Generate image causes error imagettftext invalid font filename - wordpress

Question

I am working on a wordpress project, and I need to generate an image dynamically, using PHP’s imagecreatefromjpeg() function in addition to the imagettftext() function to add custom text to the image, with fonts of my choice.

The script I developed works perfectly, but when I try to use it inside the wordpress page I can’t find the font.

Code example (works):

<?php

/*---------------------------------------*/
// Header informando que é uma imagem JPEG
header( 'Content-type: image/jpeg' );

// Carregar imagem já existente no servidor
$imagem = imagecreatefromjpeg( "cupomFinal.jpg" );    
$cor = imagecolorallocate($imagem, 119, 119, 119);
$corTitle = imagecolorallocate($imagem, 163, 72, 177);

// Texto que será escrito na imagem
$nome = "Cliente: Vinicius Ribeiro";
$email = "Email: [email protected]";
$contato = "Contato: 31-0000-0000";
$codigo = "Código:";
$codigoDesconto = "00000-00-000-2015";

$font = 'RobotoCondensed-Regular.ttf';
$fontCodigo = 'impact.ttf';

// INSERE OS TEXTOS NA IMAGEM COM AS FONTES ESCOLHIDAS
imagettftext($imagem, 16, 0, 390, 140, $cor, $font, $nome);
imagettftext($imagem, 13, 0, 390, 170, $cor, $font, $email);
imagettftext($imagem, 13, 0, 390, 200, $cor, $font, $contato);
imagettftext($imagem, 12, 0, 50, 170, $corTitle, $fontCodigo, $codigo);
imagettftext($imagem, 18, 0, 50, 200, $corTitle, $fontCodigo, $codigoDesconto);


// eEnvia a imagem para o borwser ou arquivo
imagejpeg( $imagem, NULL, 90);
imagedestroy($imagem);
?>

The above code has been tested separately and worked perfectly, but when I try to implement inside wordpress, the font is never found!

Since the "header" command indicates that the page will be an image, just comment to view the errors. So I visualized the following return:

I have tried to use several paths to the source and all without success.

In some attempts I used the function imagestring() which also writes in the image, but without the custom font, and the script worked perfectly with the syntax below:

imagestring($imagem, 5, 390, 170,  $email, $cor);

But it would be extremely important that I use the custom source.

Thanks in advance for the help.

Hug.