Canvas final readonly class

Minn\Media\Canvas · public/minn/src/Minn/Media/Canvas.php · 168 lines

One GD bitmap and the operations the media layer needs on it. Every operation returns a new canvas; alpha is preserved throughout, which is what makes PNG and WebP sub-sizes match the reference's.

Constants and properties

private	`readonly GdImage $image`	Promoted from the constructor.
prop	`readonly int $width`	Promoted from the constructor.
prop	`readonly int $height`	Promoted from the constructor.

Public

new __construct(GdImage $image, int $width, int $height)#

static

of(GdImage $image): self#

A canvas over a GD image already in hand (what WP_Image_Editor_GD::_save is given).

method

image(): GdImage#

The GD image behind the canvas (what WP_Image_Editor_GD::_resize hands back).

static

open(string $path): ?self#

A canvas from an image file, or null when it cannot be decoded or would not fit in memory. The header names the dimensions before a pixel is decoded, so a small file that claims a huge canvas is refused instead of taking the request down.

method

resample(array $box): self#

Resamples a source box onto a destination box.

$box array{0: int, 1: int, 2: int, 3: int, 4: int, 5: int, 6: int, 7: int} dst x, dst y, src x, src y, dst w, dst h, src w, src h (the GD argument order)

method

crop(int $x, int $y, int $width, int $height, ?int $targetWidth = NULL, ?int $targetHeight = NULL): self#

A canvas cut to a rectangle, resized to a target when given.

method

rotate(float $angle): ?self#

A canvas turned by an angle, or null when GD refuses.

method

flipVertical(): self#

A canvas mirrored on either axis.

method

flipHorizontal(): self#

A canvas mirrored left to right.

method

copy(): self#

An untouched copy of the canvas.

method

write(string $path, string $mime, int $quality): bool#

Writes the bitmap in the given format; the directory is created when missing.

method

progressive(): self#

The bitmap written progressively from now on (an interlaced JPEG).

method

baseline(): self#

The bitmap written line by line from now on, as it is by default.

method

stream(string $mime, int $quality): bool#

Writes the image to the output in a format, at a quality.

Internals 4

Private and protected methods: how the class does its work. Not a contract; they change whenever the code is tidied.

private	`affordable(int $width, int $height): bool`#	Whether a bitmap of these dimensions fits the memory left to this request: five bytes a pixel for the decoded image (GD keeps four and a little), twice over because every operation makes a second canvas, under what memory_limit leaves after what is already in use.
private	`memoryLimit(): ?int`#	memory_limit in bytes, or null when it is unlimited.
private	`flipped(int $mode): self`#
private	`encode(string $mime, ?string $path, int $quality): bool`#