Method convertRAMImageToOpenGLTexture

Engine/EffectInstance.cpp:1545–1617

}

ImagePtr
EffectInstance::convertRAMImageToOpenGLTexture(const ImagePtr& image)
{
    assert(image->getStorageMode() != eStorageModeGLTex);

    boost::shared_ptr<ImageParams> params( new ImageParams( *image->getParams() ) );
    CacheEntryStorageInfo& info = params->getStorageInfo();
    info.mode = eStorageModeGLTex;
    info.textureTarget = GL_TEXTURE_2D;

    RectI bounds = image->getBounds();
    OSGLContextPtr context = getThreadLocalOpenGLContext();
    assert(context);
    if (!context) {
        throw std::runtime_error("No OpenGL context attached");
    }

    GLuint pboID = context->getPBOId();
    assert(pboID != 0);
    glEnable(GL_TEXTURE_2D);
    // bind PBO to update texture source
    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, pboID);

    std::size_t dataSize = bounds.area() * 4 * info.dataTypeSize;

    // Note that glMapBufferARB() causes sync issue.
    // If GPU is working with this buffer, glMapBufferARB() will wait(stall)
    // until GPU to finish its job. To avoid waiting (idle), you can call
    // first glBufferDataARB() with NULL pointer before glMapBufferARB().
    // If you do that, the previous data in PBO will be discarded and
    // glMapBufferARB() returns a new allocated pointer immediately
    // even if GPU is still working with the previous data.
    glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_ARB, dataSize, 0, GL_DYNAMIC_DRAW_ARB);

    bool useTmpImage = image->getComponentsCount() != 4;
    ImagePtr tmpImg;
    if (useTmpImage) {
        tmpImg.reset( new Image( ImagePlaneDesc::getRGBAComponents(), image->getRoD(), bounds, 0, image->getPixelAspectRatio(), image->getBitDepth(), image->getPremultiplication(), image->getFieldingOrder(), false, eStorageModeRAM) );
        tmpImg->setKey(image->getKey());
        if (tmpImg->getComponents() == image->getComponents()) {
            tmpImg->pasteFrom(*image, bounds);
        } else {
            image->convertToFormat(bounds, eViewerColorSpaceLinear, eViewerColorSpaceLinear, -1, false, false, tmpImg.get());
        }
    }

    Image::ReadAccess racc( tmpImg ? tmpImg.get() : image.get() );
    const unsigned char* srcdata = racc.pixelAt(bounds.x1, bounds.y1);
    assert(srcdata);

    GLvoid* gpuData = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY_ARB);
    if (gpuData) {
            // update data directly on the mapped buffer
        memcpy(gpuData, srcdata, dataSize);
        GLboolean result = glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB); // release the mapped buffer
        assert(result == GL_TRUE);
        Q_UNUSED(result);
    }