DD::Image::Sampler Class Reference

#include <Sampler.h>

Public Types
enum	EdgeHandling { eEdgeZero , eEdgeClamp , eEdgeFromIop }
	What to do when sampling off the edges of the input.

Public Member Functions
	Sampler (Iop *iop, int x, int y, int r, int t, const ChannelSet &channels, Filter *filter=nullptr, EdgeHandling edges=eEdgeFromIop, InterestRatchet *ir=nullptr, bool loadOndemand=true)
	Sampler (Iop *iop, const Box &box, const ChannelSet &channels, Filter *filter=nullptr, EdgeHandling edges=eEdgeFromIop, InterestRatchet *ir=nullptr, bool loadOnDemand=true)
Iop *	iop () const
const Format &	format () const
const ChannelSet &	channels () const
Filter *	filter () const
float	at (int x, int y, Channel z) const
	Sample a single pixel, with edge clipping.
void	at (int x, int y, const ChannelSet &get, Pixel &out) const
void	at (int x, int y, Pixel &out) const
	Same except samples out.channels.
void	sample (const Vector2 &center, const Vector2 &dU, const Vector2 &dV, Filter *filter, const ChannelSet &get, Pixel &out)
void	sample (const Vector2 &center, const Vector2 &dU, const Vector2 &dV, Filter *filter, Pixel &out)
	Same except samples out.channels.
void	sample (const Vector2 &center, const Vector2 &dU, const Vector2 &dV, const ChannelSet &get, Pixel &out)
	Same except the filter used is the pre-assigned one.
void	sample (const Vector2 &center, const Vector2 &dU, const Vector2 &dV, Pixel &out)
	Same except the filter used is the pre-assigned one and samples out.channels.
void	sample (float cx, float cy, float W, float H, Filter *filter, const ChannelSet &get, Pixel &out)
	Sample a rectangular area. Note that cx,cy is the center of the rectangle, not the corner.
void	sample (float cx, float cy, float W, float H, Filter *filter, Pixel &out)
	Same except samples out.channels.
void	sample (float cx, float cy, float W, float H, const ChannelSet &get, Pixel &out)
	Same except the filter used is the pre-assigned one.
void	sample (float cx, float cy, float W, float H, Pixel &out)
	Same except the filter used is the pre-assigned one and samples out.channels.
void	sampleTextureUV (const fdk::Vec3f &UV, const fdk::Vec3f &dU, const fdk::Vec3f &dV, Filter *filter, const ChannelSet &get, Pixel &out)
void	sample (SamplePosition &samplePosition, Pixel &out)
	This version is used for two-pass sampling and uses the filter that was previously specified when the sampler was constructed.

Detailed Description

A class for sampling pixels from an image. It works like a Tile, but with sample methods. This is generally more efficient than making many calls to Iop::sample although it may render more than you need from the input if you don't sample all of the requested box.

Member Function Documentation

sample()

void DD::Image::Sampler::sample	(	const Vector2 &	center,
		const Vector2 &	dU,
		const Vector2 &	dV,
		Filter *	filter,
		const ChannelSet &	get,
		Pixel &	out
	)

Sample a parallelogram. It is centered on center and the length of the two axis are given by dU and dV. The channels requested by get are put into out.

The default implementation turns the parallelogram into a rectangle of the same area and calls the rectangle sample() function.

sampleTextureUV()

void DD::Image::Sampler::sampleTextureUV	(	const fdk::Vec3f &	UV,
		const fdk::Vec3f &	dU,
		const fdk::Vec3f &	dV,
		Filter *	filter,
		const ChannelSet &	get,
		Pixel &	out
	)

Specialized version for texture sampling where UV is a texture coordinate between 0..1 to be fitted into the Format, and dU and dV are its partial derivatives. ChannelSet get is provided separately so that a subset of out can be filled without affecting its assigned ChannelSet, which is ignored.

Referenced by slr::SlrShadingContext::sample().