1VoxelArea = { 2 MinEdge = {x=1, y=1, z=1}, 3 MaxEdge = {x=0, y=0, z=0}, 4 ystride = 0, 5 zstride = 0, 6} 7 8function VoxelArea:new(o) 9 o = o or {} 10 setmetatable(o, self) 11 self.__index = self 12 13 local e = o:getExtent() 14 o.ystride = e.x 15 o.zstride = e.x * e.y 16 17 return o 18end 19 20function VoxelArea:getExtent() 21 local MaxEdge, MinEdge = self.MaxEdge, self.MinEdge 22 return { 23 x = MaxEdge.x - MinEdge.x + 1, 24 y = MaxEdge.y - MinEdge.y + 1, 25 z = MaxEdge.z - MinEdge.z + 1, 26 } 27end 28 29function VoxelArea:getVolume() 30 local e = self:getExtent() 31 return e.x * e.y * e.z 32end 33 34function VoxelArea:index(x, y, z) 35 local MinEdge = self.MinEdge 36 local i = (z - MinEdge.z) * self.zstride + 37 (y - MinEdge.y) * self.ystride + 38 (x - MinEdge.x) + 1 39 return math.floor(i) 40end 41 42function VoxelArea:indexp(p) 43 local MinEdge = self.MinEdge 44 local i = (p.z - MinEdge.z) * self.zstride + 45 (p.y - MinEdge.y) * self.ystride + 46 (p.x - MinEdge.x) + 1 47 return math.floor(i) 48end 49 50function VoxelArea:position(i) 51 local p = {} 52 local MinEdge = self.MinEdge 53 54 i = i - 1 55 56 p.z = math.floor(i / self.zstride) + MinEdge.z 57 i = i % self.zstride 58 59 p.y = math.floor(i / self.ystride) + MinEdge.y 60 i = i % self.ystride 61 62 p.x = math.floor(i) + MinEdge.x 63 64 return p 65end 66 67function VoxelArea:contains(x, y, z) 68 local MaxEdge, MinEdge = self.MaxEdge, self.MinEdge 69 return (x >= MinEdge.x) and (x <= MaxEdge.x) and 70 (y >= MinEdge.y) and (y <= MaxEdge.y) and 71 (z >= MinEdge.z) and (z <= MaxEdge.z) 72end 73 74function VoxelArea:containsp(p) 75 local MaxEdge, MinEdge = self.MaxEdge, self.MinEdge 76 return (p.x >= MinEdge.x) and (p.x <= MaxEdge.x) and 77 (p.y >= MinEdge.y) and (p.y <= MaxEdge.y) and 78 (p.z >= MinEdge.z) and (p.z <= MaxEdge.z) 79end 80 81function VoxelArea:containsi(i) 82 return (i >= 1) and (i <= self:getVolume()) 83end 84 85function VoxelArea:iter(minx, miny, minz, maxx, maxy, maxz) 86 local i = self:index(minx, miny, minz) - 1 87 local xrange = maxx - minx + 1 88 local nextaction = i + 1 + xrange 89 90 local y = 0 91 local yrange = maxy - miny + 1 92 local yreqstride = self.ystride - xrange 93 94 local z = 0 95 local zrange = maxz - minz + 1 96 local multistride = self.zstride - ((yrange - 1) * self.ystride + xrange) 97 98 return function() 99 -- continue i until it needs to jump 100 i = i + 1 101 if i ~= nextaction then 102 return i 103 end 104 105 -- continue y until maxy is exceeded 106 y = y + 1 107 if y ~= yrange then 108 -- set i to index(minx, miny + y, minz + z) - 1 109 i = i + yreqstride 110 nextaction = i + xrange 111 return i 112 end 113 114 -- continue z until maxz is exceeded 115 z = z + 1 116 if z == zrange then 117 -- cuboid finished, return nil 118 return 119 end 120 121 -- set i to index(minx, miny, minz + z) - 1 122 i = i + multistride 123 124 y = 0 125 nextaction = i + xrange 126 return i 127 end 128end 129 130function VoxelArea:iterp(minp, maxp) 131 return self:iter(minp.x, minp.y, minp.z, maxp.x, maxp.y, maxp.z) 132end 133