NAME
SoSFImage -
The SoSFImage class is used to store pixel images.
The SoSFImage class provides storage for inline 2D image maps. Images
in Coin are mainly used for texture mapping support.
SYNOPSIS
#include <Inventor/fields/SoSFImage.h>
Inherits SoSField.
Public Types
enum CopyPolicy { COPY, NO_COPY, NO_COPY_AND_DELETE, NO_COPY_AND_FREE }
Public Member Functions
virtual SoType getTypeId (void) const
virtual void copyFrom (const SoField &field)
const SoSFImage & operator= (const SoSFImage &field)
virtual SbBool isSame (const SoField &field) const
const unsigned char * getValue (SbVec2s &size, int &nc) const
const SbImage & getValue () const
void setValue (const SbVec2s &size, const int nc, const unsigned char
*pixels, CopyPolicy copypolicy=COPY)
int operator== (const SoSFImage &field) const
int operator!= (const SoSFImage &field) const
unsigned char * startEditing (SbVec2s &size, int &nc)
void finishEditing (void)
void setSubValue (const SbVec2s &dims, const SbVec2s &offset, unsigned
char *pixels)
void setSubValues (const SbVec2s *dims, const SbVec2s *offsets, int
num, unsigned char **pixelblocks)
unsigned char * getSubTexture (int idx, SbVec2s &dims, SbVec2s &offset)
const
SbBool hasSubTextures (int &numsubtextures)
void setNeverWrite (SbBool flag)
SbBool isNeverWrite (void) const
SbBool hasTransparency (void) const
Static Public Member Functions
static void * createInstance (void)
static SoType getClassTypeId (void)
static void initClass (void)
Detailed Description
The SoSFImage class is used to store pixel images.
The SoSFImage class provides storage for inline 2D image maps. Images
in Coin are mainly used for texture mapping support.
SoSFImage instances can be exported and imported as any other field
class in Coin.
The components of an SoSFImage is: its image dimensions (width and
height), the number of bytes used for describing each pixel (number of
components) and an associated pixel buffer. The size of the pixel
buffer will be width*height*components.
For texture maps, the components / bytes-per-pixel setting translates
as follows: use 1 for a grayscale imagemap, 2 for grayscale + opacity
(i.e. alpha value), 3 for RGB (1 byte each for red, green and blue) and
4 components means 3 bytes for RGB + 1 byte opacity value (aka RGBA).
This field is serializable into the Inventor / Coin file format in the
following manner:
FIELDNAME X Y C 0xRRGGBBAA 0xRRGGBBAA ...
For 3-component images, the pixel-format is 0xXXRRGGBB, where the byte
in the pixel color value marked as ’XX’ is ignored and can be left out.
For 2-component images, the pixel-format is 0xXXXXGGAA, where the bytes
in the pixel color values marked as ’XX’ are ignored and can be left
out. ’GG’ is the part which gives a grayscale value and ’AA’ is for
opacity.
For 1-component images, the pixel-format is 0xXXXXXXGG, where the bytes
in the pixel color values marked as ’XX’ are ignored and can be left
out.
The pixels are read as being ordered in rows along X (width) and
columns along Y (height, bottom to top).
Here’s a simple example of the file format serialization, for a 2x2
RGB-image inside an SoTexture2 node, as mapped onto an SoCube:
Complexity { textureQuality 0.1 } # set low to avoid smoothing
Texture2 {
image 2 2 4
0xffffffff 0x00ff0088 # white semi-transparent green
0xff0000ff 0xffff00ff # red yellow
}
Cube { }
The mini-scenegraph above results in the following mapping on the cube:
The cube has only been slightly rotated, so as you can see from the
snapshot, the Y-rows are mapped from bottom to top, while the X-column
pixels are mapped onto the cube from left to right.
See also:
SoTexture2, SoSFImage3
Member Function Documentation
static SoType SoSFImage::getClassTypeId (void) [static] Returns a unique
type identifier for this field class.
