1 files changed, 70 insertions, 0 deletions
diff --git a/other/pamendian.c b/other/pamendian.c
new file mode 100644
index 00000000..16e1fe56
--- /dev/null
+++ b/other/pamendian.c
@@ -0,0 +1,70 @@
+/******************************************************************************
+                              pnmendian
+*******************************************************************************
+
+  Reverse the endianness of multi-byte samples in a Netpbm stream.
+  I.e. convert between the true format and the little endian variation of
+  it.
+******************************************************************************/
+  
+#include "pam.h"
+
+
+static sample
+reverseSample(sample const insample, unsigned int const bytesPerSample) {
+/*----------------------------------------------------------------------------
+  Return a sample whose value is the least significant
+  'bytes_per_sample' bytes, in reverse order.
+-----------------------------------------------------------------------------*/
+    unsigned int bytePos;
+    sample shiftedInsample;
+    sample outsample;
+    shiftedInsample = insample;  /* initial value */
+    outsample = 0;  /* initial value */
+    for (bytePos = 0; bytePos < bytesPerSample; ++bytePos) {
+        outsample = outsample * 256 + (shiftedInsample & 0xff);
+        shiftedInsample >>= 8;
+    }
+    return outsample;
+}
+
+
+
+int main(int argc, char *argv[]) {
+
+    struct pam inpam, outpam;
+    tuple * intuplerow;
+    tuple * outtuplerow;
+    unsigned int row;
+
+    pnm_init(&argc, argv);
+
+    pnm_readpaminit(stdin, &inpam, PAM_STRUCT_SIZE(tuple_type));
+
+    outpam = inpam;
+    outpam.file = stdout;
+
+    pnm_writepaminit(&outpam);
+
+    intuplerow = pnm_allocpamrow(&inpam);      
+    outtuplerow = pnm_allocpamrow(&outpam);
+
+    for (row = 0; row < inpam.height; row++) {
+        unsigned int col;
+        pnm_readpamrow(&inpam, intuplerow);
+        for (col = 0; col < inpam.width; col++) {
+            unsigned int plane;
+            for (plane = 0; plane < inpam.depth; plane++) 
+                outtuplerow[col][plane] = 
+                    reverseSample(intuplerow[col][plane], 
+                                  inpam.bytes_per_sample);
+        }
+        pnm_writepamrow(&outpam, outtuplerow);
+    }
+
+    pnm_freepamrow(outtuplerow);        
+    pnm_freepamrow(intuplerow);        
+
+    exit(0);
+}
+