:right-sidebar: True DmabufTextureBuilder =================================================================== .. currentmodule:: gi.repository.Gdk .. versionadded:: 4.14 .. class:: DmabufTextureBuilder(**properties: ~typing.Any) :no-contents-entry: Superclasses: :class:`~gi.repository.GObject.Object` ``GdkDmabufTextureBuilder`` is a builder used to construct :obj:`~gi.repository.Gdk.Texture` objects from DMA buffers. DMA buffers are commonly called ***dma-bufs***. DMA buffers are a feature of the Linux kernel to enable efficient buffer and memory sharing between hardware such as codecs, GPUs, displays, cameras and the kernel drivers controlling them. For example, a decoder may want its output to be directly shared with the display server for rendering without a copy. Any device driver which participates in DMA buffer sharing, can do so as either the exporter or importer of buffers (or both). The memory that is shared via DMA buffers is usually stored in non-system memory (maybe in device's local memory or something else not directly accessible by the CPU), and accessing this memory from the CPU may have higher-than-usual overhead. In particular for graphics data, it is not uncommon that data consists of multiple separate blocks of memory, for example one block for each of the red, green and blue channels. These blocks are called ***planes***. DMA buffers can have up to four planes. Even if the memory is a single block, the data can be organized in multiple planes, by specifying offsets from the beginning of the data. DMA buffers are exposed to user-space as file descriptors allowing to pass them between processes. If a DMA buffer has multiple planes, there is one file descriptor per plane. The format of the data (for graphics data, essentially its colorspace) is described by a 32-bit integer. These format identifiers are defined in the header file ``drm_fourcc.h`` and commonly referred to as ***fourcc*** values, since they are identified by 4 ASCII characters. Additionally, each DMA buffer has a ***modifier***, which is a 64-bit integer that describes driver-specific details of the memory layout, such as tiling or compression. For historical reasons, some producers of dma-bufs don't provide an explicit modifier, but instead return ``DMA_FORMAT_MOD_INVALID`` to indicate that their modifier is ***implicit***. GTK tries to accommodate this situation by accepting ``DMA_FORMAT_MOD_INVALID`` as modifier. The operation of ``GdkDmabufTextureBuilder`` is quite simple: Create a texture builder, set all the necessary properties, and then call :obj:`~gi.repository.Gdk.DmabufTextureBuilder.build` to create the new texture. The required properties for a dma-buf texture are * The width and height in pixels * The ``fourcc`` code and ``modifier`` which identify the format and memory layout of the dma-buf * The file descriptor, offset and stride for each of the planes ``GdkDmabufTextureBuilder`` can be used for quick one-shot construction of textures as well as kept around and reused to construct multiple textures. For further information, see * The Linux kernel `documentation `_ * The header file `drm_fourcc.h `_ Constructors ------------ .. rst-class:: interim-class .. class:: DmabufTextureBuilder :no-index: .. classmethod:: new() -> ~gi.repository.Gdk.DmabufTextureBuilder Creates a new texture builder. .. versionadded:: 4.14 Methods ------- .. rst-class:: interim-class .. class:: DmabufTextureBuilder :no-index: .. method:: build(destroy: ~typing.Callable[[~typing.Any], None] | None = None, data: ~typing.Any = None) -> ~gi.repository.Gdk.Texture | None Builds a new ``GdkTexture`` with the values set up in the builder. It is a programming error to call this function if any mandatory property has not been set. Not all formats defined in the ``drm_fourcc.h`` header are supported. You can use :obj:`~gi.repository.Gdk.Display.get_dmabuf_formats` to get a list of supported formats. If the format is not supported by GTK, :const:`None` will be returned and ``error`` will be set. The ``destroy`` function gets called when the returned texture gets released. It is the responsibility of the caller to keep the file descriptors for the planes open until the created texture is no longer used, and close them afterwards (possibly using the ``destroy`` notify). It is possible to call this function multiple times to create multiple textures, possibly with changing properties in between. .. versionadded:: 4.14 :param destroy: destroy function to be called when the texture is released :param data: user data to pass to the destroy function .. method:: get_color_state() -> ~gi.repository.Gdk.ColorState | None Gets the color state previously set via :func:`~gi.repository.Gdk.DmabufTextureBuilder.set_color_state`. .. versionadded:: 4.16 .. method:: get_display() -> ~gi.repository.Gdk.Display Returns the display that this texture builder is associated with. .. versionadded:: 4.14 .. method:: get_fd(plane: int) -> int Gets the file descriptor for a plane. .. versionadded:: 4.14 :param plane: the plane to get the fd