Utility class for line sampling. More...

#include <LineSampler.h>

Classes
struct	Result
	result type providing a Point-pointer and number of sample points More...

Public Member Functions
	LineSampler (int maxLen=0)
	create linesampler with given maximum number of points More...

	LineSampler (const utils::Rect &br)
	createe line sampler with given bounding rect More...

void	setBoundingRect (const utils::Rect &bb)
	sets a bounding rect for line sampling More...

void	removeBoundingBox (int bufferSize)
	removes the bouding rect and sets the internal buffer size More...

Result	sample (const utils::Point &a, const utils::Point &b)
	samples a line between a and b More...

void	sample (const utils::Point &a, const utils::Point &b, std::vector< utils::Point > &dst)
	samples the line into the given destination vector More...

Protected Attributes
std::vector< utils::Point >	m_buf
	internal buffer More...

std::vector< int >	m_br
	optionally given bounding rect More...

Detailed Description

Utility class for line sampling.

The LineSampler class provides a generic framework for efficient line renderig into images. It uses the Bresenham line sampling algorithm, that manages to render arbitray lines between two images points without any floating point operations. The LineSampler provides an internal bounding box check for save line rendering into images

Former Class Layout

The LineSampler replaces the former LineSampler class and the SampledLine class

Optimizations

The class uses several optimizations to speed up linesampling.

compile-time switching about several parameters (such as line steepness, and use of boundingbox)
bounding-box checks are ommitted if both start- and end-point are within the bounding box
optimization of horizontal an vertical lines

Performance

The LineSampler works faster than the core::Line class, be cause it does not have to allocate memory for the result. A test, conducted on a 2.4 GHz Core-2-Duo with an optimized build (-04 -march=native) demonstrated the speed of the line sampler. Rendering all possible lines staring at any pixel and pointing to the center of a VGA image (640x480 lines), takes about 650 ms. This leads to an approximate time of 0.002ms per line or in other words, 500 lines per millisecond;

Constructor & Destructor Documentation

◆ LineSampler() [1/2]

icl::core::LineSampler::LineSampler ( int maxLen = 0 )

create linesampler with given maximum number of points

As long a no bounding rect is given, bound-checks are suppressed

◆ LineSampler() [2/2]

icl::core::LineSampler::LineSampler ( const utils::Rect & br )

createe line sampler with given bounding rect

Member Function Documentation

◆ removeBoundingBox()

void icl::core::LineSampler::removeBoundingBox ( int bufferSize )

removes the bouding rect and sets the internal buffer size

◆ sample() [1/2]

Result icl::core::LineSampler::sample	(	const utils::Point &	a,
		const utils::Point &	b
	)

samples a line between a and b

◆ sample() [2/2]

void icl::core::LineSampler::sample	(	const utils::Point &	a,
		const utils::Point &	b,
		std::vector< utils::Point > &	dst
	)

samples the line into the given destination vector

◆ setBoundingRect()

void icl::core::LineSampler::setBoundingRect ( const utils::Rect & bb )

sets a bounding rect for line sampling

The result will only contain pixels that are within this rectangle

Member Data Documentation

◆ m_br

std::vector<int> icl::core::LineSampler::m_br

protected

optionally given bounding rect

◆ m_buf

std::vector<utils::Point> icl::core::LineSampler::m_buf