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Re: List control events

jhorstkamp11-May-04 8:13

11-May-04 8:13

Thanks - that almost works...

It fails when I want to click on an already selected item and process data.
(I'm varying some algorithm params in the dialog and observing the effect).

So, I guess all I really want to do is to be able to use the up/down arrows to scroll and automatically process AND be able to use the mouse click to randomally select list data as well as process an already selected item.

Is this the correct approach (using these events or do I need to set and clear some global bool that I create to bypass all these cascading events?)

Thanks,

John

Re: List control events

Diddy26-May-04 2:46

26-May-04 2:46

Yeah i don't think you get that event if you click on an already selected item... Have you tried processing NM_CLICK as well?

How to make code block works faster?

Kolich11-May-04 2:41

11-May-04 2:41

I have such block:

if (a > 0)
if (a > 255) b = 255;
else b = (BYTE)a;
else b = 0;

do anyone have an idea, how to make it works faster?

Thanx.

Re: How to make code block works faster?

Nitron11-May-04 2:56

11-May-04 2:56

Not really faster, but certainly more ~~obfuscated~~ elegant: Poke tongue | ;-P

Poke tongue | ;-P

b = a > 0 ? (a > 255 ? 255 : (byte)a) : 0;

~Nitron.

ññòòïðïðB A start

Re: How to make code block works faster?

Kolich11-May-04 3:01

11-May-04 3:01

thanx, but i need fast, not elegant Smile | :)

Smile | :)

such construction works even slowly.

Re: How to make code block works faster?

Nitron11-May-04 3:09

11-May-04 3:09

Try it and benchmark it. I can say nearly for certain that little block of code is nowhere near a slight resemblance of your bottleneck. (of course that is if a and b are bytes or ints as you lead me to believe) Rule number 1 of optimization: Don't do it. Rule number 2: Don't do it _yet_.^*

So... Unless a profiler is telling you your code is bottle-necking at that small comparator block, I suggest you worry more about the rest of your code and just leave what you have. Things like passing function args by value rather than by reference, useless construction and destruction of temporary objects derived from complex class heiarchies, and other such subtle things are nearly 100% of the time your bottleneck. (Save for things like disk/network IO, etc.)

^*Herb Sutter - More Exceptional C++

~Nitron.

ññòòïðïðB A start

Re: How to make code block works faster?

Kolich11-May-04 3:14

11-May-04 3:14

This block processing takes 3/4 of all code time.

Re: How to make code block works faster?

Nitron11-May-04 3:26

11-May-04 3:26

Kolich wrote:
This block processing takes 3/4 of all code time.

OMG | :OMG:

OMG | :OMG:

no way! (unless your total processing time is like 0.000012 seconds). How long is your processing time? How many elements in your matrix? Here is the disassembly for my test block:

	if (a > 0) 
00411ADE  mov         eax,dword ptr [a] 
00411AE1  cmp         dword ptr [eax],0 
00411AE4  jle         test+48h (411B08h) 
		if (a > 255) 
00411AE6  mov         eax,dword ptr [a] 
00411AE9  cmp         dword ptr [eax],0FFh 
00411AEF  jle         test+3Ch (411AFCh) 
			b = 255;
00411AF1  mov         eax,dword ptr [b] 
00411AF4  mov         dword ptr [eax],0FFh 
		else b = a;
00411AFA  jmp         test+46h (411B06h) 
00411AFC  mov         eax,dword ptr [b] 
00411AFF  mov         ecx,dword ptr [a] 
00411B02  mov         edx,dword ptr [ecx] 
00411B04  mov         dword ptr [eax],edx 
	else b = 0;
00411B06  jmp         test+51h (411B11h) 
00411B08  mov         eax,dword ptr [b] 
00411B0B  mov         dword ptr [eax],0

that's like 16 instructions! It probably takes more just to instantiate one of your matrix objects...

~Nitron.

ññòòïðïðB A start

Re: How to make code block works faster?

Kolich11-May-04 3:33

11-May-04 3:33

basic time takes operation b=a.
its bad.

Re: How to make code block works faster?

toxcct11-May-04 4:51

11-May-04 4:51

you find this elegant ?????????
i agree the ?: operator is elegant when you have few (less than 2) conditions, but it becomes really unreadable otherwise.
more, it uses exactly the same time as the previous post's code. what i prefer is expanding the code, but placing the { }. it doesn't eat bread and it is really more easy to debug.
one last thing. the first written code is (by my thinking quite fast). you can so let it like this :

<font style="color:blue;">if </font>(a > 0) {
    <font style="color:blue;">if </font>(a > 255) {
        b = 255;
    }
    <font style="color:blue;">else</font> {
        b = (BYTE)a;
    }
}
<font style="color:blue;">else </font>{
    b = 0;
}

TOXCCT >>> GEII power

Re: How to make code block works faster?

