Grid2D Class Reference

#include <Grid2D.h>

Public Member Functions
	Grid2D (size_t width, size_t height)
	Construct an empty grid initialized to zeros.
	Grid2D (size_t width, size_t height, const std::vector< float > data)
	Construct from raw data (size must equal width*height).
	Grid2D (const Grid2D &other)
	Copy‑construct from another grid.
	Grid2D (const Image &image)
	Construct from the luminance of an Image.
	Grid2D (std::istream &is)
	Read grid from a binary stream written by save().
void	save (std::ostream &os) const
	Write grid to a binary stream.
std::string	toString () const
	String dump of values in row‑major order.
std::vector< uint8_t >	toByteArray () const
	Convert to an 8‑bit RGB byte array (grayscale replicated to RGB).
Grid2D	toSignedDistance (float threshold) const
	Compute a signed distance field from a binary threshold.
GLTexture2D	toTexture () const
	Upload to an OpenGL texture (1 channel).
void	setValue (size_t x, size_t y, float value)
	Set one value.
float	getValueNormalized (float x, float y) const
	Fetch value using normalized [0,1] coordinates (nearest‑neighbor via index mapping).
float	getValue (size_t x, size_t y) const
	Fetch value by integer coordinates.
float	sample (float x, float y) const
	Bilinear sample at normalized coordinates in [0,1].
float	sample (const Vec2 &pos) const
	Bilinear sample at normalized coordinates in [0,1].
Vec3	normal (float x, float y) const
	Estimate a normal from local height differences at normalized coords.
Vec3	normal (const Vec2 &pos) const
	Estimate a normal from local height differences at normalized coords.
Grid2D	operator* (const float &value) const
	Per‑element multiply by scalar.
Grid2D	operator/ (const float &value) const
	Per‑element divide by scalar.
Grid2D	operator+ (const float &value) const
	Per‑element add scalar.
Grid2D	operator- (const float &value) const
	Per‑element subtract scalar.
Grid2D	operator+ (const Grid2D &other) const
	Per‑element addition with resampling if needed.
Grid2D	operator/ (const Grid2D &other) const
	Per‑element division with resampling if needed.
Grid2D	operator* (const Grid2D &other) const
	Per‑element multiplication with resampling if needed.
Grid2D	operator- (const Grid2D &other) const
	Per‑element subtraction with resampling if needed.
void	normalize (const float maxVal=1)
	Normalize values to [0,maxVal] by affine remapping.
Vec2t< size_t >	maxValue () const
	Location of the maximum value.
Vec2t< size_t >	minValue () const
	Location of the minimum value.
void	fill (float value)
	Fill all elements with a constant.
Geometry
size_t	getWidth () const
	Grid width in elements.
size_t	getHeight () const
	Grid height in elements.

Static Public Member Functions
static Grid2D	genRandom (size_t x, size_t y, uint32_t seed)
	Generate a grid of random values in [0,1) using a fixed seed.
static Grid2D	genRandom (size_t x, size_t y)
	Generate a grid of random values in [0,1) using a global RNG.
static Grid2D	fromBMP (const std::string &filename)
	Create a grid from the luminance of a BMP file.

Friends
std::ostream &	operator<< (std::ostream &os, const Grid2D &v)
	Stream insertion (delegates to toString()).

Constructor & Destructor Documentation

Grid2D() [1/5]

Grid2D::Grid2D	(	size_t	width,
		size_t	height )

Construct an empty grid initialized to zeros.

Parameters

width	Number of columns.
height	Number of rows.

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Grid2D() [2/5]

Grid2D::Grid2D	(	size_t	width,
		size_t	height,
		const std::vector< float >	data )

Construct from raw data (size must equal width*height).

Parameters

width	Number of columns.
height	Number of rows.
data	Row‑major values copied into the grid.

Exceptions

std::runtime_error

If data.size() != width*height.

Grid2D() [3/5]

Grid2D::Grid2D

(

const Grid2D &

other

)

Copy‑construct from another grid.

Parameters

other

Source grid.

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Grid2D() [4/5]

Grid2D::Grid2D

(

const Image &

image

)

Construct from the luminance of an Image.

Parameters

image

Source image; the first channel is sampled and normalized to [0,1]. Width/height match the image.

Grid2D() [5/5]

Grid2D::Grid2D

(

std::istream &

is

)

Read grid from a binary stream written by save().

Parameters

is	Input stream; reads width, height, then width*height floats.

Member Function Documentation

fill()

void Grid2D::fill

(

float

value

)

Fill all elements with a constant.

Parameters

value

Value to assign.

fromBMP()

Grid2D Grid2D::fromBMP ( const std::string & filename )

static

Create a grid from the luminance of a BMP file.

Parameters

filename

Path to the BMP image.

Returns

Grid with width/height of the image; values in [0,1].

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genRandom() [1/2]

Grid2D Grid2D::genRandom ( size_t x, size_t y )

static

Generate a grid of random values in [0,1) using a global RNG.

