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<?php |
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/** |
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* Copyright (C) 2019-2022 Graham Breach |
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* |
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* This program is free software: you can redistribute it and/or modify |
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* it under the terms of the GNU Lesser General Public License as published by |
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* the Free Software Foundation, either version 3 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public License |
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* along with this program. If not, see <http://www.gnu.org/licenses/>. |
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*/ |
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/** |
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* For more information, please contact <graham@goat1000.com> |
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*/ |
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|
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namespace Goat1000\SVGGraph; |
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|
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/** |
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* Colour range for RGB values |
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*/ |
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class ColourRangeRGB extends ColourRange { |
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|
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private $r1, $g1, $b1; |
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private $rdiff, $gdiff, $bdiff; |
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|
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/** |
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* RGB range |
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*/ |
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public function __construct($r1, $g1, $b1, $r2, $g2, $b2) |
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{ |
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$this->r1 = $this->clamp($r1, 0, 255); |
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$this->g1 = $this->clamp($g1, 0, 255); |
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$this->b1 = $this->clamp($b1, 0, 255); |
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$this->rdiff = $this->clamp($r2, 0, 255) - $this->r1; |
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$this->gdiff = $this->clamp($g2, 0, 255) - $this->g1; |
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$this->bdiff = $this->clamp($b2, 0, 255) - $this->b1; |
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} |
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|
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/** |
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* Return the colour from the range |
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*/ |
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#[\ReturnTypeWillChange] |
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public function offsetGet($offset) |
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{ |
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$c = max($this->count - 1, 1); |
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$offset = $this->clamp($offset, 0, $c); |
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$r = $this->r1 + $offset * $this->rdiff / $c; |
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$g = $this->g1 + $offset * $this->gdiff / $c; |
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$b = $this->b1 + $offset * $this->bdiff / $c; |
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return sprintf('#%02x%02x%02x', $r, $g, $b); |
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} |
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} |
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