fsio.cpp

graph是一款linux/unix下绘制数据曲线图形的程序

/*
 * fsio.cpp - ввод/вывод, сохранение/загрузка функций
 * Copyright (C) 2007 lester
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 * 
 */

#include "fsio.h"
#include <gsf/gsf.h>
#include <gsf/gsf-utils.h>
#include <gsf/gsf-output.h>
#include <gsf/gsf-output-stdio.h>
#include <gsf/gsf-input.h>
#include <gsf/gsf-input-stdio.h>
#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include <iostream>

/*
 * Нет, я не сошел с ума. (Хотя...)
 * Дело в том что стдлибовский атоф тупо не видит цифры после зяпятой.
 * Скажем "0.2" он возвращает как 0. Я потратил бессонную ночь на дебагинг
 * и решил забить. Поэтому выдрал из иррлихта реализацию его собственного атоф.
 * Это код Николауса Гебхардта. 
 */

const float fast_atof_table[16] =	{  // we write [16] here instead of [] to work around a swig bug
										0.f,
										0.1f,
										0.01f,
										0.001f,
										0.0001f,
										0.00001f,
										0.000001f,
										0.0000001f,
										0.00000001f,
										0.000000001f,
										0.0000000001f,
										0.00000000001f,
										0.000000000001f,
										0.0000000000001f,
										0.00000000000001f,
										0.000000000000001f
									};

inline guint strtol10( const char* in, const char* &out)
{
	guint value = 0;
	char symbol;

	while ( 1 )
	{
		symbol = *in;
		// где здесь синтакс еррор? или еклипс глючит или меня
		if ( symbol < '0' || symbol > '9' ) 
			break;

		value = ( value * 10 ) + ( symbol - '0' );
		in += 1;
	}
	out = in;
	return value;
}

//! Provides a fast function for converting a string into a float,
//! about 6 times faster than atof in win32.
// If you find any bugs, please send them to me, niko (at) irrlicht3d.org.
inline const char* fast_atof_move( const char* c, float& out)
{
	bool inv = false;
	const char *t;
	float f;

	if (*c=='-')
	{
		c++;
		inv = true;
	}

	//f = (float)strtol(c, &t, 10);
	f = (float) strtol10 ( c, t );

	c = t;

	if (*c == '.')
	{
		c++;

		//float pl = (float)strtol(c, &t, 10);
		float pl = (float) strtol10 ( c, t );
		pl *= fast_atof_table[t-c];

		f += pl;

		c = t;

		if (*c == 'e')
		{
			++c;
			//float exp = (float)strtol(c, &t, 10);
			bool einv = (*c=='-');
			if (einv)
				c++;

			float exp = (float)strtol10(c, t);
			if (einv)
				exp *= -1.0f;

			f *= (float)pow(10.0f, exp);
			c = t;
		}
	}

	if (inv)
		f *= -1.0f;

	out = f;
	return c;
}

inline float fast_atof(const char* c)
{
	float ret;
	fast_atof_move(c, ret);
	return ret;
}


void
fsio_write_function (GsfXMLOut *out, const Function *f)
{
	// я сначала хотел использовать libgsf для io, но потом перешел на libxml
	// а код сохранения переписывать влом
    gsf_xml_out_start_element (out, "graph");

    gsf_xml_out_add_cstr (out, "equation", f->eq);
    gsf_xml_out_add_float (out, "xmin", f->xmin, 4);
    gsf_xml_out_add_float (out, "xmax", f->xmax, 4);
    gsf_xml_out_add_float (out, "step", f->step, 4);
    gsf_xml_out_add_cstr (out, "style", f->style);
    gsf_xml_out_add_int (out, "draw-method", static_cast<int>(f->dmethod));
    gsf_xml_out_add_bool (out, "show", f->show );
    gsf_xml_out_end_element (out);
}

void
fsio_write_functions (const gchar *filename)
{
    GError **errors = NULL;
    GsfOutput *outfile = gsf_output_stdio_new (filename, errors);

