NAME
SoTexture2 -
The SoTexture2 class is used to map a 2D texture onto subsequent
geometry in the scenegraph.
Shape nodes within the scope of SoTexture2 nodes in the scenegraph (ie
below the same SoSeparator and to the righthand side of the SoTexture2)
will have the texture applied according to each shape type’s individual
characteristics. See the documentation of the various shape types
(SoFaceSet, SoCube, SoSphere, etc etc) for information about the
specifics of how the textures will be applied.
SYNOPSIS
#include <Inventor/nodes/SoTexture2.h>
Inherits SoTexture.
Public Types
enum Model { MODULATE = SoTextureImageElement::MODULATE, DECAL =
SoTextureImageElement::DECAL, BLEND =
SoTextureImageElement::BLEND, REPLACE =
SoTextureImageElement::REPLACE }
enum Wrap { REPEAT = SoTextureImageElement::REPEAT, CLAMP =
SoTextureImageElement::CLAMP }
Public Member Functions
SoTexture2 (void)
virtual void doAction (SoAction *action)
virtual void GLRender (SoGLRenderAction *action)
virtual void callback (SoCallbackAction *action)
virtual void rayPick (SoRayPickAction *action)
Static Public Member Functions
static void initClass (void)
static SbBool readImage (const SbString &fname, int &w, int &h, int
&nc, unsigned char *&bytes)
Public Attributes
SoSFString filename
SoSFImage image
SoSFEnum wrapS
SoSFEnum wrapT
SoSFEnum model
SoSFColor blendColor
SoSFBool enableCompressedTexture
Protected Member Functions
virtual ~SoTexture2 ()
virtual SbBool readInstance (SoInput *in, unsigned short flags)
virtual void notify (SoNotList *list)
int getReadStatus (void)
void setReadStatus (int s)
Detailed Description
The SoTexture2 class is used to map a 2D texture onto subsequent
geometry in the scenegraph.
Shape nodes within the scope of SoTexture2 nodes in the scenegraph (ie
below the same SoSeparator and to the righthand side of the SoTexture2)
will have the texture applied according to each shape type’s individual
characteristics. See the documentation of the various shape types
(SoFaceSet, SoCube, SoSphere, etc etc) for information about the
specifics of how the textures will be applied.
For a simple usage example, see the class documentation for SoSFImage.
One common flaw with many programs that has support for exporting VRML
or Inventor files, is that the same texture file is exported several
times, but as different nodes. This can cause excessive texture memory
usage and slow rendering. Below is an example program that fixes this
by replacing all instances of the same texture with a pointer to the
first node:
#include <Inventor/actions/SoSearchAction.h>
#include <Inventor/actions/SoWriteAction.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoTexture2.h>
#include <Inventor/SoDB.h>
#include <Inventor/SoInput.h>
#include <Inventor/SoOutput.h>
int main(int argc, char ** argv)
{
if (argc < 2) return -1;
SoDB::init();
SoInput in;
if (!in.openFile(argv[1])) return -1;
SoSeparator * root = SoDB::readAll(&in);
if (!root) return -1;
root->ref();
SoSearchAction sa;
sa.setType(SoTexture2::getClassTypeId());
sa.setInterest(SoSearchAction::ALL);
sa.setSearchingAll(TRUE);
sa.apply(root);
SoPathList & pl = sa.getPaths();
SbDict namedict;
for (int i = 0; i < pl.getLength(); i++) {
SoFullPath * p = (SoFullPath*) pl[i];
if (p->getTail()->isOfType(SoTexture2::getClassTypeId())) {
SoTexture2 * tex = (SoTexture2*) p->getTail();
if (tex->filename.getValue().getLength()) {
SbName name = tex->filename.getValue().getString();
unsigned long key = (unsigned long) ((void*) name.getString());
void * tmp;
if (!namedict.find(key, tmp)) {
// new texture. just insert into list
(void) namedict.enter(key, tex);
}
else if (tmp != (void*) tex) { // replace with node found in dict
SoGroup * parent = (SoGroup*) p->getNodeFromTail(1);
int idx = p->getIndexFromTail(0);
parent->replaceChild(idx, (SoNode*) tmp);
