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#ifndef lint |
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static const char RCSid[] = "$Id: rttree_reduce.c,v 2.2 2011/05/31 20:50:26 greg Exp $"; |
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#endif |
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/* |
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* A utility called by genBSDF.pl to reduce tensor tree samples and output |
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* in a standard format as required by XML specification for variable |
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* resolution BSDF data. We are not meant to be run by the user directly. |
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*/ |
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|
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#include "rtio.h" |
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#include "rterror.h" |
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#include "platform.h" |
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#include <stdlib.h> |
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#include <math.h> |
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|
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float *datarr; /* our loaded BSDF data array */ |
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int ttrank = 4; /* tensor tree rank */ |
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int log2g = 4; /* log2 of grid resolution */ |
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int infmt = 'a'; /* input format ('a','f','d') */ |
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double pctcull = 99.; /* target culling percentile */ |
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|
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#define dval3(ix,ox,oy) datarr[((((ix)<<log2g)+(ox))<<log2g)+(oy)] |
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#define dval4(ix,iy,ox,oy) datarr[((((((ix)<<log2g)+(iy))<<log2g)+(ox))<<log2g)+(oy)] |
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|
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/* Tensor tree node */ |
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typedef struct ttree_s { |
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float vmin, vmax; /* value extrema */ |
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float vavg; /* average */ |
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struct ttree_s *kid; /* 2^ttrank children */ |
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} TNODE; |
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|
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#define HISTLEN 300 /* histogram resolution */ |
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#define HISTMAX 10. /* maximum recorded measure in histogram */ |
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|
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int histo[HISTLEN]; /* histogram freq. of variance measure */ |
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|
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double tthresh; /* acceptance threshold (TBD) */ |
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|
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#define var_measure(tp) ( ((tp)->vmax - (tp)->vmin) / \ |
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(sqrt((tp)->vavg) + .03) ) |
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#define above_threshold(tp) (var_measure(tp) > tthresh) |
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|
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/* Allocate a new set of children for the given node (no checks) */ |
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static void |
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new_kids(TNODE *pn) |
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{ |
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pn->kid = (TNODE *)calloc(1<<ttrank, sizeof(TNODE)); |
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if (pn->kid == NULL) |
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error(SYSTEM, "out of memory in new_kids"); |
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} |
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|
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/* Free children for this node */ |
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static void |
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free_kids(TNODE *pn) |
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{ |
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int i; |
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|
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if (pn->kid == NULL) |
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return; |
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for (i = 1<<ttrank; i--; ) |
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free_kids(pn->kid+i); |
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free(pn->kid); |
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pn->kid = NULL; |
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} |
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|
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/* Build a tensor tree starting from the given hypercube */ |
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static void |
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build_tree(TNODE *tp, const int bmin[], int l2s) |
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{ |
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int bkmin[4]; |
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int i, j; |
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|
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tp->vmin = 1e20; |
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tp->vmax = 0; |
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tp->vavg = 0; |
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if (l2s <= 1) { /* reached upper leaves */ |
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for (i = 1<<ttrank; i--; ) { |
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float val; |
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for (j = ttrank; j--; ) |
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bkmin[j] = bmin[j] + (i>>j & 1); |
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val = (ttrank == 3) ? dval3(bkmin[0],bkmin[1],bkmin[2]) |
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: dval4(bkmin[0],bkmin[1],bkmin[2],bkmin[3]); |
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if (val < tp->vmin) |
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tp->vmin = val; |
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if (val > tp->vmax) |
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tp->vmax = val; |
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tp->vavg += val; |
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} |
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tp->vavg /= (float)(1<<ttrank); |
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/* record stats */ |
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i = (HISTLEN/HISTMAX) * var_measure(tp); |
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if (i >= HISTLEN) i = HISTLEN-1; |
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++histo[i]; |
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return; |
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} |
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--l2s; /* else still branching */ |
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new_kids(tp); /* grow recursively */ |
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for (i = 1<<ttrank; i--; ) { |
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for (j = ttrank; j--; ) |
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bkmin[j] = bmin[j] + ((i>>j & 1)<<l2s); |
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build_tree(tp->kid+i, bkmin, l2s); |
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if (tp->kid[i].vmin < tp->vmin) |
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tp->vmin = tp->kid[i].vmin; |
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if (tp->kid[i].vmax > tp->vmax) |
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tp->vmax = tp->kid[i].vmax; |
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tp->vavg += tp->kid[i].vavg; |
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} |
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tp->vavg /= (float)(1<<ttrank); |
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} |
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|
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/* Set our trimming threshold */ |
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static void |
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set_threshold() |
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{ |
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int hsum = 0; |
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int i; |
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|
