Proyectos de Subversion Moodle

/**

 * Copies a rectangular portion of the source image to another rectangle in the destination image

 *

 * This function calls imagecopyresampled() if it is available and GD version is 2 at least.

 * Otherwise it reimplements the same behaviour. See the PHP manual page for more info.

 *

 * @link http://php.net/manual/en/function.imagecopyresampled.php

 * @param resource|\GdImage $dst_img the destination GD image resource

 * @param resource|\GdImage $src_img the source GD image resource

 * @param int $dst_x vthe X coordinate of the upper left corner in the destination image

 * @param int $dst_y the Y coordinate of the upper left corner in the destination image

 * @param int $src_x the X coordinate of the upper left corner in the source image

 * @param int $src_y the Y coordinate of the upper left corner in the source image

 * @param int $dst_w the width of the destination rectangle

 * @param int $dst_h the height of the destination rectangle

 * @param int $src_w the width of the source rectangle

 * @param int $src_h the height of the source rectangle

 * @return ?bool tru on success, false otherwise

 */

function imagecopybicubic($dst_img, $src_img, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h) {

    global $CFG;

    if (function_exists('imagecopyresampled')) {

       return imagecopyresampled($dst_img, $src_img, $dst_x, $dst_y, $src_x, $src_y,

                                 $dst_w, $dst_h, $src_w, $src_h);

    }

    $totalcolors = imagecolorstotal($src_img);

    for ($i=0; $i<$totalcolors; $i++) {

        if ($colors = imagecolorsforindex($src_img, $i)) {

            imagecolorallocate($dst_img, $colors['red'], $colors['green'], $colors['blue']);

        }

    }

    $scalex = ($src_w - 1) / $dst_w;

    $scaley = ($src_h - 1) / $dst_h;

    $scalex2 = $scalex / 2.0;

    $scaley2 = $scaley / 2.0;

    for ($j = 0; $j < $dst_h; $j++) {

        $sy = $j * $scaley;

        for ($i = 0; $i < $dst_w; $i++) {

            $sx = $i * $scalex;

            $c1 = imagecolorsforindex($src_img, imagecolorat($src_img, (int)$sx, (int)$sy + $scaley2));

            $c2 = imagecolorsforindex($src_img, imagecolorat($src_img, (int)$sx, (int)$sy));

            $c3 = imagecolorsforindex($src_img, imagecolorat($src_img, (int)$sx + $scalex2, (int)$sy + $scaley2));

            $c4 = imagecolorsforindex($src_img, imagecolorat($src_img, (int)$sx + $scalex2, (int)$sy));

            $red = (int) (($c1['red'] + $c2['red'] + $c3['red'] + $c4['red']) / 4);

            $green = (int) (($c1['green'] + $c2['green'] + $c3['green'] + $c4['green']) / 4);

            $blue = (int) (($c1['blue'] + $c2['blue'] + $c3['blue'] + $c4['blue']) / 4);

            $color = imagecolorclosest($dst_img, $red, $green, $blue);

            imagesetpixel($dst_img, $i + $dst_x, $j + $dst_y, $color);

        }

    }

}