src/zoom_func.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD 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, version 2.
   4  * OpenTTD 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.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file zoom_func.h Functions related to zooming. */
   9
  10 #ifndef ZOOM_FUNC_H
  11 #define ZOOM_FUNC_H
  12
  13 #include "zoom_type.h"
  14
  15 /**
  16  * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_MIN)
  17  * When shifting right, value is rounded up
  18  * @param value value to shift
  19  * @param zoom  zoom level to shift to
  20  * @return shifted value
  21  */
  22 inline int ScaleByZoom(int value, ZoomLevel zoom)
  23 {
  24         return value << zoom;
  25 }
  26
  27 /**
  28  * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_MIN)
  29  * When shifting right, value is rounded up
  30  * @param value value to shift
  31  * @param zoom  zoom level to shift to
  32  * @return shifted value
  33  */
  34 inline int UnScaleByZoom(int value, ZoomLevel zoom)
  35 {
  36         return (value + (1 << zoom) - 1) >> zoom;
  37 }
  38
  39 /**
  40  * Adjust by zoom level; zoom < 0 shifts right, zoom >= 0 shifts left
  41  * @param value value to shift
  42  * @param zoom zoom level to shift to
  43  * @return shifted value
  44  */
  45 inline int AdjustByZoom(int value, int zoom)
  46 {
  47         return zoom < 0 ? UnScaleByZoom(value, ZoomLevel(-zoom)) : ScaleByZoom(value, ZoomLevel(zoom));
  48 }
  49
  50 /**
  51  * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_MIN)
  52  * @param value value to shift
  53  * @param zoom  zoom level to shift to
  54  * @return shifted value
  55  */
  56 inline int ScaleByZoomLower(int value, ZoomLevel zoom)
  57 {
  58         return value << zoom;
  59 }
  60
  61 /**
  62  * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_MIN)
  63  * @param value value to shift
  64  * @param zoom  zoom level to shift to
  65  * @return shifted value
  66  */
  67 inline int UnScaleByZoomLower(int value, ZoomLevel zoom)
  68 {
  69         return value >> zoom;
  70 }
  71
  72 /**
  73  * Short-hand to apply GUI zoom level.
  74  * @param value Pixel amount at #ZOOM_LVL_MIN (full zoom in).
  75  * @return Pixel amount at #ZOOM_LVL_GUI (current interface size).
  76  */
  77 inline int UnScaleGUI(int value)
  78 {
  79         return UnScaleByZoom(value, ZOOM_LVL_GUI);
  80 }
  81
  82 /**
  83  * Scale zoom level relative to GUI zoom.
  84  * @param value zoom level to scale
  85  * @return scaled zoom level
  86  */
  87 inline ZoomLevel ScaleZoomGUI(ZoomLevel value)
  88 {
  89         return std::clamp(ZoomLevel(value + (ZOOM_LVL_GUI - ZOOM_LVL_NORMAL)), ZOOM_LVL_MIN, ZOOM_LVL_MAX);
  90 }
  91
  92 /**
  93  * UnScale zoom level relative to GUI zoom.
  94  * @param value zoom level to scale
  95  * @return un-scaled zoom level
  96  */
  97 inline ZoomLevel UnScaleZoomGUI(ZoomLevel value)
  98 {
  99         return std::clamp(ZoomLevel(value - (ZOOM_LVL_GUI - ZOOM_LVL_NORMAL)), ZOOM_LVL_MIN, ZOOM_LVL_MAX);
 100 }
 101
 102 /**
 103  * Scale traditional pixel dimensions to GUI zoom level, for drawing sprites.
 104  * @param value Pixel amount at #ZOOM_BASE (traditional "normal" interface size).
 105  * @return Pixel amount at #ZOOM_LVL_GUI (current interface size).
 106  */
 107 inline int ScaleSpriteTrad(int value)
 108 {
 109         return UnScaleGUI(value * ZOOM_BASE);
 110 }
 111
 112 /**
 113  * Scale traditional pixel dimensions to GUI zoom level.
 114  * @param value Pixel amount at #ZOOM_BASE (traditional "normal" interface size).
 115  * @return Pixel amount at #ZOOM_LVL_GUI (current interface size).
 116  */
 117 inline int ScaleGUITrad(int value)
 118 {
 119         return value * _gui_scale / 100;
 120 }
 121
 122 #endif /* ZOOM_FUNC_H */