SoIndexedTexture2 Class Reference

Class for 2D indexed texture. More...

#include <Inventor/nodes/SoIndexedTexture2.h>

Inheritance diagram for SoIndexedTexture2:

Public Member Functions
virtual SoType	getTypeId () const
	Returns the type identifier for this specific instance.
void	computeDataRange ()
	Compute the min and max value of the indexed image and put the result in minValue and maxValue.
	SoIndexedTexture2 ()
	Constructor.
Public Member Functions inherited from SoTexture
void	setBitmapFileType (FileType in_type)
	Sets the texture file format.
FileType	getBitmapFileType (void)
	Gets the texture file format.
virtual void	setOverride (const SbBool state)
	Set the state of the override field.
virtual SbBool	isOverride () const
	Returns the state of the override field.
Public Member Functions inherited from SoNode
virtual SoNode *	copy (SbBool copyConnections=FALSE) const
	Creates and returns an exact copy of the node.
virtual SbBool	affectsState () const
	Returns TRUE if a node has an effect on the state during traversal.
virtual void	touch ()
	Marks an instance as modified, simulating a change to it.
Public Member Functions inherited from SoFieldContainer
void	setToDefaults ()
	Sets all fields in this object to their default values.
SbBool	hasDefaultValues () const
	Returns TRUE if all of the object's fields have their default values.
SbBool	fieldsAreEqual (const SoFieldContainer *fc) const
	Returns TRUE if this object's fields are exactly equal to fc's fields.
void	copyFieldValues (const SoFieldContainer *fc, SbBool copyConnections=FALSE)
	Copies the contents of fc's fields into this object's fields.
SoNONUNICODE SbBool	set (const char *fieldDataString)
	Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.
SbBool	set (const SbString &fieldDataString)
	Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.
void	get (SbString &fieldDataString)
	Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string.
virtual int	getFields (SoFieldList &list) const
	Appends references to all of this object's fields to resultList, and returns the number of fields appended.
virtual int	getAllFields (SoFieldList &list) const
	Returns a list of fields, including the eventIn's and eventOut's.
virtual SoField *	getField (const SbName &fieldName) const
	Returns a the field of this object whose name is fieldName.
virtual SoField *	getEventIn (const SbName &fieldName) const
	Returns a the eventIn with the given name.
virtual SoField *	getEventOut (const SbName &fieldName) const
	Returns the eventOut with the given name.
SbBool	getFieldName (const SoField *field, SbName &fieldName) const
	Returns the name of the given field in the fieldName argument.
SbBool	enableNotify (SbBool flag)
	Notification at this Field Container is enabled (if flag == TRUE) or disabled (if flag == FALSE).
SbBool	isNotifyEnabled () const
	Notification is the process of telling interested objects that this object has changed.
virtual void	setUserData (void *data)
	Sets application data.
void *	getUserData (void) const
	Gets user application data.
Public Member Functions inherited from SoBase
virtual SbName	getName () const
	Returns the name of an instance.
virtual void	setName (const SbName &name)
	Sets the name of an instance.
void	setSynchronizable (const bool b)
	Sets this to be a ScaleViz synchronizable object.
bool	isSynchronizable () const
	Gets the ScaleViz synchronizable state of this object.
Public Member Functions inherited from SoRefCounter
void	ref () const
	Adds a reference to an instance.
void	unref () const
	Removes a reference from an instance.
void	unrefNoDelete () const
	unrefNoDelete() should be called when it is desired to decrement the reference count, but not delete the instance if this brings the reference count to zero.
int	getRefCount () const
	Returns current reference count.
void	lock () const
	lock this instance.
void	unlock () const
	unlock this instance.
Public Member Functions inherited from SoTypedObject
SbBool	isOfType (const SoType &type) const
	Returns TRUE if this object is of the type specified in type or is derived from that type.
template<typename TypedObjectClass >
SbBool	isOfType () const
	Returns TRUE if this object is of the type of class TypedObjectClass or is derived from that class.

