Question

I’m trying to create a vertical button in PHP, but I have problem with the positioning, when I created a 200px height and 40px width PNG i want to put the text to the center of that image. The text long will be changing dynamically

this is a part of my code

$image = imagecreate($this->width , $this->height);
$background = ImageColorAllocate($image, $this->bg_red, $this->bg_grn, $this->bg_blu);
$foreground = ImageColorAllocate($image, $this->red, $this->grn, $this->blu);

if ($this->transparent) ImageColorTransparent($image, $background);
ImageInterlace($image, false);
// render the image
ImageTTFText($image, $this->size, $this->rot, $offset_x, $offset_y, $foreground, $this->font, $this->msg); 

how can I calculate the $offset_x and $offset_y?

Answer 1

As you can see in the documentation of imagettftext function, it

Returns an array with 8 elements
representing four points making the
bounding box of the text. The order of
the points is lower left, lower right,
upper right, upper left. The points
are relative to the text regardless of
the angle, so “upper left” means in
the top left-hand corner when you see
the text horizontally. Returns FALSE
on error.

So you can first draw the text on another image, just to see what the dimensions will be, then calculate the needed height of your button.