add proper arguments to rotate cmd

examples/rotate.scri

@@ -1,3 +1,3 @@
 load :0;
-rotate 30;
+rotate 30 #ff00ff;
 quicksave;

src/magick.zig

@@ -54,8 +54,6 @@ fn magickSave(image: *Image, wand: *mc.MagickWand) !void {
 
     std.debug.warn("\tmagick: saving to '{}'..", c_tmpnam);
 
-    _ = mc.MagickDisplayImage(wand, c":0");
-
     if (mc.MagickWriteImage(wand, c_tmpnam.ptr) != 1)
         return error.MagickWriteFail;
 
@@ -63,17 +61,19 @@ fn magickSave(image: *Image, wand: *mc.MagickWand) !void {
     std.debug.warn("OK\n");
 }
 
-pub fn runRotate(image: *Image) !void {
+/// Rotate the given image.
+/// bgfill must point to a null-terminated string.
+pub fn runRotate(image: *Image, deg: f32, bgfill: []const u8) !void {
     var mctx = try magickLoad(image);
     defer mctx.deinit();
 
     var bg = mc.NewPixelWand();
     defer mc.DestroyPixelWand(bg);
 
-    if (mc.PixelSetColor(bg, c"#000000") != 1)
+    if (mc.PixelSetColor(bg, bgfill.ptr) != 1)
         return error.PixelSetColorFail;
 
-    if (mc.MagickRotateImage(mctx.wand, bg, f64(30)) != 1)
+    if (mc.MagickRotateImage(mctx.wand, bg, deg) != 1)
         return error.RotateFail;
 
     try magickSave(image, mctx.wand);

src/runner.zig

@@ -258,9 +258,16 @@ pub const Runner = struct {
         try image.runCustomPlugin(custom.WildNoise, pos, map);
     }
 
-    fn rotateCmd(self: *Runner) !void {
+    fn rotateCmd(
+        self: *Runner,
+        deg: f32,
+        bgfill: []const u8,
+    ) !void {
         var image = try self.getImage();
-        try magick.runRotate(image);
+        var c_bgfill = try std.cstr.addNullByte(self.allocator, bgfill);
+        defer self.allocator.free(c_bgfill);
+
+        try magick.runRotate(image, deg, c_bgfill);
     }
 
     fn runCommand(self: *Runner, cmd: *lang.Command) !void {
@@ -424,7 +431,11 @@ pub const Runner = struct {
                 try self.wildNoiseCmd(pos, &map);
             },
 
-            .Rotate => try self.rotateCmd(),
+            .Rotate => blk: {
+                const deg = try cmd.floatArgAt(0);
+                const bgfill = try cmd.argAt(1);
+                try self.rotateCmd(deg, bgfill);
+            },
 
             else => blk: {
                 std.debug.warn("Unsupported command: {}\n", cmd.command);