<?php
/**
* ImageAffineMatrix
* Copyright (C) 2013-2014 Vladimir P.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/**
* Represents an affine transformation matrix.
* @copyright 2014 Vladimir P.
* @license MIT
*/
final class ImageAffineMatrix {
/**
* The 'a' component of the matrix.
* @var float
*/
private $a;
/**
* The 'b' component of the matrix.
* @var float
*/
private $b;
/**
* The 'c' component of the matrix.
* @var float
*/
private $c;
/**
* The 'd' component of the matrix.
* @var float
*/
private $d;
/**
* The translation along the x axis.
* @var float
*/
private $tx;
/**
* The translation along the y axis.
* @var float
*/
private $ty;
/**
* Creates a new affine transformation matrix.
*
* | A C Tx |
* | B D Ty |
* | 0 0 1 |
*
* @param float $a The 'a' component of the matrix.
* @param float $b The 'b' component of the matrix.
* @param float $c The 'c' component of the matrix.
* @param float $d The 'd' component of the matrix.
* @param float $tx The translation along the x axis.
* @param float $ty The translation along the y axis.
*/
public function __construct($a = 1, $b = 0, $c = 0, $d = 1, $tx = 0, $ty = 0) {
$this->setArray([ $a, $b, $c, $d, $tx, $ty ]);
}
/**
* Applies translation to the matrix.
*
* @param float $x Translation along the x axis.
* @param float $y Translation along the y axis.
* @return ImageAffineMatrix
*/
public function translate($x, $y) {
$this->tx += $x;
$this->ty += $y;
return $this;
}
/**
* Applies scaling transformation to the matrix.
*
* @param float $x Coefficient of the x axis.
* @param float $y Coefficient of the y axis.
* @return ImageAffineMatrix
*/
public function scale($x, $y) {
$this->multiply(new self($x, 0, 0, $y, 0, 0));
return $this;
}
/**
* Applies rotation transformation to the matrix.
*
* @param float $a Rotation angle in radians.
* @return ImageAffineMatrix
*/
public function rotate($a) {
$cosA = cos($a);
$sinA = sin($a);
$this->multiply(new self($cosA, $sinA, -$sinA, $cosA, 0, 0));
return $this;
}
/**
* Applies skewing transformation to the matrix.
*
* @param float $x Skew angle along the x axis in radians.
* @param float $y Skew angle along the y axis in radians.
* @return ImageAffineMatrix
*/
public function skew($x, $y) {
$this->multiply(new self(1, tan($y), tan($x), 1, 0, 0));
return $this;
}
/**
* Causes this matrix to perform an opposite transformation.
*
* @return ImageAffineMatrix
* @throws RuntimeException if the matrix is non-invertible.
*/
public function invert() {
$determinant = $this->getDeterminant();
if($determinant == 0)
throw new \RuntimeException('The matrix is non-invertible');
$this->setArray([
$this->d / $determinant,
-$this->b / $determinant,
-$this->c / $determinant,
$this->a / $determinant,
( $this->c * $this->ty) - ($this->d * $this->tx) / $determinant,
(-$this->a * $this->ty) + ($this->b * $this->tx) / $determinant
]);
return $this;
}
/**
* Multiplies this matrix by another matrix.
*
* @param ImageAffineMatrix $other The other matrix.
* @return ImageAffineMatrix
*/
public function multiply(self $other) {
$this->setArray([
$this->a * $other->getA() + $this->c * $other->getB(),
$this->b * $other->getA() + $this->d * $other->getB(),
$this->a * $other->getC() + $this->c * $other->getD(),
$this->b * $other->getC() + $this->d * $other->getD(),
$this->a * $other->getTx() + $this->c * $other->getTy() + $this->tx,
$this->b * $other->getTx() + $this->d * $other->getTy() + $this->ty
]);
return $this;
}
/**
* Returns a transformed point.
*
* @param float $x The x coordinate of a point.
* @param float $y The y coordinate of a point.
* @return array [ x, y ]
*/
public function transformPoint($x, $y) {
return array($this->a * $x + $this->c * $y + $this->tx,
$this->b * $x + $this->d * $y + $this->ty);
}
/**
* Returns a transformed image. (Requires PHP >= 5.5.0 and GD 2 library)
*
* @param resource $image An image resource.
* @return resource
*/
public function transformImage($image) {
return imageAffine($image, $this->getArray());
}
/**
* Returns the determinant of this matrix.
*
* @return float
*/
public function getDeterminant() {
return ($this->a * $this->d) - ($this->b * $this->c);
}
/**
* Sets the values of the matrix to the ones found in an array.
*
* @param array $values [ a, b, c, d, tx, ty ]
* @return void
*/
public function setArray($values) {
$this->setA($values[0]);
$this->setB($values[1]);
$this->setC($values[2]);
$this->setD($values[3]);
$this->setTx($values[4]);
$this->setTy($values[5]);
}
/**
* Returns an array of values from this matrix.
*
* @return array [ a, b, c, d, tx, ty ]
*/
public function getArray() {
return [ $this->a, $this->b, $this->c, $this->d, $this->tx, $this->ty ];
}
/**
* Returns a string for this matrix that can be used for SVG transform attribute or CSS transform property.
*
* @return string
*/
public function getTransform() {
return "matrix({$this->a},{$this->b},{$this->c},{$this->d},{$this->tx},{$this->ty})";
}
/**
* Sets the 'a' component of the matrix.
*
* @param float $a The new value of 'a'.
* @return void
*/
public function setA($a = 1) {
$this->a = (float)$a;
}
/**
* Returns the 'a' component of the matrix.
*
* @return float
*/
public function getA() {
return $this->a;
}
/**
* Sets the 'b' component of the matrix.
*
* @param float $b The new value of 'b'.
* @return void
*/
public function setB($b = 0) {
$this->b = (float)$b;
}
/**
* Returns the 'b' component of the matrix.
*
* @return float
*/
public function getB() {
return $this->b;
}
/**
* Sets the 'c' component of the matrix.
*
* @param float $c The new value of 'c'.
* @return void
*/
public function setC($c = 0) {
$this->c = (float)$c;
}
/**
* Returns the 'c' component of the matrix.
*
* @return float
*/
public function getC() {
return $this->c;
}
/**
* Sets the 'd' component of the matrix.
*
* @param float $d The new value of 'd'.
* @return void
*/
public function setD($d = 1) {
$this->d = (float)$d;
}
/**
* Returns the 'd' component of the matrix.
*
* @return float
*/
public function getD() {
return $this->d;
}
/**
* Sets the translation along the x axis.
*
* @param float $x
* @return void
*/
public function setTx($x) {
$this->tx = (float)$x;
}
/**
* Returns the translation along the x axis.
*
* @return float
*/
public function getTx() {
return $this->tx;
}
/**
* Sets the translation along the y axis.
*
* @param float $y
* @return void
*/
public function setTy($y) {
$this->ty = (float)$y;
}
/**
* Returns the translation along the y axis.
*
* @return float
*/
public function getTy() {
return $this->ty;
}
}