Parameters

x	Width.
y	Height.

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genRandom() [2/2]

Grid2D Grid2D::genRandom ( size_t x, size_t y, uint32_t seed )

static

Generate a grid of random values in [0,1) using a fixed seed.

Parameters

x	Width.
y	Height.
seed	Seed for the RNG.

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getHeight()

size_t Grid2D::getHeight

(

)

const

Grid height in elements.

getValue()

float Grid2D::getValue	(	size_t	x,
		size_t	y ) const

Fetch value by integer coordinates.

Parameters

x	Column index.
y	Row index.

Returns

Stored value.

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getValueNormalized()

float Grid2D::getValueNormalized	(	float	x,
		float	y ) const

Fetch value using normalized [0,1] coordinates (nearest‑neighbor via index mapping).

Parameters

x	Normalized x.
y	Normalized y.

Returns

Value at floor(x*(width−1)), floor(y*(height−1)).

getWidth()

size_t Grid2D::getWidth

(

)

const

Grid width in elements.

maxValue()

Vec2t< size_t > Grid2D::maxValue

(

)

const

Location of the maximum value.

Returns

Integer coordinates (x,y) of the first maximum encountered.

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minValue()

Vec2t< size_t > Grid2D::minValue

(

)

const

Location of the minimum value.

Returns

Integer coordinates (x,y) of the first minimum encountered.

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normal() [1/2]

Vec3 Grid2D::normal

(

const Vec2 &

pos

)

const

Estimate a normal from local height differences at normalized coords.

Parameters

pos	(x,y) normalized position.

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normal() [2/2]

Vec3 Grid2D::normal	(	float	x,
		float	y ) const

Estimate a normal from local height differences at normalized coords.

Parameters

x,y	Normalized coordinates.

Returns

Unit normal approximating ∇height.

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normalize()

void Grid2D::normalize

(

const float

maxVal = 1

)

Normalize values to [0,maxVal] by affine remapping.

Parameters

maxVal

Upper bound after normalization (default 1).

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operator*() [1/2]

Grid2D Grid2D::operator*

(

const float &

value

)

const

Per‑element multiply by scalar.

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operator*() [2/2]

Grid2D Grid2D::operator*

(

const Grid2D &

other

)

const

Per‑element multiplication with resampling if needed.

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operator+() [1/2]

Grid2D Grid2D::operator+

(

const float &

value

)

const

Per‑element add scalar.

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operator+() [2/2]

Grid2D Grid2D::operator+

(

const Grid2D &

other

)

const

Per‑element addition with resampling if needed.

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operator-() [1/2]

Grid2D Grid2D::operator-

(

const float &

value

)

const

Per‑element subtract scalar.

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operator-() [2/2]

Grid2D Grid2D::operator-

(

const Grid2D &

other

)

const

Per‑element subtraction with resampling if needed.

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operator/() [1/2]

Grid2D Grid2D::operator/

(

const float &

value

)

const

Per‑element divide by scalar.

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operator/() [2/2]

Grid2D Grid2D::operator/

(

const Grid2D &

other

)

const

Per‑element division with resampling if needed.

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sample() [1/2]

float Grid2D::sample

(

const Vec2 &

pos

)

const

Bilinear sample at normalized coordinates in [0,1].

Parameters

pos	(x,y) normalized position.

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sample() [2/2]

float Grid2D::sample	(	float	x,
		float	y ) const

Bilinear sample at normalized coordinates in [0,1].

Parameters

x	Normalized x.
y	Normalized y.

Returns

Interpolated value.

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save()

void Grid2D::save

(

std::ostream &

os

)

const

Write grid to a binary stream.

Parameters

os	Output stream; writes width, height, then width*height floats.

setValue()

void Grid2D::setValue	(	size_t	x,
		size_t	y,
		float	value )

Set one value.

Parameters

x	Column index in [0,width).
y	Row index in [0,height).
value	New value.

toByteArray()

std::vector< uint8_t > Grid2D::toByteArray

(

)

const

Convert to an 8‑bit RGB byte array (grayscale replicated to RGB).

Returns

Vector of size width*height*3 with bytes in 0..255.

toSignedDistance()

Grid2D Grid2D::toSignedDistance

(

float

threshold

)

const

Compute a signed distance field from a binary threshold.

Parameters

threshold

Values ≥ threshold are considered inside.

Returns

Grid whose values are distances to the nearest boundary, positive inside and negative outside.

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toString()

std::string Grid2D::toString

(

)

const

String dump of values in row‑major order.

Returns

CSV‑like multiline representation.

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toTexture()

GLTexture2D Grid2D::toTexture

(

)

const

Upload to an OpenGL texture (1 channel).

Returns

GLTexture2D with dimensions width×height.

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Friends And Related Symbol Documentation

operator<<

std::ostream & operator<< ( std::ostream & os, const Grid2D & v )

friend

Stream insertion (delegates to toString()).

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The documentation for this class was generated from the following files:

• Grid2D.h
• Grid2D.cpp