[racket] big-bang is slow to render on screen?

Thanks Sean.
(I forgot to mention that I was testing on Racket 6.0.1.4).
Apparently it does not lag on your machine, so it might be particular to my
machine then? Strange.


On Mon, Apr 21, 2014 at 4:32 PM, Sean Kanaley <skanaley at gmail.com> wrote:

> Here's my log after pasting the source into command-line racket 6.0,
> Ubuntu 12.04 32-bit:
>
> to-draw at 1649
>
> to-draw: cpu time: 0 real time: 2 gc time: 0
> on-key a at 2934
> to-draw at 2934
>
> to-draw: cpu time: 0 real time: 2 gc time: 0
> on-key s at 2970
> to-draw at 2970
>
> to-draw: cpu time: 4 real time: 3 gc time: 0
> on-key d at 3044
> on-key f at 3044
> to-draw at 3045
>
> to-draw: cpu time: 0 real time: 0 gc time: 0
> to-draw at 3069
> to-draw: cpu time: 0 real time: 1 gc time: 0
> on-key a at 3198
> on-key s at 3198
> to-draw at 3199
>
> to-draw: cpu time: 4 real time: 3 gc time: 0
> to-draw at 3329
>
> to-draw: cpu time: 4 real time: 1 gc time: 0
> to-draw at 3392
> to-draw: cpu time: 0 real time: 1 gc time: 0
> on-key g at 3430
> on-key j at 3430
> on-key k at 3430
> to-draw at 3430
>
> to-draw: cpu time: 4 real time: 1 gc time: 0
> to-draw at 3467
> to-draw: cpu time: 0 real time: 1 gc time: 0
> on-key a at 3504
> on-key l at 3504
> to-draw at 3505
>
> to-draw: cpu time: 0 real time: 1 gc time: 0
> to-draw at 3547
>
> to-draw: cpu time: 4 real time: 1 gc time: 0
> to-draw at 3572
> to-draw: cpu time: 0 real time: 1 gc time: 0
> on-key h at 3602
> to-draw at 3602
> to-draw: cpu time: 0 real time: 1 gc time: 0
> on-key k at 3659
> on-key ; at 3659
> to-draw at 3659
>
> to-draw: cpu time: 4 real time: 3 gc time: 0
> to-draw at 3689
>
> to-draw: cpu time: 0 real time: 1 gc time: 0
> to-draw at 3725
>
> to-draw: cpu time: 0 real time: 1 gc time: 0
> to-draw at 3776
> to-draw: cpu time: 0 real time: 1 gc time: 0
>
>
>
> On Mon, Apr 21, 2014 at 10:00 AM, Laurent <laurent.orseau at gmail.com>wrote:
>
>> I have a 2htdp/universe program that used to run fast enough a few months
>> ago, but now it is very slow and not usable.
>> The slowness seems to be because of the on-screen rendering, and not
>> because of the generation of the image.
>>
>> Here is a stripped-down version that shows this behavior:
>> https://gist.github.com/Metaxal/11142941
>>
>> In the following log, you see that the `on-key` events are very close one
>> to the other (in milliseconds after the beginning of the program), but the
>> corresponding `to-draw` events are separated by more than a second, even
>> though generating the image (cpu time) takes almost no time:
>>
>> on-key a at 6906
>> on-key u at 6912
>> on-key i at 6912
>> on-key e at 6913
>> to-draw at 6913
>> to-draw: cpu time: 4 real time: 3 gc time: 0
>> to-draw at 8598
>> to-draw: cpu time: 4 real time: 2 gc time: 0
>> to-draw at 11948
>> to-draw: cpu time: 4 real time: 2 gc time: 0
>> to-draw at 13631
>> to-draw: cpu time: 0 real time: 2 gc time: 0
>> to-draw at 161839
>> to-draw: cpu time: 4 real time: 9 gc time: 0
>>
>> During those long seconds, Xorg is almost at 100% cpu.
>>
>> However, using an empty scene instead of an image is fast.
>> The time also depends on the size of the grid.
>>
>> I'm using Ubuntu 12.04 64bits.
>> I have tried to replicate the behavior on older versions of racket (5.3.1
>> and 5.90.0.9) but it's the same. So maybe the problem is not on Racket's
>> side but something has changed in Ubuntu?
>>
>> Does anyone else see the same behavior, either on the same platform or on
>> a different one?
>>
>> Thanks,
>> Laurent
>>
>>
>> ____________________
>>   Racket Users list:
>>   http://lists.racket-lang.org/users
>>
>>
>
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