scale and align image with FPDF #uniformToFill #scale #fit #fpdf

Pdf.php

<?php
require("fpdf.php");

class Pdf extends \FPDF
{

    const DPI = 300;
    const MM_IN_INCH = 25.4;
    const A4_HEIGHT = 297;
    const A4_WIDTH = 210;

     /**
     * Resize et fit une image image
     *
     * @param string $imgPath
     * @param integer $x
     * @param integer $y
     * @param integer $containerWidth
     * @param integer $containerHeight
     * @param string $alignment
     * @return void
     */
    public function imageUniformToFill(string $imgPath, int $x = 0, int $y = 0, int $containerWidth = 210, int $containerHeight = 297, string $alignment = 'C')
    {
        list($width, $height) = $this->resizeToFit($imgPath, $containerWidth, $containerHeight);

        if ($alignment === 'R')
        {
            $this->Image($imgPath, $x+$containerWidth-$width, $y+($containerHeight-$height)/2, $width, $height);
        }
        else if ($alignment === 'B')
        {
            $this->Image($imgPath, $x, $y+$containerHeight-$height, $width, $height);
        }
        else if ($alignment === 'C')
        {
            $this->Image($imgPath, $x+($containerWidth-$width)/2, $y+($containerHeight-$height)/2, $width, $height);
        }
        else
        {
            $this->Image($imgPath, $x, $y, $width, $height);
        }
    }
    
    /**
     * Convertit des pixels en mm
     *
     * @param integer $val
     * @return integer
     */
    protected function pixelsToMm(int $val) : int
    {
        return (int)(round($val * $this::MM_IN_INCH / $this::DPI));
    }

    /**
     * Convertit des mm en pixels
     *
     * @param integer $val
     * @return integer
     */
    protected function mmToPixels(int $val) : int
    {
        return (int)(round($this::DPI * $val / $this::MM_IN_INCH));
    }

    /**
     * Resize une image
     *
     * @param string $imgPath
     * @param integer $maxWidth en mm
     * @param integer $maxHeight en mm
     * @return int[]
     */
    protected function resizeToFit(string $imgPath, int $maxWidth = 210, int $maxHeight = 297) : array
    {
        list($width, $height) = getimagesize($imgPath);
        $widthScale = $this->mmtopixels($maxWidth) / $width;
        $heightScale = $this->mmToPixels($maxHeight) / $height;
        $scale = min($widthScale, $heightScale);
        return array(
            $this->pixelsToMM($scale * $width),
            $this->pixelsToMM($scale * $height)
        );
    }
}

// usage:
$pdf = new Pdf();
$pdf->AddPage();
$pdf->imageUniformToFill($imgPath, $x, $y ,$containerWidth, $containerHeight, $alignment) //$alignment "B", "T", "L", "R", "C"
$pdf->Output();

Merci à https://gist.github.com/benshimmin/4088493