我绘制了以固定间隔重叠的小方block，以便在绘图应用程序中感觉像纹理刷。目前我使用管道描述符pipelineDescriptor.colorAttachments[0].rgbBlendOperation=.addpipelineDescriptor.colorAttachments[0].alphaBlendOperation=.addpipelineDescriptor.colorAttachments[0].sourceRGBBlendFactor=.sourceAlphapipelineDescriptor.colorAttachments[0].sourceAlphaBle