vrvis::Texture Class Reference

Represents a single texture in a LayerComponent as well as related figures and data. More...

#include <Texture.hpp>

List of all members.

Public Member Functions
Constructor & Destructor
	Texture (const int cOriginX, const int cOriginY, const int cWidth, const int cHeight, const int cMaxValidX, const int cMaxValidY, const ColorDataMap &crColorDataMap)
	Construct a Texture object out of relevant sizes and a ColorDataMap.
	~Texture (void)
	Destructor.
Accessors
int	getOriginX (void) const
	Get X pixel origin relative to the whole RasterData source object.
int	getOriginY (void) const
	Get Y pixel origin relative to the whole RasterData source object.
int	getSizeX (void) const
	Get width in pixels.
int	getSizeY (void) const
	Get height in pixels.
int	getMaxValidX (void) const
	Get size of the Texture part containing valid pixels; horizontal size.
int	getMaxValidY (void) const
	Get size of the Texture part containing valid pixels; vertical size.
double	getLowerLimit (void) const
	Get the lower limit of this Texture data's histogram.
double	getUpperLimit (void) const
	Get the upper limit of this Texture data's histogram.
ushort *	getTexData (void) const
	Get pointer to the texture data storage.
void	getTexCoords (float &rMinX, float &rMaxX, float &rMinY, float &rMaxY)
	Get current GL texture coordinates.
Mutators
void	setTexCoords (const float cMinX, const float cMaxX, const float cMinY, const float cMaxY)
	Set GL texture coordinates.
void	setLimits (const double cLowerLimit, const double cUpperLimit)
	Set histogram limits.
Data Initialization
void	fill (void)
	Fill the texture according to the ColorDataMap.
void	createGLTexture (void)
	Create a new GL texture object out of this Texture.
Data Manipulation
void	calculateTextureData (void)
	Converts the ColorDataMap member to the texture data array.
void	rebuildGLTexture (int offsetX=0, int offsetY=0, int width=-1, int height=-1)
	Rebuilds a given part of the GL texture.
Drawing
void	drawTexturedQuad (const float cDrawUnitX, const float cDrawUnitY)
	Draw a textured quad with this Texture mapped on it.
Static Public Member Functions
int	getMaxTexSize (void)
	Get the maximum texture size supported on this system.

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Detailed Description

Class representing one texture part of a LayerComponent. Textures are created as necessary by LayerComponents and are dependent on the maximum available GL texture size for the executing graphics system. The larger the available maximum texture size, the fewer slices, i.e. Texture objects have to be created.

Note:

On the way from RasterData to visible texture, the data values run through a three-stage process:

• First, the values are clamped to this Texture's lower and upper histogram limits, so that no data values outside that given range exist anymore.
• Second, the values of each RasterData object in the ColorDataMap - each representing exactly one color of either R, G, or B - are combined and converted to an RGB texture data array of type unsigned short.
• Third, this texture data array is used to build a GL texture object which is used in the scene drawing.

Warning:

Texture is the most crucial class concerning context-dependent function calls. Special care has to be taken in order to call context-related functions only during an active GL context!

See also:

Calling cycle, context issues

LayerComponent

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Constructor & Destructor Documentation

Texture::Texture (  const int  cOriginX, const int  cOriginY, const int  cWidth, const int  cHeight, const int  cMaxValidX, const int  cMaxValidY, const ColorDataMap &  crColorDataMap )

Creates a new Texture object of a certain size and origin. A given ColorDataMap is used to create the final pixel values of the visible texture. Parameters: [in]  cOriginX  Origin of the texture in relation to the whole RasterData size; X coordinate. [in]  cOriginY  Origin of the texture in relation to the whole RasterData size; Y coordinate. [in]  cWidth  Width of this Texture object in pixels. [in]  cHeight  Height of this Texture object in pixels. [in]  cMaxValidX  Maximum X coordinate that contains valid pixel information. [in]  cMaxValidY  Maximum Y coordinate that contains valid pixel information. [in]  crColorDataMap  Reference to the LayerComponent's ColorDataMap; used to calculate the final pixel values. Note: Since OpenGL texture objects always have to be sized in either dimension, the useful pixel part of a texture may be smaller than its real size. That is what the cMaxValid[X|Y] figures are for. See also: ColorDataMap

Texture::~Texture (  void   )

Destructor.