Static Public Member Functions
static SoType	getClassTypeId ()
	Returns the type identifier for this class.
Static Public Member Functions inherited from SoTexture
static SoType	getClassTypeId ()
	Returns the type identifier for this class.
static SbBool	isSupported (HW_Feature feature)
	Returns information about hardware support for various texture features.
static SbRasterImage *	readTexture (const SbString &filename, FileType filetype=UNKNOWN)
	Convenience function that loads the image data from any texture file supported by Open Inventor and returns an SbRasterImage object.
Static Public Member Functions inherited from SoNode
static SoType	getClassTypeId ()
	Returns the type identifier for this class.
static SoNode *	getByName (const SbName &name)
	A node's name can be set using SoBase::setName().
static int	getByName (const SbName &name, SoNodeList &list)
	A node's name can be set using SoBase::setName().
Static Public Member Functions inherited from SoFieldContainer
static SoType	getClassTypeId ()
	Returns the type of this class.
Static Public Member Functions inherited from SoBase
static SoType	getClassTypeId ()
	Returns type identifier for this class.
Static Public Member Functions inherited from SoTypedObject
static SoType	getClassTypeId ()
	Returns the type identifier for this class.

Public Attributes
SoSFFloat	minValue
	Specifies the range of values which is mapped onto the color map (see SoColorMap).
SoSFFloat	maxValue
	See minValue.
SoSFArray2D	imageIndex
	This field contains the in-memory representation of the indexed texture image.
SoSFBool	rescaleTexCoord
	This field controls the way an image with non-power-of-two dimension is handled:
SoSFEnum	wrapT
	Indicates what to do when texture coordinates in the T (vertical) direction lie outside the range 0-1.
Public Attributes inherited from SoTexture
SoSFEnum	internalFormat
	Internal format for texture storage.
SoSFBool	enableCompressedTexture
	Enables storage of textures on the graphics board in compressed form.
SoSFEnum	wrapS
	Indicates what to do when texture coordinates in the S (horizontal) direction lie outside the range 0-1.
SoSFEnum	model
	Specifies how to map texture onto surface.
SoSFColor	blendColor
	Color used for BLEND model.
SoSFBool	enableBorder
	Enables borders for textures.
SoSFVec4f	borderColor
	Defines border color used for border texture filtering.
SoSFFloat	maxAnisotropy
	Specifies on a per-texture object basis, the maximum degree of anisotropy to account for in texture filtering.
SoSFEnum	minFilter
	Specifies the OpenGL minFilter.
SoSFEnum	magFilter
	Specifies the OpenGL magFilter.

