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scale_chain.c

Go to the documentation of this file.

#include <stdlib.h>
#include "sadie.h"
#include "chain.h"


void SCALE_CHAIN (
CHAIN *chainmap,                     /* Pointer to the chain code structure */
int   scale,                         /* Scaling factor to scale chain code */
CHAIN **scaledChain                  /* Address of pointer to the scaled chain code structure */
) {
    unsigned char code;
    unsigned int j, k, prevj, prevk;
    unsigned int currj, currk;
    int skip;
    LIST_NODE *newLnode, *currLnode, **prevLnode;
    CHAIN_NODE *newCnode, *currCnode, **prevCnode;
    
    /* Allocate memory for the new chain code structure */
    (*scaledChain) = (CHAIN *)malloc(sizeof(CHAIN));

    /* Write header info into the new chain code structure */
    memcpy((char *)&((*scaledChain)->nlin), (char *)&(chainmap->nlin), CHAIN_HEADER_SIZE);
    (*scaledChain)->nlin = chainmap->nlin/scale;
    (*scaledChain)->npix = chainmap->npix/scale;
    (*scaledChain)->list = NULL;
    prevLnode = (LIST_NODE **)&((*scaledChain)->list);

    /* Scale chain code */
    currLnode = chainmap->list;
    while (currLnode != NULL) {
        j = currLnode->startj;
        k = currLnode->startk;
        prevj = j/scale;
        prevk = k/scale;
        
        newLnode = (LIST_NODE *)malloc(sizeof(LIST_NODE));
        newLnode->startj = j/scale;
        newLnode->startk = k/scale;
        newLnode->ring_type = currLnode->ring_type;
        newLnode->ring_id = currLnode->ring_id;
        newLnode->chain = NULL;
        newLnode->next = NULL;
        (*prevLnode) = newLnode;
        prevLnode = (LIST_NODE **)&(newLnode->next);
        prevCnode = (CHAIN_NODE **)&(newLnode->chain);
        
        currCnode = currLnode->chain;
        skip = 1;
        while (currCnode != NULL) {
            CHAIN_COMPUTE_COORDINATES(k, j, currCnode->code, &k, &j);
            if (!(skip%scale)) {
                currj = j/scale;
                currk = k/scale;
                CHAIN_COMPUTE_CODE(prevj, prevk, currj, currk, &code);
                newCnode = (CHAIN_NODE *)malloc(sizeof(CHAIN_NODE));
                newCnode->code = code;
                newCnode->valid = currCnode->valid;
                newCnode->next = NULL;
                (*prevCnode) = newCnode;
                prevCnode = (CHAIN_NODE **)&(newCnode->next);
                
                prevj = currj;
                prevk = currk;
            }

            skip++;
            currCnode = (CHAIN_NODE *)currCnode->next;
        }

        currLnode = currLnode->next;
    }
    
}

    
    
                  

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