//
// FBO solution
//
static void writeHiResScreenShotFBO(const char* name, UInt32 width, UInt32 height)
{
size_t num_ports = win->getMFPort()->size();
if (num_ports == 0)
return;
//
// calc image dimensions
//
UInt32 winWidth = win->getWidth();
UInt32 winHeight = win->getHeight();
if (width < winWidth ) width = winWidth;
if (height < winHeight) height = winHeight;
Real32 a = Real32(winWidth) / Real32(winHeight);
width = UInt32(a*height);
//
// output stream for writing the final image
//
std::ofstream stream(name, std::ios::binary);
if (stream.good() == false)
return;
//
// Setup the FBO
//
FrameBufferObjectUnrecPtr fbo = FrameBufferObject::create();
//
// We use two render buffers. One for the color buffer and one for the depth and
// stencil buffer. This example does not take credit of the stencil buffer. There-
// fore a depth buffer would suffice. However, the use of the combined depth and
// stencil buffer is useful in other contextes and hence used.
//
RenderBufferUnrecPtr colBuf = RenderBuffer::create();
RenderBufferUnrecPtr dsBuf = RenderBuffer::create();
//
// As we would like to read back the FBO color buffer, we must provide a fitting
// image.
//
ImageUnrecPtr buffer_image = Image::create();
buffer_image->set(Image::OSG_RGBA_PF, winWidth, winHeight);
colBuf->setImage(buffer_image);
//
// We must setup the internal image formats of the two render buffers accordingly.
//
colBuf->setInternalFormat(GL_RGBA);
dsBuf ->setInternalFormat(GL_DEPTH24_STENCIL8_EXT);
//
// we must inform the FBO about the actual used color render buffers.
//
fbo->editMFDrawBuffers()->push_back(GL_COLOR_ATTACHMENT0_EXT);
//
// The FBO takes responsibility of the render buffers. Notice, that the shared
// depth/stencil buffer is provided twice. As the depth render buffer and as the
// stencil render buffer.
//
fbo->setColorAttachment (colBuf, 0);
fbo->setDepthAttachment (dsBuf);
fbo->setStencilAttachment(dsBuf);
//
// Also the FBO must be sized correctly.
//
fbo->setWidth (winWidth );
fbo->setHeight(winHeight);
//
// In order to read the color buffer back next two statements are necessary.
//
fbo->setPostProcessOnDeactivate(true);
fbo->getColorAttachments(0)->setReadBack(true);
//
// We tile the final image and render each tile with the screen resolution
// into the FBO. The more tiles we use the bigger the resolution of the
// final image gets with respect to a provided measure of length.
//
typedef boost::tuple<TileCameraDecoratorUnrecPtr, bool, SimpleStageUnrecPtr, ViewportUnrecPtr> TupleT;
std::vector<TupleT> decorators;
decorators.resize(num_ports);
//
// Remember the stage viewports for later cleanup
//
std::stack<ViewportUnrecPtr> stage_viewports;
//
// Setup the tile camera decorators for each viewport of the window and
// disable the tile property of tileable viewport backgrounds.
//
for (size_t i = 0; i < num_ports; ++i) {
Viewport* vp = win->getPort(i);
TileCameraDecoratorUnrecPtr decorator = TileCameraDecorator::create();
decorator->setFullSize (width, height);
decorator->setDecoratee(vp->getCamera());
vp->setCamera(decorator);
bool bTiled = false;
TileableBackground* tbg = dynamic_cast<TileableBackground*>(vp->getBackground());
if (tbg) {
bTiled = tbg->getTile();
tbg->setTile(false);
}
//
// The scene manager root node does not provide the illumination of the
// scene. This is governed internally by the manager. However, to take
// credit of the illumination we scan to the final parent of the scene
// graph.
//
Node* internalRoot = rootNode(mgr->getRoot());
//
// We would like to render the scene but won't detach it from its parent.
// The VisitSubTree allows just that.
//
VisitSubTreeUnrecPtr visitor = VisitSubTree::create();
visitor->setSubTreeRoot(internalRoot);
NodeUnrecPtr visit_node = makeNodeFor(visitor);
//
// We clone the camera of the first viewport and do not swap the buffer on later
// rendering. This way the image generation process is not noticable in the
// window.
