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- title: Formspecs - title: Formspecs
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- title: HUD
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---
title: HUD
layout: default
root: ../
---
Introduction
------------
Heads Up Display (HUD) elements allow you to show text, images, and other graphical elements.
HUD doesn't except user input. For that, you should use a [Formspec](formspecs.html).
Keep in mind that **the interface for creating HUD elements may change,
as it is an experimental feature**. It is unlikely to, though.
* Basic Interface
* Positioning
* Text Elements
* Image Elements
* Other Elements
Basic Interface
---------------
HUD elements are created using a player object.
You can get the player object from a username like this:
{% highlight lua %}
local player = minetest.get_player_by_name("username")
{% endhighlight %}
Once you have the player object, you can create an element:
{% highlight lua %}
local idx = player:hud_add({
hud_elem_type = "text",
position = {x = 1, y = 0},
offset = {x=-100, y = 20},
scale = {x = 100, y = 100},
text = "My Text"
})
{% endhighlight %}
This attributes in the above table and what they do vary depending on
the `hud_elem_type`.\\
A number is returned by the hud_add function which is needed to identify the HUD element
at a later time, if you wanted to change or delete it.
You can change an attribute after creating a HUD element, such as what the text
says:
{% highlight lua %}
player:hud_change(idx, "text", "New Text")
{% endhighlight %}
You can also delete the element:
{% highlight lua %}
player:hud_remove(idx)
{% endhighlight %}
Positioning
-----------
Screens come in different sizes, and HUD elements need to work well on all sizes.
You locate an element using a combination of a position and an offset.
The position is a co-ordinate between (0, 0) and (1, 1) which determines where,
relative to the screen width and height, the element goes.
For example, an element with a position of (0.5, 0.5) will be in the center of the screen.
The offset applies a pixel offset to the position.\\
An element with a position of (0, 0) and an offset of (10, 10) will end up at the screen
co-ordinates (0 * width + 10, 0 * height + 10).
Please note that offset scales to DPI and a user defined factor.
Text Elements
-------------
A text element is the simplest form of a HUD element.\\
Here is our earlier example, but with comments to explain each part:
{% highlight lua %}
local idx = player:hud_add({
hud_elem_type = "text", -- This is a text element
position = {x = 1, y = 0},
offset = {x=-100, y = 20},
scale = {x = 100, y = 100}, -- Maximum size of text, crops off any out of these bounds
text = "My Text" -- The actual text shown
})
{% endhighlight %}
### Colors
You can apply colors to the text, using the `number` attribute.
Colors are in [Hexadecimal form](http://www.colorpicker.com/).
{% highlight lua %}
local idx = player:hud_add({
hud_elem_type = "text",
position = {x = 1, y = 0},
offset = {x=-100, y = 20},
scale = {x = 100, y = 100},
text = "My Text",
number = 0xFF0000 -- Red
})
{% endhighlight %}
Image Elements
--------------
Displays an image on the HUD.
The X co-ordinate of the `scale` attribute is the scale of the image, with 1 being the original texture size.
Negative values represent that percentage of the screen it should take; e.g. x=-100 means 100% (width).
Use `text` to specify the name of the texture.
Other Elements
--------------
Have a look at [lua_api.txt]({{ page.root }}lua_api.html#hud-element-types) for a complete list of HUD elements.