rootston: damage tracking for rotated views

include/rootston/view.h

@@ -164,6 +164,7 @@ void view_move_resize(struct roots_view *view, double x, double y,
 void view_maximize(struct roots_view *view, bool maximized);
 void view_set_fullscreen(struct roots_view *view, bool fullscreen,
 	struct wlr_output *output);
+void view_rotate(struct roots_view *view, float rotation);
 void view_close(struct roots_view *view);
 bool view_center(struct roots_view *view);
 void view_setup(struct roots_view *view);

include/wlr/types/wlr_box.h

@@ -26,4 +26,10 @@ void wlr_box_transform(const struct wlr_box *box,
 	enum wl_output_transform transform, int width, int height,
 	struct wlr_box *dest);
 
+/**
+ * Creates the smallest box that contains a rotated box.
+ */
+void wlr_box_rotated_bounds(const struct wlr_box *box, float rotation,
+	struct wlr_box *dest);
+
 #endif

rootston/cursor.c

@@ -203,7 +203,7 @@ static void roots_cursor_update_position(struct roots_cursor *cursor,
 			float angle = atan2(vx*uy - vy*ux, vx*ux + vy*uy);
 			int steps = 12;
 			angle = round(angle/M_PI*steps) / (steps/M_PI);
-			view->rotation = cursor->view_rotation + angle;
+			view_rotate(view, cursor->view_rotation + angle);
 		}
 		break;
 	}

rootston/desktop.c

@@ -200,7 +200,7 @@ void view_maximize(struct roots_view *view, bool maximized) {
 
 		view_move_resize(view, output_box->x, output_box->y, output_box->width,
 			output_box->height);
-		view->rotation = 0;
+		view_rotate(view, 0);
 	}
 
 	if (view->maximized && !maximized) {
@@ -208,7 +208,7 @@ void view_maximize(struct roots_view *view, bool maximized) {
 
 		view_move_resize(view, view->saved.x, view->saved.y, view->saved.width,
 			view->saved.height);
-		view->rotation = view->saved.rotation;
+		view_rotate(view, view->saved.rotation);
 	}
 }
 
@@ -249,7 +249,7 @@ void view_set_fullscreen(struct roots_view *view, bool fullscreen,
 			wlr_output_layout_get_box(view->desktop->layout, output);
 		view_move_resize(view, output_box->x, output_box->y, output_box->width,
 			output_box->height);
-		view->rotation = 0;
+		view_rotate(view, 0);
 
 		roots_output->fullscreen_view = view;
 		view->fullscreen_output = roots_output;
@@ -258,13 +258,23 @@ void view_set_fullscreen(struct roots_view *view, bool fullscreen,
 	if (was_fullscreen && !fullscreen) {
 		view_move_resize(view, view->saved.x, view->saved.y, view->saved.width,
 			view->saved.height);
-		view->rotation = view->saved.rotation;
+		view_rotate(view, view->saved.rotation);
 
 		view->fullscreen_output->fullscreen_view = NULL;
 		view->fullscreen_output = NULL;
 	}
 }
 
+void view_rotate(struct roots_view *view, float rotation) {
+	if (view->rotation == rotation) {
+		return;
+	}
+
+	view_damage_whole(view);
+	view->rotation = rotation;
+	view_damage_whole(view);
+}
+
 void view_close(struct roots_view *view) {
 	if (view->close) {
 		view->close(view);

rootston/output.c

@@ -155,7 +155,7 @@ struct render_data {
  */
 static bool surface_intersect_output(struct wlr_surface *surface,
 		struct wlr_output_layout *output_layout, struct wlr_output *wlr_output,
-		double lx, double ly, struct wlr_box *box) {
+		double lx, double ly, float rotation, struct wlr_box *box) {
 	double ox = lx, oy = ly;
 	wlr_output_layout_output_coords(output_layout, wlr_output, &ox, &oy);
 	box->x = ox * wlr_output->scale;
@@ -167,6 +167,7 @@ static bool surface_intersect_output(struct wlr_surface *surface,
 		.x = lx, .y = ly,
 		.width = surface->current->width, .height = surface->current->height,
 	};
+	wlr_box_rotated_bounds(&layout_box, -rotation, &layout_box);
 	return wlr_output_layout_intersects(output_layout, wlr_output, &layout_box);
 }
 
