public static bool ExtractAlpha(Texture2D texture2D, int x, int y, int width, int height)
{
if (texture2D != null && x >= 0 && y >= 0 && (x + width) <= texture2D.width && (y + height) <= texture2D.height)
{
#if UNITY_EDITOR
D2dHelper.MakeTextureReadable(texture2D);
#endif
var pixels32 = texture2D.GetPixels32();
var total = width * height;
var texture2DWidth = texture2D.width;
// Replace alpha data array?
if (AlphaData == null || AlphaData.Length != total)
{
AlphaData = new byte[total];
}
// Copy alpha from texture
for (var v = height - 1; v >= 0; v--)
{
var aOffset = v * width;
var pOffset = (y + v) * texture2DWidth + x;
for (var h = width - 1; h >= 0; h--)
{
AlphaData[aOffset + h] = pixels32[pOffset + h].a;
}
}
return(true);
}
return(false);
}