Implement animated transitions for zoom in/out.

src/compositor.c

@@ -1640,7 +1640,7 @@ notify_motion(struct wl_seat *seat, uint32_t time, wl_fixed_t x, wl_fixed_t y)
 		if (output->zoom.active &&
 		    pixman_region32_contains_point(&output->region,
 						   ix, iy, NULL))
-			weston_output_update_zoom(output, x, y, ZOOM_POINTER);
+			weston_output_update_zoom(output, x, y, ZOOM_FOCUS_POINTER);
 
 	weston_device_repick(seat);
 	interface = seat->pointer->grab->interface;
@@ -2734,7 +2734,49 @@ weston_text_cursor_position_notify(struct weston_surface *surface,
 						wl_fixed_to_int(global_y),
 						NULL))
 			weston_output_update_zoom(output, global_x, global_y,
-							  ZOOM_TEXT_CURSOR);
+							  ZOOM_FOCUS_TEXT);
+}
+
+static void
+weston_zoom_frame_z(struct weston_animation *animation,
+		struct weston_output *output, uint32_t msecs)
+{
+	if (animation->frame_counter == 0)
+		output->zoom.spring_z.timestamp = msecs;
+
+	weston_spring_update(&output->zoom.spring_z, msecs);
+
+	if (output->zoom.spring_z.current > output->zoom.max_level)
+		output->zoom.spring_z.current = output->zoom.max_level;
+	else if (output->zoom.spring_z.current < 0.0)
+		output->zoom.spring_z.current = 0.0;
+
+	if (weston_spring_done(&output->zoom.spring_z)) {
+		if (output->zoom.level <= 0.0)
+			output->zoom.active = 0;
+		output->zoom.spring_z.current = output->zoom.level;
+		wl_list_remove(&animation->link);
+		wl_list_init(&animation->link);
+	}
+
+	output->dirty = 1;
+	weston_output_damage(output);
+}
+
+static void
+weston_zoom_transition(struct weston_output *output)
+{
+	if (output->zoom.level != output->zoom.spring_z.current) {
+		output->zoom.spring_z.target = output->zoom.level;
+		if (wl_list_empty(&output->zoom.animation_z.link)) {
+			output->zoom.animation_z.frame_counter = 0;
+			wl_list_insert(output->animation_list.prev,
+				&output->zoom.animation_z.link);
+		}
+	}
+
+	output->dirty = 1;
+	weston_output_damage(output);
 }
 
 WL_EXPORT void
@@ -2745,25 +2787,35 @@ weston_output_update_zoom(struct weston_output *output,
 {
 	float global_x, global_y;
 	float trans_min, trans_max;
+	float ratio, level;
 
-	if (output->zoom.level >= 1.0)
+	level = output->zoom.spring_z.current;
+
+	if (!output->zoom.active || level > output->zoom.max_level)
 		return;
 
+	output->zoom.type = type;
+
+	output->zoom.fx = x;
+	output->zoom.fy = y;
+
 	global_x = wl_fixed_to_double(x);
 	global_y = wl_fixed_to_double(y);
 
 	output->zoom.trans_x =
 		(((global_x - output->x) / output->current->width) *
-		(output->zoom.level * 2)) - output->zoom.level;
+		(level * 2)) - level;
 	output->zoom.trans_y =
 		(((global_y - output->y) / output->current->height) *
-		(output->zoom.level * 2)) - output->zoom.level;
+		(level * 2)) - level;
 
-	if (type == ZOOM_TEXT_CURSOR) {
+	if (type == ZOOM_FOCUS_TEXT) {
-		output->zoom.trans_x *= 1 / output->zoom.level;
+		ratio = 1 / level;
-		output->zoom.trans_y *= 1 / output->zoom.level;
 
-		trans_max = output->zoom.level * 2 - output->zoom.level;
+		output->zoom.trans_x *= ratio;
+		output->zoom.trans_y *= ratio;
+
+		trans_max = level * 2 - level;
 		trans_min = -trans_max;
 
 		if (output->zoom.trans_x > trans_max)
@@ -2776,8 +2828,7 @@ weston_output_update_zoom(struct weston_output *output,
 			output->zoom.trans_y = trans_min;
 	}
 
-	output->dirty = 1;
+	weston_zoom_transition(output);
-	weston_output_damage(output);
 }
 
