Question

Simple question, I searched over there and didnt found a way to make this.

I have a string (variable one) which can be like this:

#FF9900Hel#FFFFFFlo

I need a way to make the imagettftext function recognice those colors and draw the text using those colors. For example, in the example I mentioned before, the text should be: in red: Hel and in white:lo. I hope I explained well what I mean.

Thanks in advance

Answer 1

You not only need to recognize colors, you also need to align the strings. This is not automatic as it is in HTML.

I would do this by first splitting the string into its components parts:

// Split the text using hex colors as strings:
$hex     = '[0-9a-fA-F]'; // Capital hex should be supported

$colorex = "(#{$hex}{$hex}{$hex}{$hex}{$hex}{$hex})";
// or also $colorex = "(#{$hex}{6})";

$parts = preg_split ("/{$colorex}/", $text, -1, PREG_SPLIT_DELIM_CAPTURE);

// Then you would iterate through the parts:

$color = imageColorAllocate($gd, 0, 0, 0); // Default is black
foreach($parts as $part)
{
    // Scan the hex value
    if (preg_match("/^{$colorex}\$/", $part, $gregs))
    {
        sscanf($gregs[1], "#%02x%02x%02x", &$r, &$g, &$b);
        $color = imageColorAllocate($gd, $r, $g, $b);
        continue;
    }
    // IMPROVEMENT: if count(explode("\n", $part)) > 1, $y += $height, $x = 0
    // to indicate "go to next line". So this would appear on two lines:
    //     #012345Hel#ff7700lo,
    //     #443212World 
    // Next section will be repeated for each item
    // in the exploded string.
    //! $subparts = explode("\n", $part);
    //! foreach($subparts as $part)
    //! { // We have overwritten $part

    // Here $part is printed as string at position $x, $y
    // Ask GD to calculate string width
    // with http://php.net/manual/en/function.imagettfbbox.php
    // Calculations with $angle != 0 is a bit more difficult, entails trigonometric
    // evaluation of $w and $h.
    $bbox = imagettfbbox ($size, $angle, $fontfile, $part);
    $w    = $bbox[4] - $bbox[0];  // 0,1 is lower left corner
    $h    = $bbox[5] - $bbox[1];  // 4,5 is upper right
    imagettftext ($gd, $size, $angle, $x, $y, $color, $fontfile, $part);
    // Increment $x position by $w
    $x += $w;

    //!     if (count($subparts) > 1)
    //!     {
    //!         $x = 0; $y += $h;
    //!     }
    //! }
}