//
CameraUnrecPtr camera = dynamic_pointer_cast<Camera>(vp->getCamera()->shallowCopy());
//
// The stage object does provide a render target for the frame buffer attachment.
// SimpleStage has a camera, a background and the left, right, top, bottom
// fields to let you restrict rendering to a sub-rectangle of your FBO, i.e.
// they give you a viewport.
//
SimpleStageUnrecPtr stage = SimpleStage::create();
stage->setRenderTarget(fbo);
stage->setCamera (decorator);
stage->setBackground (vp->getBackground());
//
// Give the stage core a place to live
//
NodeUnrecPtr stage_node = makeNodeFor(stage);
stage_node->addChild(visit_node);
//
// root
// |
// +- SimpleStage
// |
// +- VisitSubTree -> ApplicationScene
//
NodeUnrecPtr root = makeCoredNode<Group>();
root->addChild(stage_node);
//
// Give the root node a place to live, i.e. create a passive
// viewport and add it to the window.
//
ViewportUnrecPtr stage_viewport = PassiveViewport::create();
stage_viewport->setRoot (root);
stage_viewport->setBackground(vp->getBackground());
stage_viewport->setCamera (camera);
win->addPort(stage_viewport);
//
// remember the decorator, the background tile prop setting and the stage setup
//
decorators[i] = boost::make_tuple(decorator, bTiled, stage, stage_viewport);
}
//
// We write the image in simple ppm format. This one starts with a description
// header which we output once on first write.
//
bool write_header = true;
//
// Calc the max y start position (width). We process the tiles from bottom
// up and from left tp right as determined by the image format.
//
UInt32 yPosLast = 0;
for (; yPosLast < height-winHeight; yPosLast += winHeight);
//
// Process from bottom to top
//
for (Int32 yPos = yPosLast; yPos >= 0; yPos -= winHeight)
{
UInt32 ySize = std::min(winHeight, height - yPos);
//
// Collect the tile images for each row, i.e. we write the
// image in row manner to disk. This way the main memory is
// only moderately stressed.
//
std::vector<ImageUnrecPtr> vecColImages;
//
// Process from left to right
//
for (UInt32 xPos = 0; xPos < width; xPos += winWidth)
{
UInt32 xSize = std::min(winWidth, width - xPos);
//
// The current tile image
//
ImageUnrecPtr col_image = Image::create();
col_image->set(Image::OSG_RGBA_PF, xSize, ySize);
//
// Adapt the tile camera decorator boxes to the current tile
//
for (size_t i = 0; i < num_ports; ++i)
{
//
// this tile does not fill the whole FBO - adjust to only render
// to a part of it
//
decorators[i].get<2>()->setLeft (0.f);
decorators[i].get<2>()->setRight (xSize / float(winWidth));
decorators[i].get<2>()->setBottom(0.f);
decorators[i].get<2>()->setTop (ySize / float(winHeight));
TileCameraDecorator* decorator = decorators[i].get<0>();
decorator->setSize( xPos / float(width),
yPos / float(height),
(xPos + xSize) / float(width),
(yPos + ySize) / float(height) );
}
//
// render the tile
//
mgr->update();
win->renderNoFinish(mgr->getRenderAction());
win->frameExit();
win->deactivate ();
//
// Copy the image into the tile image stored for later processing
//
if(fbo)
{
RenderBuffer* grabber = dynamic_cast<RenderBuffer*>(fbo->getColorAttachments(0));
if(grabber)
{
grabber->getImage()->subImage(0, 0, 0, xSize, ySize, 1, col_image);
}
}
vecColImages.push_back(col_image);
}
//
// Write the image format header once
//
if (write_header) {
write_header = false;
if (!writePNMImagesHeader(vecColImages, width, height, stream)) break;
}
//
// Write the current column
//
if (!writePNMImagesData(vecColImages, stream)) break;
//
// Forget the current column images
//
vecColImages.clear();
}
//
// restore window and cleanup
//
for (size_t i = 0; i < num_ports; ++i) {
win->subPortByObj(decorators[i].get<3>());
Viewport* vp = win->getPort(i);
vp->setCamera(decorators[i].get<0>()->getDecoratee());
vp->setSize(0, 0, 1, 1);
TileableBackground* tbg = dynamic_cast<TileableBackground*>(vp->getBackground());
if (tbg)
tbg->setTile(decorators[i].get<1>());
}
}
