Provided by: libcoin80-doc_3.1.4~abc9f50-4ubuntu2_all 
NAME
SoGLImage -
The SoGLImage class is used to handle OpenGL 2D/3D textures.
SYNOPSIS
#include <include/Inventor/misc/SoGLImage.h>
Inherited by SoGLBigImage, and SoGLCubeMapImage.
Public Types
enum Wrap { REPEAT = 0, CLAMP, CLAMP_TO_EDGE, CLAMP_TO_BORDER }
enum ResizeReason { IMAGE = 0, SUBIMAGE, MIPMAP }
enum Flags { SCALE_DOWN = 0x0001, NO_MIPMAP = 0x0002, LINEAR_MAG_FILTER = 0x0004,
LINEAR_MIN_FILTER = 0x0008, LINEAR_MIPMAP_FILTER = 0x0010, FORCE_TRANSPARENCY_TRUE =
0x0020, FORCE_TRANSPARENCY_FALSE = 0x0040, FORCE_ALPHA_TEST_TRUE = 0x0080,
FORCE_ALPHA_TEST_FALSE = 0x0100, INVINCIBLE = 0x0200, RECTANGLE = 0x0400, COMPRESSED =
0x0800, USE_QUALITY_VALUE = 0X8000 }
typedef SbBool SoGLImageResizeCB (SoState *state, const SbVec3s &newsize, unsigned char
*destbuffer, ResizeReason reason, void *closure, class SoGLImage *image)
Public Member Functions
SoGLImage ()
virtual void unref (SoState *state=NULL)
virtual SoType getTypeId (void) const
virtual SbBool isOfType (SoType type) const
void setGLDisplayList (SoGLDisplayList *dl, SoState *state, const Wrap wraps=REPEAT, const
Wrap wrapt=REPEAT, const float quality=0.5f)
void setPBuffer (SoState *state, void *context, const Wrap wraps=REPEAT, const Wrap
wrapt=REPEAT, const float quality=0.5f)
void setData (const unsigned char *bytes, const SbVec2s &size, const int numcomponents,
const Wrap wraps=REPEAT, const Wrap wrapt=REPEAT, const float quality=0.5f, const int
border=0, SoState *createinstate=NULL)
void setData (const unsigned char *bytes, const SbVec3s &size, const int numcomponents,
const Wrap wraps=REPEAT, const Wrap wrapt=REPEAT, const Wrap wrapr=REPEAT, const float
quality=0.5f, const int border=0, SoState *createinstate=NULL)
virtual void setData (const SbImage *image, const Wrap wraps=REPEAT, const Wrap
wrapt=REPEAT, const float quality=0.5f, const int border=0, SoState
*createinstate=NULL)
virtual void setData (const SbImage *image, const Wrap wraps, const Wrap wrapt, const Wrap
wrapr, const float quality=0.5f, const int border=0, SoState *createinstate=NULL)
void setFlags (const uint32_t flags)
uint32_t getFlags (void) const
const SbImage * getImage (void) const
virtual SoGLDisplayList * getGLDisplayList (SoState *state)
SbBool hasTransparency (void) const
SbBool useAlphaTest (void) const
Wrap getWrapS (void) const
Wrap getWrapT (void) const
Wrap getWrapR (void) const
float getQuality (void) const
uint32_t getGLImageId (void) const
void setEndFrameCallback (void(*cb)(void *), void *closure)
int getNumFramesSinceUsed (void) const
Static Public Member Functions
static SoType getClassTypeId (void)
static void beginFrame (SoState *state)
static void tagImage (SoState *state, SoGLImage *image)
static void endFrame (SoState *state)
static void setDisplayListMaxAge (const uint32_t maxage)
static void freeAllImages (SoState *state=NULL)
static void initClass (void)
static void setResizeCallback (SoGLImageResizeCB *f, void *closure)
Protected Member Functions
void incAge (void) const
void resetAge (void) const
virtual void unrefOldDL (SoState *state, const uint32_t maxage)
virtual ~SoGLImage ()
Detailed Description
The SoGLImage class is used to handle OpenGL 2D/3D textures.
A number of environment variables can be set to control how textures are created. This is
useful to tune Coin to fit your system. E.g. if you are running on a laptop, it might be a
good idea to disable linear filtering and mipmaps.
