From bb6a7cf9ecaec1dbd2837fdddc866be285ce053a Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Mon, 2 Apr 2018 11:05:33 +0200
Subject: [PATCH] Flip and switch parameters

---
 cmds.cc  | 47 +++++++++++++++++++++++++++++++++
 jam.h    |  1 +
 parse.cc | 79 ++++++++++++++++++++++++++++++++++++--------------------
 3 files changed, 99 insertions(+), 28 deletions(-)

diff --git a/cmds.cc b/cmds.cc
index 24fb0a4..ca3f81f 100644
--- a/cmds.cc
+++ b/cmds.cc
@@ -171,6 +171,52 @@ static cmd_exec *rotate_ctor(cmd *c)
   return r;
 }
 
+/*** flip ***/
+
+class flip_cmd : public cmd_exec {
+public:
+  bool horizontal;
+  bool vertical;
+  vector<page *> process(vector<page *> &pages);
+};
+
+vector<page *> flip_cmd::process(vector<page *> &pages)
+{
+  vector<page *> out;
+  for (auto p: pages)
+    {
+      pdf_matrix m;
+      if (vertical)
+	{
+	  m.scale(1, -1);
+	  m.shift(0, p->height);
+	}
+      if (horizontal)
+	{
+	  m.scale(-1, 1);
+	  m.shift(p->width, 0);
+	}
+      out.push_back(new xform_page(p, m));
+    }
+  return out;
+}
+
+static const arg_def flip_args[] = {
+  { "h",	AT_SWITCH },
+  { "v",	AT_SWITCH },
+  { NULL,	0 }
+};
+
+static cmd_exec *flip_ctor(cmd *c)
+{
+  flip_cmd *f = new flip_cmd;
+  f->horizontal = c->args.at(0)->as_int(0);
+  f->vertical = c->args.at(1)->as_int(0);
+  if (!f->horizontal && !f->vertical)
+    die("Flip has no direction specified");
+  return f;
+}
+
 /*** select ***/
 
 class select_cmd : public cmd_exec {
@@ -383,6 +429,7 @@ const cmd_def cmd_table[] = {
   { "move",	move_args,	0,	move_ctor	},
   { "scale",	scale_args,	0,	scale_ctor	},
   { "rotate",	rotate_args,	0,	rotate_ctor	},
+  { "flip",	flip_args,	0,	flip_ctor	},
   { "select",	no_args,	1,	select_ctor	},
   { "apply",	no_args,	1,	apply_ctor	},
   { "modulo",	modulo_args,	1,	modulo_ctor	},
diff --git a/jam.h b/jam.h
index a966cea..002ad04 100644
--- a/jam.h
+++ b/jam.h
@@ -18,6 +18,7 @@ enum arg_type {
   AT_INT,
   AT_DOUBLE,
   AT_DIMEN,
+  AT_SWITCH,
   AT_TYPE_MASK = 0xffff,
   AT_MANDATORY = 0x10000,
   AT_POSITIONAL = 0x20000,
diff --git a/parse.cc b/parse.cc
index 1869b3a..d3d92cd 100644
--- a/parse.cc
+++ b/parse.cc
@@ -295,7 +295,10 @@ static void parse_args(cmd *c)
   for (;;)
     {
       t = next_token();
+      if (t == TOK_CLOSE_PAREN)
+        break;
       uint argi = 0;
+      bool has_value = false;
       if (t == TOK_IDENT)
 	{
 	  while (adefs[argi].name && token != adefs[argi].name)
@@ -305,8 +308,10 @@ static void parse_args(cmd *c)
 	  if (c->args.at(argi)->given())
 	    parse_error("Parameter %s given multiple times", token.c_str());
 	  t = next_token();
-	  if (t != TOK_EQUAL)
-	    parse_error("Parameter name must be followed by '='");
+	  if (t == TOK_EQUAL)
+	    has_value = true;
+	  else
+	    return_token();
 	  saw_named = true;
 	}
       else if (saw_named)
@@ -319,35 +324,53 @@ static void parse_args(cmd *c)
 	  if (next_pos >= num_args)
 	    parse_error("Too many positional arguments for command %s", cdef->name);
 	  argi = next_pos++;
+	  has_value = true;
 	}
 
       const arg_def *adef = &adefs[argi];
+      uint type = adef->type & AT_TYPE_MASK;
       arg_val *val = NULL;
-      switch (adef->type & AT_TYPE_MASK)
-	{
-	case AT_STRING:
-	  t = next_token();
-	  if (t != TOK_STRING)
-	    parse_error("Parameter %s must be a string", adef->name);
-	  val = new arg_string(token);
-	  break;
-	case AT_INT:
-	  t = next_token();
-	  if (t != TOK_NUMBER || !token_is_int())
-	    parse_error("Parameter %s must be an integer", adef->name);
-	  val = new arg_int((int) token_num);
-	  break;
-	case AT_DOUBLE:
-	  t = next_token();
-	  if (t != TOK_NUMBER)
-	    parse_error("Parameter %s must be a number", adef->name);
-	  val = new arg_double(token_num);
-	  break;
-	case AT_DIMEN:
-	  val = new arg_double(parse_dimen(adef));
-	  break;
-	default:
-	  abort();
+      if (has_value)
+        {
+	  switch (type)
+	    {
+	    case AT_STRING:
+	      t = next_token();
+	      if (t != TOK_STRING)
+		parse_error("Parameter %s must be a string", adef->name);
+	      val = new arg_string(token);
+	      break;
+	    case AT_INT:
+	      t = next_token();
+	      if (t != TOK_NUMBER || !token_is_int())
+		parse_error("Parameter %s must be an integer", adef->name);
+	      val = new arg_int((int) token_num);
+	      break;
+	    case AT_DOUBLE:
+	      t = next_token();
+	      if (t != TOK_NUMBER)
+		parse_error("Parameter %s must be a number", adef->name);
+	      val = new arg_double(token_num);
+	      break;
+	    case AT_DIMEN:
+	      val = new arg_double(parse_dimen(adef));
+	      break;
+	    case AT_SWITCH:
+	      t = next_token();
+	      if (t != TOK_NUMBER || !token_is_int() || ((int) token_num != 0 && (int) token_num != 1))
+		parse_error("Parameter %s must be a switch", adef->name);
+	      val = new arg_int((int) token_num);
+	      break;
+	    default:
+	      abort();
+	    }
+	}
+      else
+        {
+	  if (type == AT_SWITCH)
+	    val = new arg_int(1);
+	  else
+	    parse_error("Parameter %s must have a value", adef->name);
 	}
 
       c->args.at(argi) = val;
@@ -469,7 +492,7 @@ void help()
 
       const arg_def *arg = def->arg_defs;
       static const char * const type_names[] = {
-	"string", "int", "double", "dimen"
+	"string", "int", "double", "dimen", "switch"
       };
       while (arg->name)
 	{
-- 
2.39.5