calcualte position of text on image

[helraizer]

Hi folks,

 

I have a dynamic image made in php with the GD2 library.. the system allows users to write/send a message which then appears on the image.

 

 

^as above. How (if at all possible) could I calculate the position of the a certain word in the text on the image? Like, find/return the X and Y values for that word?

 

Hope that made sense,

 

Sam

[BenInBlack]

???-- stupid question alert  -- ???

Why on earth are you doing it in image format?

???-- stupid question alert  -- ???

 

Man that must take forever, and creating and image is one thing, trying to read data out of it, i doubt you could, due to the randomness of the background, I mean, if it was all white back ground and you used mono spaced font, you might be able to create a library of each letter, and then take that letter image and compare it to the big image you create in gd.

 

Why dont you just use a background with text on it 

[helraizer]

???-- stupid question alert  -- ???

Why on earth are you doing it in image format?

???-- stupid question alert  -- ???

 

Why dont you just use a background with text on it 

 

The idea behind it was so that I could use it as a forum signature, so I can only link it with '[ img ]' tags if it is an image. Therefore if it wasn't a picture it would be useless for the purpose it was created

 

Sam

[GingerRobot]

Why would you want to? Perhaps you could do something prior to the the text being written on the image?

 

[BenInBlack]

I guess im, lost, because what you are describing is creating the image to use as a forum signature, so why do you need to read the data out of the image?

[helraizer]

Why would you want to? Perhaps you could do something prior to the the text being written on the image?

 

 

I got the inspiration from those dynamic images that say "Your IP address is xxx.xxx.xxx.xxx" - which are generated by some random site, and seem quite pointless. So this is almost like a shoutbox to use as signature, that updates everytime someone posts a message. So it isn't entirely pointless. Try it: myChatbox

 

One problem is for the fonts, each font has a different width.. so I can easily cut that function, so the messages are all in the same font. Is there a function, or anything to decipher the x & y values of a certain word (specified) within the string? Or am I just being hopeful?

 

@ BenInBlack: The idea was/is to find the x&y positions of certain parts of the string, like on a forum to use emoticons, and use ImageCopyMerge to add the emoticon; for instance  if the user types '=)' or '' it will ImageCopyMerge an image (an emoticon)  at that position where the text is '=)' or ''.

 

I know I may be aiming a bit too high Hope that makes sense,

 

Sam

[GingerRobot]

I think what you're after is imagettfbbox(). You specify the text, font, and angle, and it returns an array of points showing the dimensions.

 

Here's a snippet from the code that generates my signiture using the above function:

 

	$size = imagettfbbox(8,0,$font,$v);
	$width = $size[2] - $size[0];
	while($width > 250){
	$v = substr($v,0,strlen($v)-4).'...';
 	$size = imagettfbbox(8,0,$font,$v);
 	$width = $size[2] - $size[0];
}

 

The idea is to keep shortening the text until it fits into the space for it.

[helraizer]

I think what you're after is imagettfbbox(). You specify the text, font, and angle, and it returns an array of points showing the dimensions.

 

Here's a snippet from the code that generates my signiture using the above function:

 

	$size = imagettfbbox(8,0,$font,$v);
	$width = $size[2] - $size[0];
	while($width > 250){
	$v = substr($v,0,strlen($v)-4).'...';
 	$size = imagettfbbox(8,0,$font,$v);
 	$width = $size[2] - $size[0];
}

 

The idea is to keep shortening the text until it fits into the space for it.

 

Thanks GingerRobot; this (below) is my code for the image; how would I impliment the imagettfbox within this?

 

<?php
include("linesfile.php5");
$linesDataFile = new DataFile("data.line");

//$image = ImageCreate(660,240); // create the image canvas
$image = ImageCreateFromPNG("background.png");
$blue = ImageColorAllocate($image, 200, 200, 255); // prepare some blueness
$black = ImageColorAllocate($image, 0, 0, 0); // ... and whiteness

$cur_line_y = 63;  // This stores how far down the image the current line will print
$cur_line_x = 24; // This stores how far across the image the current line will print
$pagecharwidth = 75; // this is the maximum length of the line before it wraps;
$lineheight = 15; // This is how much to move down to print the next line
$pagelinelimit = 12; // This is the maximum number lines of text that can be displayed

ImageFill($image, 0, 0, $blue); // fill the canvas

//ImageString($image, 3, 15, $cur_line_y, trim(stripslashes($wordwrapped[0])), $black);

$numberOfLines = $pagelinelimit;



for($i=0;$i<$numberOfLines;$i++) {
$data = $linesDataFile->getReverseIterate();
if (count($data)==0) continue;
$name = "[" . $data[0] . "] ";
$color = $data[1];
$font = $data[2];
$line = $data[3];

$line = $name . $line;



//ImageString($image, 2, $cur_line_x, $cur_line_y, trim($line), getColor($color));


		imagettftext($image,10,0,$cur_line_x,$cur_line_y,getColor($color),getfont($font),trim($line));

$cur_line_y += $lineheight;

}

function getColor($color) {
global $image;

switch($color) {
	case "black" :
		return ImageColorAllocate($image, 0, 0, 0); 
	case "white" :
		return ImageColorAllocate($image, 255, 255, 255); 
	case "blue" :
		return ImageColorAllocate($image, 0, 0, 205); 
	case "red" :      
		return ImageColorAllocate($image, 255, 0, 0); 
	case "yellow" :
		return ImageColorAllocate($image, 255, 255, 0); 
	case "green" :
		return ImageColorAllocate($image, 0, 255, 0); 
                   case "orange" :
                               return ImageColorAllocate($image, 255, 127, 36);
                   case "aqua" :
                               return ImageColorAllocate($image, 0, 255, 255);
	default: 
		return ImageColorAllocate($image, 255, 255, 255); 

}
}

function getfont($font) {
global $image;
global $font;

switch($font) {
	case "fixedsys" :
		return "fixedsys.ttf";
	case "Courbd" :
		return "courbd.ttf";
	case "arial" :
		return "arialbd.ttf";
	case "timesnr" :
		return "timesbd.ttf";
	case "calibri" :
		return "calibrib.ttf";
	case "comicsans" :
		return "comicsans.ttf";
	case "palab" :
		return "palab.ttf";
	default:
		return "courbd.ttf";
}
}


header("Content-Type: image/png"); // tell the browser what we're gonna give it
ImagePng($image); // paint the image in browser
ImagePng($image, "./chatbox.png"); //export as png file
ImageDestroy($image); // clean up resources
?>

 

Sam