/*************************************************************************/
/*  canvas_item.cpp                                                      */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md)    */
/*                                                                       */
/* 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 "canvas_item.h"
#include "core/method_bind_ext.gen.inc"
#include "message_queue.h"
#include "os/input.h"
#include "scene/main/canvas_layer.h"
#include "scene/main/viewport.h"
#include "scene/resources/font.h"
#include "scene/resources/style_box.h"
#include "scene/resources/texture.h"
#include "scene/scene_string_names.h"
#include "servers/visual_server.h"

Mutex *CanvasItemMaterial::material_mutex = NULL;
SelfList<CanvasItemMaterial>::List CanvasItemMaterial::dirty_materials;
Map<CanvasItemMaterial::MaterialKey, CanvasItemMaterial::ShaderData> CanvasItemMaterial::shader_map;

void CanvasItemMaterial::init_shaders() {

#ifndef NO_THREADS
	material_mutex = Mutex::create();
#endif
}

void CanvasItemMaterial::finish_shaders() {

#ifndef NO_THREADS
	memdelete(material_mutex);
#endif
}

void CanvasItemMaterial::_update_shader() {

	dirty_materials.remove(&element);

	MaterialKey mk = _compute_key();
	if (mk.key == current_key.key)
		return; //no update required in the end

	if (shader_map.has(current_key)) {
		shader_map[current_key].users--;
		if (shader_map[current_key].users == 0) {
			//deallocate shader, as it's no longer in use
			VS::get_singleton()->free(shader_map[current_key].shader);
			shader_map.erase(current_key);
		}
	}

	current_key = mk;

	if (shader_map.has(mk)) {

		VS::get_singleton()->material_set_shader(_get_material(), shader_map[mk].shader);
		shader_map[mk].users++;
		return;
	}

	//must create a shader!

	String code = "shader_type canvas_item;\nrender_mode ";
	switch (blend_mode) {
		case BLEND_MODE_MIX: code += "blend_mix"; break;
		case BLEND_MODE_ADD: code += "blend_add"; break;
		case BLEND_MODE_SUB: code += "blend_sub"; break;
		case BLEND_MODE_MUL: code += "blend_mul"; break;
		case BLEND_MODE_PREMULT_ALPHA: code += "blend_premul_alpha"; break;
	}

	switch (light_mode) {
		case LIGHT_MODE_NORMAL: break;
		case LIGHT_MODE_UNSHADED: code += ",unshaded"; break;
		case LIGHT_MODE_LIGHT_ONLY: code += ",light_only"; break;
	}
	code += ";\n"; //thats it.

	ShaderData shader_data;
	shader_data.shader = VS::get_singleton()->shader_create();
	shader_data.users = 1;

	VS::get_singleton()->shader_set_code(shader_data.shader, code);

	shader_map[mk] = shader_data;

	VS::get_singleton()->material_set_shader(_get_material(), shader_data.shader);
}

void CanvasItemMaterial::flush_changes() {

	if (material_mutex)
		material_mutex->lock();

	while (dirty_materials.first()) {

		dirty_materials.first()->self()->_update_shader();
	}

	if (material_mutex)
		material_mutex->unlock();
}

void CanvasItemMaterial::_queue_shader_change() {

	if (material_mutex)
		material_mutex->lock();

	if (!element.in_list()) {
		dirty_materials.add(&element);
	}

	if (material_mutex)
		material_mutex->unlock();
}

bool CanvasItemMaterial::_is_shader_dirty() const {

	bool dirty = false;

	if (material_mutex)
		material_mutex->lock();

	dirty = element.in_list();

	if (material_mutex)
		material_mutex->unlock();

	return dirty;
}
void CanvasItemMaterial::set_blend_mode(BlendMode p_blend_mode) {

	blend_mode = p_blend_mode;
	_queue_shader_change();
}

CanvasItemMaterial::BlendMode CanvasItemMaterial::get_blend_mode() const {
	return blend_mode;
}

void CanvasItemMaterial::set_light_mode(LightMode p_light_mode) {

	light_mode = p_light_mode;
	_queue_shader_change();
}

CanvasItemMaterial::LightMode CanvasItemMaterial::get_light_mode() const {

	return light_mode;
}

void CanvasItemMaterial::_validate_property(PropertyInfo &property) const {
}

void CanvasItemMaterial::_bind_methods() {

	ClassDB::bind_method(D_METHOD("set_blend_mode", "blend_mode"), &CanvasItemMaterial::set_blend_mode);
	ClassDB::bind_method(D_METHOD("get_blend_mode"), &CanvasItemMaterial::get_blend_mode);

	ClassDB::bind_method(D_METHOD("set_light_mode", "light_mode"), &CanvasItemMaterial::set_light_mode);
	ClassDB::bind_method(D_METHOD("get_light_mode"), &CanvasItemMaterial::get_light_mode);

	ADD_PROPERTY(PropertyInfo(Variant::INT, "blend_mode", PROPERTY_HINT_ENUM, "Mix,Add,Sub,Mul,Premult Alpha"), "set_blend_mode", "get_blend_mode");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "light_mode", PROPERTY_HINT_ENUM, "Normal,Unshaded,Light Only"), "set_light_mode", "get_light_mode");

