/*************************************************************************/
/*  canvas_item.h                                                        */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
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#ifndef CANVAS_ITEM_H
#define CANVAS_ITEM_H

#include "scene/main/node.h"
#include "scene/main/scene_main_loop.h"
#include "scene/resources/shader.h"
#include "scene/resources/texture.h"

class CanvasLayer;
class Viewport;
class Font;

class StyleBox;

class CanvasItemMaterial : public Resource {

	OBJ_TYPE(CanvasItemMaterial, Resource);
	RID material;
	Ref<Shader> shader;

public:
	enum ShadingMode {
		SHADING_NORMAL,
		SHADING_UNSHADED,
		SHADING_ONLY_LIGHT,
	};

protected:
	ShadingMode shading_mode;

	bool _set(const StringName &p_name, const Variant &p_value);
	bool _get(const StringName &p_name, Variant &r_ret) const;
	void _get_property_list(List<PropertyInfo> *p_list) const;

	static void _bind_methods();

	void get_argument_options(const StringName &p_function, int p_idx, List<String> *r_options) const;

public:
	void set_shader(const Ref<Shader> &p_shader);
	Ref<Shader> get_shader() const;

	void set_shader_param(const StringName &p_param, const Variant &p_value);
	Variant get_shader_param(const StringName &p_param) const;

	void set_shading_mode(ShadingMode p_mode);
	ShadingMode get_shading_mode() const;

	virtual RID get_rid() const;
	CanvasItemMaterial();
	~CanvasItemMaterial();
};

VARIANT_ENUM_CAST(CanvasItemMaterial::ShadingMode);

class CanvasItem : public Node {

	OBJ_TYPE(CanvasItem, Node);

public:
	enum BlendMode {

		BLEND_MODE_MIX, //default
		BLEND_MODE_ADD,
		BLEND_MODE_SUB,
		BLEND_MODE_MUL,
		BLEND_MODE_PREMULT_ALPHA
	};

private:
	mutable SelfList<Node> xform_change;

	RID canvas_item;
	String group;

	CanvasLayer *canvas_layer;

	float opacity;
	float self_opacity;

	List<CanvasItem *> children_items;
	List<CanvasItem *>::Element *C;

	BlendMode blend_mode;
	int light_mask;

	bool first_draw;
	bool hidden;
	bool pending_update;
	bool toplevel;
	bool pending_children_sort;
	bool drawing;
	bool block_transform_notify;
	bool behind;
	bool use_parent_material;
	bool notify_local_transform;

	Ref<CanvasItemMaterial> material;

	mutable Matrix32 global_transform;
	mutable bool global_invalid;

	void _raise_self();

	void _propagate_visibility_changed(bool p_visible);

	void _set_visible_(bool p_visible);
	bool _is_visible_() const;

	void _update_callback();

	void _enter_canvas();
	void _exit_canvas();

	void _queue_sort_children();
	void _sort_children();

	void _notify_transform(CanvasItem *p_node);

	void _set_on_top(bool p_on_top) { set_draw_behind_parent(!p_on_top); }
	bool _is_on_top() const { return !is_draw_behind_parent_enabled(); }

protected:
	_FORCE_INLINE_ void _notify_transform() {
		if (!is_inside_tree()) return;
		_notify_transform(this);
		if (!block_transform_notify && notify_local_transform) notification(NOTIFICATION_LOCAL_TRANSFORM_CHANGED);
	}

	void item_rect_changed();

	void _notification(int p_what);
	static void _bind_methods();

public:
	enum {
		NOTIFICATION_TRANSFORM_CHANGED = SceneTree::NOTIFICATION_TRANSFORM_CHANGED, //unique
		NOTIFICATION_DRAW = 30,
		NOTIFICATION_VISIBILITY_CHANGED = 31,
		NOTIFICATION_ENTER_CANVAS = 32,
		NOTIFICATION_EXIT_CANVAS = 33,
		NOTIFICATION_LOCAL_TRANSFORM_CHANGED = 35,
		NOTIFICATION_WORLD_2D_CHANGED = 36,

	};

	/* EDITOR */

	virtual Variant edit_get_state() const;
	virtual void edit_set_state(const Variant &p_state);
	virtual void edit_set_rect(const Rect2 &p_edit_rect);
	virtual void edit_rotate(float p_rot);
	virtual Size2 edit_get_minimum_size() const;

