[Qemu-devel] [PATCH 06/10] sdl2: overhaul window size handling

[Gerd Hoffmann <kraxel@redhat.com>]

Split do_sdl_resize function (which does alot more than just resizing)
into three: sdl2_window_{create,destroy,resize}.

Fix SDL_Renderer handling: must be guest display size not host window
size, and SDL2 will magically handle all scaling for us.

Make fullscreen actually enter fullscreen mode and simplify the code.
There is no need to store the original window size, the window manager
will do that for us.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 ui/sdl2.c | 172 +++++++++++++++++++++++++++++---------------------------------
 1 file changed, 79 insertions(+), 93 deletions(-)

diff --git a/ui/sdl2.c b/ui/sdl2.c
index 47a757a..70f79a5 100644
--- a/ui/sdl2.c
+++ b/ui/sdl2.c
@@ -41,9 +41,6 @@ static struct sdl2_console *sdl2_console;
 static SDL_Surface *guest_sprite_surface;
 static int gui_grab; /* if true, all keyboard/mouse events are grabbed */
 
-static bool gui_saved_scaling;
-static int gui_saved_width;
-static int gui_saved_height;
 static int gui_saved_grab;
 static int gui_fullscreen;
 static int gui_noframe;
@@ -56,7 +53,6 @@ static int absolute_enabled;
 static int guest_cursor;
 static int guest_x, guest_y;
 static SDL_Cursor *guest_sprite;
-static int scaling_active;
 static Notifier mouse_mode_notifier;
 
 static void sdl_update_caption(struct sdl2_console *scon);
@@ -72,86 +68,96 @@ static struct sdl2_console *get_scon_from_window(uint32_t window_id)
     return NULL;
 }
 
-static void do_sdl_resize(struct sdl2_console *scon, int width, int height,
-                          int bpp)
+static void sdl2_window_create(struct sdl2_console *scon)
 {
-    int flags;
+    int flags = 0;
 
-    if (scon->real_window && scon->real_renderer) {
-        if (width && height) {
-            SDL_RenderSetLogicalSize(scon->real_renderer, width, height);
-            SDL_SetWindowSize(scon->real_window, width, height);
-        } else {
-            SDL_DestroyRenderer(scon->real_renderer);
-            SDL_DestroyWindow(scon->real_window);
-            scon->real_renderer = NULL;
-            scon->real_window = NULL;
-        }
+    if (!scon->surface) {
+        return;
+    }
+    assert(!scon->real_window);
+
+    if (gui_fullscreen) {
+        flags |= SDL_WINDOW_FULLSCREEN;
     } else {
-        if (!width || !height) {
-            return;
-        }
-        flags = 0;
-        if (gui_fullscreen) {
-            flags |= SDL_WINDOW_FULLSCREEN;
-        } else {
-            flags |= SDL_WINDOW_RESIZABLE;
-        }
-        if (scon->hidden) {
-            flags |= SDL_WINDOW_HIDDEN;
-        }
+        flags |= SDL_WINDOW_RESIZABLE;
+    }
+    if (scon->hidden) {
+        flags |= SDL_WINDOW_HIDDEN;
+    }
 
-        scon->real_window = SDL_CreateWindow("", SDL_WINDOWPOS_UNDEFINED,
-                                             SDL_WINDOWPOS_UNDEFINED,
-                                             width, height, flags);
-        scon->real_renderer = SDL_CreateRenderer(scon->real_window, -1, 0);
-        sdl_update_caption(scon);
+    scon->real_window = SDL_CreateWindow("", SDL_WINDOWPOS_UNDEFINED,
+                                         SDL_WINDOWPOS_UNDEFINED,
+                                         surface_width(scon->surface),
+                                         surface_height(scon->surface),
+                                         flags);
+    scon->real_renderer = SDL_CreateRenderer(scon->real_window, -1, 0);
+    sdl_update_caption(scon);
+}
+
+static void sdl2_window_destroy(struct sdl2_console *scon)
+{
+    if (!scon->real_window) {
+        return;
     }
+
+    SDL_DestroyRenderer(scon->real_renderer);
+    scon->real_renderer = NULL;
+    SDL_DestroyWindow(scon->real_window);
+    scon->real_window = NULL;
+}
+
+static void sdl2_window_resize(struct sdl2_console *scon)
+{
+    if (!scon->real_window) {
+        return;
+    }
+
+    SDL_SetWindowSize(scon->real_window,
+                      surface_width(scon->surface),
+                      surface_height(scon->surface));
 }
 
 static void sdl_switch(DisplayChangeListener *dcl,
                        DisplaySurface *new_surface)
 {
     struct sdl2_console *scon = container_of(dcl, struct sdl2_console, dcl);
-    int format = 0;
-    int idx = scon->idx;
     DisplaySurface *old_surface = scon->surface;
+    int format = 0;
 
-    /* temporary hack: allows to call sdl_switch to handle scaling changes */
-    if (new_surface) {
-        scon->surface = new_surface;
-    }
+    scon->surface = new_surface;
 
-    if (!new_surface && idx > 0) {
-        scon->surface = NULL;
+    if (scon->texture) {
+        SDL_DestroyTexture(scon->texture);
+        scon->texture = NULL;
     }
 