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for (i = HISTLEN; i--; ) |
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hsum += histo[i]; |
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hsum = pctcull*.01 * (double)hsum; |
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for (i = 0; hsum > 0; i++) |
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hsum -= histo[i]; |
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tthresh = (HISTMAX/HISTLEN) * i; |
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} |
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|
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/* Trim our tree according to the current threshold */ |
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static void |
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trim_tree(TNODE *tp) |
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{ |
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if (tp->kid == NULL) |
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return; |
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if (above_threshold(tp)) { /* keeping branches? */ |
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int i = 1<<ttrank; |
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while (i--) |
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trim_tree(tp->kid+i); |
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return; |
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} |
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free_kids(tp); /* else trim at this point */ |
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} |
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|
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/* Print a tensor tree from the given hypercube */ |
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static void |
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print_tree(const TNODE *tp, const int bmin[], int l2s) |
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{ |
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int bkmin[4]; |
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int i, j; |
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|
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for (j = log2g-l2s; j--; ) /* indent based on branch level */ |
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fputs(" ", stdout); |
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fputc('{', stdout); /* special case for upper leaves */ |
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if (l2s <= 1 && above_threshold(tp)) { |
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for (i = 0; i < 1<<ttrank; i++) { |
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float val; |
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for (j = ttrank; j--; ) |
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bkmin[j] = bmin[j] + (i>>j & 1); |
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val = (ttrank == 3) ? dval3(bkmin[0],bkmin[1],bkmin[2]) |
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: dval4(bkmin[0],bkmin[1],bkmin[2],bkmin[3]); |
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printf(" %.4e", val); |
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} |
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fputs(" }\n", stdout); |
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return; |
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} |
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if (tp->kid == NULL) { /* trimmed limb */ |
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printf(" %.6e }\n", tp->vavg); |
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return; |
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} |
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--l2s; /* else still branching */ |
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fputc('\n', stdout); |
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for (i = 0; i < 1<<ttrank; i++) { |
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for (j = ttrank; j--; ) |
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bkmin[j] = bmin[j] + ((i>>j & 1)<<l2s); |
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print_tree(tp->kid+i, bkmin, l2s); |
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} |
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++l2s; |
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for (j = log2g-l2s; j--; ) |
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fputs(" ", stdout); |
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fputs("}\n", stdout); |
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} |
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|
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/* Read a row of data in ASCII */ |
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static int |
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read_ascii(float *rowp, int n) |
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{ |
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int n2go; |
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|
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if ((rowp == NULL) | (n <= 0)) |
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return(0); |
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for (n2go = n; n2go; n2go--) |
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if (scanf("%f", rowp++) != 1) |
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break; |
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if (n2go) |
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error(USER, "unexpected EOD on ascii input"); |
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return(n-n2go); |
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} |
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|
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/* Read a row of float data */ |
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static int |
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read_float(float *rowp, int n) |
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{ |
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int nread; |
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|
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if ((rowp == NULL) | (n <= 0)) |
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return(0); |
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nread = fread(rowp, sizeof(float), n, stdin); |
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if (nread != n) |
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error(USER, "unexpected EOF on float input"); |
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return(nread); |
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} |
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|
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/* Read a row of double data */ |
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static int |
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read_double(float *rowp, int n) |
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{ |
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static double *rowbuf = NULL; |
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static int rblen = 0; |
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int nread, i; |
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|
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if ((rowp == NULL) | (n <= 0)) { |
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if (rblen) { |
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free(rowbuf); |
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rowbuf = NULL; rblen = 0; |
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} |
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return(0); |
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} |
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if (rblen < n) { |
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rowbuf = (double *)realloc(rowbuf, sizeof(double)*(rblen=n)); |
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if (rowbuf == NULL) |
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error(SYSTEM, "out of memory in read_double"); |
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} |
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nread = fread(rowbuf, sizeof(double), n, stdin); |
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if (nread != n) |
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error(USER, "unexpected EOF on double input"); |
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for (i = 0; i < nread; i++) |
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*rowp++ = rowbuf[i]; |
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return(nread); |
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} |
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|
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/* Load data array, filling zeroes for rank 3 demi-tensor */ |
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static void |
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load_data() |
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{ |
