I'm doing some little research school project, together with learning
basics of C++ (thanks to JNI) and here is some simple example ...
Java function:
-------------------------------------------
public double doClickAction04J() {
double x = 45.0 / (180.0 / Math.PI);
double result = 0.5;
for (int i = 0; i < 1000000; i++) {
result += Math.pow(Math.cos(x), 2.0);
result -= Math.pow(Math.sin(x), 2.0);
result = Math.log(result);
result = Math.exp(result);
}
return result;
}
and C code
------------------------------------
JNIEXPORT jdouble JNICALL
Java_menion_android_jnitest_Main_doClickAction04C
(JNIEnv *env, jclass thiz) {
double x = 45.0 / (180.0 / M_PI);
double result = 0.5;
int i;
for (i = 0; i < 1000000; i++) {
result += pow(cos(x), 2.0);
result -= pow(sin(x), 2.0);
result = log(result);
result = exp(result);
}
return result;
}
and the results?
Java: 5250ms
C : 1600ms
I then enabled experimental version of JIT compilator (in 2.1-r1
system) and new results
Java: 4700ms
C : 1600ms
so ... these are facts. I'm not really experienced with C, but this
seems for me as very objective test.
On Apr 7, 6:26 pm, Ralf Schneider <[email protected]> wrote:
> There exists 4444 (GL_UNSIGNED_SHORT_4_4_4_4) Textures.
> May be this helps a litle bit.
>
> I'm not sure but switching to VBOs might not bring an improvement.
> My observation on a Nexus One is: VBOs are great if there are many tris
> (>250) to render per call. For billboards it really doesn't matter that
> match.
> But I don't have any hard numbers this is just an observation on a specific
> device.
>
> Many have observed most devices are currently fill-rate-limited. So, if you
> have lots of overdraw it might be worth checking if you can reduce it.
>
> 2010/4/7 MrChaz <[email protected]>
>
> > 100 is a low estimate but it's around that point that the frame-rate
> > seems to get into the sub 30's.
> > I'm already doing pretty much everything you've mentioned except using
> > VBOs - most sprites are rendered via the draw_texture extension.
> > Unfortunately pretty much all the sprites have some transparency so
> > I'm using ARGB_8888 for the texture atlas's.
>
>
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