🚀 go-pugleaf

Jos� wrote:

> screen becomes blank

There is nothing in your code that cares for that. Please explain.

> after one second (or more) the left picture appears.
> after another second (or more) the right picture appears.

bool toggle;
void loadphotos()

Oh. Why are you using a global bool and a standalone function ?

It is much better to make that a classmember of TForm1.
If you do you could also use two forms which display
at the same time.

void exchange(void)

ditto.

__fastcall TForm1::TForm1(TComponent* Owner)
   : TFrame(Owner)
{
   // set the second set invisible

	Image2R->Visible = false;
	Image2L->Visible = false;
}

You could as well do all in the timereventhandler.

void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
     Timer1->Enabled = false;

     Image1R->Visible = ! Image1R->Visible;
     Image1L->Visible = ! Image1L->Visible;
     Image2R->Visible = ! Image2R->Visible;
     Image2L->Visible = ! Image2L->Visible;

     Application->ProcessMessages(); // does this have effect ?

     FileR = ...
     FileL = ...

     if ( ! Image1R->Visible ) Image1R->Picture->LoadFromFile(fileR);
     if ( ! Image2R->Visible ) Image2R->Picture->LoadFromFile(fileR);
     if ( ! Image1L->Visible ) Image1L->Picture->LoadFromFile(fileL);
     if ( ! Image2L->Visible ) Image2L->Picture->LoadFromFile(fileL);

     Timer1->Enabled = true;
}

pProblems like this where you use a VCL component are better asked in:
borland.public.cppbuilder.vcl.components.using

Hans.

On Fri, 28 Apr 2006 22:42:08 +0200, Hans Galema <notused@notused.nl>
wrote in borland.public.cppbuilder.nativeapi:

>> screen becomes blank
>
>There is nothing in your code that cares for that. Please explain.

It happens. I think the TImages are made invisible intantanteously,
but that it takes time to make them visible.
Coding in the other order (first visible, then invisible) makes no
difference.

>> after one second (or more) the left picture appears.
>> after another second (or more) the right picture appears.
>
>bool toggle;
>void loadphotos()
>
>Oh. Why are you using a global bool and a standalone function ?

I always do. Never had any problems with that. But I'll try your
suggestion.

>It is much better to make that a classmember of TForm1.
>If you do you could also use two forms which display
>at the same time.

I expect this will make them behave more independently, causing a
worse synchronisation.
-- 
Jos�

On Fri, 28 Apr 2006 22:42:08 +0200, Hans Galema <notused@notused.nl>
wrote in borland.public.cppbuilder.nativeapi:

>Oh. Why are you using a global bool and a standalone function ?
>
>It is much better to make that a classmember of TForm1.

It makes no difference. Still too slow.
-- 
Jos�

Jos� wrote:

> It makes no difference. Still too slow.

How big are your pictures ?

Are you still seeing that one picture displays one second before
the other ? How long is your TTimer::Interval ?

Could you post 4 pictures in borland.public.attachments
so we can test in the same way?

Hans.

Jos� wrote:

>>Oh. Why are you using a global bool and a standalone function ?
>>
>>It is much better to make that a classmember of TForm1.
> 
> It makes no difference. Still too slow.

No that makes no difference in speed of course.

But did you try my code ? You did not even comment
on ProcessMessages().

Hans.

On Sat, 29 Apr 2006 11:04:25 +0200, Hans Galema <notused@notused.nl>
wrote in borland.public.cppbuilder.nativeapi:

>> It makes no difference. Still too slow.
>
>How big are your pictures ?

Well, 500 kB to 1 MB, and 1000x1000 pixels or bigger. Perhaps I should
make them smaller. But of course I do not want to loose quality, or
I'll have to retain two copies of each picture: a big one for storage
and a small one display.

>Are you still seeing that one picture displays one second before
>the other ? How long is your TTimer::Interval ?

Yes

>Could you post 4 pictures in borland.public.attachments
>so we can test in the same way?

I did.
-- 
Jos�

On Sat, 29 Apr 2006 11:10:14 +0200, Hans Galema <notused@notused.nl>
wrote in borland.public.cppbuilder.nativeapi:

>But did you try my code ? You did not even comment
>on ProcessMessages().

Sorry, I didn't notice ProcessMessages in your code. I included it
now, but it made no difference. 

I don't think there will be much difference between in-linde code and
subroutines, but I prefer subroutines because they are called
elsewhere in the program as well.
-- 
Jos�

Jos� <jose@127.0.0.1> wrote:
>
>>Could you post 4 pictures in borland.public.attachments
>>so we can test in the same way?
>
>I did.

Well they're not there.

What I know so far is that you're using TImages and relying
on them to do the painting when speed is an issue for you
you. This is a mistake. You need to be managing the painting
yourself and should be using a TBitmap instead.

