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osm-gps-map integration
| 1 | harbaum | 32 | /* -*- Mode: C; indent-tabs-mode: nil; c-basic-offset: 4; tab-width: 4 -*- */ |
| 2 | /* vim:set et sw=4 ts=4 cino=t0,(0: */ | ||
| 3 | /* | ||
| 4 | * converter.c | ||
| 5 | * Copyright (C) Marcus Bauer 2008 <marcus.bauer@gmail.com> | ||
| 6 | * Copyright (C) John Stowers 2008 <john.stowers@gmail.com> | ||
| 7 | * | ||
| 8 | * osm-gps-map.c is free software: you can redistribute it and/or modify it | ||
| 9 | * under the terms of the GNU General Public License as published by the | ||
| 10 | * Free Software Foundation, either version 3 of the License, or | ||
| 11 | * (at your option) any later version. | ||
| 12 | * | ||
| 13 | * osm-gps-map.c is distributed in the hope that it will be useful, but | ||
| 14 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | ||
| 16 | * See the GNU General Public License for more details. | ||
| 17 | * | ||
| 18 | * You should have received a copy of the GNU General Public License along | ||
| 19 | * with this program. If not, see <http://www.gnu.org/licenses/>. | ||
| 20 | */ | ||
| 21 | |||
| 22 | #include <math.h> | ||
| 23 | #include <stdio.h> | ||
| 24 | |||
| 25 | #include "osm-gps-map-types.h" | ||
| 26 | #include "converter.h" | ||
| 27 | |||
| 28 | |||
| 29 | float | ||
| 30 | deg2rad(float deg) | ||
| 31 | { | ||
| 32 | return (deg * M_PI / 180.0); | ||
| 33 | } | ||
| 34 | |||
| 35 | float | ||
| 36 | rad2deg(float rad) | ||
| 37 | { | ||
| 38 | return (rad / M_PI * 180.0); | ||
| 39 | } | ||
| 40 | |||
| 41 | |||
| 42 | int | ||
| 43 | lat2pixel( int zoom, | ||
| 44 | float lat) | ||
| 45 | { | ||
| 46 | float lat_m; | ||
| 47 | int pixel_y; | ||
| 48 | |||
| 49 | lat_m = atanh(sin(lat)); | ||
| 50 | |||
| 51 | /* the formula is | ||
| 52 | * | ||
| 53 | * pixel_y = -(2^zoom * TILESIZE * lat_m) / 2PI + (2^zoom * TILESIZE) / 2 | ||
| 54 | */ | ||
| 55 | pixel_y = -(int)( (lat_m * TILESIZE * (1 << zoom) ) / (2*M_PI)) + | ||
| 56 | ((1 << zoom) * (TILESIZE/2) ); | ||
| 57 | |||
| 58 | |||
| 59 | return pixel_y; | ||
| 60 | } | ||
| 61 | |||
| 62 | |||
| 63 | int | ||
| 64 | lon2pixel( int zoom, | ||
| 65 | float lon) | ||
| 66 | { | ||
| 67 | int pixel_x; | ||
| 68 | |||
| 69 | /* the formula is | ||
| 70 | * | ||
| 71 | * pixel_x = (2^zoom * TILESIZE * lon) / 2PI + (2^zoom * TILESIZE) / 2 | ||
| 72 | */ | ||
| 73 | pixel_x = (int)(( lon * TILESIZE * (1 << zoom) ) / (2*M_PI)) + | ||
| 74 | ( (1 << zoom) * (TILESIZE/2) ); | ||
| 75 | return pixel_x; | ||
| 76 | } | ||
| 77 | |||
| 78 | float | ||
| 79 | pixel2lon( float zoom, | ||
| 80 | int pixel_x) | ||
| 81 | { | ||
| 82 | float lon; | ||
| 83 | |||
| 84 | lon = ((pixel_x - ( exp(zoom * M_LN2) * (TILESIZE/2) ) ) *2*M_PI) / | ||
| 85 | (TILESIZE * exp(zoom * M_LN2) ); | ||
| 86 | |||
| 87 | return lon; | ||
| 88 | } | ||
| 89 | |||
| 90 | float | ||
| 91 | pixel2lat( float zoom, | ||
| 92 | int pixel_y) | ||
| 93 | { | ||
| 94 | float lat, lat_m; | ||
| 95 | |||
| 96 | lat_m = (-( pixel_y - ( exp(zoom * M_LN2) * (TILESIZE/2) ) ) * (2*M_PI)) / | ||
| 97 | (TILESIZE * exp(zoom * M_LN2)); | ||
| 98 | |||
| 99 | lat = asin(tanh(lat_m)); | ||
| 100 | |||
| 101 | return lat; | ||
| 102 | } |