	BIND_CONSTANT(BLEND_MODE_MIX);
	BIND_CONSTANT(BLEND_MODE_ADD);
	BIND_CONSTANT(BLEND_MODE_SUB);
	BIND_CONSTANT(BLEND_MODE_MUL);
	BIND_CONSTANT(BLEND_MODE_PREMULT_ALPHA);
	BIND_CONSTANT(LIGHT_MODE_NORMAL);
	BIND_CONSTANT(LIGHT_MODE_UNSHADED);
	BIND_CONSTANT(LIGHT_MODE_LIGHT_ONLY);
}

CanvasItemMaterial::CanvasItemMaterial()
	: element(this) {

	blend_mode = BLEND_MODE_MIX;
	light_mode = LIGHT_MODE_NORMAL;

	current_key.key = 0;
	current_key.invalid_key = 1;
	_queue_shader_change();
}

CanvasItemMaterial::~CanvasItemMaterial() {

	if (material_mutex)
		material_mutex->lock();

	if (shader_map.has(current_key)) {
		shader_map[current_key].users--;
		if (shader_map[current_key].users == 0) {
			//deallocate shader, as it's no longer in use
			VS::get_singleton()->free(shader_map[current_key].shader);
			shader_map.erase(current_key);
		}

		VS::get_singleton()->material_set_shader(_get_material(), RID());
	}

	if (material_mutex)
		material_mutex->unlock();
}

///////////////////////////////////////////////////////////////////

bool CanvasItem::is_visible_in_tree() const {

	if (!is_inside_tree())
		return false;

	const CanvasItem *p = this;

	while (p) {
		if (!p->visible)
			return false;
		p = p->get_parent_item();
	}

	return true;
}

void CanvasItem::_propagate_visibility_changed(bool p_visible) {

	notification(NOTIFICATION_VISIBILITY_CHANGED);

	if (p_visible)
		update(); //todo optimize
	else
		emit_signal(SceneStringNames::get_singleton()->hide);
	_block();

	for (int i = 0; i < get_child_count(); i++) {

		CanvasItem *c = get_child(i)->cast_to<CanvasItem>();

		if (c && c->visible) //should the toplevels stop propagation? i think so but..
			c->_propagate_visibility_changed(p_visible);
	}

	_unblock();
}

void CanvasItem::show() {

	if (visible)
		return;

	visible = true;
	VisualServer::get_singleton()->canvas_item_set_visible(canvas_item, true);

	if (!is_inside_tree())
		return;

	_propagate_visibility_changed(true);
	_change_notify("visible");
}

void CanvasItem::hide() {

	if (!visible)
		return;

	visible = false;
	VisualServer::get_singleton()->canvas_item_set_visible(canvas_item, false);

	if (!is_inside_tree())
		return;

	_propagate_visibility_changed(false);
	_change_notify("visible");
}

Variant CanvasItem::edit_get_state() const {

	return Variant();
}
void CanvasItem::edit_set_state(const Variant &p_state) {
}

void CanvasItem::edit_set_rect(const Rect2 &p_edit_rect) {

	//used by editors, implement at will
}

void CanvasItem::edit_rotate(float p_rot) {
}

Size2 CanvasItem::edit_get_minimum_size() const {

	return Size2(-1, -1); //no limit
}

void CanvasItem::_update_callback() {

	if (!is_inside_tree()) {
		pending_update = false;
		return;
	}

	VisualServer::get_singleton()->canvas_item_clear(get_canvas_item());
	//todo updating = true - only allow drawing here
	if (is_visible_in_tree()) { //todo optimize this!!
		if (first_draw) {
			notification(NOTIFICATION_VISIBILITY_CHANGED);
			first_draw = false;
		}
		drawing = true;
		notification(NOTIFICATION_DRAW);
		emit_signal(SceneStringNames::get_singleton()->draw);
		if (get_script_instance()) {
			Variant::CallError err;
			get_script_instance()->call_multilevel_reversed(SceneStringNames::get_singleton()->_draw, NULL, 0);
		}
		drawing = false;
	}
	//todo updating = false
	pending_update = false; // don't change to false until finished drawing (avoid recursive update)
}

Transform2D CanvasItem::get_global_transform_with_canvas() const {

	const CanvasItem *ci = this;
	Transform2D xform;
	const CanvasItem *last_valid = NULL;

	while (ci) {

		last_valid = ci;
		xform = ci->get_transform() * xform;
		ci = ci->get_parent_item();
	}

	if (last_valid->canvas_layer)
		return last_valid->canvas_layer->get_transform() * xform;
	else if (is_inside_tree())
		return get_viewport()->get_canvas_transform() * xform;

	return xform;
}

Transform2D CanvasItem::get_global_transform() const {
#ifdef DEBUG_ENABLED
	ERR_FAIL_COND_V(!is_inside_tree(), get_transform());
#endif
	if (global_invalid) {

		const CanvasItem *pi = get_parent_item();
		if (pi)
			global_transform = pi->get_global_transform() * get_transform();
		else
			global_transform = get_transform();

