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How to create joystick controls, crouch button and inventory system

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MS

MobileGameDev_Sam

Posted on July 22, 2025 • Intermediate

🕹️ Need help with joystick controls and game mechanics

Hey everyone! I’m working on a mobile-friendly game and I need help implementing several features:

  • 📱 Virtual joystick for movement control
  • 🦆 Crouch button functionality
  • 🎒 Inventory slot switching system

I want to make sure the controls work well on both desktop and mobile devices. The joystick should be intuitive for touch screens, and the inventory system should be easy to navigate.

Any help with implementing these features would be amazing! I’m still learning about mobile game development. 🙏

TC

TouchControl_Expert

Replied 2 hours later • ⭐ Best Answer

Great question @MobileGameDev_Sam! Mobile controls are crucial for modern games. Here’s a comprehensive guide to implement all three features:

🎮 Mobile Control System Flow

Here’s how the complete control system works:

flowchart TD A[🚀 Game Start] --> B[Initialize Controls] B --> C[🕹️ Joystick Detection] C --> D{Touch Input?} D -->|Yes| E[Calculate Direction] D -->|No| F[Stop Movement] E --> G[Move Player] F --> H[Idle Animation] G --> I{Crouch Button?} H --> I I -->|Pressed| J[🦆 Crouch Mode] I -->|Released| K[🚶 Normal Mode] J --> L{Inventory Key?} K --> L L -->|1-9 Keys| M[🎒 Switch Slot] L -->|No Input| C M --> N[Update UI] N --> C style A fill:#e1f5fe style B fill:#f3e5f5 style E fill:#e8f5e8 style J fill:#fff3e0 style M fill:#fce4ec

🕹️ Step 1: Virtual Joystick Setup

First, create the joystick sprites and variables:

    // Variables needed
set [Joystick X v] to [0]
set [Joystick Y v] to [0]
set [Touch Active v] to [false]
set [Joystick Base X v] to [-180]
set [Joystick Base Y v] to [-120]
  

📱 Step 2: Touch Detection System

For the joystick base sprite:

    when flag clicked
go to x: (Joystick Base X) y: (Joystick Base Y)
forever
if <mouse down?> then
if <(distance to [mouse-pointer v]) < [50]> then
set [Touch Active v] to [true]
end
else
set [Touch Active v] to [false]
set [Joystick X v] to [0]
set [Joystick Y v] to [0]
end
end
  

🎯 Step 3: Joystick Knob Movement

For the joystick knob sprite:

    when flag clicked
forever
if <(Touch Active) = [true]> then
// Calculate distance from base
set [Distance v] to (distance to [Joystick Base v])

if <(Distance) > [40]> then
// Limit knob to circle boundary
point towards [Joystick Base v]
turn right [180] degrees
go to [Joystick Base v]
move [40] steps
else
// Follow mouse within boundary
go to [mouse-pointer v]
end

// Calculate normalized input values
set [Joystick X v] to (((x position) - (Joystick Base X)) / [40])
set [Joystick Y v] to (((y position) - (Joystick Base Y)) / [40])
else
// Return to center
go to x: (Joystick Base X) y: (Joystick Base Y)
end
end
  

🚶 Step 4: Player Movement System

For the player sprite:

    when flag clicked
set [Speed v] to [3]
forever
// Joystick movement
change x by ((Joystick X) * (Speed))
change y by ((Joystick Y) * (Speed))

// Keyboard fallback for desktop
if <key [a v] pressed?> then
change x by ((-1) * (Speed))
end
if <key [d v] pressed?> then
change x by (Speed)
end
if <key [w v] pressed?> then
change y by (Speed)
end
if <key [s v] pressed?> then
change y by ((-1) * (Speed))
end
end
  

🦆 Step 5: Crouch Button System

Create a crouch button sprite:

    // Crouch button sprite
when flag clicked
go to x: [180] y: [-120]
set [Crouching v] to [false]
forever
if <touching [mouse-pointer v]?> then
if <mouse down?> then
set [Crouching v] to [true]
set size to [90] %
end
else
set [Crouching v] to [false]
set size to [100] %
end
end

// In player sprite - crouch mechanics
when flag clicked
forever
if <(Crouching) = [true]> then
set [Speed v] to [1.5]  // Slower when crouching
switch costume to [crouch v]
else
set [Speed v] to [3]    // Normal speed
switch costume to [normal v]
end
end
  

🎒 Step 6: Inventory System

Create inventory slot management:

    // Variables for inventory
set [Current Slot v] to [1]
set [Max Slots v] to [9]

// Inventory UI sprite
when flag clicked
forever
// Number key detection
if <key [1 v] pressed?> then
set [Current Slot v] to [1]
end
if <key [2 v] pressed?> then
set [Current Slot v] to [2]
end
if <key [3 v] pressed?> then
set [Current Slot v] to [3]
end
// ... continue for keys 4-9

// Touch-based slot switching
if <key [right arrow v] pressed?> then
if <(Current Slot) < (Max Slots)> then
change [Current Slot v] by [1]
end
end
if <key [left arrow v] pressed?> then
if <(Current Slot) > [1]> then
change [Current Slot v] by [-1]
end
end
end
  

🎨 Step 7: Visual Feedback System

Add visual indicators for better UX:

    // Inventory display sprite
when flag clicked
forever
switch costume to (join [slot ] (Current Slot))
go to x: [0] y: [160]
end

// Joystick visual feedback
when flag clicked
forever
if <(Touch Active) = [true]> then
set [ghost v] effect to [30]
else
set [ghost v] effect to [70]
end
end
  

This creates a complete mobile-friendly control system! The joystick works great on touch devices, and you have keyboard fallbacks for desktop users. 🎮

MS

MobileGameDev_Sam

Replied 1 hour later

@TouchControl_Expert This is incredible! Thank you so much! 🎉

I implemented the joystick system and it works perfectly on both mobile and desktop. The crouch button feels really responsive too!

Quick question - how can I add haptic feedback for mobile devices when buttons are pressed?

UX

UXDesigner_Maya

Replied 45 minutes later

@MobileGameDev_Sam Great question! While Scratch doesn’t have built-in haptic feedback, you can simulate it with audio cues:

    // Add tactile feedback with sound
when I receive [button pressed v]
play sound [click v] until done
set volume to [30] %

// Visual feedback for button press
set [brightness v] effect to [20]
wait [0.1] seconds
set [brightness v] effect to [0]
  

This creates a satisfying button press experience even without true haptics! 📱✨

VB

Vibelf_Community

Pinned Message • Moderator

🚀 Want to Master Mobile Game Development?

Fantastic discussion everyone! For those looking to create even more advanced mobile control systems, our community can help you implement:

  • 📱 Advanced touch gestures
  • 🎮 Custom control layouts
  • ⚡ Performance optimization for mobile
  • 🔧 Adaptive UI systems

📚 Related Discussions

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