Accessibility Features

Comparative analysis of accessibility features for inclusive game design.

Overview

This document synthesizes three Proof of Concept studies on accessibility features to make R-Type playable by the widest possible audience.

Features Comparison

Feature	Accessibility Impact	Technical Complexity	Priority
Slow Mode / Time Scaling	High (15-20% players)	Low	Critical
Custom Control Remapping	High (10-15% players)	Medium	Critical
Colorblind Support	Medium (5-8% players)	Medium	High

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Feature 1: Slow Mode and Time Scaling

Concept

Global time scale system allowing players to slow down gameplay by 30-50% to accommodate slower reaction times or motor disabilities.

Target Audience

• Players with slower reaction times (aging, cognitive disabilities)
• Players with motor disabilities requiring more time
• Beginners and casual players
• Estimated reach: 15-20% of potential player base

PoC Results

Metric	Result
Technical Validation	Complete
Physics Consistency	0.00% position error across time scales
Performance Overhead	Approximately 0.1% CPU
Integration Path	Clear and straightforward

Implementation

class TimeSystem {
public:
    void setTimeScale(float scale) {
        _timeScale = std::clamp(scale, 0.3f, 2.0f);
    }
    
    float getDeltaTime() const {
        return _rawDeltaTime * _timeScale;
    }
    
    float getRawDeltaTime() const {
        return _rawDeltaTime;  // For audio (keeps normal speed)
    }

private:
    float _timeScale = 1.0f;
    float _rawDeltaTime = 0.0f;
};

Recommended Presets

Preset	Time Scale	Use Case
Slow	50%	Accessibility / Beginner
Normal	100%	Standard gameplay
Fast	150%	Challenge mode
Custom	30-200%	Advanced users

Decision

APPROVED for immediate implementation

• Low implementation cost (1-2 sprints)
• High accessibility impact
• No significant downsides
• Core differentiator for accessibility

---

Feature 2: Custom Control Remapping

Concept

Complete input rebinding system allowing players to remap all game controls to keyboard, mouse, gamepad, or alternative input devices.

Target Audience

• Players with motor disabilities (one-handed, limited mobility)
• Left-handed players
• Users of adaptive controllers (Xbox Adaptive Controller)
• Different keyboard layouts (AZERTY, QWERTZ, Dvorak)
• Estimated reach: 10-15% of player base

Industry Requirement

Control remapping is mandatory for many platform certifications:

• Xbox Accessibility Guidelines
• PlayStation certification requirements
• Steam recommendations

Architecture

class InputMapper {
public:
    void rebind(Action action, InputBinding newBinding) {
        if (hasConflict(newBinding)) {
            resolveConflict(newBinding);
        }
        _bindings[action] = newBinding;
    }
    
    bool isActionPressed(Action action) const {
        return _bindings.at(action).isPressed();
    }
    
    void saveToFile(const std::string& path) const;
    void loadFromFile(const std::string& path);

private:
    std::unordered_map<Action, InputBinding> _bindings;
    bool hasConflict(const InputBinding& binding) const;
    void resolveConflict(const InputBinding& binding);
};

Configuration Format (JSON)

{
    "version": "1.0",
    "bindings": {
        "move_up": { "type": "keyboard", "key": "W" },
        "move_down": { "type": "keyboard", "key": "S" },
        "shoot": { "type": "mouse", "button": "left" },
        "special": { "type": "gamepad", "button": "A" }
    },
    "preset": "custom"
}

Implementation Phases

Phase	Priority	Content	Timeline
Phase 1	Critical	Core rebinding, keyboard	Sprint 1
Phase 2	Critical	UI, presets, persistence	Sprint 2
Phase 3	High	Gamepad, conflict detection	Sprint 3
Phase 4	Medium	Accessibility presets (one-handed)	Sprint 4
Phase 5	Low	Macros, voice control	Future

Decision

APPROVED (Phases 1-3 immediately)

---

Feature 3: Colorblind Support

Concept

Alternative color palettes and shape-based distinctions for players with color vision deficiencies.

Target Audience

Type	Prevalence	Colors Affected
Protanopia	1% males	Red-green confusion
Deuteranopia	6% males	Red-green confusion
Tritanopia	0.01%	Blue-yellow confusion
Total Impact	8-10% males, 0.5% females	~5-8% of players

Solution Approaches

1. Shape-Based Distinctions

Power-ups with unique shapes:
┌─────┐   ┌─────┐   ┌─────┐
│  ★  │   │  ●  │   │  ◆  │
│Speed│   │Fire │   │Shield│
└─────┘   └─────┘   └─────┘

2. Palette Swapping

class ColorPalette {
public:
    enum class Mode {
        Normal,
        Protanopia,
        Deuteranopia,
        Tritanopia,
        HighContrast
    };
    
    Color transform(Color original) const {
        switch (_mode) {
            case Mode::Protanopia:
                return applyProtanopiaMatrix(original);
            case Mode::HighContrast:
                return increaseContrast(original);
            default:
                return original;
        }
    }

private:
    Mode _mode = Mode::Normal;
};

3. High Contrast Mode

Essential for low vision players:

• Maximum contrast between game elements
• Clear outlines on all interactive objects
• Simplified backgrounds

Implementation Phases

Phase	Priority	Content
Phase 1	High	Shape distinctions, high contrast
Phase 2	Medium	Three colorblind palettes
Phase 3	Low	Custom color picker

Decision

APPROVED (Phase 1 for next update)

---

Combined Implementation Priority

Milestone 1: Core Accessibility (Sprints 1-3)

1. Slow Mode - Full implementation
2. Custom Controls - Phases 1-2

Milestone 2: Enhanced Accessibility (Sprints 4-6)

3. Custom Controls - Phase 3
4. Colorblind Support - Phase 1

Milestone 3: Advanced Features (Sprints 7-10)

5. Colorblind Support - Phase 2
6. Custom Controls - Phase 4
7. Polish and testing

---

Success Metrics

Feature	Target
Slow Mode	90%+ testers with slow reactions complete level 1
Custom Controls	100% actions rebindable without conflicts
Colorblind	90%+ colorblind testers distinguish all critical elements

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Final Decision Summary

Feature	Status	Impact	Cost
Slow Mode	Approved	High	Low
Custom Controls	Approved (Phases 1-3)	High	Medium
Colorblind Support	Approved (Phase 1)	Medium	Medium

All three features are approved because:

1. They transform "unplayable" to "playable" for many users
2. Industry standard expectations
3. Reasonable implementation cost
4. Demonstrates commitment to inclusivity

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References

• PoC implementations: /PoC/PoC_Accessibility/
• Slow Mode PoC: /PoC/PoC_Accessibility/SlowMode/
• Custom Controls PoC: /PoC/PoC_Accessibility/CustomControls/
• Colorblind PoC: /PoC/PoC_Accessibility/Colorblind/
• Decision document: /PoC/PoC_Accessibility/ACCESSIBILITY_FINAL_DECISION.md