src/objects/lunar.c

   1 /*
   2  * Copyright (C) 2008 Liam Girdwood
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include <libnova/lunar.h>
  21 #include "lunar.h"
  22
  23 static void lunar_update_cache(struct render_object *robject)
  24 {
  25         gdouble JD = robject->context.JD;
  26
  27         /* do we have to re-calc cache data */
  28         if (lunar.cache.epoch_JD + lunar.cache.diff_JD > JD ||
  29                 lunar.cache.epoch_JD - lunar.cache.diff_JD < JD) {
  30                 lunar.cache.epoch_JD = JD;
  31
  32                 lunar.cache.equ_sdiam =
  33                                 lunar.get_equ_sdiam(lunar.cache.epoch_JD);
  34                 lunar.get_equ_posn(lunar.cache.epoch_JD, &lunar.cache.posn);
  35         }
  36
  37         robject->coord[0].object_size =
  38                 (robject->context.pixels_per_degree / 3600.0) *
  39                 lunar.cache.equ_sdiam;
  40         robject->coord[0].posn = &lunar.cache.posn;
  41         robject->object = &lunar;
  42 }
  43
  44 static void lunar_render(struct render_object *robject, struct render_flags *rm)
  45 {
  46         if (robject->type == RT_FULL) {
  47
  48                 if (rm->show_label) {
  49                         gint label_offset = robject->coord[0].object_size + 15;
  50                         cairo_set_source_rgb(robject->cr, 0.8, 0.8, 0.8);
  51                         cairo_move_to(robject->cr,
  52                                         robject->coord[0].x - label_offset,
  53                                         robject->coord[0].y + label_offset);
  54                         cairo_show_text(robject->cr, lunar.sobject.name);
  55                 }
  56
  57                 if (rm->show_axis_flag) {
  58
  59                 }
  60
  61                 cairo_set_source_rgb(robject->cr, 0.8, 0.8, 0.8);
  62                 cairo_arc (robject->cr,
  63                                 robject->coord[0].x, robject->coord[0].y,
  64                                 robject->coord[0].object_size, 0, 2 * M_PI);
  65
  66                 if (!rm->show_outline) {
  67                         cairo_fill (robject->cr);
  68                 }
  69
  70                 if (rm->show_phase) {
  71
  72                 }
  73
  74         } else {
  75                 cairo_set_source_rgb(robject->cr, 0.8, 0.8, 0.8);
  76                 cairo_arc (robject->cr,
  77                                 robject->coord[0].x, robject->coord[0].y,
  78                                 robject->coord[0].object_size, 0, 2 * M_PI);
  79                 cairo_fill (robject->cr);
  80         }
  81 }
  82
  83 struct lunar lunar = {
  84         .sobject.name = "Moon",
  85         .render         = lunar_render,
  86         .update_cache   = lunar_update_cache,
  87         .get_equ_posn   = ln_get_lunar_equ_coords,
  88         .get_earth_dist = ln_get_lunar_earth_dist,
  89         .get_disk       = ln_get_lunar_disk,
  90         .get_phase      = ln_get_lunar_phase,
  91         .get_equ_sdiam  = ln_get_lunar_sdiam,
  92         .get_pol_sdiam  = ln_get_lunar_sdiam,
  93         .get_rst        = ln_get_lunar_rst,
  94         .cache.epoch_JD = 0,
  95         .cache.diff_JD  = 0.1,
  96 };