mesh and memblocks - shifting trouble

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TheComet

18

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Joined: 18th Oct 2007

Location: I`m under ur bridge eating ur goatz.

Posted: 5th Mar 2011 01:09

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Hey guys!

I'm trying to make a function that can pick out one face of an object from a memblock, shift the data for that face to the very end of the memblock, and then shift all of the data above where I "took out" the face down to patch it up again. Here's the code:

+ Code Snippet

function MC_ShiftFaceToEnd(MemNum,Pos)

   rem locals
   local n as dword
   local dim store#(53) as float

   rem load mesh data of block into array
   for n=0 to 53
      store#(n)=memblock float(MemNum,Pos*216+(n*4)+12)
   next n

   rem shift all data down
   for n=1 to memblock dword(MemNum,8)-((Pos*6)+6)
      write memblock float MemNum,Pos*216+12+((n-1)*4),memblock float(MemNum,(Pos+1)*216+12+((n-1)*4))
   next n
   
   rem write stored data at the end of memblock
   for n=0 to 53
      write memblock float MemNum,((memblock dword(MemNum,8)/6)-1)*216+(n*4)+12,store#(n)
   next n

endfunction

For me the function seem logical, but it does some weird things with the mesh... I shouldn't be able to detect any visual changes in the mesh, just that the data for one face is now at the very end of the memblock.

I designed the function so 1 face is made up of 6 vertices. So if I set Pos to a value of 1, this would mean vertices 7-12 should be shifted to the end of the memblock. A value of 0 would mean vertices 1-6, a value of 2 would mean vertices 13-18.

Any help greatly appreciated!

TheComet

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TheComet

18

Years of Service

User Offline

Joined: 18th Oct 2007

Location: I`m under ur bridge eating ur goatz.

Posted: 5th Mar 2011 01:53

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Well I solved it, the problem was that I was copying bytes instead of floats in this section:

+ Code Snippet

   rem shift all data down
   for n=1 to memblock dword(MemNum,8)-((Pos*6)+6)
      write memblock float MemNum,Pos*216+12+((n-1)*4),memblock float(MemNum,(Pos+1)*216+12+((n-1)*4))
   next n

should be:

+ Code Snippet

   rem shift all data down
   for n=1 to memblock dword(MemNum,8)*9-(pos*54)
      write memblock float MemNum,Pos*216+12+((n-1)*4),memblock float(MemNum,(Pos+1)*216+12+((n-1)*4))
   next n

complete code:

+ Code Snippet

function MC_ShiftFaceToEnd(MemNum,Pos)

   rem locals
   local n as dword
   local dim store#(53) as float

   rem load mesh data of block into array
   for n=0 to 53
      store#(n)=memblock float(MemNum,Pos*216+(n*4)+12)
   next n

   rem shift all data down
   for n=1 to memblock dword(MemNum,8)*9-(pos*54)
      write memblock float MemNum,Pos*216+12+((n-1)*4),memblock float(MemNum,(Pos+1)*216+12+((n-1)*4))
   next n
   
   rem write stored data at the end of memblock
   for n=0 to 53
      write memblock float MemNum,((memblock dword(MemNum,8)/6)-1)*216+(n*4)+12,store#(n)
   next n

endfunction

TheComet

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