/*
 *  geo-tools.h
 *
 *  Copyright (C) 2006,2007 Nils Faerber <nils.faerber@kernelconcepts.de>
 *
 *  parts taken from Maemo-Mapper (GPL)
 *
 *  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifndef _GEO_TOOLS_H
#define _GEO_TOOLS_H

/* from GNU glibc math.h - since we do not need __USE_GNU else
 * we copy it here
 */
#ifndef M_PIl
#define M_PIl          3.1415926535897932384626433832795029L
#endif

/*
 * the following unit-latlpon conversions are
 * shamelessly stolen^Wborrowed from Maemo-Mapper ;)
 * ...and will be returned in time
 * Some minor modifications have been done...
 */

#define pixel2unit(pixel) ((pixel) << _zoom)
#define unit2pixel(pixel) ((pixel) >> _zoom)


/* use 31 bits for best accuracy */
#define WORLD_SIZE_UNITS (1 << 30 /*26*/)
#define MERCATOR_SPAN (-6.28318377773622f)
#define MERCATOR_TOP (3.14159188886811f)
#define latlon2unit(lat, lon, unitx, unity) { \
    gdouble tmp; \
    unitx = (lon + 180.f) * (WORLD_SIZE_UNITS / 360.f) + 0.5f; \
    tmp = sin(lat * (M_PIl / 180.f)); \
    unity = 0.5f + (WORLD_SIZE_UNITS / MERCATOR_SPAN) \
        * (log((1.f + tmp) / (1.f - tmp)) * 0.5f - MERCATOR_TOP); \
}

#define unit2latlon(unitx, unity, lat, lon) { \
    (lon) = ((unitx) * (360.f / WORLD_SIZE_UNITS)) - 180.f; \
    (lat) = (360.f * (atan(exp(((unity) \
                                  * (MERCATOR_SPAN / WORLD_SIZE_UNITS)) \
                     + MERCATOR_TOP)))) * (1.f / M_PIl) - 90.f; \
}

#define MACRO_RECALC_OFFSET() { \
    _offsetx = grid2pixel( \
            unit2grid(_center.unitx) \
            - _screen_grids_halfwidth \
            - tile2grid(_base_tilex)); \
    _offsety = grid2pixel( \
            unit2grid(_center.unity) \
            - _screen_grids_halfheight \
            - tile2grid(_base_tiley)); \
}

#define MACRO_RECALC_FOCUS_BASE() { \
    _focus.unitx = x2unit(_screen_width_pixels * _center_ratio / 20); \
    _focus.unity = y2unit(_screen_height_pixels * _center_ratio / 20); \
}

#define MACRO_RECALC_FOCUS_SIZE() { \
    _focus_unitwidth = pixel2unit( \
            (10 - _center_ratio) * _screen_width_pixels / 10); \
    _focus_unitheight = pixel2unit( \
            (10 - _center_ratio) * _screen_height_pixels / 10); \
}

#define MACRO_RECALC_CENTER_BOUNDS() { \
  _min_center.unitx = pixel2unit(grid2pixel(_screen_grids_halfwidth)); \
  _min_center.unity = pixel2unit(grid2pixel(_screen_grids_halfheight)); \
  _max_center.unitx = WORLD_SIZE_UNITS-grid2unit(_screen_grids_halfwidth) - 1; \
  _max_center.unity = WORLD_SIZE_UNITS-grid2unit(_screen_grids_halfheight)- 1; \
}

#define MACRO_INIT_TRACK(track) { \
    (track).head = (track).tail = g_new(TrackPoint, ARRAY_CHUNK_SIZE); \
    (track).tail->unitx = (track).tail->unity = 0;  \
    (track).cap = (track).head + ARRAY_CHUNK_SIZE; \
    (track).whead = g_new(WayPoint, ARRAY_CHUNK_SIZE); \
    (track).wtail = (track).whead - 1; \
    (track).wcap = (track).whead + ARRAY_CHUNK_SIZE; \
}

#define MACRO_CLEAR_TRACK(track) if((track).head) { \
    WayPoint *curr; \
    g_free((track).head); \
    (track).head = (track).tail = (track).cap = NULL; \
    for(curr = (track).whead - 1; curr++ != (track).wtail; ) \
        g_free(curr->desc); \
    g_free((track).whead); \
    (track).whead = (track).wtail = (track).wcap = NULL; \
}

#define DISTANCE_ROUGH(point) \
    (abs((gint)((point).unitx) - _pos.unitx) \
     + abs((gint)((point).unity) - _pos.unity))

#define MACRO_QUEUE_DRAW_AREA() \
    gtk_widget_queue_draw_area( \
            _map_widget, \
            0, 0, \
            _screen_width_pixels, \
            _screen_height_pixels)

#define KEEP_DISPLAY_ON() { \
    /* Note that the flag means keep on ONLY when fullscreen. */ \
    if(_always_keep_on || _fullscreen) \
    { \
        osso_display_state_on(_osso); \
        osso_display_blanking_pause(_osso); \
    } \
}

#endif