NAME

rendertarget_metrics - Retrieve statistics about the state of a rendertarget pipeline

SYNOPSIS

table
rendertarget_metrics( vid:rtgt )

DESCRIPTION

At times you might want to make a decision based on the generic state of a pipeline. A common case is post processing filters that are too expensive to apply on every frame. The easiest approach then has been to attach it to a lower refresh clock, but that creates visible latency in the effect that might be quite visible and might still update redundantly.

The other option is to have a preframe handler that determines if it is worthwhile to add more work to the queue or not, and in order to make such a heuristic some input is needed. This function can be used to retrieve some information about what is going on in a render pipeline without forcing manual tracking.

The fields in the returned table are: *int:dirty* - how many times the dirty counter has been incremented since last render pass. *int:transfers* - the number of external uploads since last render pass. *int:updates* - the number of ongoing transforms. *int:time_move* - the relative clock of the last move transform. *int:time_scale* - the relative clock of the last scale transform. *int:time_rotate* - the relative clock of the last rotate transform. *int:time_blend* - the relative clock of the last blend transform.

EXAMPLE

function rendertarget_metrics0()
      local anim = fill_surface(32, 32, 255, 0, 0)
      show_image(anim, 100)
      move_image(anim, 100, 100, 200)
      _G[APPLID .. "_preframe_pulse"] = function()
            for k,v in pairs(rendertarget_metrics(WORLDID)) do
                  print(k, v)
            end
      end
end

NAME

SYNOPSIS

DESCRIPTION

EXAMPLE

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