Hi,
I have implemented the global tonemapping operator (Reinhard). For this task I
use a downsampling pass which downsamples the input texture (with log luminance
per pixel) to a 1x1 texture computing the avarage log luminance of the input
texture. The next step, I try to do, is to copy the avarage log luminance from
the 1x1 texture from the GPU to an array in the main application. I have to
store the average log luminance for the last n frames. These values can then be
used to compute the adaptive temporal tonemapping.
Code:
// first create the 1x1 output texture for the avarage log luminance
osg::ref_ptr<osg::Texture2D> tmLogLumAvarageTex = new osg::Texture2D();
tmLogLumAvarageTex->setTextureSize(1, 1);
tmLogLumAvarageTex->setInternalFormat(GL_LUMINANCE16F_ARB);
tmLogLumAvarageTex->setSourceFormat(GL_RGBA);
tmLogLumAvarageTex->setSourceType(GL_FLOAT);
// downsampling pass
// ....
// capture the state set from the final downsampling pass
osg::ref_ptr< osg::StateSet > currentStateSet = new osg::StateSet();
currentStateSet =
tmTexDownSampPass->getPassByIndex(tmTexDownSampPass->getNumOfPasses()-1)->getCamera()->getStateSet();
// capture the state from the final downsampling pass' state set
osg::ref_ptr< osg::State > currentState = new osg::State();
currentState->captureCurrentState(*currentStateSet);
float pixelData[4];
// create pixelbuffer object to copy the content from texture
// and copy the buffer's content to a data pointer
osg::PixelDataBufferObject* pdbo = new osg::PixelDataBufferObject();
// bind buffer in write mode and copy texture content into the buffer (write to
buffer)
pdbo->bindBufferInWriteMode(*currentState); // GL_PIXEL_PACK_BUFFER_ARB
currentState->applyTextureAttribute(/*unit*/ 0, /*texture*/
tmLogLumAvarageTex.get());
// copy content from texture to the pbo
glGetTexImage(GL_TEXTURE_2D, 0, GL_LUMINANCE16F_ARB, GL_FLOAT,
pixelData);
pdbo->unbindBuffer(currentState->getContextID());
The screen stays black and I get the following message when I run my program:
"Warning: TextureRectangle::apply(..) failed, texture rectangle is not support
by your OpenGL drivers"
Please help!!!
Thank you!
Cheers,
Dan
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http://forum.openscenegraph.org/viewtopic.php?p=36103#36103
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