parameter in osg::Image. To support this Image::setData(..) now has a new optional rowLength parameter which
defaults to 0, which provides the original behaviour, Image::setRowLength(int) and int Image::getRowLength() are also provided.
With the introduction of RowLength support in osg::Image it is now possible to create a sub image where
the t size of the image are smaller than the row length, useful for when you have a large image on the CPU
and which to use a small portion of it on the GPU. However, when these sub images are created the data
within the image is no longer contiguous so data access can no longer assume that all the data is in
one block. The new method Image::isDataContiguous() enables the user to check whether the data is contiguous,
and if not one can either access the data row by row using Image::data(column,row,image) accessor, or use the
new Image::DataIterator for stepping through each block on memory assocatied with the image.
To support the possibility of non contiguous osg::Image usage of image objects has had to be updated to
check DataContiguous and handle the case or use access via the DataIerator or by row by row. To achieve
this a relatively large number of files has had to be modified, in particular the texture classes and
image plugins that doing writing.
In osg::isGLExtensionOrVersionSupported in src/osg/GLExtensions.cpp when
using indirect X11 rendering,
glGetIntegerv( GL_NUM_EXTENSIONS, &numExt );
is leaving numExt uninitilized causing the following glGetStringi to
return NULL when the extension number isn't present. Passing NULL to
std::string() then crashes. This is with the following nVidia driver.
OpenGL version string: 3.3.0 NVIDIA 256.35
I went ahead and initialized some of the other variables before
glGetInitegerv in other files as well. I don't know for sure
which ones can fail, so I don't know which are strictly required.
"
Texture.cpp:applyTexImage2D_subload:
<code>
unsigned char* data = = (unsigned char*)image->data();
if (needImageRescale) {
// allocates rescale buffer
data = new unsigned char[newTotalSize];
// calls gluScaleImage into the data buffer
}
const unsigned char* dataPtr = image->data();
// subloads 'dataPtr'
// deletes 'data'
</code>
In effect, the scaled data would never be used.
I've also replaced bits of duplicate code in Texture1D/2D/2DArray/3D/Cubemap/Rectangle
that checks if the texture image can/should be unref'd with common functionality in
Texture.cpp.
"
To enable the automatic attachment of the required update callback to call osg::Image::update(..) subclasses from osg::Image will
need to implement the osg::Image::requestUpdateCall() and return true, and implement the osg::Image::update(NodeVisitor*) method to recieve the update call during the update traversal.
- Solves issues of loading image data into the texture memory
- Print a warning if images are of different dimensions or have different internal formats (GL specification requires images to be the same)
Patch is tested and seems to work fine. It shouldn't break any other functionality. It should go into include/osg and src/osg
"
- Implementation of integer textures as in EXT_texture_integer
- setBorderColor(Vec4) changed to setBorderColor(Vec4d) to pass double values
as border color. (Probably we have to provide an overloading function to
still support Vec4f ?)
- new method Texture::getInternalFormatType() added. Gives information if the
internal format normalized, float, signed integer or unsigned integer. Can
help people to write better code ;-)
"
Futher changes to this submission by Robert Osfield, changed the dirty mipmap
flag into a buffer_value<> vector to ensure safe handling of multiple contexts.
"A new texture class Texture2DArray derived from
Texture extends the osg to support the new
EXT_texture_array extensions. Texture arrays provides
a feature for people interesting in GPGPU programming.
Faetures and changes:
- Full support for layered 2D textures.
- New uniform types were added (sampler2DArray)
- FrameBufferObject implementation were changed to
support attaching of 2D array textures to the
framebuffer
- StateSet was slightly changed to support texture
arrays. NOTE: array textures can not be used in fixed
function pipeline. Thus using the layered texture as a
statemode for a Drawable produce invalid enumerant
OpenGL errors.
- Image class was extended to support handling of
array textures
Tests:
I have used this class as a new feature of my
application. It works for me without problems (Note:
Texture arrays were introduced only for shading
languages and not for fixed function pipelines!!!).
RTT with Texture2DArray works, as I have tested them
as texture targets for a camera with 6 layers/faces
(i.e. replacement for cube maps). I am using the array
textures in shader programming. Array textures can be
attached to the FBO and used as input and as output."
