Zabbix

<?php

/*

** Zabbix

** Copyright (C) 2001-2022 Zabbix SIA

**

** This program is free software; you can redistribute it and/or modify

** it under the terms of the GNU General Public License as published by

** the Free Software Foundation; either version 2 of the License, or

** (at your option) any later version.

**

** This program is distributed in the hope that it will be useful,

** but WITHOUT ANY WARRANTY; without even the implied warranty of

** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

** GNU General Public License for more details.

**

** You should have received a copy of the GNU General Public License

** along with this program; if not, write to the Free Software

** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

**/

​

​

/**

 * Calculate new color based on bg/fg colors and transparency index

 *

 * @param   resource  $image      image reference

 * @param   array     $bgColor    background color, array of RGB

 * @param   array     $fgColor    foreground color, array of RGB

 * @param   float     $alpha      transparency index in range of 0-1, 1 returns unchanged fgColor color

 *

 * @return int  A color index.

 */

function zbx_colormix($image, $bgColor, $fgColor, $alpha) {

    $r = $bgColor[0] + ($fgColor[0] - $bgColor[0]) * $alpha;

    $g = $bgColor[1] + ($fgColor[1] - $bgColor[1]) * $alpha;

    $b = $bgColor[2] + ($fgColor[2] - $bgColor[2]) * $alpha;

​

    return imagecolorresolvealpha($image, (int) $r, (int) $g, (int) $b, 0);

}

​

/**

 * Draw normal line.

 * PHP imageline() function is broken because it drops fraction instead of correct rounding of X/Y coordinates.

 * All calls to imageline() must be replaced by the wrapper function everywhere in the code.

 *

 * @param resource  $image  image reference

 * @param int       $x1     first x coordinate

 * @param int       $y1     first y coordinate

 * @param int       $x2     second x coordinate

 * @param int       $y2     second y coordinate

 * @param int       $color  line color

 */

function zbx_imageline($image, $x1, $y1, $x2, $y2, $color) {

        imageline($image, round($x1), round($y1), round($x2), round($y2), $color);

}

​

/**

 * Draw antialiased line

 *

 * @param resource  $image  image reference

 * @param int       $x1     first x coordinate

 * @param int       $y1     first y coordinate

 * @param int       $x2     second x coordinate

 * @param int       $y2     second y coordinate

 * @param int       $color  line color

 * @param int       $style  line style, one of LINE_TYPE_NORMAL (default), LINE_TYPE_BOLD (bold line)

 */

function zbx_imagealine($image, $x1, $y1, $x2, $y2, $color, $style = LINE_TYPE_NORMAL) {

    $x1 = round($x1);

    $y1 = round($y1);

    $x2 = round($x2);

    $y2 = round($y2);

​

    if ($x1 == $x2 && $y1 == $y2) {

        imagesetpixel($image, $x1, $y1, $color);

        return;

    }

​

    // Get foreground line color

    $lc = imagecolorsforindex($image, $color);

    $lc = [$lc['red'], $lc['green'], $lc['blue']];

​

    $dx = $x2 - $x1;

    $dy = $y2 - $y1;

​

    if (abs($dx) > abs($dy)) {

        if ($dx < 0) {

            [$x1, $x2] = [$x2, $x1];

            $y1 = $y2;

        }

        for ($x = $x1, $y = $y1; $x <= $x2; $x++, $y = $y1 + ($x - $x1) * $dy / $dx) {

            $yint = floor($y);