Additional Inherited Members
Public Types inherited from SoTexture
enum	InternalFormat {   AUTO_INTERNAL_FORMAT ,   ALPHA_FORMAT ,   ALPHA4 ,   ALPHA8 ,   ALPHA12 ,   ALPHA16 ,   LUMINANCE_FORMAT ,   LUMINANCE4 ,   LUMINANCE8 ,   LUMINANCE12 ,   LUMINANCE16 ,   LUMINANCE_ALPHA ,   LUMINANCE4_ALPHA4 ,   LUMINANCE6_ALPHA2 ,   LUMINANCE8_ALPHA8 ,   LUMINANCE12_ALPHA4 ,   LUMINANCE12_ALPHA12 ,   LUMINANCE16_ALPHA16 ,   INTENSITY_FORMAT ,   INTENSITY4 ,   INTENSITY8 ,   INTENSITY12 ,   INTENSITY16 ,   R3_G3_B2 ,   RGB_FORMAT ,   RGB4 ,   RGB5 ,   RG8 ,   RGB8 ,   RGB10 ,   RGB12 ,   RGB16 ,   RGBA_FORMAT ,   RGBA2 ,   RGBA4 ,   RGB5_ALPHA1 ,   RGBA8 ,   RGB10_ALPHA2 ,   RGBA12 ,   RGBA16 ,   RGBA_FLOAT32 ,   RGB_FLOAT32 ,   ALPHA_FLOAT32 ,   INTENSITY_FLOAT32 ,   LUMINANCE_FLOAT32 ,   LUMINANCE_ALPHA_FLOAT32 ,   RGBA_FLOAT16 ,   RGB_FLOAT16 ,   ALPHA_FLOAT16 ,   INTENSITY_FLOAT16 ,   LUMINANCE_FLOAT16 ,   LUMINANCE_ALPHA_FLOAT16 ,   COMPRESSED_ALPHA ,   COMPRESSED_LUMINANCE ,   COMPRESSED_LUMINANCE_ALPHA ,   COMPRESSED_INTENSITY ,   COMPRESSED_RGB ,   COMPRESSED_RGBA ,   COMPRESSED_LUMINANCE_LATC1 ,   COMPRESSED_SIGNED_LUMINANCE_LATC1 ,   COMPRESSED_LUMINANCE_ALPHA_LATC2 ,   COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2 ,   COMPRESSED_RED_RGTC1 ,   COMPRESSED_SIGNED_RED_RGTC1 ,   COMPRESSED_RED_GREEN_RGTC2 ,   COMPRESSED_SIGNED_RED_GREEN_RGTC2 ,   DEPTH_COMPONENT16 ,   DEPTH_COMPONENT24 ,   DEPTH24_STENCIL8 ,   R8I ,   R8UI ,   R16I ,   R16UI ,   R32I ,   R32UI ,   RG8I ,   RG8UI ,   RG16I ,   RG16UI ,   RG32I ,   RG32UI ,   RGB8I ,   RGB8UI ,   RGB16I ,   RGB16UI ,   RGB32I ,   RGB32UI ,   RGBA8I ,   RGBA8UI ,   RGBA16I ,   RGBA16UI ,   RGBA32I ,   RGBA32UI }
	Texture internal storage format. More...
enum	Model {   MODULATE = SbEnums::TEX_MODEL_MODULATE ,   DECAL = SbEnums::TEX_MODEL_DECAL ,   BLEND = SbEnums::TEX_MODEL_BLEND ,   REPLACE = SbEnums::TEX_MODEL_REPLACE ,   ADD = SbEnums::TEX_MODEL_ADD ,   COMBINE = SbEnums::TEX_MODEL_COMBINE }
	Texture Combiner Functions. More...
enum	Wrap {   REPEAT = SbEnums::TEX_ADDRESS_REPEAT ,   CLAMP = SbEnums::TEX_ADDRESS_CLAMP ,   CLAMP_TO_BORDER = SbEnums::TEX_ADDRESS_CLAMP_BORDER ,   CLAMP_TO_EDGE = SbEnums::TEX_ADDRESS_CLAMP_TO_EDGE ,   MIRRORED_REPEAT = SbEnums::TEX_ADDRESS_MIRROR_REPEAT }
	Texture wrap type. More...
enum	Filter {   AUTO = SbEnums::TEX_FILTER_AUTO ,   NEAREST = SbEnums::TEX_FILTER_NEAREST ,   LINEAR = SbEnums::TEX_FILTER_LINEAR ,   NEAREST_MIPMAP_NEAREST = SbEnums::TEX_FILTER_NEAREST_MIPMAP_NEAREST ,   NEAREST_MIPMAP_LINEAR = SbEnums::TEX_FILTER_NEAREST_MIPMAP_LINEAR ,   LINEAR_MIPMAP_NEAREST = SbEnums::TEX_FILTER_LINEAR_MIPMAP_NEAREST ,   LINEAR_MIPMAP_LINEAR = SbEnums::TEX_FILTER_LINEAR_MIPMAP_LINEAR }
	Specifies the OpenGL filtering method for minification and magnification. More...
enum	HW_Feature {   HW_NPOT = 0 ,   HW_FLOATFORMAT ,   HW_DEPTHFORMAT ,   HW_AUTOMIPMAP ,   HW_BORDER_CLAMP ,   HW_EDGE_CLAMP ,   HW_MIRRORED_REPEAT ,   HW_COMPRESSION_S3TC ,   HW_COMPRESSION_LATC ,   HW_COMPRESSION_RGTC }
enum	FileType {   UNKNOWN ,   RGB ,   SGI ,   TIFF ,   GIF ,   JPEG ,   BMP ,   PNG ,   JPEG2000 ,   DDS ,   HDRI ,   NUM_FILETYPES }
	File Type possible values. More...

Detailed Description

Class for 2D indexed texture.

This property node defines an "indexed" texture image. In a standard texture image, e.g. SoTexture2, each texel contains a color value that is directly applied to the geometry. In this node each texel contains a data value that is mapped to a color value using the color map defined by the current SoColorMap node.

This image is stored in the current texture unit (see SoTextureUnit) and the texture is applied to subsequent shapes as they are rendered.

The image data is stored in an SoSFArray2D. This array can contain different types of data (UNSIGNED_BYTE, UNSIGNED_SHORT, UNSIGNED_INT32, SIGNED_BYTE, SIGNED_SHORT, SIGNED_INT32, FLOAT).