}
}
}
}
sa.reset();
// output fixed scene to stdout
SoOutput out;
SoWriteAction wa(&out);
wa.apply(root);
root->unref();
}
When working with Inventor files, one often wants to embed external
texture image files into the Inventor files themselves. Here’s a
minimal, stand-alone example which shows how that can be accomplished
by calling SoField::touch() on the SoTexture2::image fields before
scenegraph export:
#include <Inventor/SoDB.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoTexture2.h>
#include <Inventor/actions/SoSearchAction.h>
#include <Inventor/actions/SoWriteAction.h>
int
main(void)
{
SoDB::init();
SoInput in;
SoSeparator * root = SoDB::readAll(&in);
if (!root) { exit(1); }
root->ref();
SoSearchAction searchaction;
searchaction.setType(SoTexture2::getClassTypeId());
searchaction.setSearchingAll(TRUE);
searchaction.setInterest(SoSearchAction::ALL);
searchaction.apply(root);
const SoPathList & pl = searchaction.getPaths();
for (int i=0; i < pl.getLength(); i++) {
SoFullPath * fp = (SoFullPath *)pl[i];
SoTexture2 * tex = (SoTexture2 *)fp->getTail();
assert(tex->getTypeId() == SoTexture2::getClassTypeId());
tex->image.touch();
}
SoWriteAction wa;
wa.apply(root);
root->unref();
return 0;
}
Run the example by piping the iv-file you want do texture-embedding on
from stdin, e.g. like this:
$ ./test < input.iv
.fi
FILE FORMAT/DEFAULTS:
Texture2 {
filename ’’
image 0 0 0
wrapS REPEAT
wrapT REPEAT
model MODULATE
blendColor 0 0 0
enableCompressedTexture FALSE
}
Member Enumeration Documentation
enum SoTexture2::Model Texture mapping model, for deciding how to ’merge’
the texturemap with the object it is mapped onto.
Enumerator:
MODULATE
Texture color is multiplied by the polygon color. The result
will be Phong shaded (if light model is PHONG).
DECAL Texture image overwrites polygon shading. Textured pixels will
not be Phong shaded. Has undefined behaviour for grayscale and
grayscale-alpha textures.
BLEND This model is normally used with monochrome textures (i.e.
textures with one or two components). The first component, the
intensity, is then used to blend between the shaded color of the
polygon and the SoTexture2::blendColor.
REPLACE
Texture image overwrites polygon shading. Textured pixels will
not be Phong shaded. Supports grayscale and grayscale alpha
textures. This feature requires OpenGL 1.1. MODULATE will be
used if OpenGL version < 1.1 is detected.
Please note that using this texture model will make your Inventor files
incompatible with older versions of Coin and Inventor. You need Coin >=
2.2 or TGS Inventor 4.0 to load Inventor files that uses the REPLACE
texture model.
Since:
Coin 2.2
TGS Inventor 4.0
enum SoTexture2::Wrap Enumeration of wrapping strategies which can be used
when the texturemap doesn’t cover the full extent of the geometry.
Enumerator:
REPEAT Repeat texture when coordinate is not between 0 and 1.
CLAMP Clamp coordinate between 0 and 1.
Constructor & Destructor Documentation
SoTexture2::SoTexture2 (void) Constructor.
SoTexture2::~SoTexture2 () [protected, virtual] Destructor. Frees up
internal resources used to store texture image data.
Member Function Documentation
void SoTexture2::initClass (void) [static] Sets up initialization for data
common to all instances of this class, like submitting necessary
information to the Coin type system.
Reimplemented from SoNode.
void SoTexture2::doAction (SoAction * action) [virtual] This function
performs the typical operation of a node for any action.
Reimplemented from SoNode.
void SoTexture2::GLRender (SoGLRenderAction * action) [virtual] Action
method for the SoGLRenderAction.
This is called during rendering traversals. Nodes influencing the
rendering state in any way or who wants to throw geometry primitives at
OpenGL overrides this method.
