DD::Image::TopDownPImpl Class Reference

Helper functions used by the top-down graph evaluator's private implementation. More...

Static Public Member Functions
static bool	NeedsCache (const Op &op)
	Check if the rendered output of the specified op needs to be retained in a cache. More...

Detailed Description

Helper functions used by the top-down graph evaluator's private implementation.

Member Function Documentation

bool TopDownPImpl::NeedsCache ( const Op &  op )

static

Check if the rendered output of the specified op needs to be retained in a cache.

Check if an op needs to be cached. Generally, an op needs a cache if its output data will be required more than once by its successor ops. This happens if its output feeds multiple ops, or if an output is a spatial op which will read the same scanline more than once.

References DD::Image::Op::getOutputs(), and DD::Image::op_cast().