Implement 'cammy split' command

bin/Makefile

@@ -8,7 +8,7 @@ CFLAGS		+= -fPIC -Wall -O2 -I$(INCLUDE_PATH)
 LDFLAGS		=
 
 CAMMY		= cammy
-CAMMY_OBJS	= main.o export.o import.o dither.o
+CAMMY_OBJS	= main.o export.o import.o dither.o split.o
 
 CAMMY_HEADERS	= commands.h
 

bin/commands.h

@@ -8,8 +8,7 @@ void cammy_validate_photo_number(int argc, char **argv, int num);
 int cammy_import(int argc, char **argv);
 int cammy_export(int argc, char **argv);
 int cammy_dither(int argc, char **argv);
-int cammy_rgb_split(int argc, char **argv);
+int cammy_split(int argc, char **argv);
-int cammy_rgb_merge(int argc, char **argv);
 int cammy_tile_import(int argc, char **argv);
 int cammy_tile_export(int argc, char **argv);
 int cammy_tile_convert(int argc, char **argv);

bin/main.c

@@ -14,6 +14,7 @@ static struct {
     { "import", cammy_import },
     { "export", cammy_export },
     { "dither", cammy_dither },
+    { "split",  cammy_split  },
     { NULL,           NULL   }
 };
 

bin/split.c

@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <cammy/image.h>
+#include <cammy/photo.h>
+
+#include "commands.h"
+
+static void usage(int argc, char **argv, const char *message, ...) {
+    if (message) {
+        va_list args;
+
+        va_start(args, message);
+        vfprintf(stderr, message, args);
+        va_end(args);
+         fprintf(stderr, "\n");
+    }
+
+    fprintf(stderr, "usage: %1$s split input.png output-r.png output-g.png output-b.png\n", argv[0]);
+
+    exit(1);
+}
+
+int cammy_split(int argc, char **argv) {
+    cammy_image *image_in,
+                *image_out_r,
+                *image_out_g,
+                *image_out_b;
+
+    if (argc < 3) {
+        usage(argc, argv, "No PNG input file provided");
+    } else if (argc < 6) {
+        usage(argc, argv, "Not enough PNG output filenames provided");
+    }
+
+    if ((image_in = cammy_image_open(argv[2])) == NULL) {
+        goto error_image_open;
+    }
+
+    if (cammy_image_split(image_in,
+                          &image_out_r,
+                          &image_out_g,
+                          &image_out_b) < 0) {
+        goto error_image_split;
+    }
+
+    if (cammy_image_save(image_out_r, argv[3]) < 0) {
+        goto error_image_save;
+    }
+
+    if (cammy_image_save(image_out_g, argv[4]) < 0) {
+        goto error_image_save;
+    }
+
+    if (cammy_image_save(image_out_b, argv[5]) < 0) {
+        goto error_image_save;
+    }
+
+    cammy_image_destroy(image_out_b);
+    cammy_image_destroy(image_out_g);
+    cammy_image_destroy(image_out_r);
+    cammy_image_destroy(image_in);
+
+    return 0;
+
+error_image_save:
+    cammy_image_destroy(image_out_r);
+    cammy_image_destroy(image_out_g);
+    cammy_image_destroy(image_out_b);
+
+error_image_split:
+    cammy_image_destroy(image_in);
+
+error_image_open:
+    return 1;
+}