Frame logging

[bruno-f-cruz]

We can log every single frame that is rendered on the screen, however, this would prevent people from bringing the shader's window in and out of focus. Each time this happens a brief flicker is shown and we will lose synchrony at that point. To get around this problem, I suggest we toggle the quad randomly every 10-20 seconds.

The output file would then have the following columns:

• FrameNumber (Number of rendered frames since the beginning of the workflow)
• FrameTime (Time, given by the rendering engine of when a frame was rendered. This time, while slightly jittered, it will give us a sense of dropped frames)

In a second file, we will save the correspondence between the PhotodiodeSignal and the Frame in which we toggled the quad color.

• FrameNumber (The frame number where the quad was toggle, same as above)
• FrameTime (same as above)
• QuadColor (the color that the quad transitioned to)

Then, offline we can recover the correspondence between FrameTime and HarpTime (given by the photodiode pin) and come up with a correction model.

Additionally, each software event (e.g. task logic) that have a low priority should also be logged using both the render and harp times. I would suggest using the following timestamping pattern:

[bruno-f-cruz]

This strategy should be validated and QC should be put in place on a session-based that checks the quality of the fit. Additionally, some filtering of flicker events might be needed if people are interacting with a second monitor while the render is running...

[bruno-f-cruz]

Partially implemented in #80. However, still needs to be used to actually log events

[bruno-f-cruz]

This ended up being implemented as part of the SoftwareEvent class:

"softwareEvent": {
      "type": "object",
      "properties": {
        "timestamp": {
          "type": ["null", "number"],
          "default": null
        },
        "timestampSource": {
          "type": "string",
          "enum": ["none", "harp", "render"],
          "default": "none"
        },
        "frameIndex": {
          "type": ["null", "integer"],
          "minimum": 0
        },
        "frameTimestamp":{
          "type": ["null", "number"],
          "default": null
        },
        "name": {
          "type": "string"
        },
        "data": {
          "type": ["null", "object"],
          "default": null
        },
        "dataType": {
          "type": "string",
          "enum": ["string", "number", "boolean", "object", "array", "null"],
          "default": null
        }
      }
    }