		global_invalid = false;
	}

	return global_transform;
}

void CanvasItem::_toplevel_raise_self() {

	if (!is_inside_tree())
		return;

	if (canvas_layer)
		VisualServer::get_singleton()->canvas_item_set_draw_index(canvas_item, canvas_layer->get_sort_index());
	else
		VisualServer::get_singleton()->canvas_item_set_draw_index(canvas_item, get_viewport()->gui_get_canvas_sort_index());
}

void CanvasItem::_enter_canvas() {

	if ((!get_parent() || !get_parent()->cast_to<CanvasItem>()) || toplevel) {

		Node *n = this;

		canvas_layer = NULL;

		while (n) {

			canvas_layer = n->cast_to<CanvasLayer>();
			if (canvas_layer) {
				break;
			}
			n = n->get_parent();
		}

		RID canvas;
		if (canvas_layer)
			canvas = canvas_layer->get_world_2d()->get_canvas();
		else
			canvas = get_viewport()->find_world_2d()->get_canvas();

		VisualServer::get_singleton()->canvas_item_set_parent(canvas_item, canvas);

		group = "root_canvas" + itos(canvas.get_id());

		add_to_group(group);
		if (canvas_layer)
			canvas_layer->reset_sort_index();
		else
			get_viewport()->gui_reset_canvas_sort_index();

		get_tree()->call_group_flags(SceneTree::GROUP_CALL_UNIQUE, group, "_toplevel_raise_self");

	} else {

		CanvasItem *parent = get_parent_item();
		canvas_layer = parent->canvas_layer;
		VisualServer::get_singleton()->canvas_item_set_parent(canvas_item, parent->get_canvas_item());
		VisualServer::get_singleton()->canvas_item_set_draw_index(canvas_item, get_index());
	}

	pending_update = false;
	update();

	notification(NOTIFICATION_ENTER_CANVAS);
}

void CanvasItem::_exit_canvas() {

	notification(NOTIFICATION_EXIT_CANVAS, true); //reverse the notification
	VisualServer::get_singleton()->canvas_item_set_parent(canvas_item, RID());
	canvas_layer = NULL;
	group = "";
}

void CanvasItem::_notification(int p_what) {

	switch (p_what) {
		case NOTIFICATION_ENTER_TREE: {

			first_draw = true;
			if (get_parent()) {
				CanvasItem *ci = get_parent()->cast_to<CanvasItem>();
				if (ci)
					C = ci->children_items.push_back(this);
			}
			_enter_canvas();
			if (!block_transform_notify && !xform_change.in_list()) {
				get_tree()->xform_change_list.add(&xform_change);
			}
		} break;
		case NOTIFICATION_MOVED_IN_PARENT: {

			if (!is_inside_tree())
				break;

			if (group != "") {
				get_tree()->call_group_flags(SceneTree::GROUP_CALL_UNIQUE, group, "_toplevel_raise_self");
			} else {
				CanvasItem *p = get_parent_item();
				ERR_FAIL_COND(!p);
				VisualServer::get_singleton()->canvas_item_set_draw_index(canvas_item, get_index());
			}

		} break;
		case NOTIFICATION_EXIT_TREE: {
			if (xform_change.in_list())
				get_tree()->xform_change_list.remove(&xform_change);
			_exit_canvas();
			if (C) {
				get_parent()->cast_to<CanvasItem>()->children_items.erase(C);
				C = NULL;
			}
			global_invalid = true;
		} break;
		case NOTIFICATION_DRAW: {

		} break;
		case NOTIFICATION_TRANSFORM_CHANGED: {

		} break;
		case NOTIFICATION_VISIBILITY_CHANGED: {

			emit_signal(SceneStringNames::get_singleton()->visibility_changed);
		} break;
	}
}

void CanvasItem::set_visible(bool p_visible) {

	if (p_visible)
		show();
	else
		hide();
}
bool CanvasItem::is_visible() const {

	return visible;
}

void CanvasItem::update() {

	if (!is_inside_tree())
		return;
	if (pending_update)
		return;

	pending_update = true;

	MessageQueue::get_singleton()->push_call(this, "_update_callback");
}

void CanvasItem::set_modulate(const Color &p_modulate) {

	modulate = p_modulate;
	VisualServer::get_singleton()->canvas_item_set_modulate(canvas_item, modulate);
}
Color CanvasItem::get_modulate() const {

	return modulate;
}

void CanvasItem::set_as_toplevel(bool p_toplevel) {

	if (toplevel == p_toplevel)
		return;

	if (!is_inside_tree()) {
		toplevel = p_toplevel;
		return;
	}

	_exit_canvas();
	toplevel = p_toplevel;
	_enter_canvas();
}

bool CanvasItem::is_set_as_toplevel() const {

	return toplevel;
}

CanvasItem *CanvasItem::get_parent_item() const {

	if (toplevel)
		return NULL;

