video/.claude/skills/manimgl-best-practices/rules/text.md

Text in ManimGL

ManimGL provides powerful text rendering capabilities through the Text and TexText classes.

Text Class

The Text class renders text using system fonts with extensive styling options.

Basic Text Creation

from manimlib import *

class TextExample(Scene):
    def construct(self):
        # Basic text
        text = Text("Hello ManimGL")
        self.add(text)

Font Customization

# Specify font and size
text = Text("Custom Font", font="Consolas", font_size=90)

# Different fonts for different parts
text = Text(
    "Mixed fonts example",
    t2f={"Mixed": "Consolas", "fonts": "Arial"}
)

Text Coloring

# Color entire text
text = Text("Colored Text", color=BLUE)

# Color specific words
text = Text(
    "The quick brown fox",
    t2c={"quick": BLUE, "brown": ORANGE, "fox": GREEN}
)

Text Styling

# Slant (italic)
text = Text(
    "Italic and bold text",
    t2s={"Italic": ITALIC},
    t2w={"bold": BOLD}
)

# Combine color, font, slant, and weight
text = Text(
    "Fully styled text",
    font="Arial",
    font_size=48,
    t2c={"styled": RED},
    t2s={"styled": ITALIC},
    t2w={"text": BOLD},
    t2f={"text": "Consolas"}
)

TexText Class

TexText combines LaTeX rendering with text, useful for mixing text and math.

Basic TexText

# Text with LaTeX support
text = TexText("The integral $\\int_0^1 x^2 dx$ equals $\\frac{1}{3}$")

# With font size
text = TexText("Hello World", font_size=72)

# Isolate parts for coloring
text = TexText(
    "Einstein's $E = mc^2$",
    isolate=["E", "m", "c"]
)
text.set_color_by_tex("E", BLUE)
text.set_color_by_tex("m", GREEN)
text.set_color_by_tex("c", YELLOW)

Text vs TexText

• Text: Uses system fonts, no LaTeX, better font control
• TexText: LaTeX support for math symbols, uses LaTeX's text rendering

When to Use Each

# Use Text for pure text with custom fonts
title = Text("Machine Learning", font="Helvetica", font_size=60)

# Use TexText when mixing text and inline math
description = TexText("The function $f(x) = x^2$ is convex")

# Use Tex for pure mathematical expressions
formula = Tex(R"\sum_{i=1}^n i = \frac{n(n+1)}{2}")

Text Positioning

# Basic positioning
text = Text("Top")
text.to_edge(UP)

# Arrange multiple texts
title = Text("Title")
subtitle = Text("Subtitle", font_size=36)
VGroup(title, subtitle).arrange(DOWN, buff=0.5)

# Set width
text = Text("Long text that needs to fit")
text.set_width(FRAME_WIDTH - 1)

Text with Background

# Set backstroke for readability
text = Text("With Background", font_size=60)
text.set_backstroke(BLACK, width=5)

# Background rectangle (manually)
from manimlib.mobject.svg.tex_mobject import BackgroundRectangle
text = Text("Text")
bg = BackgroundRectangle(text, color=BLACK, fill_opacity=0.8)
self.add(bg, text)

VGroup for Text Layout

# Group multiple text objects
line1 = Text("First line")
line2 = Text("Second line")
line3 = Text("Third line")

paragraph = VGroup(line1, line2, line3)
paragraph.arrange(DOWN, aligned_edge=LEFT, buff=0.3)
paragraph.to_edge(LEFT)

Full Example

class ComprehensiveTextExample(Scene):
    def construct(self):
        # Title with custom font
        title = Text(
            "Text Rendering in ManimGL",
            font="Arial",
            font_size=72,
            color=BLUE
        )
        title.to_edge(UP)

        # Description with mixed styling
        desc = Text(
            "Mix different fonts, colors, and styles",
            font="Helvetica",
            font_size=36,
            t2c={"fonts": RED, "colors": GREEN, "styles": YELLOW},
            t2w={"Mix": BOLD}
        )
        desc.next_to(title, DOWN, buff=0.5)

        # Mathematical description using TexText
        math_desc = TexText(
            "For equations like $E = mc^2$, use Tex or TexText",
            font_size=30
        )
        math_desc.next_to(desc, DOWN, buff=1)

        # Add all with animations
        self.play(Write(title))
        self.play(FadeIn(desc, shift=DOWN))
        self.play(Write(math_desc))
        self.wait()

Best Practices

1. Font availability: Ensure fonts are installed on the system
2. Use Text for UI elements: Better control over appearance
3. Use TexText for mixed content: When you need both text and math
4. Backstroke for visibility: Add backstroke to text over complex backgrounds
5. VGroup for layout: Group related text elements for easier positioning
6. t2c/t2f/t2s/t2w: Use dictionaries for per-word styling

Common Patterns

Creating a text label with background

def create_label(text_str, color=WHITE):
    label = Text(text_str, font_size=40, color=color)
    label.set_backstroke(BLACK, width=5)
    return label

Multi-line text with alignment

lines = [Text(line) for line in [
    "Line 1",
    "Longer line 2",
    "Line 3"
]]
paragraph = VGroup(*lines)
paragraph.arrange(DOWN, aligned_edge=LEFT, buff=0.2)

Highlighted text

sentence = Text(
    "This word is highlighted",
    t2c={"highlighted": YELLOW},
    t2w={"highlighted": BOLD}
)