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Member Function Documentation

void Texture::calculateTextureData (  void   )

Converts the RasterData objects stored in the ColorDataMap to a texture data array. Includes a left-handed (RasterData) to right-handed coordinate system conversion.

void Texture::createGLTexture (  void   )

Creates an OpenGL texture object out of a data-filled(!) Texture. Warning: This method requires an active OpenGL context to be executed properly!

void Texture::drawTexturedQuad (  const float  cDrawUnitX, const float  cDrawUnitY )

Draws a textured GL quad with a mapping of the created GL texture object and the current texture coordinates. Parameters: [in]  cDrawUnitX  The width of a drawn square that represents one drawn pixel. [in]  cDrawUnitY  The height of a drawn square that represents one drawn pixel.

void Texture::fill (  void   )

Fills the Texture with data for the first time. Memory is allocated and initialized, the data calculated and empty areas made invisible via alpha correction.

double Texture::getLowerLimit (  void   )  const

Get lower limit of the texture data's histogram. Returns: Current lower limit of the texture data histogram.

int Texture::getMaxTexSize (  void   )  [static]

int Texture::getMaxValidX (  void   )  const

Get this Texture's maximum valid X cordinate. Returns: The maximum valid X coordinate.

int Texture::getMaxValidY (  void   )  const

Get this Texture's maximum valid Y cordinate. Returns: The maximum valid Y coordinate.

int Texture::getOriginX (  void   )  const

Get this Texture's X origin in relation to the RasterData size. Returns: Origin; X coordinate.

int Texture::getOriginY (  void   )  const

Get this Texture's Y origin in relation to the RasterData size. Returns: Origin; Y coordinate.

int Texture::getSizeX (  void   )  const

Get this Texture's horizontal size in pixels. Returns: Width in pixels.

int Texture::getSizeY (  void   )  const

Get this Texture's vertical size in pixels. Returns: Height in pixels.

void Texture::getTexCoords (  float &  rMinX, float &  rMaxX, float &  rMinY, float &  rMaxY )

Get the current GL texture coordinates. Parameters: [out]  rMinX  Minimal X texture coordinate. [out]  rMaxX  Maximal X texture coordinate. [out]  rMinY  Minimal Y texture coordinate. [out]  rMaxY  Maximal Y texture coordinate. Note: The default minimal texture coordinates are 0.0, the default maximal coordinates are (mcMaxValid[X|Y] / mcSize[X|Y]); i.e. the whole area of valid pixels.

ushort * Texture::getTexData (  void   )  const

Get pointer to the memory where the texture data is stored. Returns: Pointer to the texture data storage.

double Texture::getUpperLimit (  void   )  const

Get upper limit of the texture data's histogram. Returns: Current upper limit of the texture data histogram.

void Texture::rebuildGLTexture (  int  offsetX = 0, int  offsetY = 0, int  width = -1, int  height = -1 )

Recreates a given part of the GL texture based on the current texture data array. Parameters: [in]  offsetX  Offset from where to start the recreation; X coordinate. [in]  offsetY  Offset from where to start the recreation; X coordinate. [in]  width  Width of the area to recreate in pixels. [in]  height  Height of the area to recreate in pixels. Note: Offsets are by default 0, both width and height -1. If either width or height have a value of -1, that value is replaced by the mcSize[X|Y] member, i.e. if the method is called without arguments, the whole valid texture is rebuilt. Warning: This method requires an active OpenGL context to be executed properly!

void Texture::setLimits (  const double  cLowerLimit, const double  cUpperLimit )

Set the lower and upper limits for this Texture data's histogram. Parameters: [in]  cLowerLimit  New lower histogram limit. [in]  cUpperLimit  New upper histogram limit. Note: This method just updates the corresponding data members. To see the histogram changes visually in the scene, you have to call calculateTextureData() and rebuildGLTexture() first.

void Texture::setTexCoords (  const float  cMinX, const float  cMaxX, const float  cMinY, const float  cMaxY )

Set the GL texture coordinates used for this texture. Parameters: [in]  cMinX  Minimal X texture coordinate. [in]  cMaxX  Maximal X texture coordinate. [in]  cMinY  Minimal Y texture coordinate. [in]  cMaxY  Maximal Y texture coordinate. Note: The default minimal texture coordinates are 0.0, the default maximal coordinates are (mcMaxValid[X|Y] / mcSize[X|Y]); i.e. the whole area of valid pixels.

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

• Texture.hpp
• Texture.cpp

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