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implement arrayaccess methods
assign and unset image bands
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‎CHANGELOG.md

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@@ -1,6 +1,11 @@
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# Changelog
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All notable changes to `:vips` will be documented in this file.
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## 1.0.2 - 2017-06-06
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### Added
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- implement array access interface [John Cupitt]
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## 1.0.1 - 2017-04-29
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### Added

‎src/Image.php

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* to append a constant 255 band to an image, perhaps to add an alpha channel. Of
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* course you can also write:
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*
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* ```ruby
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* ```php
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* $result = $image->bandjoin($image2);
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* $result = $image->bandjoin([image2, image3]);
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* $result = Image::bandjoin([image1, image2, image3]);
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*
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* and so on.
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*
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* # Array access
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*
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* Images can be treated as arrays of bands. You can write:
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*
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* ```php
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* $result = $image[1];
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* ```
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*
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* to get band 1 from an image (green, in an RGB image).
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*
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* You can assign to bands as well. You can write:
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*
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* ```php
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* $image[1] = $other_image;
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* ```
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*
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* And band 1 will be replaced by all the bands in `$other_image` using
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* `bandjoin`. Use no offset to mean append, use -1 to mean prepend:
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*
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* ```php
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* $image[] = $other_image; // append bands from other
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* $image[-1] = $other_image; // prepend bands from other
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* ```
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*
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* You can use number and array constants as well, for example:
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*
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* ```php
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* $image[] = 255; // append a constant 255
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* $image[1] = [1, 2, 3]; // swap band 1 for three constant bands
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* ```
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*
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* Finally, you can delete bands with `unset`:
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*
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* ```php
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* unset($image[1]); // remove band 1
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* ```
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*
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* # Exceptions
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*
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* The wrapper spots errors from vips operations and throws
@@ -1162,7 +1199,7 @@ public function hasAlpha(): bool
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}
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/**
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* Our ArrayAccess interface ... we allow [] to get band.
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* Does band exist in image.
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*
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* @param mixed $offset The index to fetch.
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*
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}
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/**
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* Our ArrayAccess interface ... we allow [] to get band.
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* Get band from image.
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*
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* @param mixed $offset The index to fetch.
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*
@@ -1186,28 +1223,88 @@ public function offsetGet($offset): Image
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}
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/**
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* Our ArrayAccess interface ... we allow [] to get band.
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* Set a band.
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*
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* Use `$image[1] = $other_image;' to remove band 1 from this image,
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* replacing it with all the bands in `$other_image`.
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*
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* Use `$image[] = $other_image;' to append all the bands in `$other_image`
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* to `$image`.
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*
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* @param mixed $offset The index to set.
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* Use `$image[-1] = $other_image;` to prepend all the bands in
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* `$other_image` to `$image`.
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*
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* You can use constants or arrays in place of `$other_image`. Use `$image[]
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* = 255;` to append a constant 255 band, for example, or `$image[1]
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* = [1, 2];` to replace band 1 with two constant bands.
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*
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* @param int $offset The index to set.
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* @param Image $value The band to insert
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*
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* @return Image the expanded image.
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* @return void
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*/
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public function offsetSet($offset, $value): Image
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public function offsetSet($offset, $value): void
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{
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throw new \BadMethodCallException('Image::offsetSet: not implemented');
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// no offset means append
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if (is_null($offset)) {
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$offset = $this->bands;
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}
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if (!is_int($offset)) {
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throw new \BadMethodCallException('Image::offsetSet: offset is not integer or null');
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}
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// expand constant, if necessary
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if (!($value instanceof Image)) {
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$value = self::imageize($this, $value);
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}
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// number of bands to the left and right of $value
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$n_left = min($this->bands, max(0, $offset));
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$n_right = min($this->bands, max(0, $this->bands - 1 - $offset));
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$offset = $this->bands - $n_right;
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$components = [];
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if ($n_left > 0) {
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$components[] = $this->extract_band(0, ["n" => $n_left]);
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}
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$components[] = $value;
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if ($n_right) {
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$components[] = $this->extract_band($offset, ["n" => $n_right]);
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}
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$head = array_shift($components);
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$this->image = $head->bandjoin($components)->image;
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}
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/**
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* Our ArrayAccess interface ... we allow [] to get band.
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* Remove a band from an image.
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*
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* @param mixed $offset The index to remove.
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* @param int $offset The index to remove.
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*
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* @return Image the reduced image.
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* @return void
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*/
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public function offsetUnset($offset): Image
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public function offsetUnset($offset): void
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{
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throw new \BadMethodCallException('Image::offsetUnset: not implemented');
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if (is_int($offset) and $offset >= 0 and $offset < $this->bands) {
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$components = [];
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if ($offset > 0) {
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$components[] = $this->extract_band(0, ["n" => $offset]);
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}
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if ($offset < $this->bands - 1) {
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$components[] = $this->extract_band(
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$offset + 1,
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["n" => $this->bands - 1 - $offset]
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);
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}
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$head = array_shift($components);
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if ($components != null) {
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$this->image = $head->bandjoin($components)->image;
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} else {
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$this->image = $head->image;
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}
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}
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}
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/**

