mobile

name	mobile
description	Mobile optimization — tile-based GPU, ASTC textures, draw call budget (<100), thermal throttling, battery, touch input, safe areas, App Store guidelines.
alwaysApply	true
globs	["**/*.cs"]

Mobile Optimization

GPU Architecture

Mobile GPUs use tile-based rendering (TBDR). Key implications:

• Overdraw is expensive — minimize transparent layers
• Alpha-tested geometry is costly (breaks early-Z)
• Keep fragment shader complexity low
• Avoid full-screen post-processing when possible

Performance Budgets

Metric	Low-End	Mid-Range	High-End
Draw calls	< 50	< 100	< 200
Triangles	< 50k	< 100k	< 200k
Frame time	33ms (30fps)	16.6ms (60fps)	16.6ms
Texture memory	< 100MB	< 150MB	< 256MB
Total memory	< 300MB	< 500MB	< 800MB
Build size	< 100MB	< 200MB	< 500MB

Texture Compression

• ASTC — use on both iOS and Android (best quality/size ratio)
• Max sizes: 512 for UI elements, 1024 for props, 2048 for hero characters
• Enable mipmaps for 3D objects, disable for UI sprites
• Use texture atlases to reduce draw calls

Draw Call Reduction

1. SRP Batcher — enabled by default in URP, ensure shader compatibility
2. GPU Instancing — for repeated objects (trees, rocks, enemies)
3. Static Batching — for non-moving environment
4. Texture Atlasing — combine sprite sheets
5. Material sharing — same material = same batch

Shader Complexity

• Limit math operations per fragment
• Avoid dependent texture reads
• Use half precision where possible (color, UV, normals)
• No real-time shadows on low-end (baked only)
• Avoid post-processing stack on low-end (or use simpler alternatives)

Thermal Throttling

// Adaptive Performance package
using UnityEngine.AdaptivePerformance;

private void Update()
{
    IAdaptivePerformance ap = Holder.Instance;
    if (ap != null && ap.ThermalStatus.ThermalMetrics.WarningLevel > WarningLevel.NoWarning)
    {
        // Reduce quality: lower resolution, reduce particles, cap framerate
        QualitySettings.resolutionScalingFixedDPIFactor = 0.75f;
    }
}

• Target 30fps for casual games (saves battery)
• Offer 60fps as opt-in option
• Reduce GPU load when battery < 20%
• Monitor thermal state and downscale dynamically

Touch Input

// Input System touch
[SerializeField] private float _swipeThreshold = 50f;

// Minimum tap target: 44x44 points (Apple HIG)
// Minimum tap target: 48x48 dp (Material Design)

• Tap: primary touch press+release < 0.3s
• Swipe: delta > threshold in one direction
• Pinch: two-finger distance change
• Long press: hold > 0.5s
• Drag: press + move

Safe Area

private void ApplySafeArea()
{
    Rect safeArea = Screen.safeArea;
    Vector2 anchorMin = safeArea.position;
    Vector2 anchorMax = safeArea.position + safeArea.size;

    anchorMin.x /= Screen.width;
    anchorMin.y /= Screen.height;
    anchorMax.x /= Screen.width;
    anchorMax.y /= Screen.height;

    RectTransform rect = GetComponent<RectTransform>();
    rect.anchorMin = anchorMin;
    rect.anchorMax = anchorMax;
}

Apply to the root UI panel to respect notches and rounded corners.

Audio Compression

Type	Format	Quality	Load Type
Music	Vorbis	40-60%	Streaming
SFX (short)	ADPCM	—	Decompress On Load
SFX (long)	Vorbis	70%	Compressed In Memory
UI clicks	PCM	—	Decompress On Load

Build Size

• Strip unused code (IL2CPP stripping: High)
• Compress textures aggressively
• Use Addressables for optional/DLC content
• Remove unused packages from manifest
• Target < 100MB for initial download (App Store recommendation)