 WL_EXPORT void
@@ -2799,10 +2850,14 @@ weston_output_update_matrix(struct weston_output *output)
 			    flip * 2.0 / (output->current->height + output->border.top + output->border.bottom), 1);
 
 	if (output->zoom.active) {
-		magnification = 1 / (1 - output->zoom.level);
+		magnification = 1 / (1 - output->zoom.spring_z.current);
 		weston_matrix_init(&camera);
 		weston_matrix_init(&modelview);
-		weston_matrix_translate(&camera, output->zoom.trans_x, flip * output->zoom.trans_y, 0);
+		weston_output_update_zoom(output, output->zoom.fx,
+						  output->zoom.fy,
+						  output->zoom.type);
+		weston_matrix_translate(&camera, output->zoom.trans_x,
+					  flip * output->zoom.trans_y, 0);
 		weston_matrix_invert(&modelview, &camera);
 		weston_matrix_scale(&modelview, magnification, magnification, 1.0);
 		weston_matrix_multiply(&output->matrix, &modelview);
@@ -2840,10 +2895,15 @@ weston_output_init(struct weston_output *output, struct weston_compositor *c,
 	wl_list_init(&output->read_pixels_list);
 
 	output->zoom.active = 0;
-	output->zoom.increment = 0.05;
+	output->zoom.increment = 0.07;
+	output->zoom.max_level = 0.95;
 	output->zoom.level = 0.0;
 	output->zoom.trans_x = 0.0;
 	output->zoom.trans_y = 0.0;
+	weston_spring_init(&output->zoom.spring_z, 250.0, 0.0, 0.0);
+	output->zoom.spring_z.friction = 1000;
+	output->zoom.animation_z.frame = weston_zoom_frame_z;
+	wl_list_init(&output->zoom.animation_z.link);
 
 	output->flags = flags;
 	weston_output_move(output, x, y);

src/compositor.h

@@ -94,16 +94,37 @@ struct weston_border {
 	int32_t left, right, top, bottom;
 };
 
+struct weston_animation {
+	void (*frame)(struct weston_animation *animation,
+		      struct weston_output *output, uint32_t msecs);
+	int frame_counter;
+	struct wl_list link;
+};
+
+struct weston_spring {
+	double k;
+	double friction;
+	double current;
+	double target;
+	double previous;
+	uint32_t timestamp;
+};
+
 enum {
-	ZOOM_POINTER,
+	ZOOM_FOCUS_POINTER,
-	ZOOM_TEXT_CURSOR
+	ZOOM_FOCUS_TEXT
 };
 
 struct weston_output_zoom {
 	int active;
+	uint32_t type;
 	float increment;
 	float level;
+	float max_level;
+	wl_fixed_t fx, fy;
 	float trans_x, trans_y;
+	struct weston_animation animation_z;
+	struct weston_spring spring_z;
 };
 
 /* bit compatible with drm definitions. */
@@ -228,22 +249,6 @@ struct weston_shader {
 	GLint opaque_uniform;
 };
 
-struct weston_animation {
-	void (*frame)(struct weston_animation *animation,
-		      struct weston_output *output, uint32_t msecs);
-	int frame_counter;
-	struct wl_list link;
-};
-
-struct weston_spring {
-	double k;
-	double friction;
-	double current;
-	double target;
-	double previous;
-	uint32_t timestamp;
-};
-
 enum {
 	WESTON_COMPOSITOR_ACTIVE,
 	WESTON_COMPOSITOR_IDLE,		/* shell->unlock called on activity */

src/shell.c

@@ -1706,7 +1706,7 @@ do_zoom(struct wl_seat *seat, uint32_t time, uint32_t key, uint32_t axis,
 	struct weston_seat *ws = (struct weston_seat *) seat;
 	struct weston_compositor *compositor = ws->compositor;
 	struct weston_output *output;
-	float maximum_level, increment;
+	float increment;
 
 	wl_list_for_each(output, &compositor->output_list, link) {
 		if (pixman_region32_contains_point(&output->region,
@@ -1723,23 +1723,21 @@ do_zoom(struct wl_seat *seat, uint32_t time, uint32_t key, uint32_t axis,
 			else
 				increment = 0;
 
-			output->zoom.active = 1;
 			output->zoom.level += increment;
 
-			if (output->zoom.level <= 0.0) {
+			if (output->zoom.level < 0.0)
-				output->zoom.active = 0;
 				output->zoom.level = 0.0;
-			}
+			else if (output->zoom.level > output->zoom.max_level)
+				output->zoom.level = output->zoom.max_level;
+			else
+				output->zoom.active = 1;
 
-			maximum_level = 1 - output->zoom.increment;
+			output->zoom.spring_z.target = output->zoom.level;
-
-			if (output->zoom.level > maximum_level)
-				output->zoom.level = maximum_level;
 
 			weston_output_update_zoom(output,
 			                          seat->pointer->x,
 						  seat->pointer->y,
-						  ZOOM_POINTER);
+						  ZOOM_FOCUS_POINTER);
 		}
 	}
 }