text: /*************************************************************************/
  /*  dynamic_font_stb.cpp                                                 */
  /*************************************************************************/
  /*                       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:                                             */
  /*                                                                       */
  /* 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 "dynamic_font_stb.h"
  
  #ifndef FREETYPE_ENABLED
  
  #define STB_TRUETYPE_IMPLEMENTATION
  #include "os/file_access.h"
  
  void DynamicFontData::lock() {
  
  	fr = font_data.read();
  
  	if (fr.ptr() != last_data_ptr) {
  
  		last_data_ptr = fr.ptr();
  
  		if (!stbtt_InitFont(&info, last_data_ptr, 0)) {
  			valid = false;
  		} else {
  			valid = true;
  		}
  
  		last_data_ptr = fr.ptr();
  	}
  }
  
  void DynamicFontData::unlock() {
  
  	fr = PoolVector<uint8_t>::Read();
  }
  
  void DynamicFontData::set_font_data(const PoolVector<uint8_t> &p_font) {
  	//clear caches and stuff
  	ERR_FAIL_COND(font_data.size());
  	font_data = p_font;
  
  	lock();
  
  	if (valid) {
  		stbtt_GetFontVMetrics(&info, &ascent, &descent, &linegap);
  		descent = -descent + linegap;
  
  		for (int i = 32; i < 1024; i++) {
  			for (int j = 32; j < 1024; j++) {
  
  				int kern = stbtt_GetCodepointKernAdvance(&info, i, j);
  				if (kern != 0) {
  					KerningPairKey kpk;
  					kpk.A = i;
  					kpk.B = j;
  					kerning_map[kpk] = kern;
  				}
  			}
  		}
  	}
  
  	unlock();
  	//clear existing stuff
  
  	ERR_FAIL_COND(!valid);
  }
  
  Ref<DynamicFontAtSize> DynamicFontData::_get_dynamic_font_at_size(int p_size) {
  
  	ERR_FAIL_COND_V(!valid, Ref<DynamicFontAtSize>());
  
  	if (size_cache.has(p_size)) {
  		return Ref<DynamicFontAtSize>(size_cache[p_size]);
  	}
  
  	Ref<DynamicFontAtSize> dfas;
  	dfas.instance();
  
  	dfas->font = Ref<DynamicFontData>(this);
  
  	size_cache[p_size] = dfas.ptr();
  
  	dfas->size = p_size;
  
  	lock();
  
  	dfas->scale = stbtt_ScaleForPixelHeight(&info, p_size);
  
  	unlock();
  
  	return dfas;
  }
  
  DynamicFontData::DynamicFontData() {
  	last_data_ptr = NULL;
  	valid = false;
  }
  
  DynamicFontData::~DynamicFontData() {
  }
  
  ////////////////////
  
  float DynamicFontAtSize::get_height() const {
  
  	return (font->ascent + font->descent) * scale;
  }
  
  float DynamicFontAtSize::get_ascent() const {
  
  	return font->ascent * scale;
  }
  float DynamicFontAtSize::get_descent() const {
  
  	return font->descent * scale;
  }
  
  Size2 DynamicFontAtSize::get_char_size(CharType p_char, CharType p_next) const {
  
  	const_cast<DynamicFontAtSize *>(this)->_update_char(p_char);
  
  	const Character *c = char_map.getptr(p_char);
  	ERR_FAIL_COND_V(!c, Size2());
  
  	Size2 ret(c->advance, get_height());
  
  	if (p_next) {
  		DynamicFontData::KerningPairKey kpk;
  		kpk.A = p_char;
  		kpk.B = p_next;
  
  		const Map<DynamicFontData::KerningPairKey, int>::Element *K = font->kerning_map.find(kpk);
  		if (K) {
  			ret.x += K->get() * scale;
  		}
  	}
  
  	return ret;
  }
  
  float DynamicFontAtSize::draw_char(RID p_canvas_item, const Point2 &p_pos, CharType p_char, CharType p_next, const Color &p_modulate, bool p_outline) const {
  
  	const_cast<DynamicFontAtSize *>(this)->_update_char(p_char);
  
  	const Character *c = char_map.getptr(p_char);
  
  	if (!c) {
  		return 0;
  	}
  
  	if (!p_outline) {
  		Point2 cpos = p_pos;
  		cpos.x += c->h_align;
  		cpos.y -= get_ascent();
  		cpos.y += c->v_align;
  		ERR_FAIL_COND_V(c->texture_idx < -1 || c->texture_idx >= textures.size(), 0);
  		if (c->texture_idx != -1)
  			VisualServer::get_singleton()->canvas_item_add_texture_rect_region(p_canvas_item, Rect2(cpos, c->rect.size), textures[c->texture_idx].texture->get_rid(), c->rect, p_modulate);
  	}
  
