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/****** path_finder.c ***********************************************
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This recursive function traces the least cost path backwards
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to cells from which the cumulative cost was determined
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*********************************************************************/
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#include <grass/segment.h>
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#include "local_proto.h"
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void path_finder(int row, int col, int backrow, int backcol)
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int data, new_backrow, new_backcol;
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extern int nrows, ncols;
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extern SEGMENT in_row_seg, in_col_seg, out_seg;
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if (row < 0 || row >= nrows || col < 0 || col >= ncols)
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return; /* outside the window */
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/* if the pt has already been traversed, return */
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value = (char *)&data;
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segment_get(&out_seg, value, row, col);
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return; /* already traversed */
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/* otherwise, draw a line on output */
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drawline(row, col, backrow, backcol);
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printf("\nrow=%d, col=%d, backrow=%d, backcol=%d", row, col, backrow, backcol);
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/* update path position */
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if (row == backrow && col == backcol) {
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} /* reach an origin */
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value = (char *)&new_backrow;
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segment_get(&in_row_seg, value, backrow, backcol);
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value = (char *)&new_backcol;
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segment_get(&in_col_seg, value, backrow, backcol);
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path_finder(backrow, backcol, new_backrow, new_backcol);