minetest_modding_book/en/chapters/hud.md
2017-09-21 17:07:32 +01:00

3.4 KiB

title layout root
HUD default ../../

Introduction

Heads Up Display (HUD) elements allow you to show text, images, and other graphical elements.

The HUD doesn't accept user input. For that, you should use a Formspec.

Basic Interface

HUD elements are created using a player object. You can get the player object from a username:

{% highlight lua %} local player = minetest.get_player_by_name("username") {% endhighlight %}

Once you have the player object, you can create a HUD 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 %}

The attributes in the HUD element table and what they do vary depending on the hud_elem_type.\ The hud_add function returns a number which is needed to identify the HUD element if you wanted to change or delete it.

You can change an attribute after creating a HUD element. For example, you can change the text:

{% 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 screens. 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 is located. 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.\ For example, an element with a position of (0, 0) and an offset of (10, 10) will be 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 type of HUD element.\ Here is the 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, text outside these bounds is cropped text = "My Text" -- The actual text shown }) {% endhighlight %}

Colors

Use the number attribute to apply colors to the text. Colors are in Hexadecimal form. For example:

{% 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

Image elements display 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 the percentage of the screen the image should use. For example, x=-100 means 100% (width).

Use text to specify the name of the texture.

Other Elements

Read [lua_api.txt]({{ page.root }}lua_api.html#hud-element-types) for a complete list of HUD elements.