client/zoom.c

   1 /***********************************************************************
   2  Freeciv - Copyright (C) 2005 - The Freeciv Team
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; either version 2, or (at your option)
   6    any later version.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12 ***********************************************************************/
  13
  14 #ifdef HAVE_CONFIG_H
  15 #include <fc_config.h>
  16 #endif
  17
  18 /* client */
  19 #include "mapview_common.h"
  20
  21 #include "zoom.h"
  22
  23
  24 float map_zoom = 1.0;
  25 bool zoom_enabled = FALSE;
  26
  27 static float zoom_steps[] = {
  28   -1.0, 0.13, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 2.0, 2.5, 3.0, 4.0, -1.0
  29 };
  30
  31 static struct zoom_data
  32 {
  33   bool active;
  34   float tgt;
  35   float factor;
  36   float interval;
  37   bool tgt_1_0;
  38 } zdata = { FALSE, 0.0, 0.0 };
  39
  40 /**************************************************************************
  41   Set map zoom level.
  42 **************************************************************************/
  43 void zoom_set(float new_zoom)
  44 {
  45   zoom_enabled = TRUE;
  46   map_zoom = new_zoom;
  47
  48   map_canvas_resized(mapview.width, mapview.height);
  49 }
  50
  51 /**************************************************************************
  52   Set map zoom level to exactly one.
  53 **************************************************************************/
  54 void zoom_1_0(void)
  55 {
  56   zoom_enabled = FALSE;
  57   map_zoom = 1.0;
  58
  59   map_canvas_resized(mapview.width, mapview.height);
  60 }
  61
  62 /**************************************************************************
  63   Zoom level one step up
  64 **************************************************************************/
  65 void zoom_step_up(void)
  66 {
  67   int i;
  68
  69   /* Even if below previous step, close enough is considered to be in
  70    * previous step so that change is not miniscule */
  71   for (i = 1 ;
  72        zoom_steps[i] < map_zoom * 1.05 && zoom_steps[i] > 0.0 ;
  73        i++ ) {
  74     /* empty */
  75   }
  76
  77   if (zoom_steps[i] > 0.0) {
  78     if (zoom_steps[i] > 0.99 && zoom_steps[i] < 1.01) {
  79       zoom_1_0();
  80     } else {
  81       zoom_set(zoom_steps[i]);
  82     }
  83   }
  84 }
  85
  86 /**************************************************************************
  87   Zoom level one step down
  88 **************************************************************************/
  89 void zoom_step_down(void)
  90 {
  91   int i;
  92
  93   /* Even if above previous step, close enough is considered to be in
  94    * previous step so that change is not miniscule */
  95   for (i = ARRAY_SIZE(zoom_steps) - 2 ;
  96        zoom_steps[i] * 1.05 > map_zoom && zoom_steps[i] > 0.0 ;
  97        i-- ) {
  98     /* empty */
  99   }
 100
 101   if (zoom_steps[i] > 0.0) {
 102     if (zoom_steps[i] > 0.99 && zoom_steps[i] < 1.01) {
 103       zoom_1_0();
 104     } else {
 105       zoom_set(zoom_steps[i]);
 106     }
 107   }
 108 }
 109
 110 /**************************************************************************
 111   Start zoom animation.
 112 **************************************************************************/
 113 void zoom_start(float tgt, bool tgt_1_0, float factor, float interval)
 114 {
 115   zdata.tgt = tgt;
 116   if ((tgt < map_zoom && factor > 1.0)
 117       || (tgt > map_zoom && factor < 1.0)) {
 118     factor = 1.0 / factor;
 119   }
 120   zdata.factor = factor;
 121   zdata.interval = interval;
 122   zdata.tgt_1_0 = tgt_1_0;
 123   zdata.active = TRUE;
 124 }
 125
 126 /**************************************************************************
 127   Next step from the active zoom.
 128 **************************************************************************/
 129 bool zoom_update(double time_until_next_call)
 130 {
 131   if (zdata.active) {
 132     float new_zoom = map_zoom * zdata.factor;
 133
 134     if ((zdata.factor > 1.0 && new_zoom > zdata.tgt)
 135         || (zdata.factor < 1.0 && new_zoom < zdata.tgt)) {
 136       new_zoom = zdata.tgt;
 137       zdata.active = FALSE;
 138       if (zdata.tgt_1_0) {
 139         zoom_1_0();
 140       } else {
 141         zoom_set(new_zoom);
 142       }
 143     } else {
 144       zoom_set(new_zoom);
 145
 146       return MIN(time_until_next_call, zdata.interval);
 147     }
 148   }
 149
 150   return time_until_next_call;
 151 }