initial commit, 4.5 stable

editor/inspector/editor_resource_preview.cpp

@@ -0,0 +1,613 @@
+/**************************************************************************/
+/*  editor_resource_preview.cpp                                           */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include "editor_resource_preview.h"
+
+#include "core/config/project_settings.h"
+#include "core/io/file_access.h"
+#include "core/io/resource_loader.h"
+#include "core/io/resource_saver.h"
+#include "core/variant/variant_utility.h"
+#include "editor/editor_node.h"
+#include "editor/editor_string_names.h"
+#include "editor/file_system/editor_paths.h"
+#include "editor/settings/editor_settings.h"
+#include "editor/themes/editor_scale.h"
+#include "scene/main/window.h"
+#include "scene/resources/image_texture.h"
+#include "servers/rendering/rendering_server_globals.h"
+
+bool EditorResourcePreviewGenerator::handles(const String &p_type) const {
+	bool success = false;
+	if (GDVIRTUAL_CALL(_handles, p_type, success)) {
+		return success;
+	}
+	ERR_FAIL_V_MSG(false, "EditorResourcePreviewGenerator::_handles needs to be overridden.");
+}
+
+Ref<Texture2D> EditorResourcePreviewGenerator::generate(const Ref<Resource> &p_from, const Size2 &p_size, Dictionary &p_metadata) const {
+	Ref<Texture2D> preview;
+	if (GDVIRTUAL_CALL(_generate, p_from, p_size, p_metadata, preview)) {
+		return preview;
+	}
+	ERR_FAIL_V_MSG(Ref<Texture2D>(), "EditorResourcePreviewGenerator::_generate needs to be overridden.");
+}
+
+Ref<Texture2D> EditorResourcePreviewGenerator::generate_from_path(const String &p_path, const Size2 &p_size, Dictionary &p_metadata) const {
+	Ref<Texture2D> preview;
+	if (GDVIRTUAL_CALL(_generate_from_path, p_path, p_size, p_metadata, preview)) {
+		return preview;
+	}
+
+	Ref<Resource> res = ResourceLoader::load(p_path);
+	if (res.is_null()) {
+		return res;
+	}
+	return generate(res, p_size, p_metadata);
+}
+
+bool EditorResourcePreviewGenerator::generate_small_preview_automatically() const {
+	bool success = false;
+	GDVIRTUAL_CALL(_generate_small_preview_automatically, success);
+	return success;
+}
+
+bool EditorResourcePreviewGenerator::can_generate_small_preview() const {
+	bool success = false;
+	GDVIRTUAL_CALL(_can_generate_small_preview, success);
+	return success;
+}
+
+void EditorResourcePreviewGenerator::_bind_methods() {
+	GDVIRTUAL_BIND(_handles, "type");
+	GDVIRTUAL_BIND(_generate, "resource", "size", "metadata");
+	GDVIRTUAL_BIND(_generate_from_path, "path", "size", "metadata");
+	GDVIRTUAL_BIND(_generate_small_preview_automatically);
+	GDVIRTUAL_BIND(_can_generate_small_preview);
+}
+
+void EditorResourcePreviewGenerator::DrawRequester::request_and_wait(RID p_viewport) {
+	Callable request_vp_update_once = callable_mp(RS::get_singleton(), &RS::viewport_set_update_mode).bind(p_viewport, RS::VIEWPORT_UPDATE_ONCE);
+
+	if (EditorResourcePreview::get_singleton()->is_threaded()) {
+		RS::get_singleton()->connect(SNAME("frame_pre_draw"), request_vp_update_once, Object::CONNECT_ONE_SHOT);
+		RS::get_singleton()->request_frame_drawn_callback(callable_mp(this, &EditorResourcePreviewGenerator::DrawRequester::_post_semaphore));
+
+		semaphore.wait();
+	} else {
+		// Avoid the main viewport and children being redrawn.