	Node *parent = get_parent();
	if (!parent)
		return NULL;

	return parent->cast_to<CanvasItem>();
}

void CanvasItem::set_self_modulate(const Color &p_self_modulate) {

	self_modulate = p_self_modulate;
	VisualServer::get_singleton()->canvas_item_set_self_modulate(canvas_item, self_modulate);
}
Color CanvasItem::get_self_modulate() const {

	return self_modulate;
}

void CanvasItem::set_light_mask(int p_light_mask) {

	light_mask = p_light_mask;
	VS::get_singleton()->canvas_item_set_light_mask(canvas_item, p_light_mask);
}

int CanvasItem::get_light_mask() const {

	return light_mask;
}

void CanvasItem::item_rect_changed(bool p_size_changed) {

	if (p_size_changed)
		update();
	emit_signal(SceneStringNames::get_singleton()->item_rect_changed);
}

void CanvasItem::draw_line(const Point2 &p_from, const Point2 &p_to, const Color &p_color, float p_width, bool p_antialiased) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	VisualServer::get_singleton()->canvas_item_add_line(canvas_item, p_from, p_to, p_color, p_width, p_antialiased);
}

void CanvasItem::draw_rect(const Rect2 &p_rect, const Color &p_color, bool p_filled) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	if (p_filled) {

		VisualServer::get_singleton()->canvas_item_add_rect(canvas_item, p_rect, p_color);
	} else {
		VisualServer::get_singleton()->canvas_item_add_line(canvas_item, p_rect.position, p_rect.position + Size2(p_rect.size.width, 0), p_color);
		VisualServer::get_singleton()->canvas_item_add_line(canvas_item, p_rect.position, p_rect.position + Size2(0, p_rect.size.height), p_color);
		VisualServer::get_singleton()->canvas_item_add_line(canvas_item, p_rect.position + Point2(0, p_rect.size.height), p_rect.position + p_rect.size, p_color);
		VisualServer::get_singleton()->canvas_item_add_line(canvas_item, p_rect.position + Point2(p_rect.size.width, 0), p_rect.position + p_rect.size, p_color);
	}
}

void CanvasItem::draw_circle(const Point2 &p_pos, float p_radius, const Color &p_color) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	VisualServer::get_singleton()->canvas_item_add_circle(canvas_item, p_pos, p_radius, p_color);
}

void CanvasItem::draw_texture(const Ref<Texture> &p_texture, const Point2 &p_pos, const Color &p_modulate, const Ref<Texture> &p_normal_map) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	ERR_FAIL_COND(p_texture.is_null());

	p_texture->draw(canvas_item, p_pos, p_modulate);
}

void CanvasItem::draw_texture_rect(const Ref<Texture> &p_texture, const Rect2 &p_rect, bool p_tile, const Color &p_modulate, bool p_transpose, const Ref<Texture> &p_normal_map) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	ERR_FAIL_COND(p_texture.is_null());
	p_texture->draw_rect(canvas_item, p_rect, p_tile, p_modulate, p_transpose, p_normal_map);
}
void CanvasItem::draw_texture_rect_region(const Ref<Texture> &p_texture, const Rect2 &p_rect, const Rect2 &p_src_rect, const Color &p_modulate, bool p_transpose, const Ref<Texture> &p_normal_map, bool p_clip_uv) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}
	ERR_FAIL_COND(p_texture.is_null());
	p_texture->draw_rect_region(canvas_item, p_rect, p_src_rect, p_modulate, p_transpose, p_normal_map, p_clip_uv);
}

void CanvasItem::draw_style_box(const Ref<StyleBox> &p_style_box, const Rect2 &p_rect) {
	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	ERR_FAIL_COND(p_style_box.is_null());

	p_style_box->draw(canvas_item, p_rect);
}
void CanvasItem::draw_primitive(const Vector<Point2> &p_points, const Vector<Color> &p_colors, const Vector<Point2> &p_uvs, Ref<Texture> p_texture, float p_width, const Ref<Texture> &p_normal_map) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	RID rid = p_texture.is_valid() ? p_texture->get_rid() : RID();
	RID rid_normal = p_normal_map.is_valid() ? p_normal_map->get_rid() : RID();

	VisualServer::get_singleton()->canvas_item_add_primitive(canvas_item, p_points, p_colors, p_uvs, rid, p_width, rid_normal);
}
void CanvasItem::draw_set_transform(const Point2 &p_offset, float p_rot, const Size2 &p_scale) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	Transform2D xform(p_rot, p_offset);
	xform.scale_basis(p_scale);
	VisualServer::get_singleton()->canvas_item_add_set_transform(canvas_item, xform);
}

void CanvasItem::draw_set_transform_matrix(const Transform2D &p_matrix) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	VisualServer::get_singleton()->canvas_item_add_set_transform(canvas_item, p_matrix);
}

void CanvasItem::draw_polygon(const Vector<Point2> &p_points, const Vector<Color> &p_colors, const Vector<Point2> &p_uvs, Ref<Texture> p_texture, const Ref<Texture> &p_normal_map) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	RID rid = p_texture.is_valid() ? p_texture->get_rid() : RID();
	RID rid_normal = p_normal_map.is_valid() ? p_normal_map->get_rid() : RID();