• COIN_TEX2_LINEAR_LIMIT: Linear filtering is enabled if Complexity::textureQuality is
greater or equal to this value. Default value is 0.2.
• COIN_TEX2_MIPMAP_LIMIT: Mipmaps are created if textureQuality is greater or equal to
this value. Default value is 0.5.
• COIN_TEX2_LINEAR_MIPMAP_LIMIT: Linear filtering between mipmap levels is enabled if
textureQuality is greater or equal to this value. Default value is 0.8.
• COIN_TEX2_SCALEUP_LIMIT: Textures with width or height not equal to a power of two will
always be scaled up if textureQuality is greater or equal to this value. Default value
is 0.7. If textureQuality is lower than this value, and the width or height is larger
than 256 pixels, the texture is only scaled up if it's relatively close to the next
power of two size. This could save a lot of texture memory.
• COIN_TEX2_USE_GLTEXSUBIMAGE: When set, and when the new texture data has the same
attributes as the old data, glTexSubImage() will be used to copy new data into the
texture instead of recreating the texture. This is not enabled by default, since it
seems to trigger a bug in the Linux nVidia drivers. It just happens in some
unreproducable cases. It could be a bug in our glTexSubImage() code, of course. :)
• COIN_TEX2_USE_SGIS_GENERATE_MIPMAP: When set, use the GL_SGIS_generate_mip extension (if
available) to generate mipmaps, otherwise use a fast internal routine to generate them.
Use of SGIS_generate_mipmap is not enabled by default since we suspect some ATi drivers
have problems with this extensions.
• COIN_ENABLE_CONFORMANT_GL_CLAMP: When set, GL_CLAMP will be used when SoGLImage::CLAMP
is specified as the texture wrap mode. By default GL_CLAMP_TO_EDGE is used, since this
is usually what people want. See
http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/007306.html for a discussion
regarding GL_CLAMP and GL_CLAMP_TO_EDGE.
• COIN_TEX2_ANISOTROPIC_LIMIT: Anisotropic filtering is enabled for textures when the
texture quality is higher than this value. Default value is 0.85
Be aware that this class is an extension for Coin, and it is not available in the original
SGI Open Inventor v2.1 API.
Since:
Coin 2.0
Member Typedef Documentation
bool SoGLImage::SoGLImageResizeCB
Image resize callback type. If registered using setResizeCallback(), this function will be
called whenever Coin needs to resize an image. The function will be called both for 2D and
3D images.
state is the current state at the time of resizing. newsize is the requested new image
size. Note that the z size of a 2D image is 0. destbuffer is a pre-allocated buffer big
enough to hold the pixels for the resized image. The # of bytes per pixel is the same as
for the original image. reason is a hint about why the image is resized. At the moment,
only IMAGE is supported. image is the original image.
Return value: TRUE if the resize ahs been resized, FALSE if not. If FALSE is returned,
Coin will resize the image instead.
Member Enumeration Documentation
enum SoGLImage::Wrap
Used to specify how texture coordinates < 0.0 and > 1.0 should be handled. It can either
be repeated (REPEAT), clamped (CLAMP) or clamped to edge (CLAMP_TO_EDGE), which is useful
when tiling textures. Since 2002-11-18, CLAMP will be treated as CLAMP_TO_EDGE. The
environment variable COIN_ENABLE_CONFORMANT_GL_CLAMP can be used to override this
behaviour.
enum SoGLImage::ResizeReason
Sent as a parameter to SoGLImageResizeCB as a hint to why an image is being resized. IMAGE
means that a whole image is being initially resized (e.g. a texture image). SUBIMAGE and
MIPMAP are not in use and reserved for future use.
enum SoGLImage::Flags
Can be used to tune/optimize the GL texture handling. Normally the texture quality will be
used to decide scaling and filtering, and the image data will be scanned to decide if the
image is (partly) transparent, and if the texture can be rendered using the cheaper alpha
test instead of blending if it does contain transparency. If you know the contents of your
texture image, or if you have special requirements on how the texture should be rendered,
you can set the flags using the SoGLImage::setFlags() method.
Constructor & Destructor Documentation
SoGLImage::SoGLImage (void)
Constructor.
SoGLImage::~SoGLImage () [protected], [virtual]
Destructor.
