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# SoSFImage Class Reference
[Field classes]

The SoSFImage class is used to store pixel images. More...

`#include <Inventor/fields/SoSFImage.h>`

Inheritance diagram for SoSFImage:

List of all members.

## Public Methods
const unsigned char * | getValue (SbVec2s &size, int &nc) 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 Methods
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 ...

"X" and "Y" are the image dimensions along the given axes, "C" is the number of components in the image. The number of 0xRRGGBBAA pixel color specifications needs to equal the exact number of pixels, which of course is given by X*Y. Each part of the pixel color value is in the range 0x00 to 0xff (hexadecimal, 0 to 255 decimal).

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 unto an SoCube:

      Texture2 {
         image 2 2 3

         0xffffff 0x00ff00   # white   green
         0xff0000 0xffff00   #  red    yellow
      }

      Complexity { textureQuality 0.1 }   # set low to avoid smoothing
      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 unto the cube from left to right.

See also:
  SoTexture2, SoSFImage3

## Member Function Documentation

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.

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. 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, set size to contain the image dimensions and nc to the number of components in the image. 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.

void SoSFImage::setSubValue | ( | const SbVec2s & | dims,
|  | const SbVec2s & | offset,
|  | unsigned char * | pixels
| ) |

| Not yet implemented for Coin. Get in touch if you need this method. Since: Coin 2.0 TGS Inventor 3.0

void SoSFImage::setSubValues | ( | const SbVec2s * | dims,
|  | const SbVec2s * | offsets,
|  | int | num,
|  | unsigned char ** | pixelblocks
| ) |

| Not yet implemented for Coin. Get in touch if you need this method. Since: Coin 2.0 TGS Inventor 3.0

unsigned char * SoSFImage::getSubTexture | ( | int | idx,
|  | SbVec2s & | dims,
|  | SbVec2s & | offset
| ) | const

| Not yet implemented for Coin. Get in touch if you need this method. Since: Coin 2.0 TGS Inventor 3.0

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

void SoSFImage::setNeverWrite | ( | SbBool | flag | ) |

| Set this flag to true to avoid writing out the texture to file. This can save a lot on file size. Default value is `FALSE` (i.e. write texture data to file.) (Note: yet unimplemented for Coin.) Since: Coin 2.0 TGS Inventor ?.?

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 ?.?

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

- SoSFImage.h
- SoSFImage.cpp