‎tests/shortcuts.php

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@@ -236,6 +236,92 @@ public function testVipsIndex()
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$this->assertEquals($vips->bands, 1);
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}
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public function testOffsetSet()
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{
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$base = Vips\Image::newFromArray([1, 2, 3]);
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$image = $base->bandjoin([$base->add(1), $base->add(2)]);
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// replace band with image
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$test = $image->copy();
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$test[1] = $base;
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$this->assertEquals($test->bands, 3);
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$this->assertEquals($test[0]->avg(), 2);
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$this->assertEquals($test[1]->avg(), 2);
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$this->assertEquals($test[2]->avg(), 4);
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// replace band with constant
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$test = $image->copy();
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$test[1] = 12;
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$this->assertEquals($test->bands, 3);
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$this->assertEquals($test[0]->avg(), 2);
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$this->assertEquals($test[1]->avg(), 12);
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$this->assertEquals($test[2]->avg(), 4);
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// replace band with array
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$test = $image->copy();
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$test[1] = [12, 13];
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$this->assertEquals($test->bands, 4);
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$this->assertEquals($test[0]->avg(), 2);
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$this->assertEquals($test[1]->avg(), 12);
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$this->assertEquals($test[2]->avg(), 13);
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$this->assertEquals($test[3]->avg(), 4);
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// insert at start
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$test = $image->copy();
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$test[-1] = 12;
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$this->assertEquals($test->bands, 4);
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$this->assertEquals($test[0]->avg(), 12);
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$this->assertEquals($test[1]->avg(), 2);
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$this->assertEquals($test[2]->avg(), 3);
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$this->assertEquals($test[3]->avg(), 4);
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// append at end
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$test = $image->copy();
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$test[] = 12;
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$this->assertEquals($test->bands, 4);
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$this->assertEquals($test[0]->avg(), 2);
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$this->assertEquals($test[1]->avg(), 3);
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$this->assertEquals($test[2]->avg(), 4);
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$this->assertEquals($test[3]->avg(), 12);
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}
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public function testOffsetUnset()
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{
291+
$base = Vips\Image::newFromArray([1, 2, 3]);
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$image = $base->bandjoin([$base->add(1), $base->add(2)]);
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// remove middle
295+
$test = $image->copy();
296+
unset($test[1]);
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$this->assertEquals($test->bands, 2);
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$this->assertEquals($test[0]->avg(), 2);
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$this->assertEquals($test[1]->avg(), 4);
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// remove first
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$test = $image->copy();
303+
unset($test[0]);
304+
$this->assertEquals($test->bands, 2);
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$this->assertEquals($test[0]->avg(), 3);
306+
$this->assertEquals($test[1]->avg(), 4);
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// remove last
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$test = $image->copy();
311+
unset($test[2]);
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$this->assertEquals($test->bands, 2);
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$this->assertEquals($test[0]->avg(), 2);
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$this->assertEquals($test[1]->avg(), 3);
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// remove outside range
317+
$test = $image->copy();
318+
unset($test[12]);
319+
$this->assertEquals($test->bands, 3);
320+
$this->assertEquals($test[0]->avg(), 2);
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$this->assertEquals($test[1]->avg(), 3);
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$this->assertEquals($test[2]->avg(), 4);
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}
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}
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/*

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