Add gamma support to ply-image.

src/ply-image.c

Index: src/ply-image.c
diff --git a/src/ply-image.c b/src/ply-image.c
index 3395c9200b6d3697678562d79b786d510cf27e8f..1230492f2b7c44248073db0079e17721d90de53a 100644
--- a/src/ply-image.c
+++ b/src/ply-image.c
@@ -451,6 +451,7 @@ ply_image_from_file(const char *path)
 }
 
 #include "ply-frame-buffer.h"
+#include "ply-gamma.h"
 
 #include <math.h>
 #include <signal.h>
@@ -517,7 +518,8 @@ int usage(void)
 {
   fprintf(stderr,
           "usage: ply-image --clear\n"
-          "       ply-image <background> [<x-offset> <y-offset> "
+          "       ply-image [--gamma <gammafile>] "
+          "<background> [<x-offset> <y-offset> "
           "<frame-1> ... <frame-n>]\n");
   exit(1);
 }
@@ -529,6 +531,7 @@ main (int    argc,
 {
   int exit_code = 0;
   int clear = 0;
+  int gamma = 0;
   int help = 0;
   ply_frame_buffer_t *buffer;
   int i;
@@ -544,11 +547,12 @@ main (int    argc,
   if (argc > 1)
     {
       clear = strcasecmp (argv[1], "--clear") == 0;
+      gamma = strcasecmp (argv[1], "--gamma") == 0;
       help = strcasecmp (argv[1], "--help") == 0 ||
         strcasecmp (argv[1], "-h") == 0;
     }
 
-  if (help || argc == 1 || argc == 3 || argc == 4)
+  if (help)
     {
       usage();
     }
@@ -568,6 +572,19 @@ main (int    argc,
     }
   else
     {
+      int num_gamma_args = 0;
+      if (gamma)
+        {
+          if (argc < 6)
+            usage();
+          ply_gamma_set(argv[2]);
+          argv += 2;
+          argc -= 2;
+        }
+      else
+        if (argc < 4)
+          usage();
+
       /*
        * Display main image.
        */