Image Library text_watermark placement.

[bitbucket-import]

The vertical placement of text when using TTF's seems a bit erratic. On looking through the code for the text_watermark() method in Image_lib.php, I find:

{{{

!php

$fontwidth = $this->wm_font_size-($this->wm_font_size/4);
$fontheight = $this->wm_font_size;
$this->wm_vrt_offset += $this->wm_font_size;
}}}

On my develoment system, I've replaced this with the following using the php imagettfbbox function to determine the boundaries of the text. It seems to give a much more accurate result.

{{{

!php

$wm_text_box = imagettfbbox($this->wm_font_size,0,$this->wm_font_path,$this->wm_text);
$wm_text_width = $wm_text_box[2] - $wm_text_box[0];
$wm_text_height = $wm_text_box[1] - $wm_text_box[7];
$fontheight = $wm_text_height;
$fontwidth = $wm_text_width/strlen($this->wm_text);
$this->wm_vrt_offset += $fontheight;
}}}

[rcstr]

done!

[YorrickDL]

There's still a glitch with this code.

Horizontal positioning is perfect, though the vertical position gets messed up.
I've tested this with rendering different letters/words/sentences, only to see them change vertical position by a pixel or two, depending on which letters/words/sentences you use.

Corrected code:

{{{
#!php
$wm_text_box = imagettfbbox($this->wm_font_size,0,$this->wm_font_path,$this->wm_text);
$wm_text_width = $wm_text_box[2] - $wm_text_box[0];
$fontheight = $wm_font_size;
$fontwidth = $wm_text_width/strlen($this->wm_text);
$this->wm_vrt_offset += $fontheight;
}}}

All I did was re-use the original CI font-size code to get the correct vertical bounding box dimensions.

[narfbg]

Thanks for your efforts guys.