Dither-16bit的抖动优化
使用小插件, keijiro 的 github:unity-dither4444
将需要优化的大图后缀改为.Dither.png。
图片资源的 [硬盘/内存] 大小和图片设置的格式有关
实测
IOS中质量堪比trueColor,在pvrtc质量较差的情况下使用
Android中与ETC2差距不大,但更消耗内存
结论:仅IOS可用
优化
对IOS和Android区别对待,代码如下
using UnityEngine;
using UnityEditor;
using System.Collections;
class TextureModifier : AssetPostprocessor
{
void OnPreprocessTexture()
{
if (assetPath.EndsWith ("Dither.png")) {
var importer = (assetImporter as TextureImporter);
importer.textureFormat = TextureImporterFormat.RGBA32;
importer.SetPlatformTextureSettings (BuildTarget.Android.ToString(), 2048, TextureImporterFormat.ETC2_RGBA8);
}
}
void OnPostprocessTexture (Texture2D texture)
{
if (!assetPath.EndsWith ("Dither.png")) {
return;
}
if (EditorUserBuildSettings.activeBuildTarget == BuildTarget.Android) {
//Android时弃用
return;
}
var texw = texture.width;
var texh = texture.height;
var pixels = texture.GetPixels ();
var offs = 0;
var k1Per15 = 1.0f / 15.0f;
var k1Per16 = 1.0f / 16.0f;
var k3Per16 = 3.0f / 16.0f;
var k5Per16 = 5.0f / 16.0f;
var k7Per16 = 7.0f / 16.0f;
for (var y = 0; y < texh; y++) {
for (var x = 0; x < texw; x++) {
float a = pixels [offs].a;
float r = pixels [offs].r;
float g = pixels [offs].g;
float b = pixels [offs].b;
var a2 = Mathf.Clamp01 (Mathf.Floor (a * 16) * k1Per15);
var r2 = Mathf.Clamp01 (Mathf.Floor (r * 16) * k1Per15);
var g2 = Mathf.Clamp01 (Mathf.Floor (g * 16) * k1Per15);
var b2 = Mathf.Clamp01 (Mathf.Floor (b * 16) * k1Per15);
var ae = a - a2;
var re = r - r2;
var ge = g - g2;
var be = b - b2;
pixels [offs].a = a2;
pixels [offs].r = r2;
pixels [offs].g = g2;
pixels [offs].b = b2;
var n1 = offs + 1;
var n2 = offs + texw - 1;
var n3 = offs + texw;
var n4 = offs + texw + 1;
if (x < texw - 1) {
pixels [n1].a += ae * k7Per16;
pixels [n1].r += re * k7Per16;
pixels [n1].g += ge * k7Per16;
pixels [n1].b += be * k7Per16;
}
if (y < texh - 1) {
pixels [n3].a += ae * k5Per16;
pixels [n3].r += re * k5Per16;
pixels [n3].g += ge * k5Per16;
pixels [n3].b += be * k5Per16;
if (x > 0) {
pixels [n2].a += ae * k3Per16;
pixels [n2].r += re * k3Per16;
pixels [n2].g += ge * k3Per16;
pixels [n2].b += be * k3Per16;
}
if (x < texw - 1) {
pixels [n4].a += ae * k1Per16;
pixels [n4].r += re * k1Per16;
pixels [n4].g += ge * k1Per16;
pixels [n4].b += be * k1Per16;
}
}
offs++;
}
}
texture.SetPixels (pixels);
EditorUtility.CompressTexture (texture, TextureFormat.RGBA4444, TextureCompressionQuality.Best);
}
}