Reimplemented from SoNode.
void SoTexture2::callback (SoCallbackAction * action) [virtual] Action
method for SoCallbackAction.
Simply updates the state according to how the node behaves for the
render action, so the application programmer can use the
SoCallbackAction for extracting information about the scene graph.
Reimplemented from SoNode.
void SoTexture2::rayPick (SoRayPickAction * action) [virtual] Action method
for SoRayPickAction.
Checks the ray specification of the action and tests for intersection
with the data of the node.
Nodes influencing relevant state variables for how picking is done also
overrides this method.
Reimplemented from SoNode.
SbBool SoTexture2::readImage (const SbString & fname, int & w, int & h, int
& nc, unsigned char *& bytes) [static] Not implemented in Coin; should
probably not have been public in the original SGI Open Inventor API.
We’ll consider to implement it if requested.
SbBool SoTexture2::readInstance (SoInput * in, unsigned short flags)
[protected, virtual] This method is mainly intended for internal use
during file import operations.
It reads a definition of an instance from the input stream in. The
input stream state points to the start of a serialized / persistant
representation of an instance of this class type.
TRUE or FALSE is returned, depending on if the instantiation and
configuration of the new object of this class type went ok or not. The
import process should be robust and handle corrupted input streams by
returning FALSE.
flags is used internally during binary import when reading user
extension nodes, group nodes or engines.
Reimplemented from SoNode.
void SoTexture2::notify (SoNotList * l) [protected, virtual] Notifies all
auditors for this instance when changes are made.
Reimplemented from SoNode.
int SoTexture2::getReadStatus (void) [protected] Returns read status. 1 for
success, 0 for failure.
void SoTexture2::setReadStatus (int s) [protected] Sets read status.
See also:
getReadStatus()
Member Data Documentation
SoSFString SoTexture2::filename Texture filename, referring to a file on
disk in a supported image bitmap format.
By default contains an empty string, which means the texture will be
fetched from SoTexture2::image and not from disk. (Specify either this
field or use SoTexture2::image, not both.)
FIXME: Section about simage is outdated.
For reading texture image files from disk, Coin uses the ’simage’
library from Kongsberg Oil & Gas Technologies. This library must be
installed for it to be possible to load any image files at all.
The set of image formats you can actually read with the simage library
depends on how the simage library was built, as simage is again
dependent on a few other low-level file import/export libraries (for
instance for JPEG, GIF, TIFF and PNG support). To make sure all wanted
formats are supported, you should build the simage library yourself.
The set of image formats guaranteed to be supported by simage is Targa
(.tga), PIC (.pic), SGI RGB (.rgb, .bw) and XWD (.xwd).
For more information about the simage library, including download and
build instructions, see the Coin www-pages.
SoSFImage SoTexture2::image Inline image data. Defaults to contain an empty
image.
See documentation of the SoSFImage class for a very detailed
description of how the format specification for the image data is layed
out, and what different image formats for color textures, semi-
transparent textures, grayscale textures, etc etc, are supported.
SoSFEnum SoTexture2::wrapS Wrapping strategy for the S coordinate when the
texturemap is narrower than the object to map onto.
Default value is SoTexture2::REPEAT.
SoSFEnum SoTexture2::wrapT Wrapping strategy for the T coordinate when the
texturemap is shorter than the object to map onto.
Default value is SoTexture2::REPEAT.
SoSFEnum SoTexture2::model Texturemapping model for how the texturemap is
’merged’ with the polygon primitives it is applied to. Default value is
SoTexture2::MODULATE.
SoSFColor SoTexture2::blendColor Blend color. Used when SoTexture2::model
is SoTexture2::BLEND.
Default color value is [0, 0, 0], black, which means no contribution to
the blending is made.
SoSFBool SoTexture2::enableCompressedTexture Hint to Coin that compressed
textures should be used if this is supported by the graphics hardware
and OpenGL drivers. Using compressed textures usually reduces texture
memory usage for a texture by 4-6 times.
Since:
Coin 2.4.2
TGS Inventor 4.0
Author
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