	VisualServer::get_singleton()->canvas_item_add_polygon(canvas_item, p_points, p_colors, p_uvs, rid, rid_normal);
}

void CanvasItem::draw_colored_polygon(const Vector<Point2> &p_points, const Color &p_color, const Vector<Point2> &p_uvs, Ref<Texture> p_texture, const Ref<Texture> &p_normal_map) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	Vector<Color> colors;
	colors.push_back(p_color);
	RID rid = p_texture.is_valid() ? p_texture->get_rid() : RID();
	RID rid_normal = p_normal_map.is_valid() ? p_normal_map->get_rid() : RID();

	VisualServer::get_singleton()->canvas_item_add_polygon(canvas_item, p_points, colors, p_uvs, rid, rid_normal);
}

void CanvasItem::draw_string(const Ref<Font> &p_font, const Point2 &p_pos, const String &p_text, const Color &p_modulate, int p_clip_w) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL();
	}

	ERR_FAIL_COND(p_font.is_null());
	p_font->draw(canvas_item, p_pos, p_text, p_modulate, p_clip_w);
}

float CanvasItem::draw_char(const Ref<Font> &p_font, const Point2 &p_pos, const String &p_char, const String &p_next, const Color &p_modulate) {

	if (!drawing) {
		ERR_EXPLAIN("Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");
		ERR_FAIL_V(0);
	}

	ERR_FAIL_COND_V(p_char.length() != 1, 0);
	ERR_FAIL_COND_V(p_font.is_null(), 0);

	return p_font->draw_char(canvas_item, p_pos, p_char[0], p_next.c_str()[0], p_modulate);
}

void CanvasItem::_notify_transform(CanvasItem *p_node) {

	if (/*p_node->xform_change.in_list() &&*/ p_node->global_invalid) {
		return; //nothing to do
	}

	p_node->global_invalid = true;

	if (p_node->notify_transform && !p_node->xform_change.in_list()) {
		if (!p_node->block_transform_notify) {
			if (p_node->is_inside_tree())
				get_tree()->xform_change_list.add(&p_node->xform_change);
		}
	}

	for (List<CanvasItem *>::Element *E = p_node->children_items.front(); E; E = E->next()) {

		CanvasItem *ci = E->get();
		if (ci->toplevel)
			continue;
		_notify_transform(ci);
	}
}

Rect2 CanvasItem::get_viewport_rect() const {

	ERR_FAIL_COND_V(!is_inside_tree(), Rect2());
	return get_viewport()->get_visible_rect();
}

RID CanvasItem::get_canvas() const {

	ERR_FAIL_COND_V(!is_inside_tree(), RID());

	if (canvas_layer)
		return canvas_layer->get_world_2d()->get_canvas();
	else
		return get_viewport()->find_world_2d()->get_canvas();
}

CanvasItem *CanvasItem::get_toplevel() const {

	CanvasItem *ci = const_cast<CanvasItem *>(this);
	while (!ci->toplevel && ci->get_parent() && ci->get_parent()->cast_to<CanvasItem>()) {
		ci = ci->get_parent()->cast_to<CanvasItem>();
	}

	return ci;
}

Ref<World2D> CanvasItem::get_world_2d() const {

	ERR_FAIL_COND_V(!is_inside_tree(), Ref<World2D>());

	CanvasItem *tl = get_toplevel();

	if (tl->canvas_layer) {
		return tl->canvas_layer->get_world_2d();
	} else if (tl->get_viewport()) {
		return tl->get_viewport()->find_world_2d();
	} else {
		return Ref<World2D>();
	}
}

RID CanvasItem::get_viewport_rid() const {

	ERR_FAIL_COND_V(!is_inside_tree(), RID());
	return get_viewport()->get_viewport_rid();
}

void CanvasItem::set_block_transform_notify(bool p_enable) {
	block_transform_notify = p_enable;
}

bool CanvasItem::is_block_transform_notify_enabled() const {

	return block_transform_notify;
}

void CanvasItem::set_draw_behind_parent(bool p_enable) {

	if (behind == p_enable)
		return;
	behind = p_enable;
	VisualServer::get_singleton()->canvas_item_set_draw_behind_parent(canvas_item, behind);
}

bool CanvasItem::is_draw_behind_parent_enabled() const {

	return behind;
}

void CanvasItem::set_material(const Ref<Material> &p_material) {

	material = p_material;
	RID rid;
	if (material.is_valid())
		rid = material->get_rid();
	VS::get_singleton()->canvas_item_set_material(canvas_item, rid);
	_change_notify(); //properties for material exposed
}

void CanvasItem::set_use_parent_material(bool p_use_parent_material) {

	use_parent_material = p_use_parent_material;
	VS::get_singleton()->canvas_item_set_use_parent_material(canvas_item, p_use_parent_material);
}

bool CanvasItem::get_use_parent_material() const {

	return use_parent_material;
}

Ref<Material> CanvasItem::get_material() const {

	return material;
}

Vector2 CanvasItem::make_canvas_pos_local(const Vector2 &screen_point) const {

	ERR_FAIL_COND_V(!is_inside_tree(), screen_point);

