Terminal typing animation with AI tool cycling and particle explosion effect

typing-animation.sh

#!/bin/bash

# Hide the real cursor
tput civis

# Restore cursor on exit
trap 'tput cnorm' EXIT

# ANSI color codes
BOLD="\033[1m"
DARK_PURPLE="\033[38;5;54m"
TEAL="\033[38;5;30m"
RESET="\033[0m"
CURSOR_BG="\033[48;5;55m"

# Indentation
INDENT="        "

# Column where typed text starts (8 indent + 10 "faster.dev" + 1 space + 4 "main" + 1 space + 1 "›" + 1 space = 26, so column 27)
TEXT_START_COL=27

# Current typed text
TYPED=""

# Function to print the prompt (call once)
print_prompt() {
    printf "${INDENT}${BOLD}${DARK_PURPLE}faster.dev${RESET} ${TEAL}main ${RESET}› "
}

# Function to render just the typed text (doesn't touch prompt)
render() {
    local show_cursor="${1:-true}"
    # Move to the column where text starts, clear to end of line
    printf "\033[${TEXT_START_COL}G\033[K"
    # Print typed text
    printf "%s" "$TYPED"
    # Show cursor block if requested
    if [ "$show_cursor" = "true" ]; then
        printf "${CURSOR_BG} ${RESET}"
    fi
}

# Function to render with first character highlighted (for cycling loops)
render_highlighted() {
    # Move to the column where text starts, clear to end of line
    printf "\033[${TEXT_START_COL}G\033[K"
    # Print first character with block cursor and white text
    if [ ${#TYPED} -gt 0 ]; then
        printf "${CURSOR_BG}\033[97m%s${RESET}" "${TYPED:0:1}"
        # Print rest of the text
        if [ ${#TYPED} -gt 1 ]; then
            printf "%s" "${TYPED:1}"
        fi
    fi
}

# Function to blink cursor
blink_cursor() {
    local duration=$1
    local i=0
    local iterations=$(echo "$duration * 2" | bc | cut -d. -f1)
    while [ $i -lt $iterations ]; do
        if [ $((i % 2)) -eq 0 ]; then
            render true
        else
            render false
            printf " "
        fi
        sleep 0.5
        i=$((i + 1))
    done
    render true
}

# Function to type out text
type_text() {
    local text="$1"
    local delay="${2:-0.1}"
    local i=0
    while [ $i -lt ${#text} ]; do
        TYPED="${TYPED}${text:$i:1}"
        render true
        sleep "$delay"
        i=$((i + 1))
    done
}

# Function to backspace text
backspace_text() {
    local count=$1
    local delay="${2:-0.05}"
    local i=0
    while [ $i -lt $count ]; do
        local len=${#TYPED}
        if [ $len -gt 0 ]; then
            TYPED="${TYPED:0:$((len - 1))}"
            render true
            sleep "$delay"
        fi
        i=$((i + 1))
    done
}

# Clear screen and start
clear

# Add vertical padding (4 lines)
printf "\n\n\n\n"

# Print the prompt once (never redrawn)
print_prompt

# Initial render with just cursor
TYPED=""
render true

# Initial pause for camera setup
blink_cursor 2

# Type "code ."
type_text "code ." 0.1

# Blink cursor for 1.5 seconds
blink_cursor 1.5

# Backspace "code ." (6 characters)
backspace_text 6 0.08

# Hold on blank line
sleep 0.25

# Type "claude"
type_text "claude" 0.1

# Hold with blinking cursor (same as after "code .")
blink_cursor 1.5

# Backspace "claude" faster (6 characters)
backspace_text 6 0.04

# Type "gemini"
type_text "gemini" 0.1

sleep 0.2

# Backspace "gemini" (6 characters)
backspace_text 6 0.04

# Type "codex"
type_text "codex" 0.1

sleep 0.2

# Backspace "codex" (5 characters)
backspace_text 5 0.04

# Type "amp"
type_text "amp" 0.1

sleep 0.2

# Backspace "amp" (3 characters) so cursor is at start for loops
backspace_text 3 0.04

# AI tools to cycle through
AI_TOOLS=("claude" "gemini" "codex" "amp")

# Total iterations
TOTAL_WORDS=37
START_DELAY=0.1
END_DELAY=0.04

# Gradually speed up from START_DELAY to END_DELAY
for i in $(seq 0 $((TOTAL_WORDS - 1))); do
    tool_idx=$((i % 4))
    TYPED="${AI_TOOLS[$tool_idx]}"
    render_highlighted
    # Calculate delay: linear interpolation from START_DELAY to END_DELAY
    delay=$(echo "scale=3; $START_DELAY - ($START_DELAY - $END_DELAY) * $i / ($TOTAL_WORDS - 1)" | bc)
    sleep "$delay"
done

# Particle explosion animation
explosion() {
    local frames=30
    local chars='!@#$%^&*()_+-=[]{}|;:,.<>?/~`\|/-_=+*#@$%&'

    # Get terminal dimensions
    local cols=$(tput cols)
    local rows=$(tput lines)

    # Center point (where the text was)
    local center_x=$((TEXT_START_COL + 3))
    local center_y=3

    for frame in $(seq 1 $frames); do
        # Number of particles increases then decreases (much denser)
        local num_particles
        if [ $frame -lt 15 ]; then
            num_particles=$((frame * 80))
        else
            num_particles=$(( (frames - frame) * 60 ))
        fi

        # Draw particles
        for p in $(seq 1 $num_particles); do
            # Random position expanding from center
            local spread=$((frame * 3))
            local x=$((center_x + RANDOM % (spread * 2 + 1) - spread))
            local y=$((center_y + RANDOM % (spread + 1) - spread / 2))

            # Keep in bounds
            [ $x -lt 1 ] && x=1
            [ $x -gt $cols ] && x=$cols
            [ $y -lt 1 ] && y=1
            [ $y -gt $rows ] && y=$rows

            # Random character
            local char_idx=$((RANDOM % ${#chars}))
            local char="${chars:$char_idx:1}"

            # Random color (dark blues, dark purples, dark reds, light greys)
            local colors=(17 18 19 24 25 53 54 55 89 90 52 88 124 160 250 251 252 253 254 255)
            local color=${colors[$((RANDOM % ${#colors[@]}))]}

            # Draw particle
            printf "\033[%d;%dH\033[38;5;%dm%s\033[0m" "$y" "$x" "$color" "$char"
        done

        sleep 0.03
    done

    # Final flash - fill screen with characters then fade
    for fade in 1 2 3; do
        printf "\033[H\033[J"
        local density=$((400 / fade))
        for i in $(seq 1 $density); do
            local x=$((RANDOM % cols + 1))
            local y=$((RANDOM % rows + 1))
            local char_idx=$((RANDOM % ${#chars}))
            local char="${chars:$char_idx:1}"
            printf "\033[%d;%dH\033[38;5;%dm%s" "$y" "$x" "$((232 + 23 / fade))" "$char"
        done
        sleep 0.05
    done

    # Clear to black
    printf "\033[H\033[J"
    printf "\033[0m"
}

# Run explosion
explosion

# Final pause
sleep 1

echo