1 files changed, 49 insertions, 0 deletions
diff --git a/crawl-ref/source/rltiles/tool/tile_convert.cc b/crawl-ref/source/rltiles/tool/tile_convert.cc
new file mode 100644
index 0000000000..b65518cfb2
--- /dev/null
+++ b/crawl-ref/source/rltiles/tool/tile_convert.cc
@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <string.h>
+
+// This is a standalone utility to convert old-style palettized BMPs 
+// to transparent PNGs.
+
+#include "tile.h"
+
+int main(int argc, char **argv)
+{
+    if (argc < 2)
+    {
+        printf("Usage: %s (filename.bmp)\n", argv[0]);
+        return -1;
+    }
+
+    char dest[1024];
+    strcpy(dest, argv[1]);
+
+    size_t len = strlen(dest);
+    if (strcmp(&dest[len-4], ".bmp"))
+    {
+        printf("File '%s' does not end in bmp.\n", argv[1]);
+        return -2;
+    }
+
+    dest[len-3] = 'p';
+    dest[len-2] = 'n';
+    dest[len-1] = 'g';
+
+    tile conv;
+    if (!conv.load(argv[1]))
+    {
+        printf("Failed to load '%s'.\n", argv[1]);
+        return -3;
+    }
+
+    conv.replace_colour(tile_colour::background, tile_colour::transparent);
+
+    if (!write_png(dest, &conv.get_pixel(0,0), conv.width(), conv.height()))
+    {
+        printf("Failed to write dest '%s'.\n", dest);
+        return -4;
+    }
+
+    printf("Converted '%s'.\n", argv[1]);
+
+    return 0;
+}