See also:
getTypeId(), SoType
Reimplemented from SoSField.
virtual SoType SoSFImage::getTypeId (void) const [virtual] Returns the type
identification instance which uniquely identifies the Coin field class
the object belongs to.
See also:
getClassTypeId(), SoType
Implements SoField.
virtual void SoSFImage::copyFrom (const SoField & f) [virtual] Copy
value(s) from f into this field. f must be of the same type as this
field.
Implements SoField.
virtual SbBool SoSFImage::isSame (const SoField & f) const [virtual] Check
for equal type and value(s).
Implements SoField.
void SoSFImage::initClass (void) [static] Internal method called upon
initialization of the library (from SoDB::init()) to set up the type
system.
Reimplemented from SoSField.
const unsigned char * SoSFImage::getValue (SbVec2s & size, int & nc) const
Return pixel buffer, set size to contain the image dimensions and nc to
the number of components in the image.
const SbImage & SoSFImage::getValue (void) const Return values:
SbImage contained by this SoSFImage
void SoSFImage::setValue (const SbVec2s & size, const int nc, const
unsigned char * pixels, SoSFImage::CopyPolicy copypolicy = COPY)
Initialize this field to size and nc.
If pixels is not NULL, the image data is copied from pixels into this
field. If pixels is NULL, the image data is cleared by setting all
bytes to 0 (note that the behavior on passing a NULL pointer is
specific for Coin, Open Inventor will crash if you try it).
The image dimensions is given by the size argument, and the nc argument
specifies the number of bytes-pr-pixel. A 24-bit RGB image would for
instance have an nc equal to 3.
The copypolicy argument makes it possible to share image data with
SoSFImage without the data being copied (thereby using less memory
resources). The default is to copy image data from the pixels source
into an internal copy.
Important note: if you call this with copypolicy as either
NO_COPY_AND_DELETE or NO_COPY_AND_FREE, and your application is running
on Mirosoft Windows, be aware that you will get mysterious crashes if
your application is not using the same C library run-time as the Coin
library.
The cause of this is that a memory block would then be allocated by the
application on the memory heap of one C library run-time (say, for
instance MSVCRT.LIB), but attempted deallocated in the memory heap of
another C library run-time (e.g. MSVCRTD.LIB), which typically leads to
hard-to-debug crashes.
Since:
The CopyPolicy argument was added in Coin 2.0.
CopyPolicy was added to TGS Inventor 3.0.
int SoSFImage::operator== (const SoSFImage & field) const Compare image of
field with the image in this field and return TRUE if they are equal.
int SoSFImage::operator!= (const SoSFImage & field) const [inline] Compare
image of field with the image in this field and return FALSE if they
are equal.
unsigned char * SoSFImage::startEditing (SbVec2s & size, int & nc) Return
pixel buffer. Return the image size and components in size and nc.
You can not use this method to set a new image size. Use setValue() to
change the size of the image buffer.
The field’s container will not be notified about the changes until you
call finishEditing().
void SoSFImage::finishEditing (void) Notify the field’s auditors that the
image data has been modified.
SbBool SoSFImage::hasSubTextures (int & numsubtextures) Returns whether or
not sub textures was set up for this field.
If TRUE is returned, the numsubtextures argument will be set to the
number of sub textures in this image. This number can be used for
iterating over all textures with the SoSFImage::getSubTextures()
method.
Since:
Coin 2.0
TGS Inventor 3.0
SbBool SoSFImage::isNeverWrite (void) const Returns value of ’never write
texture data’ flag.
See also:
SoSFImage::setNeverWrite()
Since:
Coin 2.0
TGS Inventor ?.?
SbBool SoSFImage::hasTransparency (void) const Returns TRUE if at least one
pixel of the image in this field is not completely opaque, otherwise
FALSE.
Since:
Coin 2.0
TGS Inventor ?.?
Author
Generated automatically by Doxygen for Coin from the source code.