Reference video buffer from screen

This paves the way to handle EVENT_NEW_FRAME from screen.c, by allowing
to call screen_update_frame() without an explicit video_buffer instance.

app/src/scrcpy.c

@@ -30,7 +30,7 @@
 #include "util/net.h"
 
 static struct server server;
-static struct screen screen = SCREEN_INITIALIZER;
+static struct screen screen;
 static struct fps_counter fps_counter;
 static struct video_buffer video_buffer;
 static struct stream stream;
@@ -179,7 +179,7 @@ handle_event(SDL_Event *event, const struct scrcpy_options *options) {
                 // this is the very first frame, show the window
                 screen_show_window(&screen);
             }
-            if (!screen_update_frame(&screen, &video_buffer)) {
+            if (!screen_update_frame(&screen)) {
                 return EVENT_RESULT_CONTINUE;
             }
             break;
@@ -429,6 +429,8 @@ scrcpy(const struct scrcpy_options *options) {
         const char *window_title =
             options->window_title ? options->window_title : device_name;
 
+        screen_init(&screen, &video_buffer);
+
         if (!screen_init_rendering(&screen, window_title, frame_size,
                                    options->always_on_top, options->window_x,
                                    options->window_y, options->window_width,

app/src/screen.c

@@ -191,8 +191,9 @@ screen_update_content_rect(struct screen *screen) {
 }
 
 void
-screen_init(struct screen *screen) {
+screen_init(struct screen *screen, struct video_buffer *vb) {
     *screen = (struct screen) SCREEN_INITIALIZER;
+    screen->vb = vb;
 }
 
 static inline SDL_Texture *
@@ -446,8 +447,8 @@ update_texture(struct screen *screen, const AVFrame *frame) {
 }
 
 bool
-screen_update_frame(struct screen *screen, struct video_buffer *vb) {
+screen_update_frame(struct screen *screen) {
-    const AVFrame *frame = video_buffer_take_rendering_frame(vb);
+    const AVFrame *frame = video_buffer_take_rendering_frame(screen->vb);
     struct size new_frame_size = {frame->width, frame->height};
     if (!prepare_for_frame(screen, new_frame_size)) {
         return false;

app/src/screen.h

@@ -13,6 +13,7 @@
 struct video_buffer;
 
 struct screen {
+    struct video_buffer *vb;
     SDL_Window *window;
     SDL_Renderer *renderer;
     SDL_Texture *texture;
@@ -37,6 +38,7 @@ struct screen {
 };
 
 #define SCREEN_INITIALIZER { \
+    .vb = NULL, \
     .window = NULL, \
     .renderer = NULL, \
     .texture = NULL, \
@@ -70,7 +72,7 @@ struct screen {
 
 // initialize default values
 void
-screen_init(struct screen *screen);
+screen_init(struct screen *screen, struct video_buffer *vb);
 
 // initialize screen, create window, renderer and texture (window is hidden)
 // window_x and window_y accept SC_WINDOW_POSITION_UNDEFINED
@@ -91,7 +93,7 @@ screen_destroy(struct screen *screen);
 
 // resize if necessary and write the rendered frame into the texture
 bool
-screen_update_frame(struct screen *screen, struct video_buffer *vb);
+screen_update_frame(struct screen *screen);
 
 // render the texture to the renderer
 //