Description

Gnome::Gdk4::Texture is the basic element used to refer to pixel data.

It is primarily meant for pixel data that will not change over multiple frames, and will be used for a long time.

There are various ways to create Gnome::Gdk4::Texture objects from a Gnome::Gdk4::Texture, or a Cairo surface, or other pixel data.

The ownership of the pixel data is transferred to the Gnome::Gdk4::Texture instance; you can only make a copy of it, via .download().

Gnome::Gdk4::Texture is an immutable object: That means you cannot change anything about it other than increasing the reference count via .ref() in class Gnome::GObject::Object, and consequently, it is a thread-safe object.

Class initialization

new

:native-object

Create an object using a native object from elsewhere. See also Gnome::N::TopLevelSupportClass.

multi method new ( N-Object :$native-object! )

new-for-pixbuf

Creates a new texture object representing the Gnome::GdkPixbuf::Pixbuf.

This function is threadsafe, so that you can e.g. use GTask and .run-in-thread() in class Gnome::Gio::Task to avoid blocking the main thread while loading a big image.

method new-for-pixbuf ( N-Object() $pixbuf --> Gnome::Gdk4::Texture \)

• $pixbuf; a Gnome::GdkPixbuf::Pixbuf.

new-from-bytes

Creates a new texture by loading an image from memory,

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

If undefined is returned, then $error will be set.

This function is threadsafe, so that you can e.g. use GTask and .run-in-thread() in class Gnome::Gio::Task to avoid blocking the main thread while loading a big image.

method new-from-bytes ( N-Object $bytes, CArray[N-Error] $err --> Gnome::Gdk4::Texture \)

• $bytes; a Gnome::Glib::N-Bytes containing the data to load

• $err; Error object. When defined, an error can be returned when there is one. Use Pointer when you want to ignore the error. .

new-from-file

Creates a new texture by loading an image from a file.

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

If undefined is returned, then $error will be set.

This function is threadsafe, so that you can e.g. use GTask and .run-in-thread() in class Gnome::Gio::Task to avoid blocking the main thread while loading a big image.

method new-from-file ( N-Object() $file, CArray[N-Error] $err --> Gnome::Gdk4::Texture \)

• $file; Gnome::Gio::R-File to load.

• $err; Error object. When defined, an error can be returned when there is one. Use Pointer when you want to ignore the error. .

new-from-filename

Creates a new texture by loading an image from a file.

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

If undefined is returned, then $error will be set.

This function is threadsafe, so that you can e.g. use GTask and .run-in-thread() in class Gnome::Gio::Task to avoid blocking the main thread while loading a big image.

method new-from-filename ( Str $path, CArray[N-Error] $err --> Gnome::Gdk4::Texture \)

• $path; the filename to load.

• $err; Error object. When defined, an error can be returned when there is one. Use Pointer when you want to ignore the error. .

new-from-resource

Creates a new texture by loading an image from a resource.

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

It is a fatal error if $resource-path does not specify a valid image resource and the program will abort if that happens. If you are unsure about the validity of a resource, use .new-from-file() to load it.

This function is threadsafe, so that you can e.g. use GTask and .run-in-thread() in class Gnome::Gio::Task to avoid blocking the main thread while loading a big image.

method new-from-resource ( Str $resource-path --> Gnome::Gdk4::Texture \)

• $resource-path; the path of the resource file.

Methods

download

Downloads the $texture into local memory.

This may be an expensive operation, as the actual texture data may reside on a GPU or on a remote display server.

The data format of the downloaded data is equivalent to %CAIRO_FORMAT_ARGB32, so every downloaded pixel requires 4 bytes of memory.

Downloading a texture into a Cairo image surface:

method download ( Str $data, Int() $stride )

• $data; pointer to enough memory to be filled with the downloaded data of $texture.

• $stride; rowstride in bytes.

get-height

Returns the height of the $texture, in pixels.

method get-height (--> Int )

Return value; the height of the Gnome::Gdk4::Texture.

get-width

Returns the width of $texture, in pixels.

method get-width (--> Int )

Return value; the width of the Gnome::Gdk4::Texture.

save-to-png

Store the given $texture to the $filename as a PNG file.

This is a utility function intended for debugging and testing. If you want more control over formats, proper error handling or want to store to a Gnome::Gdk4::Texture or other location, you might want to use .save-to-png-bytes() or look into the gdk-pixbuf library.

method save-to-png ( Str $filename --> Bool )

• $filename; the filename to store to.

Return value; True if saving succeeded, False on failure..

save-to-png-bytes

Store the given $texture in memory as a PNG file.

Use .new-from-bytes() to read it back.

If you want to serialize a texture, this is a convenient and portable way to do that.

If you need more control over the generated image, such as attaching metadata, you should look into an image handling library such as the gdk-pixbuf library.

If you are dealing with high dynamic range float data, you might also want to consider .save-to-tiff-bytes() instead.

method save-to-png-bytes (--> N-Object )

Return value; a newly allocated Gnome::Glib::N-Bytes containing PNG data.

save-to-tiff

Store the given $texture to the $filename as a TIFF file.

GTK will attempt to store data without loss.

method save-to-tiff ( Str $filename --> Bool )

• $filename; the filename to store to.

Return value; True if saving succeeded, False on failure..

save-to-tiff-bytes

Store the given $texture in memory as a TIFF file.

Use .new-from-bytes() to read it back.

This function is intended to store a representation of the texture's data that is as accurate as possible. This is particularly relevant when working with high dynamic range images and floating-point texture data.

If that is not your concern and you are interested in a smaller size and a more portable format, you might want to use .save-to-png-bytes().

method save-to-tiff-bytes (--> N-Object )

Return value; a newly allocated Gnome::Glib::N-Bytes containing TIFF data.