  	//textures[c->texture_idx].texture->draw(p_canvas_item,Vector2());
  
  	float ret = c->advance;
  	if (p_next) {
  		DynamicFontData::KerningPairKey kpk;
  		kpk.A = p_char;
  		kpk.B = p_next;
  
  		const Map<DynamicFontData::KerningPairKey, int>::Element *K = font->kerning_map.find(kpk);
  		if (K) {
  			ret += K->get() * scale;
  		}
  	}
  
  	return ret;
  }
  
  void DynamicFontAtSize::_update_char(CharType p_char) {
  
  	if (char_map.has(p_char))
  		return;
  
  	font->lock();
  
  	int w, h, xofs, yofs;
  	unsigned char *cpbitmap = stbtt_GetCodepointBitmap(&font->info, scale, scale, p_char, &w, &h, &xofs, &yofs);
  
  	if (!cpbitmap) {
  		//no glyph
  
  		int advance;
  		stbtt_GetCodepointHMetrics(&font->info, p_char, &advance, 0);
  		Character ch;
  		ch.texture_idx = -1;
  		ch.advance = advance * scale;
  		ch.h_align = 0;
  		ch.v_align = 0;
  
  		char_map[p_char] = ch;
  
  		font->unlock();
  
  		return;
  	}
  
  	int mw = w + rect_margin * 2;
  	int mh = h + rect_margin * 2;
  
  	if (mw > 4096 || mh > 4096) {
  
  		stbtt_FreeBitmap(cpbitmap, NULL);
  		font->unlock();
  		ERR_FAIL_COND(mw > 4096);
  		ERR_FAIL_COND(mh > 4096);
  	}
  
  	//find a texture to fit this...
  
  	int tex_index = -1;
  	int tex_x = 0;
  	int tex_y = 0;
  
  	for (int i = 0; i < textures.size(); i++) {
  
  		CharTexture &ct = textures[i];
  
  		if (mw > ct.texture_size || mh > ct.texture_size) //too big for this texture
  			continue;
  
  		tex_y = 0x7FFFFFFF;
  		tex_x = 0;
  
  		for (int j = 0; j < ct.texture_size - mw; j++) {
  
  			int max_y = 0;
  
  			for (int k = j; k < j + mw; k++) {
  
  				int y = ct.offsets[k];
  				if (y > max_y)
  					max_y = y;
  			}
  
  			if (max_y < tex_y) {
  				tex_y = max_y;
  				tex_x = j;
  			}
  		}
  
  		if (tex_y == 0x7FFFFFFF || tex_y + mh > ct.texture_size)
  			continue; //fail, could not fit it here
  
  		tex_index = i;
  		break;
  	}
  
  	if (tex_index == -1) {
  		//could not find texture to fit, create one
  		tex_x = 0;
  		tex_y = 0;
  
  		int texsize = MAX(size * 8, 256);
  		if (mw > texsize)
  			texsize = mw; //special case, adapt to it?
  		if (mh > texsize)
  			texsize = mh; //special case, adapt to it?
  
  		texsize = next_power_of_2(texsize);
  
  		texsize = MIN(texsize, 4096);
  
  		CharTexture tex;
  		tex.texture_size = texsize;
  		tex.imgdata.resize(texsize * texsize * 2); //grayscale alpha
  
  		{
  			//zero texture
  			PoolVector<uint8_t>::Write w = tex.imgdata.write();
  			ERR_FAIL_COND(texsize * texsize * 2 > tex.imgdata.size());
  			for (int i = 0; i < texsize * texsize * 2; i++) {
  				w[i] = 0;
  			}
  		}
  		tex.offsets.resize(texsize);
  		for (int i = 0; i < texsize; i++) //zero offsets
  			tex.offsets[i] = 0;
  
  		textures.push_back(tex);
  		tex_index = textures.size() - 1;
  	}
  
  	//fit character in char texture
  
  	CharTexture &tex = textures[tex_index];
  
  	{
  		PoolVector<uint8_t>::Write wr = tex.imgdata.write();
  
  		for (int i = 0; i < h; i++) {
  			for (int j = 0; j < w; j++) {
  
  				int ofs = ((i + tex_y + rect_margin) * tex.texture_size + j + tex_x + rect_margin) * 2;
  				ERR_FAIL_COND(ofs >= tex.imgdata.size());
  				wr[ofs + 0] = 255; //grayscale as 1
  				wr[ofs + 1] = cpbitmap[i * w + j]; //alpha as 0
  			}
  		}
  	}
  
  	//blit to image and texture
  	{
  		Ref<Image> img = memnew(Image(tex.texture_size, tex.texture_size, 0, Image::FORMAT_LA8, tex.imgdata));
  
  		if (tex.texture.is_null()) {
  			tex.texture.instance();
  			tex.texture->create_from_image(img, Texture::FLAG_FILTER);
  		} else {
  			tex.texture->set_data(img); //update
  		}
  	}
  
  	// update height array
  
  	for (int k = tex_x; k < tex_x + mw; k++) {
  
  		tex.offsets[k] = tex_y + mh;
  	}
  
  	int advance;
  	stbtt_GetCodepointHMetrics(&font->info, p_char, &advance, 0);
  
