clone method
Returns a deep copy of this instance, preserving op if present.
Implementation
@override
RlRenderBatchD clone() => .new(
op: op,
bufferCount: bufferCount,
currentBuffer: currentBuffer,
vertexBuffer: vertexBuffer.map((e) => e.clone()).toList(),
draws: draws.map((e) => e.clone()).toList(),
drawCounter: drawCounter,
currentDepth: currentDepth,
);