+		SceneTree *st = Object::cast_to<SceneTree>(OS::get_singleton()->get_main_loop());
+		ERR_FAIL_NULL_MSG(st, "Editor's MainLoop is not a SceneTree. This is a bug.");
+		RID root_vp = st->get_root()->get_viewport_rid();
+		RenderingServer::get_singleton()->viewport_set_active(root_vp, false);
+
+		request_vp_update_once.call();
+		RS::get_singleton()->draw(false);
+
+		// Let main viewport and children be drawn again.
+		RenderingServer::get_singleton()->viewport_set_active(root_vp, true);
+	}
+}
+
+void EditorResourcePreviewGenerator::DrawRequester::abort() {
+	if (EditorResourcePreview::get_singleton()->is_threaded()) {
+		semaphore.post();
+	}
+}
+
+Variant EditorResourcePreviewGenerator::DrawRequester::_post_semaphore() {
+	semaphore.post();
+	return Variant(); // Needed because of how the callback is used.
+}
+
+bool EditorResourcePreview::is_threaded() const {
+	return RSG::rasterizer->can_create_resources_async();
+}
+
+void EditorResourcePreview::_thread_func(void *ud) {
+	EditorResourcePreview *erp = (EditorResourcePreview *)ud;
+	erp->_thread();
+}
+
+void EditorResourcePreview::_preview_ready(const String &p_path, int p_hash, const Ref<Texture2D> &p_texture, const Ref<Texture2D> &p_small_texture, ObjectID id, const StringName &p_func, const Variant &p_ud, const Dictionary &p_metadata) {
+	{
+		MutexLock lock(preview_mutex);
+
+		uint64_t modified_time = 0;
+
+		if (!p_path.begins_with("ID:")) {
+			modified_time = FileAccess::get_modified_time(p_path);
+			String import_path = p_path + ".import";
+			if (FileAccess::exists(import_path)) {
+				modified_time = MAX(modified_time, FileAccess::get_modified_time(import_path));
+			}
+		}
+
+		Item item;
+		item.preview = p_texture;
+		item.small_preview = p_small_texture;
+		item.last_hash = p_hash;
+		item.modified_time = modified_time;
+		item.preview_metadata = p_metadata;
+
+		cache[p_path] = item;
+	}
+
+	Callable(id, p_func).call_deferred(p_path, p_texture, p_small_texture, p_ud);
+}
+
+void EditorResourcePreview::_generate_preview(Ref<ImageTexture> &r_texture, Ref<ImageTexture> &r_small_texture, const QueueItem &p_item, const String &cache_base, Dictionary &p_metadata) {
+	String type;
+
+	uint64_t started_at = OS::get_singleton()->get_ticks_usec();
+
+	if (p_item.resource.is_valid()) {
+		type = p_item.resource->get_class();
+	} else {
+		type = ResourceLoader::get_resource_type(p_item.path);
+	}
+
+	if (type.is_empty()) {
+		r_texture = Ref<ImageTexture>();
+		r_small_texture = Ref<ImageTexture>();
+
+		if (is_print_verbose_enabled()) {
+			print_line(vformat("Generated '%s' preview in %d usec", p_item.path, OS::get_singleton()->get_ticks_usec() - started_at));
+		}
+		return; //could not guess type
+	}
+
+	int thumbnail_size = EDITOR_GET("filesystem/file_dialog/thumbnail_size");
+	thumbnail_size *= EDSCALE;
+
+	r_texture = Ref<ImageTexture>();
+	r_small_texture = Ref<ImageTexture>();
+
+	for (int i = 0; i < preview_generators.size(); i++) {
+		if (!preview_generators[i]->handles(type)) {
+			continue;
+		}
+
+		Ref<Texture2D> generated;
+		if (p_item.resource.is_valid()) {
+			generated = preview_generators.write[i]->generate(p_item.resource, Vector2(thumbnail_size, thumbnail_size), p_metadata);
+		} else {
+			generated = preview_generators.write[i]->generate_from_path(p_item.path, Vector2(thumbnail_size, thumbnail_size), p_metadata);
+		}
+		r_texture = generated;
+
+		if (preview_generators[i]->can_generate_small_preview()) {
+			Ref<Texture2D> generated_small;
+			Dictionary d;
+			if (p_item.resource.is_valid()) {
+				generated_small = preview_generators.write[i]->generate(p_item.resource, Vector2(small_thumbnail_size, small_thumbnail_size), d);
+			} else {
+				generated_small = preview_generators.write[i]->generate_from_path(p_item.path, Vector2(small_thumbnail_size, small_thumbnail_size), d);
+			}
+			r_small_texture = generated_small;
+		}
+
+		if (r_small_texture.is_null() && r_texture.is_valid() && preview_generators[i]->generate_small_preview_automatically()) {
+			Ref<Image> small_image = r_texture->get_image()->duplicate();
+			Vector2i new_size = Vector2i(1, 1) * small_thumbnail_size;
+			const real_t aspect = small_image->get_size().aspect();
+			if (aspect > 1.0) {
+				new_size.y = MAX(1, new_size.y / aspect);
+			} else if (aspect < 1.0) {
+				new_size.x = MAX(1, new_size.x * aspect);
+			}
+			small_image->resize(new_size.x, new_size.y, Image::INTERPOLATE_CUBIC);
+
+			// Make sure the image is always square.
