gameplay::HeightField Class Reference

#include <HeightField.h>

Inheritance diagram for gameplay::HeightField:

List of all members.

Public Member Functions
float *	getArray () const
float	getHeight (float column, float row) const
unsigned int	getRowCount () const
unsigned int	getColumnCount () const
Static Public Member Functions
static HeightField *	create (unsigned int rows, unsigned int columns)
static HeightField *	createFromImage (const char *path, float heightMin=0, float heightMax=1)
static HeightField *	createFromRAW (const char *path, unsigned int width, unsigned int height, float heightMin=0, float heightMax=1)

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Detailed Description

Defines height data used to store values representing elevation.

Heightfields can be used to construct both Terrain objects as well as PhysicsCollisionShape heightfield defintions, which are used in heightfield rigid body creation. Heightfields can be populated manually, or loaded from images and RAW files.

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Member Function Documentation

static HeightField* gameplay::HeightField::create	(	unsigned int	rows,
		unsigned int	columns
	)		[static]

Creates a new HeightField of the given dimensions, with uninitialized height data.

Parameters:

rows	Number of rows in the height field.
columns	Number of columns in the height field.

Returns:

The new HeightField.

static HeightField* gameplay::HeightField::createFromImage	(	const char *	path,
		float	heightMin = 0,
		float	heightMax = 1
	)		[static]

Creates a HeightField from the specified heightfield image.

The specified image path must refer to a valid heightfield image. Supported images are the same as those supported by the Image class (i.e. PNG).

The minHeight and maxHeight parameters provides a mapping from heightfield pixel intensity to height values. The minHeight parameter is mapped to zero intensity pixel, while maxHeight maxHeight is mapped to full intensity pixels.

Parameters:

path	Path to a heightfield image.
heightMin	Minimum height value for a zero intensity pixel.
heightMax	Maximum height value for a full intensity heightfield pixel (must be >= minHeight).

Returns:

The new HeightField.

static HeightField* gameplay::HeightField::createFromRAW	(	const char *	path,
		unsigned int	width,
		unsigned int	height,
		float	heightMin = 0,
		float	heightMax = 1
	)		[static]

Creates a HeightField from the specified RAW8 or RAW16 file.

RAW files are header-less files containing intensity values, either in 8-bit (RAW8) or 16-bit (RAW16) format. RAW16 files must have little endian (PC) byte ordering. Since RAW files have no header, you must specify the dimensions of the data in the file. This method automatically determines (based on file size) whether the input file is RAW8 or RAW16. RAW files must have a .raw or .r16 file extension.

RAW files are commonly used in software that produces heightmap images. Using RAW16 is preferred or any 8-bit heightfield source since it allows greater precision, resulting in smoother height transitions.

The minHeight and maxHeight parameters provides a mapping from heightfield pixel intensity to height values. The minHeight parameter is mapped to zero intensity pixel, while maxHeight maxHeight is mapped to full intensity pixels.

Parameters:

path	Path to the RAW file (must end in a .raw or .r16 file extension).
width	Width of the RAW data.
height	Height of the RAW data.
heightMin	Minimum height value for a zero intensity pixel.
heightMax	Maximum height value for a full intensity heightfield pixel (must be >= minHeight).

Returns:

The new HeightField.

float* gameplay::HeightField::getArray

(

)

const

Returns a pointer to the underlying height array.

The array is packed in row major order, meaning that the data is aligned in rows, from top left to bottom right.

Returns:

The underlying height array.

unsigned int gameplay::HeightField::getColumnCount

(

)

const

Returns the number of columns in the heightfield.

Returns:

The column count.

float gameplay::HeightField::getHeight	(	float	column,
		float	row
	)		const

Returns the height at the specified row and column.

The specified row and column are specified as floating point numbers so that values between points can be specified. In this case, a height value is calculated that is interpolated between neighboring height values.

If the specified point lies outside the heightfield, it is clamped to the boundary of the heightfield.

Parameters:

column	The column of the height value to query.
row	The row of the height value to query.

Returns:

The height value.

unsigned int gameplay::HeightField::getRowCount

(

)

const

Returns the number of rows in the heightfield.

Returns:

The number of rows.