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int (*readf)(float *, int) = NULL; |
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|
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switch (infmt) { |
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case 'a': |
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readf = &read_ascii; |
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break; |
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case 'f': |
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readf = &read_float; |
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break; |
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case 'd': |
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readf = &read_double; |
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break; |
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default: |
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error(COMMAND, "unsupported input format"); |
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break; |
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} |
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datarr = (float *)calloc(1<<(log2g*ttrank), sizeof(float)); |
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if (datarr == NULL) |
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error(SYSTEM, "out of memory in load_data"); |
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if (ttrank == 3) { |
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int ix, ox; |
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for (ix = 0; ix < 1<<log2g; ix++) |
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for (ox = 0; ox < 1<<log2g; ox++) |
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(*readf)(datarr+((((ix)<<log2g)+(ox))<<log2g), |
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1<<(log2g-1)); |
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} else /* ttrank == 4 */ { |
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int ix, iy, ox; |
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for (ix = 0; ix < 1<<log2g; ix++) |
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for (iy = 0; iy < 1<<log2g; iy++) |
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for (ox = 0; ox < 1<<log2g; ox++) |
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(*readf)(datarr + |
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((((((ix)<<log2g)+(iy))<<log2g)+(ox))<<log2g), |
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1<<log2g); |
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} |
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(*readf)(NULL, 0); /* releases any buffers */ |
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if (infmt == 'a') { |
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int c; |
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while ((c = getc(stdin)) != EOF) { |
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switch (c) { |
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case ' ': |
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case '\t': |
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case '\r': |
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case '\n': |
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continue; |
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} |
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error(WARNING, "data past end of expected input"); |
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break; |
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} |
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} else if (getc(stdin) != EOF) |
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error(WARNING, "binary data past end of expected input"); |
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} |
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|
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/* Load BSDF array, coalesce uniform regions and format as tensor tree */ |
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int |
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main(int argc, char *argv[]) |
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{ |
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int doheader = 1; |
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int bmin[4]; |
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TNODE gtree; |
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int i; |
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/* get options and parameters */ |
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for (i = 1; i < argc && argv[i][0] == '-'; i++) |
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switch (argv[i][1]) { |
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case 'h': |
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doheader = !doheader; |
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break; |
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case 'r': |
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ttrank = atoi(argv[++i]); |
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if (ttrank != 3 && ttrank != 4) |
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goto userr; |
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break; |
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case 'g': |
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log2g = atoi(argv[++i]); |
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if (log2g <= 1) |
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goto userr; |
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break; |
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case 't': |
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pctcull = atof(argv[++i]); |
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if ((pctcull < 0) | (pctcull >= 100.)) |
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goto userr; |
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break; |
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case 'f': |
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infmt = argv[i][2]; |
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if (!infmt || strchr("afd", infmt) == NULL) |
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goto userr; |
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break; |
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default: |
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goto userr; |
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} |
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if (i < argc-1) |
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goto userr; |
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/* load input data */ |
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if (i == argc-1 && freopen(argv[i], "rb", stdin) == NULL) { |
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sprintf(errmsg, "cannot open input file '%s'", argv[i]); |
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error(SYSTEM, errmsg); |
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} |
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if (infmt != 'a') |
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SET_FILE_BINARY(stdin); |
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load_data(); |
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if (doheader) { |
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for (i = 0; i < argc; i++) { |
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fputs(argv[i], stdout); |
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fputc(i < argc-1 ? ' ' : '\n', stdout); |
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} |
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fputc('\n', stdout); |
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} |
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gtree.kid = NULL; /* create our tree */ |
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bmin[0] = bmin[1] = bmin[2] = bmin[3] = 0; |
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build_tree(>ree, bmin, log2g); |
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/* compute threshold & trim tree */ |
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set_threshold(); |
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trim_tree(>ree); |
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/* format to stdout */ |
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print_tree(>ree, bmin, log2g); |
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/* Clean up isn't necessary for main()... |
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free_kids(>ree); |
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free(datarr); |
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*/ |
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return(0); |
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userr: |
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fprintf(stderr, "Usage: %s [-h][-f{a|f|d}][-r {3|4}][-g log2grid][-t trim%%] [input]\n", |
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argv[0]); |
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return(1); |
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} |