+			if (aspect != 1.0) {
+				Ref<Image> rect = small_image;
+				const Vector2i rect_size = rect->get_size();
+				small_image = Image::create_empty(small_thumbnail_size, small_thumbnail_size, false, rect->get_format());
+				// Blit the rectangle in the center of the square.
+				small_image->blit_rect(rect, Rect2i(Vector2i(), rect_size), (Vector2i(1, 1) * small_thumbnail_size - rect_size) / 2);
+			}
+
+			r_small_texture.instantiate();
+			r_small_texture->set_image(small_image);
+		}
+
+		if (generated.is_valid()) {
+			break;
+		}
+	}
+
+	if (p_item.resource.is_null()) {
+		// Cache the preview in case it's a resource on disk.
+		if (r_texture.is_valid()) {
+			// Wow it generated a preview... save cache.
+			bool has_small_texture = r_small_texture.is_valid();
+			ResourceSaver::save(r_texture, cache_base + ".png");
+			if (has_small_texture) {
+				ResourceSaver::save(r_small_texture, cache_base + "_small.png");
+			}
+			Ref<FileAccess> f = FileAccess::open(cache_base + ".txt", FileAccess::WRITE);
+			ERR_FAIL_COND_MSG(f.is_null(), "Cannot create file '" + cache_base + ".txt'. Check user write permissions.");
+
+			uint64_t modtime = FileAccess::get_modified_time(p_item.path);
+			String import_path = p_item.path + ".import";
+			if (FileAccess::exists(import_path)) {
+				modtime = MAX(modtime, FileAccess::get_modified_time(import_path));
+			}
+
+			_write_preview_cache(f, thumbnail_size, has_small_texture, modtime, FileAccess::get_md5(p_item.path), p_metadata);
+		}
+	}
+
+	if (is_print_verbose_enabled()) {
+		print_line(vformat("Generated '%s' preview in %d usec", p_item.path, OS::get_singleton()->get_ticks_usec() - started_at));
+	}
+}
+
+const Dictionary EditorResourcePreview::get_preview_metadata(const String &p_path) const {
+	ERR_FAIL_COND_V(!cache.has(p_path), Dictionary());
+	return cache[p_path].preview_metadata;
+}
+
+void EditorResourcePreview::_iterate() {
+	preview_mutex.lock();
+
+	if (queue.is_empty()) {
+		preview_mutex.unlock();
+		return;
+	}
+
+	QueueItem item = queue.front()->get();
+	queue.pop_front();
+
+	if (cache.has(item.path)) {
+		Item cached_item = cache[item.path];
+		// Already has it because someone loaded it, just let it know it's ready.