Nitron11-May-04 5:00

11-May-04 5:00

Actually, it's 2 _more_ instructions than the previous code. Wink | ;)

Wink | ;)

I was really only kidding, I would never put that into production code... Suspicious | :suss:

Suspicious | :suss:

On a side note, I see you are a same-line bracer Eek! | :eek:

Eek! | :eek:

the horror! I'd much rather wade through deeply obfuscated code than to subject my tender eyes to such bracing schemes... Poke tongue | ;-P

Poke tongue | ;-P

~Nitron.

ññòòïðïðB A start

Re: How to make code block works faster?

toxcct11-May-04 5:03

11-May-04 5:03

Nitron wrote:
I see you are a same-line bracer

where, which ? what is wrong in my code ?
i don't exactly understand your sentence. could you rephrase it please ?

TOXCCT >>> GEII power

Re: How to make code block works faster?

Nitron11-May-04 5:09

11-May-04 5:09

You do this:

if (a > 0) {
   if (a > 255) {
     b = 255;
   }
   else {
      b = (BYTE)a;
   }
}
else {
   b = 0;}

instead of this:

if (a > 0)
{
   if (a > 255)
     b = 255;
   else
     b = (BYTE)a;
}
else
   b = 0;

i.e. you put your opening braces on the same line as your conditional statement.

~Nitron.

ññòòïðïðB A start

Re: How to make code block works faster?

toxcct11-May-04 5:14

11-May-04 5:14

and so what ??? didn't you ever saw that ?? is it a code fault ? pfffffff poor guy.
moreover, i said that it was more readable to write the code with the braces. when you cat multiple if statements, we are not sure to whose if the esle is associated with.
My code is correct, if you don't like this, it's your point of view, but it is efficient !
Mad | :mad:

Mad | :mad:

TOXCCT >>> GEII power

Re: How to make code block works faster?

Nitron11-May-04 5:16

11-May-04 5:16

dude, chill. The code is fine, I was just giving you a hard time. I guess I know how to push your buttons Wink | ;)

Wink | ;)

~Nitron.

ññòòïðïðB A start

Re: How to make code block works faster?

gUrM33T11-May-04 3:02

11-May-04 3:02

If you can also provide us with the data types of a and b, then may be we can find out some idea. And if you can explain what you are actually trying to do, that would be much better.

Gurmeet

BTW, can Google help me search my lost pajamas?

My Articles: HTML Reader C++ Class Library, Numeric Edit Control

Re: How to make code block works faster?

Kolich11-May-04 3:05

11-May-04 3:05

b is BYTE, a is float.

I'm making convolution of 2 matrix. they are BYTE type. So i need to control bounds.

Re: How to make code block works faster?

gUrM33T11-May-04 3:15

11-May-04 3:15

May be this can help:

b = 0;
if (a > 0)
  b = (a > 255 ? 255 : (BYTE)a);

Gurmeet

BTW, can Google help me search my lost pajamas?

My Articles: HTML Reader C++ Class Library, Numeric Edit Control

Re: How to make code block works faster?

gUrM33T11-May-04 3:23

11-May-04 3:23

or may be this:

b = (a > 255 : 255 : (a <= 0 ? 0 : (BYTE)a));

Gurmeet

BTW, can Google help me search my lost pajamas?

My Articles: HTML Reader C++ Class Library, Numeric Edit Control

Re: How to make code block works faster?

Kolich11-May-04 3:24

11-May-04 3:24

No! its useless Frown | :(

Frown | :(

Re: How to make code block works faster?

toxcct11-May-04 4:59

11-May-04 4:59

he asked for fast, not undebugable unreadable useless code Poke tongue | ;-P

Poke tongue | ;-P

TOXCCT >>> GEII power

Re: How to make code block works faster?

David Crow11-May-04 3:15

11-May-04 3:15

If you really think optimizing this code is worth the effort, you couldn't be more wrong. For a detailed analysis on this topic, see this article. I'm not saying that it isn't possible, but in the grand scheme of things, saving a handful of operations is pointless.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: How to make code block works faster?

Tim Smith11-May-04 3:44

11-May-04 3:44

If these lines of code are taking most of the time and the algorithm is correct, then yes, he should look at these lines.

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

Re: How to make code block works faster?

Diddy11-May-04 3:24

11-May-04 3:24

Try:

b = (BYTE)a;
(void)(!(a > 0xFF)||((b = 0xFF)));

Re: How to make code block works faster?

Kolich11-May-04 3:28

11-May-04 3:28

same result :/

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