Dynamic Image

[liguehs]

Hi guys,
OK so I have a number that I am getting from a DB...

So what I want is that the number retreieved is the width of an image.

So for easy, but here is the tough part:

If that number is a negative, I want the image starting from the middle and goes to the left, and if its positive, starts from the middle and goes to the right.

I attached an image of what I would like to make...

Thanks for your help,

[Scoochi2]

edit: see next post by descalzo

[descalzo]

## constants depending on the size/margins of image
$image_width = XXX; # width of image
$image_margin = XXX; # size of left/right margins if you do not want to edge
$value_max = XXXX; # max abs input value, probably 100
 
 
$value = From DB ;
 
# maximum width of color bar
 
$bar_max = floor( ($image_width - 2*$image_margin) / 2 ) ;
 
$image_midpoint = floor( $image_width/2 );
 
# actual width of color bar
 
$bar_length = (abs($value) /$value_max ) * $bar_max ;
 
# find left and right enpoints of bar, and the color
 
if( $value > 0 ){
   $left = $image_midpoint ;
   $right = $left + $bar_length ;
   $color = POSITIVE_COLOR ;
} else {
   $right = $image_midpoint ;
   $left = $image_midpoint - $bar_length ;
   $color = NEGATIVE_COLOR ;
} 

Then use $left, $right, $color in your drawing program (GD based?).

Edit:

Like this

[liguehs]

Thanks so much,

I will try it as soon as I get home.

[diabolo]

if you need further help: i also wrote a tutorial on this before. the link is in my sig.

[liguehs]

Hi,
Just wondering, how do I show the bar?
What should i echo?

[descalzo]

In your code to display the page you put

$value = value you want to display...
 
<img src="plusminus.php?value=<?php echo($value) ?>" height="30" width="100" 
         alt="test" id="plusminus" name="plusminus">

plusminus.php would be a separate script that gets called with a query string of '?value=XX' an outputs the dynamic image.

[liguehs]

I dont quite follow you here..

So what is $value on the same page equlas too?

And also, The value changes for each players...
so it would be best if its get called in the while loop no?

[descalzo]

I dont quite follow you here..

So what is $value on the same page equlas too?

And also, The value changes for each players...
so it would be best if its get called in the while loop no?

It's this number....

OK so I have a number that I am getting from a DB...

[liguehs]

plusminus.php would be a separate script that gets called with a query string of '?value=XX' an outputs the dynamic image.

Ok,
but why call it in a separate file?

Thats where I am getting lost...