Hi,
using OSG 2.2
I'm currently rendering to a texture using a FBO with an attached texture:
Code:
_texture = new osg::Texture2D();
_texture->setTextureSize((int)_camera->getViewport()->width(),(int)_camera->getViewport()->height());
_texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
_texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
_camera->attach(osg::Camera::COLOR_BUFFER, _texture.get(), 0,0,false);
_camera->setRenderTargetImplementation(osg::Camera::FRAME_BUFFER_OBJECT);
_camera->setRenderOrder(osg::Camera::PRE_RENDER);
A 3rd party lib processes the texture in a postCallBack call:
Code:
virtual void operator()(const osg::Camera &cam) const
{
if (cam.isRenderToTextureCamera())
{
osg::Camera::BufferAttachmentMap bam = cam.getBufferAttachmentMap();
osg::Camera::BufferAttachmentMap::iterator iter =
bam.find(osg::Camera::COLOR_BUFFER);
if (iter != bam.end())
{
osg::Texture *tex = iter->second._texture.get();
if (tex)
{
osg::Texture::TextureObject *texObj = ((osg::Texture2D
*)tex)->getTextureObject(0);
int id = ((osg::Texture2D *)tex)->getTextureObject(0)->_id;
//do some processing here
copyToImage(cam, tex);
}
}
My copyToImage() method creates a PBO to the texture and attempt to dump the
memory into an associated osg::Image (really just a block of memory). This code
was used to pull from the frame buffer using ReadPixels() which worked fine.
Code:
void copyToImage(const osg::Camera &camera, osg::Texture* tex =
NULL) const
{
if (image.valid() && image->data())
{
int pixel_depth_bytes;
OpenThreads::ScopedLock<OpenThreads::Mutex>
lock(_mutex);
const osg::GraphicsContext *gc =
camera.getGraphicsContext();
osg::BufferObject::Extensions* ext =
osg::BufferObject::getExtensions(gc->getState()->getContextID(), true);
if (ext->isPBOSupported())
{
if (gc->getTraits())
{
int width =
(int)camera.getViewport()->width();//gc->getTraits()->width;
int height =
(int)camera.getViewport()->height();//gc->getTraits()->height;
int x =
(int)camera.getViewport()->x();
int y =
(int)camera.getViewport()->y();
pixel_depth_bytes =
gc->getTraits()->depth / 8;
if (width != _width || height
!= _height || x != _x || y != _y)
{
_width = width;
_height = height;
_x = x;
_y = y;
if (_pbo)
{
ext->glDeleteBuffers(1,&_pbo);
_pbo = 0;
}
}
}
//disable clamping
osg::ClampColor::Extensions *clamp_ext
= osg::ClampColor::getExtensions(gc->getState()->getContextID(), true);
if (clamp_ext->isClampColorSupported())
{
clamp_ext->glClampColor(
GL_CLAMP_READ_COLOR, GL_FALSE );
clamp_ext->glClampColor(
GL_CLAMP_VERTEX_COLOR, GL_FALSE );
clamp_ext->glClampColor(
GL_CLAMP_FRAGMENT_COLOR, GL_FALSE );
}
glReadBuffer(GL_BACK);
//configure pbo
unsigned int data_size = _width *
_height * sizeof(float) * 4;
if (_pbo)
{
//bind for writing (pack)
ext->glBindBuffer(GL_PIXEL_PACK_BUFFER, _pbo);
} else
{
//create and bind for writing
(pack)
ext->glGenBuffers(1, &_pbo);
ext->glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, _pbo);
ext->glBufferData(GL_PIXEL_PACK_BUFFER_ARB, data_size, NULL, GL_STREAM_READ);
}
//read data
if (tex)
glGetTexImage(tex->getTextureTarget(), 0,
osg::Image::computePixelFormat(tex->getInternalFormat()),
osg::Image::computeNumComponents(tex->getInternalFormat()), NULL);
else glReadPixels(_x,_y,_width,
_height, image->getPixelFormat(), image->getDataType(), 0);
//map and write data
GLubyte* src =
(GLubyte*)ext->glMapBuffer(GL_PIXEL_PACK_BUFFER_ARB, GL_READ_ONLY);
if (src)
{
debug<<Debug::verbose<<"copy
"<<_width<<"*"<<_height<<"*"<<pixel_depth_bytes<<" =
"<<_width*_height*pixel_depth_bytes<<" bytes to image buffer\n'";
memcpy(image->data(), src,
_width*_height*pixel_depth_bytes);
ext->glUnmapBuffer(GL_PIXEL_PACK_BUFFER_ARB);
}
//reset buffer
ext->glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 0);
}
}
}
I've tried assigning the attached texture (without running the callback) to a
quad in the scene and it is still blank.
I've tried just about everything I can think of and I cant seem to figure out
what could be going wrong but I suspect its somewhere on the RTT side.
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=15982#15982
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