init

computer/4/structure

@@ -0,0 +1,106 @@
+v = 0.55
+X = vector.new(0,-0.92836897,0.28899258)
+Y = vector.new(-0.94538565,0.06753674,0.21695717)
+Z = vector.new(0.23369713,0.28899258,0.92836897)
+r1 = 40
+r2 = 10
+a = {1,-2,3,1,0,-1,-1,2,0,0}
+b = {-1.2314479651658854,-1.5872747213793104,0.04683103835434217,1.9674748180974897,1.153043896136355,-0.10238369338887907,1.7042206782594087,-1.242120063575402,0.5603127510670854,2.66234724349466}
+c = {4.321312860949716,2.116116100402904,2.7194094703705165,3.0821962706516177,5.994638109825947,0.8990716738267982,0.06271719387139103,0.7355961093238955,2.1949825399445198,5.522266625688897}
+l = vector.new(0.57735027,0.57735027,0.57735027)
+function surface(uv)
+    --print("surface")
+    total = 0
+    for i = 1,#a do
+        total = total + math.sin(a[i]*uv.x+math.floor(.5+b[i])*uv.y+c[i])
+    end
+    return math.pow(math.mod(total,2)-1,2)
+end    
+function map(xyz)
+    --print("map")
+    local u = math.atan2(
+        xyz:dot(X),xyz:dot(Y)
+    )
+    local v = math.atan2(
+        xyz:dot(Z:normalize()),
+        math.sqrt(
+            xyz:dot(X)^2+xyz:dot(X)^2
+        )
+        -r1
+    )
+    return vector.new(u,v)
+end
+function lerp(x,y,t)
+    --print("lerp")
+    return x - (x-y)*t
+end
+function project(x,y)
+    --print("project x:",x," y:",y)
+    return x-(
+        y*(
+            (
+                x:dot(
+                    y
+                )
+            )/(
+                y:dot(
+                    y
+                )
+            )
+        )
+    )
+end
+function setmag(x,y)
+    --print("setmag")
+    return x:normalize()*y
+end
+function f(x,y,z)
+    --print("f")
+    xyz = vector.new(x,y,z)
+    dist = (xyz-setmag(project(xyz,Z),r1)):length()-r2
+    detail = lerp(5*surface(map(xyz)),r1,v)
+    return dist-detail
+end
+function blockat(x,y,z)
+    --print("blockat")
+    if f(x,y,z) < 0 then
+        flag = false
+        for k,v in pairs({
+            {1,0,0},
+            {0,1,0},
+            {0,0,1},
+            {-1,0,0},
+            {0,-1,0},
+            {0,0,-1}
+        })do
+            flag = f(x+v[1],y+v[2],z+v[3])>0 or flag
+        end
+        if flag then
+            dx = f(x+0.1,y,z)-f(x-0.1,y,z)
+            dy = f(x,y+0.1,z)-f(x,y-0.1,z)
+            dz = f(x,y,z+0.1)-f(x,y,z-0.1)
+            normal = vector.new(dx,dy,dz):normalize()
+            if normal:dot(vector.new(0,0,1)) > 0.5 then
+                return true, "minecraft:moss_block"
+            end
+            dot = normal:dot(l)
+            lighttable = {
+                {-.7,"minecraft:cobbled_deepslate"},
+                {-.5,"minecraft:andesite"},
+                {-.3,"minecraft:tuff"},
+                {0,"minecraft:cobblestone"},
+                {.5,"minecraft:diorite"},
+                {.7,"create:cut_limestone"},
+                {2,"minecraft:calcite"}
+            }
+            for i,v in ipairs(lighttable) do
+                if dot < v[1] then
+                    return true, v[2]
+                end
+            end            
+        end
+    end
+--    print(x,y,z,"is not part of the set")
+    return false  
+end
+return {blockat = blockat}