Add origin options to FormSpec labels

doc/lua_api.txt

@@ -2310,12 +2310,12 @@ Elements
 * The label formspec element displays the text set in `label`
   at the specified position.
 * **Note**: If the new coordinate system is enabled, labels are
-  positioned from the center of the text, not the top.
+  positioned from the center of the text by default, not the top.
 * The text is displayed directly without automatic line breaking,
-  so label should not be used for big text chunks.  Newlines can be
+  so label should not be used for big text chunks. Newlines can be
   used to make labels multiline.
-* **Note**: With the new coordinate system, newlines are spaced with
-  half a coordinate.  With the old system, newlines are spaced 2/5 of
+* **Note**: With the new coordinate system, newlines are defaultly spaced
+  with half a coordinate. With the old system, newlines are spaced 2/5 of
   an inventory slot.
 
 ### `hypertext[<X>,<Y>;<W>,<H>;<name>;<text>]`
@@ -2328,8 +2328,9 @@ Elements
 ### `vertlabel[<X>,<Y>;<label>]`
 * Textual label drawn vertically
 * `label` is the text on the label
-* **Note**: If the new coordinate system is enabled, vertlabels are
-  positioned from the center of the text, not the left.
+* **Note**: If the new coordinate system is enabled, vertlabels are positioned
+  from the center of the text by default, not the left.
+* Newlines in a vertlabel add columns to the right of the starting text.
 
 ### `button[<X>,<Y>;<W>,<H>;<name>;<label>]`
 
@@ -2725,6 +2726,25 @@ Some types may inherit styles from parent types.
     * noclip - boolean, set to true to allow the element to exceed formspec bounds. Default to false.
 * label, vertlabel
     * noclip - boolean, set to true to allow the element to exceed formspec bounds.
+    * horigin - Sets horizontal origin in relation to label text. Possible values:
+        * `left`: Left side of the bounding box
+        * `center`: Center of the bounding box
+        * `right`: Right side of the bounding box
+        * `leftline` (vertlabel only): Left end of first column
+        * `centerline` (vertlabel only): Center of first column
+        * `rightline` (vertlabel only): Right end of first column
+      Default `left` for label and `centerline` for vertlabel.
+    * vorigin - Sets vertical origin in relation to label text. Possible values:
+        * `top`: Top of the bounding box
+        * `center`: Center of the bounding box
+        * `bottom`: Bottom of the bounding box
+        * `topline` (label only): Top of first line
+        * `centerline` (label only): Center of first line
+        * `bottomline` (label only): Bottom of first line
+      Default `centerline` for label and `top` for vertlabel.
+    * newline_spacing - number, sets space between lines/columns of text. If
+      the number is prefixed with `*`, the spacing is set to a multiple of the
+      label's font height or width, otherwise it's in coordinates. Default `0.5`.
 * image_button (additional properties)
     * fgimg - standard image. Defaults to none.
     * fgimg_hovered - image when hovered. Defaults to fgimg when not provided.

src/gui/StyleSpec.h

@@ -46,6 +46,9 @@ class StyleSpec
 		ALPHA,
 		CONTENT_OFFSET,
 		PADDING,
+		HORIGIN,
+		VORIGIN,
+		NEWLINE_SPACING,
 		NUM_PROPERTIES,
 		NONE
 	};
@@ -98,6 +101,12 @@ class StyleSpec
 			return CONTENT_OFFSET;
 		} else if (name == "padding") {
 			return PADDING;
+		} else if (name == "horigin") {
+			return HORIGIN;
+		} else if (name == "vorigin") {
+			return VORIGIN;
+		} else if (name == "newline_spacing") {
+			return NEWLINE_SPACING;
 		} else {
 			return NONE;
 		}