+		_preview_ready(item.path, cached_item.last_hash, cached_item.preview, cached_item.small_preview, item.id, item.function, item.userdata, cached_item.preview_metadata);
+		preview_mutex.unlock();
+		return;
+	}
+	preview_mutex.unlock();
+
+	Ref<ImageTexture> texture;
+	Ref<ImageTexture> small_texture;
+
+	int thumbnail_size = EDITOR_GET("filesystem/file_dialog/thumbnail_size");
+	thumbnail_size *= EDSCALE;
+
+	if (item.resource.is_valid()) {
+		Dictionary preview_metadata;
+		_generate_preview(texture, small_texture, item, String(), preview_metadata);
+		_preview_ready(item.path, item.resource->hash_edited_version_for_preview(), texture, small_texture, item.id, item.function, item.userdata, preview_metadata);
+		return;
+	}
+
+	Dictionary preview_metadata;
+	String temp_path = EditorPaths::get_singleton()->get_cache_dir();
+	String cache_base = ProjectSettings::get_singleton()->globalize_path(item.path).md5_text();
+	cache_base = temp_path.path_join("resthumb-" + cache_base);
+
+	// Does not have it, try to load a cached thumbnail.
+
+	String file = cache_base + ".txt";
+	Ref<FileAccess> f = FileAccess::open(file, FileAccess::READ);
+	if (f.is_null()) {
+		// No cache found, generate.
+		_generate_preview(texture, small_texture, item, cache_base, preview_metadata);
+	} else {
+		uint64_t modtime = FileAccess::get_modified_time(item.path);
+		String import_path = item.path + ".import";
+		if (FileAccess::exists(import_path)) {
+			modtime = MAX(modtime, FileAccess::get_modified_time(import_path));
+		}
+
+		int tsize;
+		bool has_small_texture;
+		uint64_t last_modtime;
+		String hash;
+		bool outdated;
+		_read_preview_cache(f, &tsize, &has_small_texture, &last_modtime, &hash, &preview_metadata, &outdated);
+
+		bool cache_valid = true;
+
+		if (tsize != thumbnail_size) {
+			cache_valid = false;
+			f.unref();
+		} else if (outdated) {
+			cache_valid = false;
+			f.unref();
+		} else if (last_modtime != modtime) {
+			String last_md5 = f->get_line();
+			String md5 = FileAccess::get_md5(item.path);
+			f.unref();
+
+			if (last_md5 != md5) {
+				cache_valid = false;
+			} else {
+				// Update modified time.
+
+				Ref<FileAccess> f2 = FileAccess::open(file, FileAccess::WRITE);
+				if (f2.is_null()) {
+					// Not returning as this would leave the thread hanging and would require
+					// some proper cleanup/disabling of resource preview generation.
+					ERR_PRINT("Cannot create file '" + file + "'. Check user write permissions.");
+				} else {
+					_write_preview_cache(f2, thumbnail_size, has_small_texture, modtime, md5, preview_metadata);
+				}
+			}
+		} else {
+			f.unref();
+		}
+
+		if (cache_valid) {
+			Ref<Image> img;
+			img.instantiate();
+			Ref<Image> small_img;
+			small_img.instantiate();
+
+			if (img->load(cache_base + ".png") != OK) {
+				cache_valid = false;
+			} else {
+				texture.instantiate();
+				texture->set_image(img);
+
+				if (has_small_texture) {
+					if (small_img->load(cache_base + "_small.png") != OK) {
+						cache_valid = false;
+					} else {
+						small_texture.instantiate();
+						small_texture->set_image(small_img);
+					}
+				}
+			}
+		}
+
+		if (!cache_valid) {
+			_generate_preview(texture, small_texture, item, cache_base, preview_metadata);
+		}
+	}
+	_preview_ready(item.path, 0, texture, small_texture, item.id, item.function, item.userdata, preview_metadata);
+}
+
+void EditorResourcePreview::_write_preview_cache(Ref<FileAccess> p_file, int p_thumbnail_size, bool p_has_small_texture, uint64_t p_modified_time, const String &p_hash, const Dictionary &p_metadata) {
