1 チャンネルあたり 8 ビットで構成されたアルファチャンネルを持つカラーのテクスチャ形式
Each of RGBA color channels is stored as an 8-bit value in [0..1] range. In memory, the channel data is ordered this way: A, R, G, B bytes one after another.
Note that RGBA32 format might be slightly more efficient as the data layout in memory more
closely matches what the graphics APIs expect.
関連項目: Texture2D, texture assets.