Performance issues

Android Processing

boub_pops..

in Android Processing • 8 months ago

Hi all !

I'm trying to port some oldschool demo effect to processing/android.

With the same code in java mode I reach something like 240fps but on android only ~30.

It seems the bottleneck is the "pixel fill rate", my inner loop is something like this:

buffer.beginDraw();
buffer.loadPixels();
for(x = 0; x < buffer.width ; x++)
for(y = 0; y < buffer.height ; y++)
{
buffer.pixels[x+y*buffer.width] = somevalue;
}
buffer.updatePixels();
buffer.endDraw();
}

"somevalue" is just an example, being a fixed value or reading a LUT is almost the same writing speed.

(and my actual buffer is a 320*240 image so not a big one)

Any idea to go faster ?

Cheers,

Olivier

Replies(4)

amnon.owed

Re: Performance issues

8 months ago

You could use a fragment shader.

boub_pops..

Re: Performance issues

8 months ago

I forgot to thank you for the idea ... the shader works :)

IMHO there's still an issue about this poor performance when accessing the pixels in android mode :/ May be one day it will be faster ;)

gralab

Re: Performance issues

8 months ago

could you post your code, I'm pretty interesting in that too ;)
thx
g.

boub_pops..

Re: Performance issues

8 months ago

Instead the "somevalue" calculating in processing I wrote a fragment shader.

Then above code is replaced by:

In my inits:

myShader= loadShader("fragment.glsl");

(with the file fragent.glsl in the /data subdirectory of your sketche)

then called from draw:

buffer.beginDraw();
buffer.shader(myShader);
buffer.rect(0, 0, buffer.width, buffer.height);
buffer.endDraw();

The hardest part is writting the shader but there's lot's of examples like on "shader toy".

Just dont forget to add

textureWrap(REPEAT);

in your setup() to try those examples :)

(I had a hard time finding the texture wrapping issue so I document it here)

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