bresenham

bresenham_line

A 'pseudo' container that generates coordinates on a line between two points using the Bresenham line algorithm.

The class has an STL-like API and is a forward iterator type container.

Note: The iterator only supports pre-increment.

etl::bresenham_line<typename T>

Where T is the coordinate element type.

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Member types

value_type etl::coordinate_2d<T>

size_type std::size_t

difference_type std::ptrdiff_t

const_reference const value_type&

const_pointer const value_type*

const_iterator Constant forward iterator

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Constructor

etl::bresenham_line<T>;

etl::bresenham_line<T>(T first_x, T first_y, T last_x, T last_y);

etl::bresenham_line<T>(const etl::coordinate_2d<T>& first, const etl::coordinate_2d<T>& last);

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Initialization

void reset(T first_x, T first_y, T last_x, T last_y);

void reset(const etl::coordinate_2d<T>& first, const etl::coordinate_2d<T>& last);

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Element access

const_reference front() const

Returns a const reference to the first coordinate in the line.

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const_reference back() const

Returns a const reference to the last coordinate in the line.

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Iterators

const_iterator begin()

Returns an iterator to the beginning of the coordinate series.

This will reset the Bresenham line algorithm to the first coordinate.

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const_iterator end() const

Returns an iterator to the end of the coordinate series.

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Capacity

size_t size() const

Returns the number of coordinates in the series.

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Non-member functions

== true if the two lines are equal, otherwise false.

!= true if the two lines are not equal, otherwise false.

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Examples

Plot pixels on a line

std::ostream& operator << (std::ostream& os, const etl::coordinate_2d<int>& coordinate)

{

os << "(" << coordinate.x << "," << coordinate.y << ")";

return os;

}

etl::coordinate_2d<int> first = { -3, 5 };

etl::coordinate_2d<int> last = { 3, -5 };

etl::bresenham_line<int> line(first, last);

std::cout << "There are " << line.size() << " coordinates between " << line.front() << " and "

<< line.back();

// Plot the pixels between first and last.

std::for_each(line.begin(), line.end(), PlotPixel);

Create a vector of pixels on a line

etl::coordinate_2d<int> first = { -3, 5 };

etl::coordinate_2d<int> last = { 3, -5 };

etl::bresenham_line<int> line(first, last);

std::vector<etl::coordinate_2d<int>> coordinates;

// Create the vector of points on the line between first and last.

std::copy(line.begin(), line.end(), std::back_inserter(coordinates));

bresenham_line.h