	/* VISIBILITY */

	bool is_visible() const;
	bool is_hidden() const;
	void show();
	void hide();
	void set_hidden(bool p_hidden);

	void update();

	void set_blend_mode(BlendMode p_blend_mode);
	BlendMode get_blend_mode() const;

	virtual void set_light_mask(int p_light_mask);
	int get_light_mask() const;

	void set_opacity(float p_opacity);
	float get_opacity() const;

	void set_self_opacity(float p_self_opacity);
	float get_self_opacity() const;

	/* DRAWING API */

	void draw_line(const Point2 &p_from, const Point2 &p_to, const Color &p_color, float p_width = 1.0);
	void draw_rect(const Rect2 &p_rect, const Color &p_color);
	void draw_circle(const Point2 &p_pos, float p_radius, const Color &p_color);
	void draw_texture(const Ref<Texture> &p_texture, const Point2 &p_pos, const Color &p_modulate = Color(1, 1, 1, 1));
	void draw_texture_rect(const Ref<Texture> &p_texture, const Rect2 &p_rect, bool p_tile = false, const Color &p_modulate = Color(1, 1, 1), bool p_transpose = false);
	void draw_texture_rect_region(const Ref<Texture> &p_texture, const Rect2 &p_rect, const Rect2 &p_src_rect, const Color &p_modulate = Color(1, 1, 1), bool p_transpose = false);
	void draw_style_box(const Ref<StyleBox> &p_style_box, const Rect2 &p_rect);
	void draw_primitive(const Vector<Point2> &p_points, const Vector<Color> &p_colors, const Vector<Point2> &p_uvs, Ref<Texture> p_texture = Ref<Texture>(), float p_width = 1);
	void draw_polygon(const Vector<Point2> &p_points, const Vector<Color> &p_colors, const Vector<Point2> &p_uvs = Vector<Point2>(), Ref<Texture> p_texture = Ref<Texture>());
	void draw_colored_polygon(const Vector<Point2> &p_points, const Color &p_color, const Vector<Point2> &p_uvs = Vector<Point2>(), Ref<Texture> p_texture = Ref<Texture>());

	void draw_string(const Ref<Font> &p_font, const Point2 &p_pos, const String &p_text, const Color &p_modulate = Color(1, 1, 1), int p_clip_w = -1);
	float draw_char(const Ref<Font> &p_font, const Point2 &p_pos, const String &p_char, const String &p_next = "", const Color &p_modulate = Color(1, 1, 1));

	void draw_set_transform(const Point2 &p_offset, float p_rot, const Size2 &p_scale);
	void draw_set_transform_matrix(const Matrix32 &p_matrix);

	/* RECT / TRANSFORM */

	void set_as_toplevel(bool p_toplevel);
	bool is_set_as_toplevel() const;

	void set_draw_behind_parent(bool p_enable);
	bool is_draw_behind_parent_enabled() const;

	CanvasItem *get_parent_item() const;

	virtual Rect2 get_item_rect() const = 0;
	virtual Matrix32 get_transform() const = 0;

	virtual Matrix32 get_global_transform() const;
	virtual Matrix32 get_global_transform_with_canvas() const;

	Rect2 get_item_and_children_rect() const;

	CanvasItem *get_toplevel() const;
	_FORCE_INLINE_ RID get_canvas_item() const { return canvas_item; }

	void set_block_transform_notify(bool p_enable);
	bool is_block_transform_notify_enabled() const;

	Matrix32 get_canvas_transform() const;
	Matrix32 get_viewport_transform() const;
	Rect2 get_viewport_rect() const;
	RID get_viewport_rid() const;
	RID get_canvas() const;
	Ref<World2D> get_world_2d() const;

	virtual void set_material(const Ref<CanvasItemMaterial> &p_material);
	Ref<CanvasItemMaterial> get_material() const;

	virtual void set_use_parent_material(bool p_use_parent_material);
	bool get_use_parent_material() const;

	InputEvent make_input_local(const InputEvent &pevent) const;
	Vector2 make_canvas_pos_local(const Vector2 &screen_point) const;

	Vector2 get_global_mouse_pos() const;
	Vector2 get_local_mouse_pos() const;

	void set_notify_local_transform(bool p_enable);
	bool is_local_transform_notification_enabled() const;

	int get_canvas_layer() const;

	CanvasItem();
	~CanvasItem();
};

VARIANT_ENUM_CAST(CanvasItem::BlendMode);

#endif // CANVAS_ITEM_H