The general order of operation should be:

    1) Load the image
    2) StretchDraw it to a bitmap in the appropriate size
    3) Display it
    4) While waiting for the timer, repeat 1 & 2 on the next image
    5) Timer activates so begin at step 3

I have a print preview that zooms to 400% for 8.5 x 11 paper
and it's a huge bitmap that paints instantly because it uses
StretchDraw to a temporary bitmap that is then painted. If you
use StretchDraw directly to the screen, performance will
suffer greatly and I suspect that this is exactly what you're
doing by setting the Stretched property of the TImage.

~ JD

On 29 Apr 2006 10:30:12 -0700, "JD" <nospam@nospam.com> wrote in
borland.public.cppbuilder.nativeapi:

>>>Could you post 4 pictures in borland.public.attachments
>>>so we can test in the same way?
>>
>>I did.
>
>Well they're not there.

I tried. The server rejects files which are bigger than 1 MB (small
MB). Mine are approximately that size.
-- 
Jos�

Jos� wrote:

> I tried. The server rejects files which are bigger than 1 MB (small
> MB). Mine are approximately that size.

Jpg or bmp ?

Hans.

On Sat, 29 Apr 2006 23:10:36 +0200, Hans Galema <notused@notused.nl>
wrote in borland.public.cppbuilder.nativeapi:

>> I tried. The server rejects files which are bigger than 1 MB (small
>> MB). Mine are approximately that size.
>
>Jpg or bmp ?

JPG. But of course you mean to say that 1MB is a lot for a JPG file.
Well, I thin that smaller files will be faster indeed, but it amazes
me that it takes time to make a picture visible, when it has already
been loaded.

I modified the program to skip loading new images, so that the program
shows the same pictures all the time. This was a lot quicker, but
there is still a noticeble delay. So there is obviously a delay in
Visible=true.

Perhaps I should try smaller files.

-- 
Jos�

Jos� wrote:

> JPG. But of course you mean to say that 1MB is a lot for a JPG file.

No.

> Well, I thin that smaller files will be faster indeed, but it amazes
> me that it takes time to make a picture visible, when it has already
> been loaded.

No, making visible does not take time here. The timeconsuming factor
is in the loading.

> I modified the program to skip loading new images, so that the program
> shows the same pictures all the time. This was a lot quicker, but
> there is still a noticeble delay.

I did that too. But no delay.

But when loading the invisible set there was delay between the left and
right that were shown. I do not understand that. The delay about 1/3 s.

Hans.

On Sat, 29 Apr 2006 23:39:42 +0200, Hans Galema <notused@notused.nl>
wrote in borland.public.cppbuilder.nativeapi:

>No, making visible does not take time here. The timeconsuming factor
>is in the loading.

This was my modified program:

wait 10 seconds.
make pictures 1 and 2 invisible
make pictures 3 and 4 visible
wait 10 seconds.
make pictures 1 and 2 visible
make pictures 3 and 4 invisible
repeat

Note that no files were loaded. The pictures disappeared immediately,
and then it took approximately a second for the other two pictures to
appear, one by one.

>> I modified the program to skip loading new images, so that the program
>> shows the same pictures all the time. This was a lot quicker, but
>> there is still a noticeble delay.
>
>I did that too. But no delay.
>
>But when loading the invisible set there was delay between the left and
>right that were shown. I do not understand that. The delay about 1/3 s.

As I say.
-- 
Jos�

Jos� wrote:

> wait 10 seconds.
> make pictures 1 and 2 invisible
> make pictures 3 and 4 visible
> wait 10 seconds.
> make pictures 1 and 2 visible
> make pictures 3 and 4 invisible
> repeat

Please in such case show actual code that compiles and links.
Like I did.

You are forcing people who want to help you do produce
code that would handle that. As that can be coded
in many ways one might look at different outputs.

Hans.

"JD" <nospam@nospam.com> wrote in message 
news:4453a2a4$1@newsgroups.borland.com...
> The general order of operation should be:
>
>    1) Load the image
>    2) StretchDraw it to a bitmap in the appropriate size
>    3) Display it
>    4) While waiting for the timer, repeat 1 & 2 on the next image
>    5) Timer activates so begin at step 3

What function do you use for step 3? For example, in one of my programs I use 
:-

Image1->Canvas->StretchDraw(Rect(0,0,wid,hei),mybitmp);

Is this slow? Is there a faster way?
-- 

Mark Jacobs
DK Computing
http://www.dkcomputing.co.uk

On Tue, 2 May 2006 11:39:20 +0100, "Mark Jacobs"
<http://www.jacobsm.com/mjmsg?Borland%20Newsgroup> wrote in
borland.public.cppbuilder.nativeapi:

>>    1) Load the image
>>    2) StretchDraw it to a bitmap in the appropriate size
>>    3) Display it
>>    4) While waiting for the timer, repeat 1 & 2 on the next image
>>    5) Timer activates so begin at step 3
>
>What function do you use for step 3? For example, in one of my programs I use 
>:-
>
>Image1->Canvas->StretchDraw(Rect(0,0,wid,hei),mybitmp);
>
>Is this slow? Is there a faster way?

Image->Visible=true;
-- 
Jos