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-rw-r--r--other/pamendian.c51
1 files changed, 32 insertions, 19 deletions
diff --git a/other/pamendian.c b/other/pamendian.c
index c24d9629..8826b06f 100644
--- a/other/pamendian.c
+++ b/other/pamendian.c
@@ -1,20 +1,21 @@
-/******************************************************************************
+/*=============================================================================
                               pamendian
-*******************************************************************************
+===============================================================================
 
   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) {
+reverseSample(sample       const insample,
+              unsigned int const bytesPerSample) {
 /*----------------------------------------------------------------------------
   Return a sample whose value is the least significant
-  'bytes_per_sample' bytes, in reverse order.
+  'bytesPerSample' bytes, in reverse order.
 -----------------------------------------------------------------------------*/
     unsigned int bytePos;
     sample shiftedInsample;
@@ -30,14 +31,14 @@ reverseSample(sample const insample, unsigned int const bytesPerSample) {
 
 
 
-int main(int argc, char *argv[]) {
+int main(int argc, const char ** argv) {
 
     struct pam inpam, outpam;
     tuple * intuplerow;
     tuple * outtuplerow;
     unsigned int row;
 
-    pnm_init(&argc, argv);
+    pm_proginit(&argc, argv);
 
     pnm_readpaminit(stdin, &inpam, PAM_STRUCT_SIZE(tuple_type));
 
@@ -46,27 +47,39 @@ int main(int argc, char *argv[]) {
 
     pnm_writepaminit(&outpam);
 
-    intuplerow = pnm_allocpamrow(&inpam);      
-    outtuplerow = pnm_allocpamrow(&outpam);
-
+    /* We read the samples as if the maxval is 65535 so pnm_readpamrow, which
+       assumes big-endian samples, doesn't choke on a little-endian sample,
+       finding it to exceed the maxval.  (The pure way to do this would be not
+       to use libnetpbm row reading and writing facilities on little-endian
+       pseudo-Netpbm images, but this program isn't important enough to
+       justify that effort).
+    */
     inpam.maxval = 65535;
 
-    for (row = 0; row < inpam.height; row++) {
+    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++) {
+        for (col = 0; col < inpam.width; ++col) {
             unsigned int plane;
-            for (plane = 0; plane < inpam.depth; plane++) 
-                outtuplerow[col][plane] = 
-                    reverseSample(intuplerow[col][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);        
+    pnm_freepamrow(outtuplerow);
+    pnm_freepamrow(intuplerow);
 
-    exit(0);
+    return 0;
 }
 
+
+