Accessibility Hci

Core: Accessibility Settings

// --- IAccessibilitySettings.cs ---
public interface IAccessibilitySettings
{
    float FontScale          { get; set; } // 0.75 – 2.0
    ColorblindMode Colorblind { get; set; }
    bool  HighContrast       { get; set; }
    bool  ReduceMotion       { get; set; }
    bool  AudioCuesEnabled   { get; set; }
    float SubtitleScale      { get; set; }
}

public enum ColorblindMode { None, Protanopia, Deuteranopia, Tritanopia }

// --- AccessibilitySettings.cs ---
using UnityEngine;

public class AccessibilitySettings : IAccessibilitySettings
{
    private const string KEY_FONT     = "a11y_font_scale";
    private const string KEY_COLORBLIND = "a11y_colorblind";

    public float FontScale
    {
        get => PlayerPrefs.GetFloat(KEY_FONT, 1f);
        set { PlayerPrefs.SetFloat(KEY_FONT, Mathf.Clamp(value, 0.75f, 2.0f)); ApplyFontScale(value); }
    }

    public ColorblindMode Colorblind
    {
        get => (ColorblindMode)PlayerPrefs.GetInt(KEY_COLORBLIND, 0);
        set { PlayerPrefs.SetInt(KEY_COLORBLIND, (int)value); ApplyColorblindMode(value); }
    }

    public bool ReduceMotion
    {
        get => PlayerPrefs.GetInt("a11y_reduce_motion", 0) == 1;
        set => PlayerPrefs.SetInt("a11y_reduce_motion", value ? 1 : 0);
    }

    public bool  HighContrast     { get; set; }
    public bool  AudioCuesEnabled { get; set; } = true;
    public float SubtitleScale    { get; set; } = 1f;

    private void ApplyFontScale(float scale)
    {
        // UI Toolkit: set custom property on root element
        var root = UnityEngine.UIElements.UIDocument.FindObjectOfType<UnityEngine.UIElements.UIDocument>();
        root?.rootVisualElement.style.fontSize = new UnityEngine.UIElements.StyleLength(16f * scale);
    }

    private void ApplyColorblindMode(ColorblindMode mode)
    {
        // Apply via post-processing Color Lookup or shader global
        Shader.SetGlobalInt("_ColorblindMode", (int)mode);
    }
}

Colorblind Mode Shader

// Add to any post-process pass or full-screen blit shader:
int _ColorblindMode; // 0=None, 1=Protanopia, 2=Deuteranopia, 3=Tritanopia

float3 ApplyColorblind(float3 col)
{
    if (_ColorblindMode == 1) // Protanopia (red-blind)
        return float3(0.567*col.r + 0.433*col.g, 0.558*col.r + 0.442*col.g, 0.242*col.g + 0.758*col.b);
    if (_ColorblindMode == 2) // Deuteranopia (green-blind)
        return float3(0.625*col.r + 0.375*col.g, 0.700*col.r + 0.300*col.g, 0.300*col.g + 0.700*col.b);
    if (_ColorblindMode == 3) // Tritanopia (blue-blind)
        return float3(0.950*col.r + 0.050*col.g, 0.433*col.g + 0.567*col.b, 0.475*col.g + 0.525*col.b);
    return col;
}

Control Remapping (New Input System)

using UnityEngine.InputSystem;

public class ControlRemapper
{
    public void StartRebind(InputAction action, int bindingIndex, System.Action onComplete)
    {
        action.Disable();
        action.PerformInteractiveRebinding(bindingIndex)
              .WithCancelingThrough("<Keyboard>/escape")
              .OnComplete(op =>
              {
                  op.Dispose();
                  action.Enable();
                  onComplete?.Invoke();
                  // Save: PlayerPrefs.SetString(action.id.ToString(), action.SaveBindingOverridesAsJson())
              })
              .Start();
    }
}

WCAG 2.1 Color Contrast Quick Reference

Use the WebAIM Contrast Checker for any UI color combination.

Best Practices

• ✅ Never convey information by color alone — also use icons, patterns, or text labels.
• ✅ Provide a dedicated Accessibility menu in Settings, not buried in sub-menus.
• ✅ All interactive elements must be reachable via keyboard/controller navigation.
• ✅ Use the Reduce Motion flag to skip camera shake and flash VFX.
• ❌ NEVER use red/green as the sole indicator for success/failure (protanopia/deuteranopia).
• ❌ NEVER use text smaller than 12pt at 1080p for critical UI.

TDD Contract

⚠️ Legacy Skill — Refactor Pending Este skill NO tiene tests automatizados aún. El siguiente boilerplate es un punto de partida.

// Escribe estos tests ANTES de implementar:

// Test 1: should [expected behavior] when [condition]
[Test]
public void AccessibilityHci_Should{ExpectedBehavior}_When{Condition}()
{{
    // Arrange
    // TODO: Setup test fixtures
    
    // Act
    // TODO: Execute system under test
    
    // Assert
    Assert.Fail("Not implemented — write test first");
}}

// Test 2: should handle [edge case]
[Test]
public void AccessibilityHci_ShouldHandle{EdgeCase}()
{{
    // Arrange
    // TODO: Setup edge case scenario
    
    // Act
    // TODO: Execute
    
    // Assert
    Assert.Fail("Not implemented");
}}

// Test 3: should throw when [invalid input]
[Test]
public void AccessibilityHci_ShouldThrow_When{InvalidInput}()
{{
    // Arrange
    var invalidInput = default;
    
    // Act & Assert
    Assert.Throws<Exception>(() => {{ /* execute */ }});
}}

Pasos para completar el TDD:

1. Descomenta los tests above
2. Implementa la funcionalidad mínima para que compile
3. Ejecuta los tests — deben fallar (RED)
4. Implementa la funcionalidad real
5. Verifica que los tests pasen (GREEN)
6. Refactorea manteniendo los tests verdes

Nota: Este skill fue marcado como tdd_first: false durante la auditoría v2.0.1. La sección TDD fue agregada automáticamente pero requiere customización manual para reflejar el comportamiento real del skill.

Related Skills

• @ui-toolkit-modern — USS font-size and custom properties
• @input-system-new — Rebinding foundation
• @mvvm-binding-system — Bind IAccessibilitySettings to UI controls