@@ -215,15 +216,18 @@ static void render_surface(struct wlr_surface *surface, double lx, double ly,
 
 	struct wlr_box box;
 	bool intersects = surface_intersect_output(surface, output->desktop->layout,
-		output->wlr_output, lx, ly, &box);
+		output->wlr_output, lx, ly, rotation, &box);
 	if (!intersects) {
 		return;
 	}
 
+	struct wlr_box rotated;
+	wlr_box_rotated_bounds(&box, -rotation, &rotated);
+
 	pixman_region32_t damage;
 	pixman_region32_init(&damage);
-	pixman_region32_union_rect(&damage, &damage, box.x, box.y,
+	pixman_region32_union_rect(&damage, &damage, rotated.x, rotated.y,
-		box.width, box.height);
+		rotated.width, rotated.height);
 	pixman_region32_intersect(&damage, &damage, data->damage);
 	bool damaged = pixman_region32_not_empty(&damage);
 	if (!damaged) {
@@ -415,6 +419,8 @@ static void render_output(struct roots_output *output) {
 		goto renderer_end;
 	}
 
+	wlr_renderer_clear(output->desktop->server->renderer, 1, 1, 1, 1);
+
 	int nrects;
 	pixman_box32_t *rects = pixman_region32_rectangles(&damage, &nrects);
 	for (int i = 0; i < nrects; ++i) {
@@ -526,12 +532,14 @@ static void damage_whole_surface(struct wlr_surface *surface,
 	}
 
 	struct wlr_box box;
-	bool intersects = surface_intersect_output(surface,
+	bool intersects = surface_intersect_output(surface, output->desktop->layout,
-		output->desktop->layout, output->wlr_output, lx, ly, &box);
+		output->wlr_output, lx, ly, rotation, &box);
 	if (!intersects) {
 		return;
 	}
 
+	wlr_box_rotated_bounds(&box, -rotation, &box);
+
 	pixman_region32_union_rect(&output->damage, &output->damage,
 		box.x, box.y, box.width, box.height);
 
@@ -547,6 +555,8 @@ static void damage_whole_decoration(struct roots_view *view,
 	struct wlr_box box;
 	get_decoration_box(view, output, &box);
 
+	wlr_box_rotated_bounds(&box, -view->rotation, &box);
+
 	pixman_region32_union_rect(&output->damage, &output->damage,
 		box.x, box.y, box.width, box.height);
 }
@@ -576,8 +586,8 @@ static void damage_from_surface(struct wlr_surface *surface,
 	}
 
 	struct wlr_box box;
-	bool intersects = surface_intersect_output(surface,
+	bool intersects = surface_intersect_output(surface, output->desktop->layout,
-		output->desktop->layout, output->wlr_output, lx, ly, &box);
+		output->wlr_output, lx, ly, rotation, &box);
 	if (!intersects) {
 		return;
 	}
@@ -599,6 +609,11 @@ void output_damage_from_view(struct roots_output *output,
 		return;
 	}
 
+	if (view->rotation != 0) {
+		output_damage_whole_view(output, view);
+		return;
+	}
+
 	view_for_each_surface(view, damage_from_surface, output);
 }
 

types/wlr_box.c

@@ -114,3 +114,32 @@ void wlr_box_transform(const struct wlr_box *box,
 		break;
 	}
 }
+
+void wlr_box_rotated_bounds(const struct wlr_box *box, float rotation,
+		struct wlr_box *dest) {
+	if (rotation == 0) {
+		*dest = *box;
+		return;
+	}
+
+	double ox = box->x + (double)box->width/2;
+	double oy = box->y + (double)box->height/2;
+
+	double c = fabs(cos(rotation));
+	double s = fabs(sin(rotation));
+
+	double x1 = ox + (box->x - ox) * c + (box->y - oy) * s;
+	double x2 = ox +
+		(box->x + box->width - ox) * c +
+		(box->y + box->height - oy) * s;
+
+	double y1 = oy + (box->x - ox) * s + (box->y - oy) * c;
+	double y2 = oy +
+		(box->x + box->width - ox) * s +
+		(box->y + box->height - oy) * c;
+
+	dest->x = fmin(x1, x2);
+	dest->width = fmax(x1, x2) - fmin(x1, x2);
+	dest->y = fmin(y1, y2);
+	dest->height = fmax(y1, y2) - fmin(y1, y2);
+}