  	Character chr;
  	chr.h_align = xofs;
  	chr.v_align = yofs + get_ascent();
  	chr.advance = advance * scale;
  	chr.texture_idx = tex_index;
  
  	chr.rect = Rect2(tex_x + rect_margin, tex_y + rect_margin, w, h);
  
  	char_map[p_char] = chr;
  
  	stbtt_FreeBitmap(cpbitmap, NULL);
  
  	font->unlock();
  }
  
  DynamicFontAtSize::DynamicFontAtSize() {
  
  	rect_margin = 1;
  }
  
  DynamicFontAtSize::~DynamicFontAtSize() {
  
  	ERR_FAIL_COND(!font.ptr());
  	font->size_cache.erase(size);
  }
  
  /////////////////////////
  
  void DynamicFont::_bind_methods() {
  
  	ClassDB::bind_method(D_METHOD("set_font_data", "data"), &DynamicFont::set_font_data);
  	ClassDB::bind_method(D_METHOD("get_font_data"), &DynamicFont::get_font_data);
  
  	ClassDB::bind_method(D_METHOD("set_size", "data"), &DynamicFont::set_size);
  	ClassDB::bind_method(D_METHOD("get_size"), &DynamicFont::get_size);
  
  	ADD_PROPERTY(PropertyInfo(Variant::INT, "font/size"), "set_size", "get_size");
  	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "font/font", PROPERTY_HINT_RESOURCE_TYPE, "DynamicFontData"), "set_font_data", "get_font_data");
  }
  
  void DynamicFont::set_font_data(const Ref<DynamicFontData> &p_data) {
  
  	data = p_data;
  	data_at_size = data->_get_dynamic_font_at_size(size);
  }
  
  Ref<DynamicFontData> DynamicFont::get_font_data() const {
  
  	return data;
  }
  
  void DynamicFont::set_size(int p_size) {
  
  	if (size == p_size)
  		return;
  	size = p_size;
  	ERR_FAIL_COND(p_size < 1);
  	if (!data.is_valid())
  		return;
  	data_at_size = data->_get_dynamic_font_at_size(size);
  }
  int DynamicFont::get_size() const {
  
  	return size;
  }
  
  float DynamicFont::get_height() const {
  
  	if (!data_at_size.is_valid())
  		return 1;
  
  	return data_at_size->get_height();
  }
  
  float DynamicFont::get_ascent() const {
  
  	if (!data_at_size.is_valid())
  		return 1;
  
  	return data_at_size->get_ascent();
  }
  
  float DynamicFont::get_descent() const {
  
  	if (!data_at_size.is_valid())
  		return 1;
  
  	return data_at_size->get_descent();
  }
  
  Size2 DynamicFont::get_char_size(CharType p_char, CharType p_next) const {
  
  	if (!data_at_size.is_valid())
  		return Size2(1, 1);
  
  	return data_at_size->get_char_size(p_char, p_next);
  }
  
  bool DynamicFont::is_distance_field_hint() const {
  
  	return false;
  }
  
  float DynamicFont::draw_char(RID p_canvas_item, const Point2 &p_pos, CharType p_char, CharType p_next, const Color &p_modulate, bool p_outline) const {
  
  	if (!data_at_size.is_valid())
  		return 0;
  
  	return data_at_size->draw_char(p_canvas_item, p_pos, p_char, p_next, p_modulate, p_outline);
  }
  
  DynamicFont::DynamicFont() {
  
  	size = 16;
  }
  
  DynamicFont::~DynamicFont() {
  }
  
  /////////////////////////
  
  RES ResourceFormatLoaderDynamicFont::load(const String &p_path, const String &p_original_path, Error *r_error) {
  
  	if (r_error)
  		*r_error = ERR_FILE_CANT_OPEN;
  
  	FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
  	ERR_FAIL_COND_V(!f, RES());
  
  	PoolVector<uint8_t> data;
  
  	data.resize(f->get_len());
  
  	ERR_FAIL_COND_V(data.size() == 0, RES());
  
  	{
  		PoolVector<uint8_t>::Write w = data.write();
  		f->get_buffer(w.ptr(), data.size());
  	}
  
  	Ref<DynamicFontData> dfd;
  	dfd.instance();
  	dfd->set_font_data(data);
  
  	if (r_error)
  		*r_error = OK;
  
  	return dfd;
  }
  
  void ResourceFormatLoaderDynamicFont::get_recognized_extensions(List<String> *p_extensions) const {
  
  	p_extensions->push_back("ttf");
  }
  
  bool ResourceFormatLoaderDynamicFont::handles_type(const String &p_type) const {
  
  	return (p_type == "DynamicFontData");
  }
  
  String ResourceFormatLoaderDynamicFont::get_resource_type(const String &p_path) const {
  
  	String el = p_path.get_extension().to_lower();
  	if (el == "ttf")
  		return "DynamicFontData";
  	return "";
  }
  
  #endif
  