+	p_file->store_line(itos(p_thumbnail_size));
+	p_file->store_line(itos(p_has_small_texture));
+	p_file->store_line(itos(p_modified_time));
+	p_file->store_line(p_hash);
+	p_file->store_line(VariantUtilityFunctions::var_to_str(p_metadata).replace_char('\n', ' '));
+	p_file->store_line(itos(CURRENT_METADATA_VERSION));
+}
+
+void EditorResourcePreview::_read_preview_cache(Ref<FileAccess> p_file, int *r_thumbnail_size, bool *r_has_small_texture, uint64_t *r_modified_time, String *r_hash, Dictionary *r_metadata, bool *r_outdated) {
+	*r_thumbnail_size = p_file->get_line().to_int();
+	*r_has_small_texture = p_file->get_line().to_int();
+	*r_modified_time = p_file->get_line().to_int();
+	*r_hash = p_file->get_line();
+	*r_metadata = VariantUtilityFunctions::str_to_var(p_file->get_line());
+	*r_outdated = p_file->get_line().to_int() < CURRENT_METADATA_VERSION;
+}
+
+void EditorResourcePreview::_thread() {
+	exited.clear();
+	while (!exiting.is_set()) {
+		preview_sem.wait();
+		_iterate();
+	}
+	exited.set();
+}
+
+void EditorResourcePreview::_idle_callback() {
+	if (!singleton) {
+		// Just in case the shutdown of the editor involves the deletion of the singleton
+		// happening while additional idle callbacks can happen.
+		return;
+	}
+
+	// Process preview tasks, trying to leave a little bit of responsiveness worst case.
+	uint64_t start = OS::get_singleton()->get_ticks_msec();
+	while (!singleton->queue.is_empty() && OS::get_singleton()->get_ticks_msec() - start < 100) {
+		singleton->_iterate();
+	}
+}
+
+void EditorResourcePreview::_update_thumbnail_sizes() {
+	if (small_thumbnail_size == -1) {
+		// Kind of a workaround to retrieve the default icon size.
+		small_thumbnail_size = EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Object"), EditorStringName(EditorIcons))->get_width();
+	}
+}
+
+EditorResourcePreview::PreviewItem EditorResourcePreview::get_resource_preview_if_available(const String &p_path) {
+	PreviewItem item;
+	{
+		MutexLock lock(preview_mutex);
+
+		HashMap<String, EditorResourcePreview::Item>::Iterator I = cache.find(p_path);
+		if (!I) {
+			return item;
+		}
+
+		EditorResourcePreview::Item &cached_item = I->value;
+		item.preview = cached_item.preview;
+		item.small_preview = cached_item.small_preview;
+	}
+	preview_sem.post();
+	return item;
+}
+
+void EditorResourcePreview::queue_edited_resource_preview(const Ref<Resource> &p_res, Object *p_receiver, const StringName &p_receiver_func, const Variant &p_userdata) {
+	ERR_FAIL_NULL(p_receiver);
+	ERR_FAIL_COND(p_res.is_null());
+	_update_thumbnail_sizes();
+
+	{
+		MutexLock lock(preview_mutex);
+
+		String path_id = "ID:" + itos(p_res->get_instance_id());
+
+		if (cache.has(path_id) && cache[path_id].last_hash == p_res->hash_edited_version_for_preview()) {
+			p_receiver->call(p_receiver_func, path_id, cache[path_id].preview, cache[path_id].small_preview, p_userdata);
+			return;
+		}
+
+		cache.erase(path_id); //erase if exists, since it will be regen
+
+		QueueItem item;
+		item.function = p_receiver_func;
+		item.id = p_receiver->get_instance_id();
+		item.resource = p_res;
+		item.path = path_id;
+		item.userdata = p_userdata;
+
+		queue.push_back(item);
+	}
+	preview_sem.post();
+}
+
+void EditorResourcePreview::queue_resource_preview(const String &p_path, Object *p_receiver, const StringName &p_receiver_func, const Variant &p_userdata) {
+	ERR_FAIL_NULL(p_receiver);
+	_update_thumbnail_sizes();
+
+	{
+		MutexLock lock(preview_mutex);
+
