/*************************************************************************/
/*  dynamic_font.h                                                       */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2018 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:                                             */
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/* 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,       */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
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/*************************************************************************/

#ifndef DYNAMIC_FONT_H
#define DYNAMIC_FONT_H

#ifdef FREETYPE_ENABLED
#include "io/resource_loader.h"
#include "os/mutex.h"
#include "os/thread_safe.h"
#include "scene/resources/font.h"

#include <ft2build.h>
#include FT_FREETYPE_H

class DynamicFontAtSize;
class DynamicFont;

class DynamicFontData : public Resource {

	GDCLASS(DynamicFontData, Resource);

public:
	struct CacheID {

		union {
			struct {
				uint32_t size : 16;
				bool mipmaps : 1;
				bool filter : 1;
			};
			uint32_t key;
		};
		bool operator<(CacheID right) const;
		CacheID() {
			key = 0;
		}
	};

private:
	const uint8_t *font_mem;
	int font_mem_size;
	bool force_autohinter;

	String font_path;
	Map<CacheID, DynamicFontAtSize *> size_cache;

	friend class DynamicFontAtSize;

	friend class DynamicFont;

	Ref<DynamicFontAtSize> _get_dynamic_font_at_size(CacheID p_cache_id);

protected:
	static void _bind_methods();

public:
	void set_font_ptr(const uint8_t *p_font_mem, int p_font_mem_size);
	void set_font_path(const String &p_path);
	String get_font_path() const;
	void set_force_autohinter(bool p_force);

	DynamicFontData();
	~DynamicFontData();
};

class DynamicFontAtSize : public Reference {

	GDCLASS(DynamicFontAtSize, Reference)

	_THREAD_SAFE_CLASS_

	FT_Library library; /* handle to library     */
	FT_Face face; /* handle to face object */
	FT_StreamRec stream;

	float ascent;
	float descent;
	float linegap;
	float rect_margin;
	float oversampling;

	uint32_t texture_flags;

	bool valid;

	struct CharTexture {

		PoolVector<uint8_t> imgdata;
		int texture_size;
		Vector<int> offsets;
		Ref<ImageTexture> texture;
	};

	Vector<CharTexture> textures;

	struct Character {

		bool found;
		int texture_idx;
		Rect2 rect;
		Rect2 rect_uv;
		float v_align;
		float h_align;
		float advance;

		Character() {
			texture_idx = 0;
			v_align = 0;
		}
	};

	static unsigned long _ft_stream_io(FT_Stream stream, unsigned long offset, unsigned char *buffer, unsigned long count);
	static void _ft_stream_close(FT_Stream stream);

	HashMap<CharType, Character> char_map;

	_FORCE_INLINE_ void _update_char(CharType p_char);

	friend class DynamicFontData;
	Ref<DynamicFontData> font;
	DynamicFontData::CacheID id;

	static HashMap<String, Vector<uint8_t> > _fontdata;
	Error _load();

public:
	static float font_oversampling;

	float get_height() const;

	float get_ascent() const;
	float get_descent() const;

	Size2 get_char_size(CharType p_char, CharType p_next, const Vector<Ref<DynamicFontAtSize> > &p_fallbacks) const;

	float draw_char(RID p_canvas_item, const Point2 &p_pos, CharType p_char, CharType p_next, const Color &p_modulate, const Vector<Ref<DynamicFontAtSize> > &p_fallbacks) const;

	void set_texture_flags(uint32_t p_flags);
	bool update_oversampling();

	DynamicFontAtSize();
	~DynamicFontAtSize();
};

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

class DynamicFont : public Font {

	GDCLASS(DynamicFont, Font);

public:
	enum SpacingType {
		SPACING_TOP,
		SPACING_BOTTOM,
		SPACING_CHAR,
		SPACING_SPACE
	};

private:
	Ref<DynamicFontData> data;
	Ref<DynamicFontAtSize> data_at_size;

	Vector<Ref<DynamicFontData> > fallbacks;
	Vector<Ref<DynamicFontAtSize> > fallback_data_at_size;

	DynamicFontData::CacheID cache_id;
	bool valid;
	int spacing_top;
	int spacing_bottom;
	int spacing_char;
	int spacing_space;

protected:
	void _reload_cache();

	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();

public:
	void set_font_data(const Ref<DynamicFontData> &p_data);
	Ref<DynamicFontData> get_font_data() const;

	void set_size(int p_size);
	int get_size() const;

	bool get_use_mipmaps() const;
	void set_use_mipmaps(bool p_enable);

	bool get_use_filter() const;
	void set_use_filter(bool p_enable);

	int get_spacing(int p_type) const;
	void set_spacing(int p_type, int p_value);

	void add_fallback(const Ref<DynamicFontData> &p_data);
	void set_fallback(int p_idx, const Ref<DynamicFontData> &p_data);
	int get_fallback_count() const;
	Ref<DynamicFontData> get_fallback(int p_idx) const;
	void remove_fallback(int p_idx);

	virtual float get_height() const;

	virtual float get_ascent() const;
	virtual float get_descent() const;

	virtual Size2 get_char_size(CharType p_char, CharType p_next = 0) const;

	virtual bool is_distance_field_hint() const;

	virtual float draw_char(RID p_canvas_item, const Point2 &p_pos, CharType p_char, CharType p_next = 0, const Color &p_modulate = Color(1, 1, 1)) const;

	SelfList<DynamicFont> font_list;

	static Mutex *dynamic_font_mutex;
	static SelfList<DynamicFont>::List dynamic_fonts;

	static void initialize_dynamic_fonts();
	static void finish_dynamic_fonts();
	static void update_oversampling();

	DynamicFont();
	~DynamicFont();
};

VARIANT_ENUM_CAST(DynamicFont::SpacingType);

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

class ResourceFormatLoaderDynamicFont : public ResourceFormatLoader {
public:
	virtual RES load(const String &p_path, const String &p_original_path = "", Error *r_error = NULL);
	virtual void get_recognized_extensions(List<String> *p_extensions) const;
	virtual bool handles_type(const String &p_type) const;
	virtual String get_resource_type(const String &p_path) const;
};

#endif

#endif