text: /*************************************************************************/
  /*  bitmap_loader_pbm.cpp                                                */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://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 "bitmap_loader_pbm.h"
  #include "os/file_access.h"
  #include "scene/resources/bit_mask.h"
  
  static bool _get_token(FileAccessRef &f, uint8_t &saved, PoolVector<uint8_t> &r_token, bool p_binary = false, bool p_single_chunk = false) {
  
  	int token_max = r_token.size();
  	PoolVector<uint8_t>::Write w;
  	if (token_max)
  		w = r_token.write();
  	int ofs = 0;
  	bool lf = false;
  
  	while (true) {
  
  		uint8_t b;
  		if (saved) {
  			b = saved;
  			saved = 0;
  		} else {
  			b = f->get_8();
  		}
  		if (f->eof_reached()) {
  			if (ofs) {
  				w = PoolVector<uint8_t>::Write();
  				r_token.resize(ofs);
  				return true;
  			} else {
  				return false;
  			}
  		}
  
  		if (!ofs && !p_binary && b == '#') {
  			//skip comment
  			while (b != '\n') {
  				if (f->eof_reached()) {
  					return false;
  				}
  
  				b = f->get_8();
  			}
  
  			lf = true;
  
  		} else if (b <= 32 && !(p_binary && (ofs || lf))) {
  
  			if (b == '\n') {
  				lf = true;
  			}
  
  			if (ofs && !p_single_chunk) {
  				w = PoolVector<uint8_t>::Write();
  				r_token.resize(ofs);
  				saved = b;
  
  				return true;
  			}
  		} else {
  
  			bool resized = false;
  			while (ofs >= token_max) {
  				if (token_max)
  					token_max <<= 1;
  				else
  					token_max = 1;
  				resized = true;
  			}
  			if (resized) {
  				// Note: Certain C++ static analyzers might point out that the following assigment is unnecessary.
  				// This is wrong since PoolVector<class T>::Write has an operator= method where the lhs gets updated under certain conditions.
  				// See core/dvector.h.
  				w = PoolVector<uint8_t>::Write();
  				r_token.resize(token_max);
  				w = r_token.write();
  			}
  			w[ofs++] = b;
  		}
  	}
  
  	return false;
  }
  
  static int _get_number_from_token(PoolVector<uint8_t> &r_token) {
  
  	int len = r_token.size();
  	PoolVector<uint8_t>::Read r = r_token.read();
  	return String::to_int((const char *)r.ptr(), len);
  }
  
  RES ResourceFormatPBM::load(const String &p_path, const String &p_original_path, Error *r_error) {
  
  #define _RETURN(m_err)        \
  	{                         \
  		if (r_error)          \
  			*r_error = m_err; \
  		ERR_FAIL_V(RES());    \
  	}
  
  	FileAccessRef f = FileAccess::open(p_path, FileAccess::READ);
  	uint8_t saved = 0;
  	if (!f)
  		_RETURN(ERR_CANT_OPEN);
  
  	PoolVector<uint8_t> token;
  
  	if (!_get_token(f, saved, token)) {
  		_RETURN(ERR_PARSE_ERROR);
  	}
  
  	if (token.size() != 2) {
  		_RETURN(ERR_FILE_CORRUPT);
  	}
  	if (token[0] != 'P') {
  		_RETURN(ERR_FILE_CORRUPT);
  	}
  	if (token[1] != '1' && token[1] != '4') {
  		_RETURN(ERR_FILE_CORRUPT);
  	}
  
  	bool bits = token[1] == '4';
  
  	if (!_get_token(f, saved, token)) {
  		_RETURN(ERR_PARSE_ERROR);
  	}
  
  	int width = _get_number_from_token(token);
  	if (width <= 0) {
  		_RETURN(ERR_FILE_CORRUPT);
  	}
  
  	if (!_get_token(f, saved, token)) {
  		_RETURN(ERR_PARSE_ERROR);
  	}
  
  	int height = _get_number_from_token(token);
  	if (height <= 0) {
  		_RETURN(ERR_FILE_CORRUPT);
  	}
  
  	Ref<BitMap> bm;
  	bm.instance();
  	bm->create(Size2i(width, height));
  
  	if (!bits) {
  
  		int required_bytes = width * height;
  		if (!_get_token(f, saved, token, false, true)) {
  			_RETURN(ERR_PARSE_ERROR);
  		}
  
  		if (token.size() < required_bytes) {
  			_RETURN(ERR_FILE_CORRUPT);
  		}
  
  		PoolVector<uint8_t>::Read r = token.read();
  
  		for (int i = 0; i < height; i++) {
  			for (int j = 0; j < width; j++) {
  
  				char num = r[i * width + j];
  				bm->set_bit(Point2i(j, i), num == '0');
  			}
  		}
  
  	} else {
  		//a single, entire token of bits!
  		if (!_get_token(f, saved, token, true)) {
  			_RETURN(ERR_PARSE_ERROR);
  		}
  		int required_bytes = Math::ceil((width * height) / 8.0);
  		if (token.size() < required_bytes) {
  			_RETURN(ERR_FILE_CORRUPT);
  		}
  
  		PoolVector<uint8_t>::Read r = token.read();
  		int bitwidth = width;
  		if (bitwidth % 8)
  			bitwidth += 8 - (bitwidth % 8);
  
  		for (int i = 0; i < height; i++) {
  			for (int j = 0; j < width; j++) {
  
  				int ofs = bitwidth * i + j;
  
  				uint8_t byte = r[ofs / 8];
  				bool bit = (byte >> (7 - (ofs % 8))) & 1;
  
  				bm->set_bit(Point2i(j, i), !bit);
  			}
  		}
  	}
  
  	return bm;
  }
  
  void ResourceFormatPBM::get_recognized_extensions(List<String> *p_extensions) const {
  	p_extensions->push_back("pbm");
  }
  bool ResourceFormatPBM::handles_type(const String &p_type) const {
  	return p_type == "BitMap";
  }
  String ResourceFormatPBM::get_resource_type(const String &p_path) const {
  
  	if (p_path.get_extension().to_lower() == "pbm")
  		return "BitMap";
  	return "";
  }
  