C struct layout algorithm

This algorithm finds the offset from the previous field to the start of the next field in a C struct. It worked when tested (part of the Laddie C struct translation). I put this up because there doesnt seem to be one posted. Feel free to use, modify, etc.

- Lea Wittie

Input: 
int size; // field size
int prev_size; // size of previous field
int total_size; // total used (fields + padding) size so far
int BLOCK_SIZE; // aka word size, usually 4 (32 bits)
ALGORITHM
  int pad = 0;

  // it starts on a new block
  if (total_size%BLOCK_SIZE == 0) {
     // nothing
  } 
  // it fits in the last block with the previous one
  else if (size + (BLOCK_SIZE - (total_size%BLOCK_SIZE)) <= BLOCK_SIZE
	   && prev_size <= BLOCK_SIZE) {
    // nothing    
  }
  // it doesnt fit in the last block with company
  else {
    pad = BLOCK_SIZE - (total_size%BLOCK_SIZE);
    prev_size += pad;
  }

  output << offset is prev_size

  // set up for the next one
  total_size += size + pad
  prev_size = size