1 files changed, 155 insertions, 0 deletions
diff --git a/editor/pamshuffle.c b/editor/pamshuffle.c
new file mode 100644
index 00000000..bffb79c5
--- /dev/null
+++ b/editor/pamshuffle.c
@@ -0,0 +1,155 @@
+/*=============================================================================
+                               pamshuffle
+===============================================================================
+  Part of the Netpbm package.
+
+  Relocate pixels in row, randomly, using Fisher-Yates shuffling.
+
+  By Akira F. Urushibata
+
+  Contributed to the public domain by its author.
+=============================================================================*/
+
+#include <assert.h>
+#include "pm_c_util.h"
+#include "pam.h"
+#include "rand.h"
+#include "shhopt.h"
+
+struct CmdlineInfo {
+    /* All the information the user supplied in the command line,
+       in a form easy for the program to use.
+    */
+    const char * inputFileName;
+    unsigned int column;
+    unsigned int randomseedSpec;
+    unsigned int randomseed;
+};
+
+static void
+parseCommandLine(int argc, const char ** const argv,
+                 struct CmdlineInfo * const cmdlineP) {
+/*----------------------------------------------------------------------------
+   Note that the file spec array we return is stored in the storage that
+   was passed to us as the argv array.
+-----------------------------------------------------------------------------*/
+    optEntry * option_def;
+        /* Instructions to OptParseOptions3 on how to parse our options. */
+    optStruct3 opt;
+
+    unsigned int option_def_index;
+
+    MALLOCARRAY(option_def, 100);
+
+    opt.opt_table = option_def;
+    opt.short_allowed = false;  /* We have no short (old-fashioned) options */
+    opt.allowNegNum = true;  /* We have no parms that are negative numbers */
+
+    option_def_index = 0;   /* incremented by OPTENT3 */
+    OPTENT3(0,   "column",     OPT_FLAG,   NULL,
+                               &cmdlineP->column,                    0);
+    OPTENT3(0,   "randomseed", OPT_UINT,   &cmdlineP->randomseed,
+                               &cmdlineP->randomseedSpec,            0);
+
+    pm_optParseOptions3(&argc, (char **)argv, opt, sizeof(opt), 0);
+        /* Uses and sets argc, argv, and some of *cmdlineP and others. */
+
+    free(option_def);
+
+    if (argc-1 > 1)
+        pm_error("Too many arguments (%u). "
+                 "The only possible argument is the input file name.", argc-1);
+    else if (argc-1 < 1)
+        cmdlineP->inputFileName = "-";
+    else
+        cmdlineP->inputFileName = argv[1];
+
+}
+
+
+
+static void
+shuffleRow(tuple *            const tuplerow,
+           unsigned int       const cols,
+           struct pm_randSt * const randStP) {
+
+    unsigned int col;
+
+    for (col = 0; col + 1 < cols; ++col) {
+        tuple        const temp    = tuplerow[col];
+        unsigned int const randcol = col + pm_rand(randStP) % (cols - col);
+
+        assert(randcol >= col );
+        assert(randcol < cols);
+
+        /* swap */
+        tuplerow[col]     = tuplerow[randcol];
+        tuplerow[randcol] = temp;
+    }
+}
+
+
+
+int
+main(int argc, const char * argv[]) {
+
+    FILE * ifP;
+    int    eof;     /* no more images in input stream */
+
+    struct CmdlineInfo cmdline;
+    struct pam inpam;   /* Input PAM image */
+    struct pam outpam;  /* Output PAM image */
+    struct pm_randSt randSt;
+
+    pm_proginit(&argc, argv);
+
+    parseCommandLine(argc, argv, &cmdline);
+
+    ifP = pm_openr(cmdline.inputFileName);
+
+    pm_randinit(&randSt);
+    pm_srand2(&randSt, cmdline.randomseedSpec, cmdline.randomseed);
+
+    for (eof = FALSE; !eof;) {
+        tuple * inrow;   /* Input row buffer */
+        tuple * outrow;  /* Pointers into the input row buffer to reorder it */
+        unsigned int row, col;
+
+        pnm_readpaminit(ifP, &inpam, PAM_STRUCT_SIZE(tuple_type));
+
+        outpam = inpam;
+        outpam.file = stdout;
+
+        pnm_writepaminit(&outpam);
+
+        inrow = pnm_allocpamrow(&inpam);
+
+        MALLOCARRAY(outrow, inpam.width);
+
+        if (!outrow)
+            pm_error("Unable to allocate memory for %u-column output buffer",
+                     inpam.width);
+
+        for (col = 0; col < inpam.width; ++col)
+            outrow[col] = inrow[col];
+
+        for (row = 0; row < inpam.height; ++row) {
+            pnm_readpamrow(&inpam, inrow);
+
+            if (cmdline.column && row > 0) {
+                /* Use the same shuffle ('outrow') as the previous row */
+            } else
+                shuffleRow(outrow, inpam.width, &randSt);
+
+            pnm_writepamrow(&outpam, outrow);
+        }
+
+        pnm_freepamrow(inrow);
+        free(outrow);
+        pnm_nextimage(ifP, &eof);
+    }
+
+    pm_randterm(&randSt);
+
+    return 0;
+}