Method convertImageTosRGBOpenGLTexture

Engine/TrackerNodeInteract.cpp:1150–1276

}

void
TrackerNodeInteract::convertImageTosRGBOpenGLTexture(const ImagePtr& image,
                                                     const TexturePtr& tex,
                                                     const RectI& renderWindow)
{
    RectI bounds;
    RectI roi;

    if (image) {
        bounds = image->getBounds();
        renderWindow.intersect(bounds, &roi);
    } else {
        bounds = renderWindow;
        roi = bounds;
    }
    if ( roi.isNull() ) {
        return;
    }


    std::size_t bytesCount = 4 * sizeof(unsigned char) * roi.area();
    TextureRect region;
    region.x1 = roi.x1;
    region.x2 = roi.x2;
    region.y1 = roi.y1;
    region.y2 = roi.y2;

    GLint currentBoundPBO = 0;
    glGetIntegerv(GL_PIXEL_UNPACK_BUFFER_BINDING_ARB, &currentBoundPBO);

    if (pboID == 0) {
        glGenBuffers(1, &pboID);
    }

    // bind PBO to update texture source
    glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, pboID );

    // 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, bytesCount, NULL, GL_DYNAMIC_DRAW_ARB);

    // map the buffer object into client's memory
    GLvoid *buf = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY_ARB);
    glCheckError();
    assert(buf);
    if (buf) {
        // update data directly on the mapped buffer
        if (!image) {
            int pixelsCount = roi.area();
            unsigned int* dstPixels = (unsigned int*)buf;
            for (int i = 0; i < pixelsCount; ++i, ++dstPixels) {
                *dstPixels = toBGRA(0, 0, 0, 255);
            }