When Open Inventor creates the OpenGL texture image from the data array, the data values must be scaled into the range of values of the texture (0-255 for an 8-bit indexed texture). The minValue and maxValue fields specify the range of data values that will be scaled into the range of texture values. For example, if minValue is set to 10000 and maxValue to 38000, all values less than or equal to 10000 will be mapped to the entry 0 of the color map and all values greater than or equal to 38000 to the last entry. The image below illustrates the process of mapping and shows how it can be used to map only the used data range to the color map:

br

If minValue or maxValue change, then the OpenGL texture must be recreated. If the texture is large, this may be time consuming. Generally it's more efficient to modify the SoColorMap node because the OpenGL texture corresponding to the data does not need to be recreated – only the texture containing the colormap, which is normally quite small.

NOTE: Texture data values are stored with 12 bits of precision instead of the usual 8 bits, when:

• ARB_fragment_program is supported by the graphics card.
• The number of color map entries is greater than 256.
• The texture data type has more than 8 bits of precision (i.e., not UNSIGNED_BYTE or SIGNED_BYTE).

EXAMPLE

The following example shows how to apply an indexed texture on a geometry node:

SoColorMap *colorMap = new SoColorMap();
  colorMap->predefinedColorMap = SoColorMap::TEMPERATURE;
  colorMap->min.setValue( -1000 );
  colorMap->max.setValue( 20000 );
 
SoIndexedTexture2 *indexedTexture = new SoIndexedTexture2();
  indexedTexture->imageIndex.setValue(size, SoSFArray2D::SIGNED_SHORT, data);
 
root->addChild( colorMap );
root->addChild( indexedTexture );
root->addChild( geometry );

EXAMPLE

On graphics cards supporting ARB_fragment_program , the model field will be ignored and multitexturing will not work. It is possible to circumvent this limitation by using a custom shader. The following GLSL code shows how to do multitexturing between two indexed textures sharing the same color map:

// Fragment shader
uniform sampler2D colormap;
uniform sampler2D indexedTex1; 
uniform sampler2D indexedTex2;  
 
void main()
{
  // Fetch first value and its assigned color
  float value1 = texture(indexedTex1, gl_TexCoord[0].xy).x;
  vec4  color1 = texture(colormap, vec2(value1, 0));
 
  // Fetch second and its assigned color
  float value2 = texture(indexedTex2, gl_TexCoord[0].xy).x;
  vec4  color2 = texture(colormap, vec2(value2, 0));
 
  // Combine the colors
  gl_FragColor = color1 * color2 * gl_Color;
}

The scene graph would be initialized like this:

SoColorMap* colorMap = new SoColorMap();
  . . .
SoIndexedTexture2* indexedTex1 = new SoIndexedTexture2();
  . . .
SoIndexedTexture2* indexedTex2 = new SoIndexedTexture2();
  . . .
 
SoFragmentShader* fragShader = new SoFragmentShader();
  fragShader->sourceProgram = "filename.glsl";
  fragShader->addShaderParameter1i( "colorMap"   , 0 );
  fragShader->addShaderParameter1i( "indexedTex1", 1 );
  fragShader->addShaderParameter1i( "indexedTex2", 2 );
 
SoShaderProgram*  shaderProgram = new SoShaderProgram();
  shaderProgram->shaderObject = fragShader;
 
SoTextureUnit* textureUnit = new SoTextureUnit();
textureUnit->unit = 2;  //Texture unit for the second indexed texture
 
root->addChild(colorMap);      //Color map must come first (texture unit 1)
root->addChild(indexedTex1);   //First indexed texture (texture unit 0)
root->addChild(textureUnit); 
root->addChild(indexedTex2);   //Second indexed texture (texture unit 2)
root->addChild(shaderProgram);
root->addChild(geometry);

FILE FORMAT/DEFAULT

IndexedTexture2 {

minValue	0
maxValue	0
imageIndex	0 0
rescaleTexCoord	FALSE
wrapS	REPEAT
wrapT	REPEAT
model	MODULATE
blendColor	0 0 0
enableBorder	FALSE
borderColor	0 0 0 0
maxAnisotropy	1.0
minFilter	AUTO
magFilter	AUTO
useAutoMipmap	FALSE
internalFormat	AUTO_INTERNAL_FORMAT

}

ACTION BEHAVIOR

SoGLRenderAction, SoCallbackAction
Sets: SoTextureImageElement

SEE ALSO

SoTexture2Transform, SoTextureCoordinate2,
SoTextureCoordinateFunction, SoColorMap, SoSFArray2D.