Member Function Documentation
void SoGLImage::unref (SoState *state = NULL) [virtual]
This class has a private destuctor since we want users to supply the current GL state when
deleting the image. This is to make sure gl texture objects are freed as soon as possible.
If you supply NULL to this method, the gl texture objects won't be deleted until the next
time an GLRenderAction is applied in the image's cache context(s).
Reimplemented in SoGLBigImage, and SoGLCubeMapImage.
SoType SoGLImage::getClassTypeId (void) [static]
Returns the type id for this class.
SoType SoGLImage::getTypeId (void) const [virtual]
Returns the type id for an SoGLImage instance.
Reimplemented in SoGLBigImage, and SoGLCubeMapImage.
SbBool SoGLImage::isOfType (SoTypetype) const [virtual]
Returns whether an SoGLImage instance inherits (or is of) type type.
void SoGLImage::setGLDisplayList (SoGLDisplayList *dl, SoState *state, const Wrapwraps =
REPEAT, const Wrapwrapt = REPEAT, const floatquality = 0.5f)
Can be used for creating a custom OpenGL texture inside an SoGLImage instance.
Example use (creates a depth texture):
SoGLDisplayList * depthmap = new SoGLDisplayList(state, SoGLDisplayList::TEXTURE_OBJECT);
depthmap->ref(); depthmap->open(state);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, // GL_DEPTH_COMPONENT24 size[0],
size[1], 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
depthmap->close(state);
SoGLImage * image = new SoGLImage; image->setGLDisplayList(depthmap, state);
Since:
Coin 2.5
void SoGLImage::setPBuffer (SoState *state, void *pbuffer, const Wrapwraps = REPEAT, const
Wrapwrapt = REPEAT, const floatquality = 0.5f)
Sets the pbuffer for this texture. Experimental code, use with care.
void SoGLImage::setData (const unsigned char *bytes, const SbVec2s &size, const
intnumcomponents, const Wrapwraps = REPEAT, const Wrapwrapt = REPEAT, const floatquality =
0.5f, const intborder = 0, SoState *createinstate = NULL)
2D setData() wrapper. Supplies raw data, size and numcomponents instead of an SbImage.
Creates a temporary image, then calls the read setData(). This is an overloaded member
function, provided for convenience. It differs from the above function only in what
argument(s) it accepts.
void SoGLImage::setData (const unsigned char *bytes, const SbVec3s &size, const
intnumcomponents, const Wrapwraps = REPEAT, const Wrapwrapt = REPEAT, const Wrapwrapr =
REPEAT, const floatquality = 0.5f, const intborder = 0, SoState *createinstate = NULL)
3D setData() wrapper. Supplies raw data, size and numcomponents instead of an SbImage.
Creates a temporary image, then calls the read setData(). This is an overloaded member
function, provided for convenience. It differs from the above function only in what
argument(s) it accepts.
void SoGLImage::setData (const SbImage *image, const Wrapwraps = REPEAT, const Wrapwrapt =
REPEAT, const floatquality = 0.5f, const intborder = 0, SoState *createinstate = NULL)
[virtual]
Convenience 2D wrapper function around the 3D setData().
Reimplemented in SoGLCubeMapImage, and SoGLBigImage.
void SoGLImage::setData (const SbImage *image, const Wrapwraps, const Wrapwrapt, const
Wrapwrapr, const floatquality = 0.5f, const intborder = 0, SoState *createinstate = NULL)
[virtual]
Sets the data for this GL image. Should only be called when one of the parameters have
changed, since this will cause the GL texture object to be recreated. Caller is
responsible for sending legal Wrap values. CLAMP_TO_EDGE is only supported on OpenGL v1.2
implementations, and as an extension on some earlier SGI implementations
(GL_SGIS_texture_edge_clamp).
For now, if quality > 0.5 when created, we create mipmaps, otherwise a regular texture is
created. Be aware, if you for instance create a texture with texture quality 0.4, and then
later try to apply the texture with a texture quality greater than 0.5, the texture object
will be recreated as a mipmap texture object. This will happen only once though, of
course.
If border != 0, the OpenGL texture will be created with this border size. Be aware that
this might be extremely slow on most PC hardware.
