builtin/game/item_s.lua

   1 -- Minetest: builtin/item_s.lua
   2 -- The distinction of what goes here is a bit tricky, basically it's everything
   3 -- that does not (directly or indirectly) need access to ServerEnvironment,
   4 -- Server or writable access to IGameDef on the engine side.
   5 -- (The '_s' stands for standalone.)
   6
   7 --
   8 -- Item definition helpers
   9 --
  10
  11 function core.inventorycube(img1, img2, img3)
  12         img2 = img2 or img1
  13         img3 = img3 or img1
  14         return "[inventorycube"
  15                         .. "{" .. img1:gsub("%^", "&")
  16                         .. "{" .. img2:gsub("%^", "&")
  17                         .. "{" .. img3:gsub("%^", "&")
  18 end
  19
  20 function core.dir_to_facedir(dir, is6d)
  21         --account for y if requested
  22         if is6d and math.abs(dir.y) > math.abs(dir.x) and math.abs(dir.y) > math.abs(dir.z) then
  23
  24                 --from above
  25                 if dir.y < 0 then
  26                         if math.abs(dir.x) > math.abs(dir.z) then
  27                                 if dir.x < 0 then
  28                                         return 19
  29                                 else
  30                                         return 13
  31                                 end
  32                         else
  33                                 if dir.z < 0 then
  34                                         return 10
  35                                 else
  36                                         return 4
  37                                 end
  38                         end
  39
  40                 --from below
  41                 else
  42                         if math.abs(dir.x) > math.abs(dir.z) then
  43                                 if dir.x < 0 then
  44                                         return 15
  45                                 else
  46                                         return 17
  47                                 end
  48                         else
  49                                 if dir.z < 0 then
  50                                         return 6
  51                                 else
  52                                         return 8
  53                                 end
  54                         end
  55                 end
  56
  57         --otherwise, place horizontally
  58         elseif math.abs(dir.x) > math.abs(dir.z) then
  59                 if dir.x < 0 then
  60                         return 3
  61                 else
  62                         return 1
  63                 end
  64         else
  65                 if dir.z < 0 then
  66                         return 2
  67                 else
  68                         return 0
  69                 end
  70         end
  71 end
  72
  73 -- Table of possible dirs
  74 local facedir_to_dir = {
  75         vector.new( 0,  0,  1),
  76         vector.new( 1,  0,  0),
  77         vector.new( 0,  0, -1),
  78         vector.new(-1,  0,  0),
  79         vector.new( 0, -1,  0),
  80         vector.new( 0,  1,  0),
  81 }
  82 -- Mapping from facedir value to index in facedir_to_dir.
  83 local facedir_to_dir_map = {
  84         [0]=1, 2, 3, 4,
  85         5, 2, 6, 4,
  86         6, 2, 5, 4,
  87         1, 5, 3, 6,
  88         1, 6, 3, 5,
  89         1, 4, 3, 2,
  90 }
  91 function core.facedir_to_dir(facedir)
  92         return facedir_to_dir[facedir_to_dir_map[facedir % 32]]
  93 end
  94
  95 function core.dir_to_wallmounted(dir)
  96         if math.abs(dir.y) > math.max(math.abs(dir.x), math.abs(dir.z)) then
  97                 if dir.y < 0 then
  98                         return 1
  99                 else
 100                         return 0
 101                 end
 102         elseif math.abs(dir.x) > math.abs(dir.z) then
 103                 if dir.x < 0 then
 104                         return 3
 105                 else
 106                         return 2
 107                 end
 108         else
 109                 if dir.z < 0 then
 110                         return 5
 111                 else
 112                         return 4
 113                 end
 114         end
 115 end
 116
 117 -- table of dirs in wallmounted order
 118 local wallmounted_to_dir = {
 119         [0] = vector.new( 0,  1,  0),
 120         vector.new( 0, -1,  0),
 121         vector.new( 1,  0,  0),
 122         vector.new(-1,  0,  0),
 123         vector.new( 0,  0,  1),
 124         vector.new( 0,  0, -1),
 125 }
 126 function core.wallmounted_to_dir(wallmounted)
 127         return wallmounted_to_dir[wallmounted % 8]
 128 end
 129
 130 function core.dir_to_yaw(dir)
 131         return -math.atan2(dir.x, dir.z)
 132 end
 133
 134 function core.yaw_to_dir(yaw)
 135         return vector.new(-math.sin(yaw), 0, math.cos(yaw))
 136 end
 137
 138 function core.is_colored_paramtype(ptype)
 139         return (ptype == "color") or (ptype == "colorfacedir") or
 140                 (ptype == "colorwallmounted") or (ptype == "colordegrotate")
 141 end
 142
 143 function core.strip_param2_color(param2, paramtype2)
 144         if not core.is_colored_paramtype(paramtype2) then
 145                 return nil
 146         end
 147         if paramtype2 == "colorfacedir" then
 148                 param2 = math.floor(param2 / 32) * 32
 149         elseif paramtype2 == "colorwallmounted" then
 150                 param2 = math.floor(param2 / 8) * 8
 151         elseif paramtype2 == "colordegrotate" then
 152                 param2 = math.floor(param2 / 32) * 32
 153         end
 154         -- paramtype2 == "color" requires no modification.
 155         return param2
 156 end