Definition at line 317 of file SoIndexedTexture2.h.

Constructor & Destructor Documentation

SoIndexedTexture2()

SoIndexedTexture2::SoIndexedTexture2

(

)

Constructor.

Member Function Documentation

computeDataRange()

void SoIndexedTexture2::computeDataRange

(

)

Compute the min and max value of the indexed image and put the result in minValue and maxValue.

getClassTypeId()

static SoType SoIndexedTexture2::getClassTypeId ( )

static

Returns the type identifier for this class.

getTypeId()

virtual SoType SoIndexedTexture2::getTypeId ( ) const

virtual

Returns the type identifier for this specific instance.

Reimplemented from SoTexture.

Member Data Documentation

imageIndex

SoSFArray2D SoIndexedTexture2::imageIndex

This field contains the in-memory representation of the indexed texture image.

Each value of this array is a color index. In the case of float values, data must be between 0 and 1.

Definition at line 350 of file SoIndexedTexture2.h.

maxValue

SoSFFloat SoIndexedTexture2::maxValue

See minValue.

Definition at line 343 of file SoIndexedTexture2.h.

minValue

SoSFFloat SoIndexedTexture2::minValue

Specifies the range of values which is mapped onto the color map (see SoColorMap).

When minValue and maxValue are equal to 0 (the default), the entire range of the data type is mapped onto the color map, except in the case of float data. For example, for a color map of size N:

• With unsigned byte values, [0-255] is mapped onto the color map [0 - N-1]
• With unsigned short values, [0-65535] is mapped onto the color map [0 - N-1]
• With signed short values, [-32768 - 32767] is mapped onto the color map [0 - N-1].
• With float data type, [0-1] is mapped onto the color map [0 - N-1]

All values less than or equal to minValue will be mapped to the first entry of the color map. Likewise, all values greater than or equal to maxValue will be mapped to the last entry of the color map.

Definition at line 338 of file SoIndexedTexture2.h.

rescaleTexCoord

SoSFBool SoIndexedTexture2::rescaleTexCoord

This field controls the way an image with non-power-of-two dimension is handled:

• If the graphics card supports GL_ARB_texture_non_power_of_two , this field is ignored and the image is sent directly to OpenGL.
• If rescaleTexCoord is FALSE (the default), the image is rescaled to the next lower power-of-two dimensions. The scaling is done with a box filter.
• If rescaleTexCoord is TRUE, the image is not rescaled but is only copied into a texture with the next higher power-of-two dimension, and its texture coordinates are scaled by applying a texture transform in order to only display the actual image.

Default is FALSE.

When this field is enabled, if other texture transforms are applied to the texture coordinates (especially if the texture is repeated), the unused part of the larger texture could be displayed. Furthermore, in this mode, if non-power-of-two textures occur one after another in the scene graph, an incorrect image may result because texture transforms are cumulative. For example, the following code would give incorrect results:

root->addChild( colorMap );
root->addChild( nonPowerOfTwoIndexedTexture1 );
root->addChild( nonPowerOfTwoIndexedTexture2 );
root->addChild( nonPowerOfTwoIndexedTexture3 );

The correct way is to use a separator above each texture, as shown:

root->addChild( colorMap );
root->addChild( separator1 );
  separator1->addChild( nonPowerOfTwoIndexedTexture1 );
root->addChild( separator2);
  separator2->addChild( nonPowerOfTwoIndexedTexture2 );
root->addChild( separator3);
  separator3->addChild( nonPowerOfTwoIndexedTexture3 );

Definition at line 439 of file SoIndexedTexture2.h.

wrapT

SoSFEnum SoIndexedTexture2::wrapT

Indicates what to do when texture coordinates in the T (vertical) direction lie outside the range 0-1.

Use enum SoTexture::Wrap. Default is REPEAT.

Definition at line 446 of file SoIndexedTexture2.h.

---

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

• Inventor/nodes/SoIndexedTexture2.h