A point in an image map area !!!

johnie

Hi.
How can i look if two variables cord_x and cord_y are in the area created by let's say an image map (100, 200, 400, 300).
Is there a way of defining this area?
I need this for a map application.

Thanks

John

Mega

http://hotwired.lycos.com/webmonkey/html/96/39/index2a.html

johnie

My question is not how to define an image map or how to use it.
It's about how to have a predefined area (or more) of my own with 4 coordinates as a variable or an array and see if the user clicked in that area according to the x,y i get from the image map

John

sirblack

My best guess would be for you to make an IMAGE form element
<form .....>
<input type="image" src=".....">
</form>

that way when the user clicks on the image, it acts as a submit button, and passes x and y coordinate data to the page specified in the forms ACTION tag.

from there, you can just write a simple PHP script utilizing many clever "if" statements

if (x is between this and that and y is between this and that) { do this }

I hope that clears SOMETHING up.

If you ahve any further questions, just reply, I have e-mail notification on.

johnie

This is how i have it.
However i want to extend it and instead of having a lot of if's, i want to have some variables that represent the rectangles defined by some predefined coordinates and see if the x,y belong to that range.

In simple words what i want is something like
$var = (100, 200, 500, 400)
and see if
coord_x = 300
coord_y = 350
i get from an image map or elsewhere belong in that range.

John

sirblack

i suppose you can set multiple arrays

$x = whatever the user's x was
$y = whatever the user's y was

$var1 = (x1, x2, y1, y2);
$var2 = (x1, x2, y1, y2);
$var3 = (x1, x2, y1, y2);
$var4 = (x1, x2, y1, y2);

and then use a for() or while() statement mixed with variable-variables.

somethign that loops through

the $var# ....

that way.. you only use one if() statement inside of the loop to go through all of the possible areas..

johnie

Thanks Sirblack
I'll give it a try although i don't quite understand how to use
$var1 = (x1, x2, y1, y2);
as a variable but i'll have a look at the manual.

John

sirblack

let me clarify

$x = user's x input;
$y = user's y input;

$var1 = (0, 100, 0, 100);
$var2 = (100, 200, 0, 100);

for ($i = 1; $i =< 2; $i++) {

if ((($x >= $var$i[0]) && ($x =< $var$i[1])) && (($y >= $var$i[2]) && ($y >= $var$i[4]))) {

.. do something ..

}
}

of course... $var$i won't work.. but speaking theoretically, so that the PHP engine understands you're trying to tell it to go from

$var1 to $var2 .. and onwards...

sirblack

Oye, i'm really sorry, I'm being more confusing than I am being helpful

If you want to assign more than one value to a variable, that's called an array.. you can set an array as follows:

$var = array("value0", "value1", "value2" ... );

then to call individual values out of the array you use the following

$var[x], where x is the position of the value in the array.. ..

so.. $var[0] would return "value0", $var[1] would return "value1".. from the above array.. you can get more info here

johnie

$var1 = (0, 100, 0, 100);
$var2 = (100, 200, 0, 100);

for ($i = 1; $i =< 2; $i++) {

if ((($x >= $var$i[0]) && ($x =< $var$i[1])) && (($y >= $var$i[2]) && ($y >= $var$i[4]))) {
.....

I guess that you define an area as (x_left, x_right, y_top, y_bottom). What i was thinking was to define it as an area (x_left, y_top, y_bottom, x_right)
But in any case aren't there any chances of overlapping?

After a second thought 🙂 , probably not cause you are checking all four values

I'll check it out. Thanks Sirblack

John