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External interface still too slow

I've been aware that using External Interface in flash 8 was rather slow, although I never had the need to test it myself. Unfortunately the general speed improvements in AS3/AVM2 . Don't seem to of helped external interface. I don't have any old speed stats to compare to, but in my recent tests AS3 external interface seems to begin to choke at around 3Kb/s . Once this limit gets hit, events start to queue up and fire at some (much) later time.

Fortunately Binary Socket rocks. With very little pain, i've manged to implement a Socket Server/Client solution, which quite happily flies along consuming 13Kb/s of Wiimote Data. This Has had no noticeable effect on frame-rate of the test movie, on my machine it belts along at a nice 55Fps.

The great thing here is I can cut the 13KB/s figure drastically by implementing smoothing of wii data at either the C or Haxe level of Flii. The current wiimote drivers only support one wiimote, but i'm imaging that with smoothing implemented like this, it would certainly be possible to support a full roster of four of them.

By pete at 2007-03-01 16:15 | | pete's blog | login or register to post comments

What is the point of

What is the point of that?

To calibrate sensor data you have to send sensor, sensor0, sensorG - makes 3bytes. An IEEE single-precision floating point value is 32bit (4bytes). So there is only a 1byte difference.

But you can take the calculation (sensor - sensor0) / (sensorG - sensor0) out of Flash.

Or do you mean by smoothing actual value smoothing and not calibration?

By joa (not verified) at Sat, 2007-04-07 14:21 | login or register to post comments

Value smoothing. My

Value smoothing.

My Reasoning is that there is a little too much wiimote data for flash to really make use of, and without smoothing you get a lot of those unintentional tiny jumps.

Regarding the calibration - i just send sensor0 and sensorG in an initial packet after wiimote detection - are you saying these values change and need to be resent? I thought they are per- wiimote-constants??

By pete at Sat, 2007-04-07 14:43 | login or register to post comments

You are right on the values.

You are right on the values. But there is an actual difference between the frames Flash can render(say 255 as a standart maximum) and the ticks you can have.

I tried it out with a drum application and if you smooth the values you will loose too much data. And Flash can handle it well. I think currently we have 500 packets per second and no problems on the Flash side.

By Joa Ebert (not verified) at Tue, 2007-04-10 14:30 | login or register to post comments