-    if (new_surface == NULL) {
-        do_sdl_resize(scon, 0, 0, 0);
-    } else {
-        do_sdl_resize(scon, surface_width(scon->surface),
-                      surface_height(scon->surface), 0);
+    if (!new_surface) {
+        sdl2_window_destroy(scon);
+        return;
     }
 
-    if (old_surface && scon->texture) {
-        SDL_DestroyTexture(scon->texture);
-        scon->texture = NULL;
+    if (!scon->real_window) {
+        sdl2_window_create(scon);
+    } else if (old_surface &&
+               ((surface_width(old_surface)  != surface_width(new_surface)) ||
+                (surface_height(old_surface) != surface_height(new_surface)))) {
+        sdl2_window_resize(scon);
     }
 
-    if (new_surface) {
-        if (!scon->texture) {
-            if (surface_bits_per_pixel(scon->surface) == 16) {
-                format = SDL_PIXELFORMAT_RGB565;
-            } else if (surface_bits_per_pixel(scon->surface) == 32) {
-                format = SDL_PIXELFORMAT_ARGB8888;
-            }
+    SDL_RenderSetLogicalSize(scon->real_renderer,
+                             surface_width(new_surface),
+                             surface_height(new_surface));
 
-            scon->texture = SDL_CreateTexture(scon->real_renderer, format,
-                                              SDL_TEXTUREACCESS_STREAMING,
-                                              surface_width(new_surface),
-                                              surface_height(new_surface));
-        }
+    if (surface_bits_per_pixel(scon->surface) == 16) {
+        format = SDL_PIXELFORMAT_RGB565;
+    } else if (surface_bits_per_pixel(scon->surface) == 32) {
+        format = SDL_PIXELFORMAT_ARGB8888;
     }
+    scon->texture = SDL_CreateTexture(scon->real_renderer, format,
+                                      SDL_TEXTUREACCESS_STREAMING,
+                                      surface_width(new_surface),
+                                      surface_height(new_surface));
 }
 
 static void sdl_update_caption(struct sdl2_console *scon)
@@ -338,39 +344,19 @@ static void sdl_send_mouse_event(struct sdl2_console *scon, int dx, int dy,
     qemu_input_event_sync();
 }
 
-static void sdl_scale(struct sdl2_console *scon, int width, int height)
-{
-    int bpp = 0;
-    do_sdl_resize(scon, width, height, bpp);
-    scaling_active = 1;
-}
-
 static void toggle_full_screen(struct sdl2_console *scon)
 {
-    int width = surface_width(scon->surface);
-    int height = surface_height(scon->surface);
-    int bpp = surface_bits_per_pixel(scon->surface);
-
     gui_fullscreen = !gui_fullscreen;
     if (gui_fullscreen) {
-        SDL_GetWindowSize(scon->real_window,
-                          &gui_saved_width, &gui_saved_height);
-        gui_saved_scaling = scaling_active;
-
-        do_sdl_resize(scon, width, height, bpp);
-        scaling_active = 0;
-
+        SDL_SetWindowFullscreen(scon->real_window,
+                                SDL_WINDOW_FULLSCREEN_DESKTOP);
         gui_saved_grab = gui_grab;
         sdl_grab_start(scon);
     } else {
-        if (gui_saved_scaling) {
-            sdl_scale(scon, gui_saved_width, gui_saved_height);
-        } else {
-            do_sdl_resize(scon, width, height, 0);
-        }
         if (!gui_saved_grab) {
             sdl_grab_end(scon);
         }
+        SDL_SetWindowFullscreen(scon->real_window, 0);
     }
     graphic_hw_invalidate(scon->dcl.con);
     graphic_hw_update(scon->dcl.con);
@@ -419,14 +405,13 @@ static void handle_keydown(SDL_Event *ev)
             gui_keysym = 1;
             break;
         case SDL_SCANCODE_U:
-            if (scaling_active) {
-                scaling_active = 0;
-                sdl_switch(&scon->dcl, NULL);
-                graphic_hw_invalidate(scon->dcl.con);
-                graphic_hw_update(scon->dcl.con);
-            }
+            sdl2_window_destroy(scon);
+            sdl2_window_create(scon);
+            graphic_hw_invalidate(scon->dcl.con);
+            graphic_hw_update(scon->dcl.con);
             gui_keysym = 1;
             break;
+#if 0
         case SDL_SCANCODE_KP_PLUS:
         case SDL_SCANCODE_KP_MINUS:
             if (!gui_fullscreen) {
@@ -439,12 +424,14 @@ static void handle_keydown(SDL_Event *ev)
                             160);
                 height = (surface_height(scon->surface) * width) /
                     surface_width(scon->surface);
-
+                fprintf(stderr, "%s: scale to %dx%d\n",
+                        __func__, width, height);
                 sdl_scale(scon, width, height);
                 graphic_hw_invalidate(NULL);
                 graphic_hw_update(NULL);
                 gui_keysym = 1;
             }
+#endif
         default:
             break;
         }
@@ -571,7 +558,6 @@ static void handle_windowevent(DisplayChangeListener *dcl, SDL_Event *ev)
 
     switch (ev->window.event) {
     case SDL_WINDOWEVENT_RESIZED:
-        sdl_scale(scon, ev->window.data1, ev->window.data2);
         {
             QemuUIInfo info;
             memset(&info, 0, sizeof(info));
-- 
1.8.3.1