	Transform2D local_matrix = (get_canvas_transform() * get_global_transform()).affine_inverse();

	return local_matrix.xform(screen_point);
}

Ref<InputEvent> CanvasItem::make_input_local(const Ref<InputEvent> &p_event) const {

	ERR_FAIL_COND_V(!is_inside_tree(), p_event);

	return p_event->xformed_by((get_canvas_transform() * get_global_transform()).affine_inverse());
}

Vector2 CanvasItem::get_global_mouse_position() const {

	ERR_FAIL_COND_V(!get_viewport(), Vector2());
	return get_canvas_transform().affine_inverse().xform(get_viewport()->get_mouse_position());
}
Vector2 CanvasItem::get_local_mouse_pos() const {

	ERR_FAIL_COND_V(!get_viewport(), Vector2());

	return get_global_transform().affine_inverse().xform(get_global_mouse_position());
}

void CanvasItem::_bind_methods() {

	ClassDB::bind_method(D_METHOD("_toplevel_raise_self"), &CanvasItem::_toplevel_raise_self);
	ClassDB::bind_method(D_METHOD("_update_callback"), &CanvasItem::_update_callback);

	ClassDB::bind_method(D_METHOD("edit_set_state", "state"), &CanvasItem::edit_set_state);
	ClassDB::bind_method(D_METHOD("edit_get_state:Variant"), &CanvasItem::edit_get_state);
	ClassDB::bind_method(D_METHOD("edit_set_rect", "rect"), &CanvasItem::edit_set_rect);
	ClassDB::bind_method(D_METHOD("edit_rotate", "degrees"), &CanvasItem::edit_rotate);

	ClassDB::bind_method(D_METHOD("get_item_rect"), &CanvasItem::get_item_rect);
	ClassDB::bind_method(D_METHOD("get_item_and_children_rect"), &CanvasItem::get_item_and_children_rect);
	//ClassDB::bind_method(D_METHOD("get_transform"),&CanvasItem::get_transform);

	ClassDB::bind_method(D_METHOD("get_canvas_item"), &CanvasItem::get_canvas_item);

	ClassDB::bind_method(D_METHOD("set_visible"), &CanvasItem::set_visible);
	ClassDB::bind_method(D_METHOD("is_visible"), &CanvasItem::is_visible);
	ClassDB::bind_method(D_METHOD("is_visible_in_tree"), &CanvasItem::is_visible_in_tree);
	ClassDB::bind_method(D_METHOD("show"), &CanvasItem::show);
	ClassDB::bind_method(D_METHOD("hide"), &CanvasItem::hide);

	ClassDB::bind_method(D_METHOD("update"), &CanvasItem::update);

	ClassDB::bind_method(D_METHOD("set_as_toplevel", "enable"), &CanvasItem::set_as_toplevel);
	ClassDB::bind_method(D_METHOD("is_set_as_toplevel"), &CanvasItem::is_set_as_toplevel);

	ClassDB::bind_method(D_METHOD("set_light_mask", "light_mask"), &CanvasItem::set_light_mask);
	ClassDB::bind_method(D_METHOD("get_light_mask"), &CanvasItem::get_light_mask);

	ClassDB::bind_method(D_METHOD("set_modulate", "modulate"), &CanvasItem::set_modulate);
	ClassDB::bind_method(D_METHOD("get_modulate"), &CanvasItem::get_modulate);
	ClassDB::bind_method(D_METHOD("set_self_modulate", "self_modulate"), &CanvasItem::set_self_modulate);
	ClassDB::bind_method(D_METHOD("get_self_modulate"), &CanvasItem::get_self_modulate);

	ClassDB::bind_method(D_METHOD("set_draw_behind_parent", "enable"), &CanvasItem::set_draw_behind_parent);
	ClassDB::bind_method(D_METHOD("is_draw_behind_parent_enabled"), &CanvasItem::is_draw_behind_parent_enabled);

	ClassDB::bind_method(D_METHOD("_set_on_top", "on_top"), &CanvasItem::_set_on_top);
	ClassDB::bind_method(D_METHOD("_is_on_top"), &CanvasItem::_is_on_top);
	//ClassDB::bind_method(D_METHOD("get_transform"),&CanvasItem::get_transform);

