Text Rendering¶
Flame has some dedicated classes to help you render text.
TextRenderer¶
TextRenderer
is the abstract class used by Flame to render text. Flame provides one
implementation for this called TextPaint
but anyone can implement this abstraction
and create a custom way to render text.
TextPaint¶
A TextPaint
is the built in implementation of text rendering in Flame, it is based on top of
Flutter’s TextPainter
class (hence the name), it can be configured by the style class TextStyle
which contains all typographical information required to render text; i.e., font size and color,
font family, etc.
Example usage:
const TextPaint textPaint = TextPaint(
style: TextStyle(
fontSize: 48.0,
fontFamily: 'Awesome Font',
),
);
Note: there are several packages that contain the class TextStyle
, make sure that you import
either package:flutter/material.dart
or package:flutter/painting.dart
and if you also need to
import dart:ui
you need to import it like this (since that contains another class that is also
named TextStyle
):
import 'dart:ui' hide TextStyle;
Some common properties of TextStyle
are the following (here is the
full list):
fontFamily
: a commonly available font, like Arial (default), or a custom font added in your pubspec (see here how to do it).fontSize
: font size, in pts (default24.0
).height
: height of text line, as a multiple of font size (defaultnull
).color
: the color, as aui.Color
(default white).
For more information regarding colors and how to create then, see the Colors and the Palette guide.
After the creation of the TextPaint
object you can use its render
method to draw strings on
a canvas:
textPaint.render(canvas, "Flame is awesome", Vector2(10, 10));
If you want to set the anchor of the text you can also do that in the render call, with the optional
anchor
parameter:
textPaint.render(canvas, 'Flame is awesome', Vector2(10, 10), anchor: Anchor.topCenter);
Text Components¶
Flame provides two text components that make it even easier to render text in your game:
TextComponent
and TextBoxComponent
.
TextComponent¶
TextComponent
is a simple component that renders a single line of text.
Example usage:
final style = TextStyle(color: BasicPalette.white.color);
final regular = TextPaint(style: style);
class MyGame extends FlameGame {
@override
Future<void> onLoad() async {
add(TextComponent('Hello, Flame', textRenderer: regular)
..anchor = Anchor.topCenter
..x = size.width / 2 // size is a property from game
..y = 32.0);
}
}
TextBoxComponent¶
TextBoxComponent
is very similar to TextComponent
, but as its name suggest it is used to render
text inside a bounding box, creating line breaks according to the provided box size.
You can decide if the box should grow as the text is written or if it should be static by the
growingBox
variable in the TextBoxConfig
.
If you want to change the margins of the box use the margins
variable in the TextBoxConfig
.
Example usage:
class MyTextBox extends TextBoxComponent {
MyTextBox(String text) : super(text, textRenderer: tiny, boxConfig: TextBoxConfig(timePerChar: 0.05));
@override
void drawBackground(Canvas c) {
Rect rect = Rect.fromLTWH(0, 0, width, height);
c.drawRect(rect, Paint()..color = Color(0xFFFF00FF));
c.drawRect(
rect.deflate(boxConfig.margin),
BasicPalette.black.Paint()
..style = PaintingStyle.stroke,
);
}
}
Both components are showcased in an example here