simplify some indexing increments

Author: sjkelly

src/marching_cubes.jl

@@ -310,9 +310,10 @@ function marching_cubes{ST,FT,M<:AbstractMesh}(sdf::SignedDistanceField{3,ST,FT}
         sdf[xi+1,yi,zi+1] < iso && (cubeindex |= 32)
         sdf[xi+1,yi+1,zi+1] < iso && (cubeindex |= 64)
         sdf[xi,yi+1,zi+1] < iso && (cubeindex |= 128)
+        cubeindex += 1
 
         # Cube is entirely in/out of the surface
-        edge_table[cubeindex+1] == 0 && continue
+        edge_table[cubeindex] == 0 && continue
 
         points = (Point{3,Float64}(xi-1,yi-1,zi-1).*s,
                   Point{3,Float64}(xi,yi-1,zi-1).*s,
@@ -324,61 +325,61 @@ function marching_cubes{ST,FT,M<:AbstractMesh}(sdf::SignedDistanceField{3,ST,FT}
                   Point{3,Float64}(xi-1,yi,zi).*s)
 
         # Find the vertices where the surface intersects the cube
-        if (edge_table[cubeindex+1] & 1 != 0)
+        if (edge_table[cubeindex] & 1 != 0)
           vertlist[1] =
              vertex_interp(iso,points[1],points[2],sdf[xi,yi,zi],sdf[xi+1,yi,zi])
         end
-        if (edge_table[cubeindex+1] & 2 != 0)
+        if (edge_table[cubeindex] & 2 != 0)
           vertlist[2] =
              vertex_interp(iso,points[2],points[3],sdf[xi+1,yi,zi],sdf[xi+1,yi+1,zi])
         end
-        if (edge_table[cubeindex+1] & 4 != 0)
+        if (edge_table[cubeindex] & 4 != 0)
           vertlist[3] =
              vertex_interp(iso,points[3],points[4],sdf[xi+1,yi+1,zi],sdf[xi,yi+1,zi])
         end
-        if (edge_table[cubeindex+1] & 8 != 0)
+        if (edge_table[cubeindex] & 8 != 0)
           vertlist[4] =
              vertex_interp(iso,points[4],points[1],sdf[xi,yi+1,zi],sdf[xi,yi,zi])
         end
-        if (edge_table[cubeindex+1] & 16 != 0)
+        if (edge_table[cubeindex] & 16 != 0)
           vertlist[5] =
              vertex_interp(iso,points[5],points[6],sdf[xi,yi,zi+1],sdf[xi+1,yi,zi+1])
         end
-        if (edge_table[cubeindex+1] & 32 != 0)
+        if (edge_table[cubeindex] & 32 != 0)
           vertlist[6] =
              vertex_interp(iso,points[6],points[7],sdf[xi+1,yi,zi+1],sdf[xi+1,yi+1,zi+1])
         end
-        if (edge_table[cubeindex+1] & 64 != 0)
+        if (edge_table[cubeindex] & 64 != 0)
           vertlist[7] =
              vertex_interp(iso,points[7],points[8],sdf[xi+1,yi+1,zi+1],sdf[xi,yi+1,zi+1])
         end
-        if (edge_table[cubeindex+1] & 128 != 0)
+        if (edge_table[cubeindex] & 128 != 0)
           vertlist[8] =
              vertex_interp(iso,points[8],points[5],sdf[xi,yi+1,zi+1],sdf[xi,yi,zi+1])
         end
-        if (edge_table[cubeindex+1] & 256 != 0)
+        if (edge_table[cubeindex] & 256 != 0)
           vertlist[9] =
              vertex_interp(iso,points[1],points[5],sdf[xi,yi,zi],sdf[xi,yi,zi+1])
         end
-        if (edge_table[cubeindex+1] & 512 != 0)
+        if (edge_table[cubeindex] & 512 != 0)
           vertlist[10] =
              vertex_interp(iso,points[2],points[6],sdf[xi+1,yi,zi],sdf[xi+1,yi,zi+1])
         end
-        if (edge_table[cubeindex+1] & 1024 != 0)
+        if (edge_table[cubeindex] & 1024 != 0)
           vertlist[11] =
              vertex_interp(iso,points[3],points[7],sdf[xi+1,yi+1,zi],sdf[xi+1,yi+1,zi+1])
         end
-        if (edge_table[cubeindex+1] & 2048 != 0)
+        if (edge_table[cubeindex] & 2048 != 0)
           vertlist[12] =
              vertex_interp(iso,points[4],points[8],sdf[xi,yi+1,zi],sdf[xi,yi+1,zi+1])
         end
 
         # Create the triangle
         for i = 1:3:13
-            tri_table[cubeindex+1][i] == -1 && break
-            push!(vts, vertlist[tri_table[cubeindex+1][i  ]])
-            push!(vts, vertlist[tri_table[cubeindex+1][i+1]])
-            push!(vts, vertlist[tri_table[cubeindex+1][i+2]])
+            tri_table[cubeindex][i] == -1 && break
+            push!(vts, vertlist[tri_table[cubeindex][i  ]])
+            push!(vts, vertlist[tri_table[cubeindex][i+1]])
+            push!(vts, vertlist[tri_table[cubeindex][i+2]])
             fct = length(vts)
             push!(fcs, Face{3,Int,0}(fct, fct-1, fct-2))
         end