;
+            rect.x = (size.width - size.height) / 2;
-            rect.w = screen->rect.h;
+            rect.y = (size.height - size.width) / 2;
-            rect.h = screen->rect.w;
+            rect.w = size.height;
+            rect.h = size.width;
             dstrect = &rect;
-        } else {
-            assert(screen->rotation == 2);
-            dstrect = &screen->rect;
         }
 
         SDL_RenderCopyEx(screen->renderer, screen->texture, NULL, dstrect,
@@ -523,15 +479,20 @@ screen_switch_fullscreen(struct screen *screen) {
     }
 
     LOGD("Switched to %s mode", screen->fullscreen ? "fullscreen" : "windowed");
-    screen_render(screen, true);
+    screen_render(screen);
 }
 
 void
 screen_resize_to_fit(struct screen *screen) {
-    if (screen->fullscreen || screen->maximized) {
+    if (screen->fullscreen) {
         return;
     }
 
+    if (screen->maximized) {
+        SDL_RestoreWindow(screen->window);
+        screen->maximized = false;
+    }
+
     struct size optimal_size =
         get_optimal_window_size(screen, screen->content_size);
     SDL_SetWindowSize(screen->window, optimal_size.width, optimal_size.height);
@@ -556,31 +517,41 @@ screen_resize_to_pixel_perfect(struct screen *screen) {
                                             content_size.height);
 }
 
+static inline bool
+is_fullscreen(const struct screen *screen) {
+    uint32_t flags = SDL_GetWindowFlags(screen->window);
+    return !!(flags & (SDL_WINDOW_FULLSCREEN | SDL_WINDOW_FULLSCREEN_DESKTOP));
+}
+
+static void
+update_fullscreen_state(struct screen *screen) {
+    // There is no SDL event to detect fullscreen changes, so store the
+    // state in a field and compare on every "size changed" event
+    bool fullscreen = is_fullscreen(screen);
+    if (fullscreen != screen->fullscreen) {
+        // Fullscreen state have changed
+        screen->fullscreen = fullscreen;
+        if (!fullscreen && !screen->maximized) {
+            apply_pending_resize(screen);
+        }
+    }
+}
+
 void
 screen_handle_window_event(struct screen *screen,
                            const SDL_WindowEvent *event) {
     switch (event->event) {
         case SDL_WINDOWEVENT_EXPOSED:
-            LOGI("EXPOSED");
+            screen_render(screen);
-            screen_render(screen, true);
             break;
         case SDL_WINDOWEVENT_SIZE_CHANGED:
-            LOGI("SIZE_CHANGED %dx%d", event->data1, event->data2);
+            update_fullscreen_state(screen);
-            screen_render(screen, true);
+            screen_render(screen);
             break;
         case SDL_WINDOWEVENT_MAXIMIZED:
-            LOGI("MAXIMIZED");
             screen->maximized = true;
             break;
         case SDL_WINDOWEVENT_RESTORED:
-            LOGI("RESTORED");
-            if (screen->fullscreen) {
-                // On Windows, in maximized+fullscreen, disabling fullscreen
-                // mode unexpectedly triggers the "restored" then "maximized"
-                // events, leaving the window in a weird state (maximized
-                // according to the events, but not maximized visually).
-                break;
-            }
             screen->maximized = false;
             apply_pending_resize(screen);
             break;
@@ -594,13 +565,6 @@ screen_convert_to_frame_coords(struct screen *screen, int32_t x, int32_t y) {
 
     int32_t w = screen->content_size.width;
     int32_t h = screen->content_size.height;
-
-    screen_hidpi_scale_coords(screen, &x, &y);
-
-    x = (int64_t) (x - screen->rect.x) * w / screen->rect.w;
-    y = (int64_t) (y - screen->rect.y) * h / screen->rect.h;
-
-    // rotate
     struct point result;
     switch (rotation) {
         case 0:
@@ -623,15 +587,3 @@ screen_convert_to_frame_coords(struct screen *screen, int32_t x, int32_t y) {
     }
     return result;
 }
-
-void
-screen_hidpi_scale_coords(struct screen *screen, int32_t *x, int32_t *y) {
-    // take the HiDPI scaling (dw/ww and dh/wh) into account
-    int ww, wh, dw, dh;
-    SDL_GetWindowSize(screen->window, &ww, &wh);
-    SDL_GL_GetDrawableSize(screen->window, &dw, &dh);
-
-    // scale for HiDPI (64 bits for intermediate multiplications)
-    *x = (int64_t) *x * dw / ww;
-    *y = (int64_t) *y * dh / wh;
-}

app/src/screen.h

@@ -29,8 +29,6 @@ struct screen {
 
     // client rotation: 0, 1, 2 or 3 (x90 degrees counterclockwise)
     unsigned rotation;
-    // rectangle of the content (excluding black borders)
-    struct SDL_Rect rect;
     bool has_frame;
     bool fullscreen;
     bool maximized;
@@ -58,12 +56,6 @@ struct screen {
         .height = 0, \
     }, \
     .rotation = 0, \
-    .rect = { \
-        .x = 0, \
-        .y = 0, \
-        .w = 0, \
-        .h = 0, \
-    }, \
     .has_frame = false, \
     .fullscreen = false, \
     .maximized = false, \
@@ -97,11 +89,8 @@ bool
 screen_update_frame(struct screen *screen, struct video_buffer *vb);
 
 // render the texture to the renderer
-//
-// Set the update_content_rect flag if the window or content size may have
-// changed, so that the content rectangle is recomputed
 void
-screen_render(struct screen *screen, bool update_content_rect);
+screen_render(struct screen *screen);
 
 // switch the fullscreen mode
 void
@@ -128,11 +117,4 @@ screen_handle_window_event(struct screen *screen, const SDL_WindowEvent *event);
 struct point
 screen_convert_to_frame_coords(struct screen *screen, int32_t x, int32_t y);
 
-// Convert coordinates from window to drawable.
-// Events are expressed in window coordinates, but content is expressed in
-// drawable coordinates. They are the same if HiDPI scaling is 1, but differ
-// otherwise.
-void
-screen_hidpi_scale_coords(struct screen *screen, int32_t *x, int32_t *y);
-
 #endif