	ClassDB::bind_method(D_METHOD("draw_line", "from", "to", "color", "width", "antialiased"), &CanvasItem::draw_line, DEFVAL(1.0), DEFVAL(false));
	ClassDB::bind_method(D_METHOD("draw_rect", "rect", "color", "filled"), &CanvasItem::draw_rect, DEFVAL(true));
	ClassDB::bind_method(D_METHOD("draw_circle", "pos", "radius", "color"), &CanvasItem::draw_circle);
	ClassDB::bind_method(D_METHOD("draw_texture", "texture:Texture", "pos", "modulate", "normal_map:Texture"), &CanvasItem::draw_texture, DEFVAL(Color(1, 1, 1, 1)), DEFVAL(Variant()));
	ClassDB::bind_method(D_METHOD("draw_texture_rect", "texture:Texture", "rect", "tile", "modulate", "transpose", "normal_map:Texture"), &CanvasItem::draw_texture_rect, DEFVAL(Color(1, 1, 1)), DEFVAL(false), DEFVAL(Variant()));
	ClassDB::bind_method(D_METHOD("draw_texture_rect_region", "texture:Texture", "rect", "src_rect", "modulate", "transpose", "normal_map:Texture", "clip_uv"), &CanvasItem::draw_texture_rect_region, DEFVAL(Color(1, 1, 1)), DEFVAL(false), DEFVAL(Variant()), DEFVAL(true));
	ClassDB::bind_method(D_METHOD("draw_style_box", "style_box:StyleBox", "rect"), &CanvasItem::draw_style_box);
	ClassDB::bind_method(D_METHOD("draw_primitive", "points", "colors", "uvs", "texture:Texture", "width", "normal_map:Texture"), &CanvasItem::draw_primitive, DEFVAL(Variant()), DEFVAL(1.0), DEFVAL(Variant()));
	ClassDB::bind_method(D_METHOD("draw_polygon", "points", "colors", "uvs", "texture:Texture", "normal_map:Texture"), &CanvasItem::draw_polygon, DEFVAL(PoolVector2Array()), DEFVAL(Variant()), DEFVAL(Variant()));
	ClassDB::bind_method(D_METHOD("draw_colored_polygon", "points", "color", "uvs", "texture:Texture", "normal_map:Texture"), &CanvasItem::draw_colored_polygon, DEFVAL(PoolVector2Array()), DEFVAL(Variant()), DEFVAL(Variant()));
	ClassDB::bind_method(D_METHOD("draw_string", "font:Font", "pos", "text", "modulate", "clip_w"), &CanvasItem::draw_string, DEFVAL(Color(1, 1, 1)), DEFVAL(-1));
	ClassDB::bind_method(D_METHOD("draw_char", "font:Font", "pos", "char", "next", "modulate"), &CanvasItem::draw_char, DEFVAL(Color(1, 1, 1)));

	ClassDB::bind_method(D_METHOD("draw_set_transform", "pos", "rot", "scale"), &CanvasItem::draw_set_transform);
	ClassDB::bind_method(D_METHOD("draw_set_transform_matrix", "xform"), &CanvasItem::draw_set_transform_matrix);
	ClassDB::bind_method(D_METHOD("get_transform"), &CanvasItem::get_transform);
	ClassDB::bind_method(D_METHOD("get_global_transform"), &CanvasItem::get_global_transform);
	ClassDB::bind_method(D_METHOD("get_global_transform_with_canvas"), &CanvasItem::get_global_transform_with_canvas);
	ClassDB::bind_method(D_METHOD("get_viewport_transform"), &CanvasItem::get_viewport_transform);
	ClassDB::bind_method(D_METHOD("get_viewport_rect"), &CanvasItem::get_viewport_rect);
	ClassDB::bind_method(D_METHOD("get_canvas_transform"), &CanvasItem::get_canvas_transform);
	ClassDB::bind_method(D_METHOD("get_local_mouse_pos"), &CanvasItem::get_local_mouse_pos);
	ClassDB::bind_method(D_METHOD("get_global_mouse_position"), &CanvasItem::get_global_mouse_position);
	ClassDB::bind_method(D_METHOD("get_canvas"), &CanvasItem::get_canvas);
	ClassDB::bind_method(D_METHOD("get_world_2d"), &CanvasItem::get_world_2d);
	//ClassDB::bind_method(D_METHOD("get_viewport"),&CanvasItem::get_viewport);

	ClassDB::bind_method(D_METHOD("set_material", "material:Material"), &CanvasItem::set_material);
	ClassDB::bind_method(D_METHOD("get_material:Material"), &CanvasItem::get_material);

	ClassDB::bind_method(D_METHOD("set_use_parent_material", "enable"), &CanvasItem::set_use_parent_material);
	ClassDB::bind_method(D_METHOD("get_use_parent_material"), &CanvasItem::get_use_parent_material);

	ClassDB::bind_method(D_METHOD("set_notify_local_transform", "enable"), &CanvasItem::set_notify_local_transform);
	ClassDB::bind_method(D_METHOD("is_local_transform_notification_enabled"), &CanvasItem::is_local_transform_notification_enabled);

	ClassDB::bind_method(D_METHOD("set_notify_transform", "enable"), &CanvasItem::set_notify_transform);
	ClassDB::bind_method(D_METHOD("is_transform_notification_enabled"), &CanvasItem::is_transform_notification_enabled);

	ClassDB::bind_method(D_METHOD("make_canvas_pos_local", "screen_point"),
			&CanvasItem::make_canvas_pos_local);
	ClassDB::bind_method(D_METHOD("make_input_local", "event"), &CanvasItem::make_input_local);

	BIND_VMETHOD(MethodInfo("_draw"));

