1 files changed, 83 insertions, 0 deletions
diff --git a/converter/other/cameratopam/util.c b/converter/other/cameratopam/util.c
new file mode 100644
index 00000000..b3ccf7e9
--- /dev/null
+++ b/converter/other/cameratopam/util.c
@@ -0,0 +1,83 @@
+#define _XOPEN_SOURCE   /* Make sure unistd.h contains swab() */
+#include <unistd.h>
+#include <stdio.h>
+
+#include "pm.h"
+#include "global_variables.h"
+#include "util.h"
+
+#ifndef LONG_BITS
+#define LONG_BITS (8 * sizeof(long))
+#endif
+/*
+   Get a 2-byte integer, making no assumptions about CPU byte order.
+   Nor should we assume that the compiler evaluates left-to-right.
+ */
+unsigned short
+get2(FILE * const ifp)
+{
+    unsigned char a, b;
+
+    a = fgetc(ifp);  b = fgetc(ifp);
+
+    if (order == 0x4949)      /* "II" means little-endian */
+        return a | b << 8;
+    else              /* "MM" means big-endian */
+        return a << 8 | b;
+}
+
+/*
+   Same for a 4-byte integer.
+ */
+int
+get4(FILE * const ifp)
+{
+    unsigned char a, b, c, d;
+
+    a = fgetc(ifp);  b = fgetc(ifp);
+    c = fgetc(ifp);  d = fgetc(ifp);
+
+    if (order == 0x4949)
+        return a | b << 8 | c << 16 | d << 24;
+    else
+        return a << 24 | b << 16 | c << 8 | d;
+}
+
+/*
+   Faster than calling get2() multiple times.
+ */
+void
+read_shorts (FILE * const ifp, unsigned short *pixel, int count)
+{
+    fread (pixel, 2, count, ifp);
+    if ((order == 0x4949) == (BYTE_ORDER == BIG_ENDIAN))
+        swab (pixel, pixel, count*2);
+}
+
+/*
+   getbits(-1) initializes the buffer
+   getbits(n) where 0 <= n <= 25 returns an n-bit integer
+ */
+unsigned 
+getbits (FILE * const ifp, int nbits)
+{
+    static unsigned long bitbuf=0;
+    static int vbits=0;
+    unsigned c, ret;
+
+    if (nbits == 0) return 0;
+    if (nbits == -1)
+        ret = bitbuf = vbits = 0;
+    else {
+        ret = bitbuf << (LONG_BITS - vbits) >> (LONG_BITS - nbits);
+        vbits -= nbits;
+    }
+    while (vbits < LONG_BITS - 7) {
+        c = fgetc(ifp);
+        bitbuf = (bitbuf << 8) + c;
+        if (c == 0xff && zero_after_ff)
+            fgetc(ifp);
+        vbits += 8;
+    }
+    return ret;
+}