Initial commit

1 files changed, 132 insertions, 0 deletions

diff --git a/unix/gdev/sgidev/sgiUtil.c b/unix/gdev/sgidev/sgiUtil.c
new file mode 100644
index 00000000..25214450
--- /dev/null
+++ b/unix/gdev/sgidev/sgiUtil.c
@@ -0,0 +1,132 @@
+/**
+ *  SGIUTIL.C -- Shared utility procedures for the SGI translators.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+
+#define	import_spp
+#define	import_error
+#include <iraf.h>
+
+
+/** 
+ *  BSWAP2 -- Move bytes from array "a" to array "b", swapping successive
+ *  pairs of bytes.  The two arrays may be the same but may not be offset
+ *  and overlapping.
+ */
+void
+bswap2 (
+    unsigned char *a,			/* input array			*/
+    unsigned char *b,			/* output array			*/
+    int	  nbytes		/* number of bytes to swap	*/
+)
+{
+    register unsigned char *ip, *op, *otop;
+    register unsigned int temp;
+
+    ip = a;
+    op = b;
+    otop = op + (nbytes & ~1);
+
+    /* Swap successive pairs of bytes.
+     */
+    while (op < otop) {
+        temp  = *ip++;
+        *op++ = *ip++;
+        *op++ = temp;
+    }
+
+    /* If there is an odd byte left, move it to the output array.
+     */
+    if (nbytes & 1)
+        *op = *ip;
+}
+
+
+/* BSWAP4 - Move bytes from array "a" to array "b", swapping the four bytes
+ * in each successive 4 byte group, i.e., 12345678 becomes 43218765.
+ * The input and output arrays may be the same but may not partially overlap.
+*/
+void
+bswap4 (
+    unsigned char  *a,                     /* input array                  */
+    unsigned char  *b,                     /* output array                 */
+    int    nbytes                 /* number of bytes to swap      */
+)
+{
+    register int    n;
+    register unsigned char *ip, *op, *tp;
+    static   unsigned char  temp[4];
+
+    tp = temp;
+    ip = (unsigned char *)a;
+    op = (unsigned char *)b;
+
+    /* Swap successive four byte groups.
+     */
+    for (n = nbytes >> 2;  --n >= 0;  ) {
+        *tp++ = *ip++;
+        *tp++ = *ip++;
+        *tp++ = *ip++;
+        *tp++ = *ip++;
+        *op++ = *--tp;
+        *op++ = *--tp;
+        *op++ = *--tp;
+        *op++ = *--tp;
+    }
+
+    /* If there are any odd bytes left, move them to the output array.
+     * Do not bother to swap as it is unclear how to swap a partial
+     * group, and really incorrect if the data is not modulus 4.
+     */
+    for (n = nbytes & 03;  --n >= 0;  )
+        *op++ = *ip++;
+}
+
+
+/**
+ *  ISSWAPPED -- Test whether we are running on a byte-swapped machine.
+ */
+int
+isSwapped (void)
+{
+    union {
+        short   tswap;
+        char    b[2];
+    } test;
+
+    test.tswap = 1;
+    return ((int) test.b[0]);
+}	
+
+
+/**
+ *  GET_IARG -- Get an integer argument, whether appended directly to flag
+ *  or separated by a whitespace character; if error, report and assign
+ *  default.
+ */
+int
+get_iarg (
+    char   argp,
+    char **argv,
+    int    argno,
+    int    def_val
+)
+{
+    int     temp_val;
+
+    if (argp == (char) 0) {
+        if (argv[argno+1] == NULL) {
+            fprintf (stderr, "missing arg to switch `%c';", argp);
+            fprintf (stderr, " reset to %d\n", def_val);
+            temp_val = def_val;
+        } else
+            temp_val = atoi (argv[++argno]);
+    } else
+        temp_val = atoi (argv[argno]+2);
+
+    return (temp_val);
+}