Statistics Overlay

Author: eilemann@gmail.com
State: Implemented in svn

Overview

Statistics Overlay

Statistics are send as events to the application thread. On the application thread, Config::handleEvent sorts the events per frame and per originator (channel, window, config). Events for up to latency + 1 frames are kept by the application node config.

Statistics can be visualized by calling Channel::drawStatistics. The Equalizer examples use the key 's' to toggle statistics drawing on and off.

Details

Statistics Overlay with Explanations

• The statistics are for a static 2D compound using two nodes.
• The X axis is the time. One pixel on the screen corresponds to one millisecond. The right-most pixel is the most current time.
• On the Y axis are the rendering entities: channels, windows and the config.
• The remote machine is a Mac Mini, the local a MacBook Pro. The draw times are unbalanced due to the speed difference of the machines, and the transmit time is relatively long since 100 MBit Ethernet is used.
• Frames overlap due to asynchronous execution, in the example above for one frame.
• Older frames are gradually attenuated for easier identification of tasks to frames.
• Frame borders are identified by vertical lines, green is the start of a frame, gray the finish.
• The swap buffer task includes the time to wait for the vertical retrace (vsync is on).
• The waiting for images task is a subset of the assemble task.
• Swap barriers (not used in the example) are sold red tasks directly before the white swap buffer task.

API

    virtual void Channel::drawStatistics();

File Format

Additional statistics file format:

  global
  {
      EQ_WINDOW_IATTR_HINT_STATISTICS    off | fastest [on] | nicest
  }
  window
  {
      attributes
      {
          hint_statistics     off | fastest [on] | nicest
      }
  }

Open Issues

None