gl-renderer: Add hook to fill weston_buffer for EGL

Rather than only filling weston_buffer information when we first come to
use it, add an explicit hook so we can fill the dimensions the first
time the buffer's attached.

Signed-off-by: Daniel Stone <daniels@collabora.com>

compositor/weston-screenshooter.c

@@ -68,8 +68,9 @@ screenshooter_take_shot(struct wl_client *client,
 {
 	struct weston_output *output =
 		weston_head_from_resource(output_resource)->output;
+	struct weston_compositor *ec = output->compositor;
 	struct weston_buffer *buffer =
-		weston_buffer_from_resource(buffer_resource);
+		weston_buffer_from_resource(ec, buffer_resource);
 
 	if (buffer == NULL) {
 		wl_resource_post_no_memory(resource);

include/libweston/libweston.h

@@ -934,7 +934,6 @@ struct weston_renderer {
 			       float blue, float alpha);
 	void (*destroy)(struct weston_compositor *ec);
 
-
 	/** See weston_surface_get_content_size() */
 	void (*surface_get_content_size)(struct weston_surface *surface,
 					 int *width, int *height);
@@ -951,6 +950,9 @@ struct weston_renderer {
 
 	const struct weston_drm_format_array *
 			(*get_supported_formats)(struct weston_compositor *ec);
+
+	bool (*fill_buffer_info)(struct weston_compositor *ec,
+				 struct weston_buffer *buffer);
 };
 
 enum weston_capability {
@@ -1818,7 +1820,8 @@ weston_surface_copy_content(struct weston_surface *surface,
 			    int width, int height);
 
 struct weston_buffer *
-weston_buffer_from_resource(struct wl_resource *resource);
+weston_buffer_from_resource(struct weston_compositor *ec,
+			    struct wl_resource *resource);
 
 void
 weston_compositor_get_time(struct timespec *time);

libweston/compositor.c

@@ -2385,7 +2385,8 @@ weston_buffer_destroy_handler(struct wl_listener *listener, void *data)
 }
 
 WL_EXPORT struct weston_buffer *
-weston_buffer_from_resource(struct wl_resource *resource)
+weston_buffer_from_resource(struct weston_compositor *ec,
+			    struct wl_resource *resource)
 {
 	struct weston_buffer *buffer;
 	struct wl_shm_buffer *shm;
@@ -2418,9 +2419,20 @@ weston_buffer_from_resource(struct wl_resource *resource)
 		buffer->height = dmabuf->attributes.height;
 		buffer->y_inverted =
 			!(dmabuf->attributes.flags & ZWP_LINUX_BUFFER_PARAMS_V1_FLAGS_Y_INVERT);
+	} else {
+		/* Only taken for legacy EGL buffers */
+		if (!ec->renderer->fill_buffer_info ||
+		    !ec->renderer->fill_buffer_info(ec, buffer)) {
+			goto fail;
+		}
 	}
 
 	return buffer;
+
+fail:
+	wl_list_remove(&buffer->destroy_listener.link);
+	free(buffer);
+	return NULL;
 }
 
 static void
@@ -3440,10 +3452,11 @@ surface_attach(struct wl_client *client,
 	       struct wl_resource *buffer_resource, int32_t sx, int32_t sy)
 {
 	struct weston_surface *surface = wl_resource_get_user_data(resource);
+	struct weston_compositor *ec = surface->compositor;
 	struct weston_buffer *buffer = NULL;
 
 	if (buffer_resource) {
-		buffer = weston_buffer_from_resource(buffer_resource);
+		buffer = weston_buffer_from_resource(ec, buffer_resource);
 		if (buffer == NULL) {
 			wl_client_post_no_memory(client);
 			return;

libweston/renderer-gl/gl-renderer.c

@@ -2153,6 +2153,28 @@ unsupported:
 	}
 }
 
+static bool
+gl_renderer_fill_buffer_info(struct weston_compositor *ec,
+			     struct weston_buffer *buffer)
+{
+	struct gl_renderer *gr = get_renderer(ec);
+	bool ret = true;
+
+	buffer->legacy_buffer = (struct wl_buffer *)buffer->resource;
+	ret &= gr->query_buffer(gr->egl_display, buffer->legacy_buffer,
+			        EGL_WIDTH, &buffer->width);
+	ret &= gr->query_buffer(gr->egl_display, buffer->legacy_buffer,
+				EGL_HEIGHT, &buffer->height);
+
+	/* Assume scanout co-ordinate space i.e. (0,0) is top-left
+	 * if the query fails */
+	buffer->y_inverted = true;
+	gr->query_buffer(gr->egl_display, buffer->legacy_buffer,
+			 EGL_WAYLAND_Y_INVERTED_WL, &buffer->y_inverted);
+
+	return ret;
+}
+
 static void
 gl_renderer_attach_egl(struct weston_surface *es, struct weston_buffer *buffer,
 		       uint32_t format)
@@ -2164,14 +2186,6 @@ gl_renderer_attach_egl(struct weston_surface *es, struct weston_buffer *buffer,
 	GLenum target;
 	int i, num_planes;
 
-	buffer->legacy_buffer = (struct wl_buffer *)buffer->resource;
-	gr->query_buffer(gr->egl_display, buffer->legacy_buffer,
-			 EGL_WIDTH, &buffer->width);
-	gr->query_buffer(gr->egl_display, buffer->legacy_buffer,
-			 EGL_HEIGHT, &buffer->height);
-	gr->query_buffer(gr->egl_display, buffer->legacy_buffer,
-			 EGL_WAYLAND_Y_INVERTED_WL, &buffer->y_inverted);
-
 	for (i = 0; i < gs->num_images; i++) {
 		egl_image_unref(gs->images[i]);
 		gs->images[i] = NULL;
@@ -3674,6 +3688,7 @@ gl_renderer_display_create(struct weston_compositor *ec,
 	gr->base.surface_get_content_size =
 		gl_renderer_surface_get_content_size;
 	gr->base.surface_copy_content = gl_renderer_surface_copy_content;
+	gr->base.fill_buffer_info = gl_renderer_fill_buffer_info;
 
 	if (gl_renderer_setup_egl_display(gr, options->egl_native_display) < 0)
 		goto fail;