+		if (cache.has(p_path)) {
+			p_receiver->call(p_receiver_func, p_path, cache[p_path].preview, cache[p_path].small_preview, p_userdata);
+			return;
+		}
+
+		QueueItem item;
+		item.function = p_receiver_func;
+		item.id = p_receiver->get_instance_id();
+		item.path = p_path;
+		item.userdata = p_userdata;
+
+		queue.push_back(item);
+	}
+	preview_sem.post();
+}
+
+void EditorResourcePreview::add_preview_generator(const Ref<EditorResourcePreviewGenerator> &p_generator) {
+	preview_generators.push_back(p_generator);
+}
+
+void EditorResourcePreview::remove_preview_generator(const Ref<EditorResourcePreviewGenerator> &p_generator) {
+	preview_generators.erase(p_generator);
+}
+
+EditorResourcePreview *EditorResourcePreview::get_singleton() {
+	return singleton;
+}
+
+void EditorResourcePreview::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("queue_resource_preview", "path", "receiver", "receiver_func", "userdata"), &EditorResourcePreview::queue_resource_preview);
+	ClassDB::bind_method(D_METHOD("queue_edited_resource_preview", "resource", "receiver", "receiver_func", "userdata"), &EditorResourcePreview::queue_edited_resource_preview);
+	ClassDB::bind_method(D_METHOD("add_preview_generator", "generator"), &EditorResourcePreview::add_preview_generator);
+	ClassDB::bind_method(D_METHOD("remove_preview_generator", "generator"), &EditorResourcePreview::remove_preview_generator);
+	ClassDB::bind_method(D_METHOD("check_for_invalidation", "path"), &EditorResourcePreview::check_for_invalidation);
+
+	ADD_SIGNAL(MethodInfo("preview_invalidated", PropertyInfo(Variant::STRING, "path")));
+}
+
+void EditorResourcePreview::_notification(int p_what) {
+	switch (p_what) {
+		case NOTIFICATION_EXIT_TREE: {
+			stop();
+		} break;
+	}
+}
+
+void EditorResourcePreview::check_for_invalidation(const String &p_path) {
+	bool call_invalidated = false;
+	{
+		MutexLock lock(preview_mutex);
+
+		if (cache.has(p_path)) {
+			uint64_t modified_time = FileAccess::get_modified_time(p_path);
+			String import_path = p_path + ".import";
+			if (FileAccess::exists(import_path)) {
+				modified_time = MAX(modified_time, FileAccess::get_modified_time(import_path));
+			}
+
+			if (modified_time != cache[p_path].modified_time) {
+				cache.erase(p_path);
+				call_invalidated = true;
+			}
+		}
+	}
+
+	if (call_invalidated) { //do outside mutex
+		call_deferred(SNAME("emit_signal"), "preview_invalidated", p_path);
+	}
+}
+
+void EditorResourcePreview::start() {
+	if (DisplayServer::get_singleton()->get_name() == "headless") {
+		return;
+	}
+
+	if (is_threaded()) {
+		ERR_FAIL_COND_MSG(thread.is_started(), "Thread already started.");
+		thread.start(_thread_func, this);
+	} else {
+		SceneTree *st = Object::cast_to<SceneTree>(OS::get_singleton()->get_main_loop());
+		ERR_FAIL_NULL_MSG(st, "Editor's MainLoop is not a SceneTree. This is a bug.");
+		st->add_idle_callback(&_idle_callback);
+	}
+}
+
+void EditorResourcePreview::stop() {
+	if (is_threaded()) {
+		if (thread.is_started()) {
+			exiting.set();
+			preview_sem.post();
+
+			for (int i = 0; i < preview_generators.size(); i++) {
+				preview_generators.write[i]->abort();
+			}
+
+			while (!exited.is_set()) {
+				// Sync pending work.
+				OS::get_singleton()->delay_usec(10000);
+				RenderingServer::get_singleton()->sync();
+				MessageQueue::get_singleton()->flush();
+			}
+
+			thread.wait_to_finish();
+		}
+	}
+}
+
+EditorResourcePreview::EditorResourcePreview() {
+	singleton = this;
+}
+
+EditorResourcePreview::~EditorResourcePreview() {
+	stop();
+}