Normally, the OpenGL texture object isn't created until the first time it is needed, but
if createinstate is != NULL, the texture object is created immediately. This is useful if
you use a temporary buffer to hold the texture data. Be careful when using this feature,
since the texture data might be needed at a later stage (for instance to create a texture
object for another context). It will not be possible to create texture objects for other
cache contexts when createinstate is != NULL.
Also if createinstate is supplied, and all the attributes are the same as the current data
in the image, glTexSubImage() will be used to insert the image data instead of creating a
new texture object. This is much faster on most OpenGL drivers, and is very useful, for
instance when doing animated textures.
If you supply NULL for image, the instance will be reset, causing all display lists and
memory to be freed.
Reimplemented in SoGLCubeMapImage, and SoGLBigImage.
void SoGLImage::setFlags (const uint32_tflags)
Sets flags to control how the texture is handled/initialized.
uint32_t SoGLImage::getFlags (void) const
Returns the flags.
See Also:
setFlags()
const SbImage * SoGLImage::getImage (void) const
Returns a pointer to the image data.
SoGLDisplayList * SoGLImage::getGLDisplayList (SoState *state) [virtual]
Returns or creates a SoGLDisplayList to be used for rendering. Returns NULL if no
SoDLDisplayList could be created.
Reimplemented in SoGLCubeMapImage, and SoGLBigImage.
SbBool SoGLImage::hasTransparency (void) const
Returns TRUE if this texture has some pixels with alpha != 255
SbBool SoGLImage::useAlphaTest (void) const
Returns TRUE if this image has some alpha value != 255, and all these values are 0. If
this is the case, alpha test can be used to render this texture instead of for instance
blending, which is usually slower and might yield z-buffer artifacts.
SoGLImage::Wrap SoGLImage::getWrapS (void) const
Returns the wrap strategy for the S (horizontal) direction.
SoGLImage::Wrap SoGLImage::getWrapT (void) const
Returns the wrap strategy for the T (vertical) direction.
SoGLImage::Wrap SoGLImage::getWrapR (void) const
Returns the wrap strategy for the R (depth) direction.
float SoGLImage::getQuality (void) const
Returns the texture quality for this texture image.
Since:
Coin 2.5
uint32_t SoGLImage::getGLImageId (void) const
Returns an unique if for this GL image. This id can be used to test for changes in an
SoGLImage's internal data.
void SoGLImage::unrefOldDL (SoState *state, const uint32_tmaxage) [protected], [virtual]
Virtual method that will be called once each frame. The method should unref display lists
that has an age bigger or equal to maxage, and increment the age for other display lists.
Reimplemented in SoGLBigImage.
void SoGLImage::beginFrame (SoState *state) [static]
When doing texture resource control, call this method before rendering the scene,
typically in the viewer's actualRedraw(). state should be your SoGLRenderAction state.
See Also:
endFrame(), tagImage(), setDisplayListMaxAge()
void SoGLImage::tagImage (SoState *state, SoGLImage *image) [static]
Should be called when a texture image is used. In Coin this is handled by
SoGLTextureImageElement, but if you use an SoGLImage on your own, you should call this
method to avoid that the display list is deleted too soon. state should be your
SoGLRenderAction state, image the image you are about to use/have used.
void SoGLImage::endFrame (SoState *state) [static]
Should be called after your scene is rendered. Old display lists will be deleted when you
call this method. state should be your SoGLRenderAction state.
See Also:
beginFrame(), tagImage(), setDisplayListMaxAge()
void SoGLImage::setDisplayListMaxAge (const uint32_tmaxage) [static]
Set the maximum age for a texture object/display list. The age of an image is the number
of frames since it has been used. Default maximum age is 60.
void SoGLImage::freeAllImages (SoState *state = NULL) [static]
Free all GL images currently used. This can be used to help the operating system and/or
OpenGL driver's resource handling. If you know you're not going to render for a while,
maybe you're switching to a different application or something, calling this method could
be a good idea since it will release all the texture memory used by your application.
void SoGLImage::initClass (void) [static]
This API member is considered internal to the library, as it is not likely to be of
interest to the application programmer.
void SoGLImage::setResizeCallback (SoGLImageResizeCB *f, void *closure) [static]
Sets a custom image resize function.
Since:
Coin 2.5
Author
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