private void ComputeSliceAndMask(ShaderKeyword keyword, out uint slice, out uint mask)
{
int index = keyword.GetKeywordIndex();
slice = (uint)(index / k_SizeInBits);
mask = (uint)(1 << (index % k_SizeInBits));
}
public ShaderKeyword(Shader shader, string keywordName)
{
this.m_KeywordIndex = ShaderKeyword.GetKeywordIndex(shader, keywordName);
}