    GsfXMLOut *xmlout = gsf_xml_out_new (outfile);

    FunctionList &flist = functions_get_function_list ();

    FunctionList::iterator it;

    float xmin, xmax, ymin, ymax;

    graph_get_dims (xmin, xmax, ymin, ymax);

    gsf_xml_out_start_element (xmlout, "sheet");

    gsf_xml_out_add_float (xmlout, "xmin", xmin, -1);
    gsf_xml_out_add_float (xmlout, "xmax", xmax, -1);
    gsf_xml_out_add_float (xmlout, "ymin", ymin, -1);
    gsf_xml_out_add_float (xmlout, "ymax", ymax, -1);

    for (it = flist.begin(); it != flist.end(); ++it)
    {
        fsio_write_function (xmlout, *it);
    }

    gsf_xml_out_end_element (xmlout);

    gsf_output_close (outfile);

}

// наверно так делать нельзя
#define CHECK_ERROR \
    if (text == NULL ) \
    { \
        delete function; \
        return -1; \
    }

int
fsio_get_graph_nodes (xmlDocPtr doc, xmlNodePtr cur)
{
    cur = cur->xmlChildrenNode;

    gchar *text = NULL;

    Function *function = NULL;

    while (cur != NULL)
    {
        if (!xmlStrcmp (cur->name, (const xmlChar *) "graph"))
        {

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "xmin");
        CHECK_ERROR
        gdouble xmin = fast_atof ((const char *)text);

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "xmax");
        CHECK_ERROR
        gdouble xmax = fast_atof ((const char *)text);

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "step");
        CHECK_ERROR
        gdouble step = fast_atof ((const char *)text);

        function = functions_add_function_with_dims1 (xmin, xmax, step);

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "equation");
        CHECK_ERROR
        functions_modify_function1 (function, std::string ((const char *)text));

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "style");
        CHECK_ERROR
        function->style = (gchar *)xmlStrdup ((const xmlChar *)text);

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "draw-method");
        CHECK_ERROR
        function->dmethod = (DRAW_METHOD)atoi ((const char *)text);

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "show");
        CHECK_ERROR
        function->show = (xmlStrcmp((const xmlChar *)text, (const xmlChar *)"0") == 0)? FALSE : TRUE;

        std::cout << function->eq << std::endl;
        }
        cur = cur->next;
    }
    return 0;
}
#undef CHECK_ERROR

int
fsio_read_functions (const char *filename)
{
    xmlDocPtr doc;
    xmlNodePtr cur;

    doc = xmlParseFile (filename);

    if (doc == NULL )
    {
        return -1;
    }

    cur = xmlDocGetRootElement (doc);

    if (cur == NULL)
    {
        xmlFreeDoc (doc);
    }

    if (xmlStrcmp (cur->name, (const xmlChar *) "sheet"))
    {
        xmlFreeDoc (doc);
        return -1;
    } else
    {
        gchar *text = NULL;

        gfloat xmin, xmax, ymin, ymax;

        // господи, как я люблю libxml2 с ее типом xmlChar
        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "xmin");
        if (text == NULL)
        {
            return -1;
        }
        xmin = fast_atof ((const char *)text);

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "xmax");
        if (text == NULL)
        {
            return -1;
        }
        xmax = fast_atof ((const char *)text);

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "ymin");
        if (text == NULL)
        {
            return -1;
        }
        ymin = fast_atof ((const char *)text);

        text = (gchar *) xmlGetProp (cur, (const xmlChar *) "ymax");
        if (text == NULL)
        {
            return -1;
        }
        ymax = fast_atof ((const char *)text);

        graph_set_dims (xmin, xmax, ymin, ymax);

    }

    if (fsio_get_graph_nodes (doc, cur))
    {
        xmlFreeDoc (doc);
        return -1; // надо както похендлить это, ну там ворнинг показать чтоли
    }

    xmlFreeDoc (doc);

    return 0;

}