Oh....That mode of operation.RealNC wrote:I'm talking about front-buffer rendering, where you ride the tearline during rasterisation. That's single-buffered rendering, and it's only possible in VR (unless something changed lately.) It provides near zero latency between the rasterizer and the player's eyes.
Related Article and ImgTec article and NVIDIA VRWorks. It's a creative trick.
I remember it used to be possible back in the 3Dfx days to render to the front buffer, watching the graphics flicker as you redrew the frame over and over. Yeah, you could raster-follow the polygonal rendering, making sure you're finished all rendering right near below the current raster.
Related topic, I recently wrote an article about raster-synchronized VSYNC OFF buffer flipping at Emulator Developers: Lagless VSYNC ON Algorithm (advanced link only useful to software developers). Basically an emulator developer can implement a virtually lagless form of VSYNC ON simulated with high framerate VSYNC OFF with raster-synchronized buffer flips. This algorithm is mainly useful for emulators, however. Ideally, front-buffer rendering would make this simpler (and less bandwidth wasted), but this can be done without direct access to a front buffer.