	ADD_GROUP("Visibility", "");
	ADD_PROPERTYNO(PropertyInfo(Variant::BOOL, "visible"), "set_visible", "is_visible");
	ADD_PROPERTYNO(PropertyInfo(Variant::COLOR, "modulate"), "set_modulate", "get_modulate");
	ADD_PROPERTYNO(PropertyInfo(Variant::COLOR, "self_modulate"), "set_self_modulate", "get_self_modulate");
	ADD_PROPERTYNZ(PropertyInfo(Variant::BOOL, "show_behind_parent"), "set_draw_behind_parent", "is_draw_behind_parent_enabled");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "show_on_top", PROPERTY_HINT_NONE, "", 0), "_set_on_top", "_is_on_top"); //compatibility
	ADD_PROPERTYNO(PropertyInfo(Variant::INT, "light_mask", PROPERTY_HINT_LAYERS_2D_RENDER), "set_light_mask", "get_light_mask");

	ADD_GROUP("Material", "");
	ADD_PROPERTYNZ(PropertyInfo(Variant::OBJECT, "material", PROPERTY_HINT_RESOURCE_TYPE, "ShaderMaterial,CanvasItemMaterial"), "set_material", "get_material");
	ADD_PROPERTYNZ(PropertyInfo(Variant::BOOL, "use_parent_material"), "set_use_parent_material", "get_use_parent_material");
	//exporting these two things doesn't really make much sense i think
	//ADD_PROPERTY( PropertyInfo(Variant::BOOL,"transform/toplevel"), "set_as_toplevel","is_set_as_toplevel") ;
	//ADD_PROPERTY(PropertyInfo(Variant::BOOL,"transform/notify"),"set_transform_notify","is_transform_notify_enabled");

	ADD_SIGNAL(MethodInfo("draw"));
	ADD_SIGNAL(MethodInfo("visibility_changed"));
	ADD_SIGNAL(MethodInfo("hide"));
	ADD_SIGNAL(MethodInfo("item_rect_changed"));

	BIND_CONSTANT(BLEND_MODE_MIX);
	BIND_CONSTANT(BLEND_MODE_ADD);
	BIND_CONSTANT(BLEND_MODE_SUB);
	BIND_CONSTANT(BLEND_MODE_MUL);
	BIND_CONSTANT(BLEND_MODE_PREMULT_ALPHA);

	BIND_CONSTANT(NOTIFICATION_DRAW);
	BIND_CONSTANT(NOTIFICATION_VISIBILITY_CHANGED);
	BIND_CONSTANT(NOTIFICATION_ENTER_CANVAS);
	BIND_CONSTANT(NOTIFICATION_EXIT_CANVAS);
	BIND_CONSTANT(NOTIFICATION_TRANSFORM_CHANGED);
}

Transform2D CanvasItem::get_canvas_transform() const {

	ERR_FAIL_COND_V(!is_inside_tree(), Transform2D());

	if (canvas_layer)
		return canvas_layer->get_transform();
	else if (get_parent()->cast_to<CanvasItem>())
		return get_parent()->cast_to<CanvasItem>()->get_canvas_transform();
	else
		return get_viewport()->get_canvas_transform();
}

Transform2D CanvasItem::get_viewport_transform() const {

	ERR_FAIL_COND_V(!is_inside_tree(), Transform2D());

	if (canvas_layer) {

		if (get_viewport()) {
			return get_viewport()->get_final_transform() * canvas_layer->get_transform();
		} else {
			return canvas_layer->get_transform();
		}

	} else {
		return get_viewport()->get_final_transform() * get_viewport()->get_canvas_transform();
	}
}

void CanvasItem::set_notify_local_transform(bool p_enable) {
	notify_local_transform = p_enable;
}

bool CanvasItem::is_local_transform_notification_enabled() const {
	return notify_local_transform;
}

void CanvasItem::set_notify_transform(bool p_enable) {
	if (notify_transform == p_enable)
		return;

	notify_transform = p_enable;

	if (notify_transform && is_inside_tree()) {
		//this ensures that invalid globals get resolved, so notifications can be received
		get_global_transform();
	}
}

bool CanvasItem::is_transform_notification_enabled() const {
	return notify_transform;
}

int CanvasItem::get_canvas_layer() const {

	if (canvas_layer)
		return canvas_layer->get_layer();
	else
		return 0;
}

Rect2 CanvasItem::get_item_and_children_rect() const {

	Rect2 rect = get_item_rect();

	for (int i = 0; i < get_child_count(); i++) {
		CanvasItem *c = get_child(i)->cast_to<CanvasItem>();
		if (c) {
			Rect2 sir = c->get_transform().xform(c->get_item_and_children_rect());
			rect = rect.merge(sir);
		}
	}

	return rect;
}

CanvasItem::CanvasItem()
	: xform_change(this) {

	canvas_item = VisualServer::get_singleton()->canvas_item_create();
	visible = true;
	pending_update = false;
	modulate = Color(1, 1, 1, 1);
	self_modulate = Color(1, 1, 1, 1);
	toplevel = false;
	first_draw = false;
	drawing = false;
	behind = false;
	block_transform_notify = false;
	//viewport=NULL;
	canvas_layer = NULL;
	use_parent_material = false;
	global_invalid = true;
	notify_local_transform = false;
	notify_transform = false;
	light_mask = 1;

	C = NULL;
}

CanvasItem::~CanvasItem() {

	VisualServer::get_singleton()->free(canvas_item);
}