for .. method:: get_fourcc() -> int Gets the format previously set via :func:`~gi.repository.Gdk.DmabufTextureBuilder.set_fourcc` or 0 if the format wasn't set. The format is specified as a fourcc code. .. versionadded:: 4.14 .. method:: get_height() -> int Gets the height previously set via :func:`~gi.repository.Gdk.DmabufTextureBuilder.set_height` or 0 if the height wasn't set. .. versionadded:: 4.14 .. method:: get_modifier() -> int Gets the modifier value. .. versionadded:: 4.14 .. method:: get_n_planes() -> int Gets the number of planes. .. versionadded:: 4.14 .. method:: get_offset(plane: int) -> int Gets the offset value for a plane. .. versionadded:: 4.14 :param plane: the plane to get the offset for .. method:: get_premultiplied() -> bool Whether the data is premultiplied. .. versionadded:: 4.14 .. method:: get_stride(plane: int) -> int Gets the stride value for a plane. .. versionadded:: 4.14 :param plane: the plane to get the stride for .. method:: get_update_region() -> ~gi.repository.cairo.Region | None Gets the region previously set via :func:`~gi.repository.Gdk.DmabufTextureBuilder.set_update_region` or :const:`None` if none was set. .. versionadded:: 4.14 .. method:: get_update_texture() -> ~gi.repository.Gdk.Texture | None Gets the texture previously set via :func:`~gi.repository.Gdk.DmabufTextureBuilder.set_update_texture` or :const:`None` if none was set. .. versionadded:: 4.14 .. method:: get_width() -> int Gets the width previously set via :func:`~gi.repository.Gdk.DmabufTextureBuilder.set_width` or 0 if the width wasn't set. .. versionadded:: 4.14 .. method:: set_color_state(color_state: ~gi.repository.Gdk.ColorState | None = None) -> None Sets the color state for the texture. By default, the colorstate is ``NULL``. In that case, GTK will choose the correct colorstate based on the format. If you don't know what colorstates are, this is probably the right thing. .. versionadded:: 4.16 :param color_state: a ``GdkColorState`` or ``NULL`` to unset the colorstate. .. method:: set_display(display: ~gi.repository.Gdk.Display) -> None Sets the display that this texture builder is associated with. The display is used to determine the supported dma-buf formats. .. versionadded:: 4.14 :param display: the display .. method:: set_fd(plane: int, fd: int) -> None Sets the file descriptor for a plane. .. versionadded:: 4.14 :param plane: the plane to set the fd for :param fd: the file descriptor .. method:: set_fourcc(fourcc: int) -> None Sets the format of the texture. The format is specified as a fourcc code. The format must be set before calling :obj:`~gi.repository.Gdk.DmabufTextureBuilder.build`. .. versionadded:: 4.14 :param fourcc: the texture's format or 0 to unset .. method:: set_height(height: int) -> None Sets the height of the texture. The height must be set before calling :obj:`~gi.repository.Gdk.DmabufTextureBuilder.build`. .. versionadded:: 4.14 :param height: the texture's height or 0 to unset .. method:: set_modifier(modifier: int) -> None Sets the modifier. .. versionadded:: 4.14 :param modifier: the modifier value .. method:: set_n_planes(n_planes: int) -> None Sets the number of planes of the texture. .. versionadded:: 4.14 :param n_planes: the number of planes .. method:: set_offset(plane: int, offset: int) -> None Sets the offset for a plane. .. versionadded:: 4.14 :param plane: the plane to set the offset for :param offset: the offset value .. method:: set_premultiplied(premultiplied: bool) -> None Sets whether the data is premultiplied. Unless otherwise specified, all formats including alpha channels are assumed to be premultiplied. .. versionadded:: 4.14 :param premultiplied: whether the data is premultiplied .. method:: set_stride(plane: int, stride: int) -> None Sets the stride for a plane. The stride must be set for all planes before calling :obj:`~gi.repository.Gdk.DmabufTextureBuilder.build`. .. versionadded:: 4.14 :param plane: the plane to set the stride for :param stride: the stride value .. method:: set_update_region(region: ~gi.repository.cairo.Region | None = None) -> None Sets the region to be updated by this texture. Together with :obj:`~gi.repository.Gdk.DmabufTextureBuilder.props.update_texture` this describes an update of a previous texture. When rendering animations of large textures, it is possible that consecutive textures are only updating contents in parts of the texture. It is then possible to describe this update via these two properties, so that GTK can avoid rerendering parts that did not change. An example would be a screen recording where only the mouse pointer moves. .. versionadded:: 4.14 :param region: the region to update .. method:: set_update_texture(texture: ~gi.repository.Gdk.Texture | None = None) -> None Sets the texture to be updated by this texture. See :obj:`~gi.repository.Gdk.DmabufTextureBuilder.set_update_region` for an explanation. .. versionadded:: 4.14 :param texture: the texture to update .. method:: set_width(width: int) -> None Sets the width of the texture. The width must be set before calling :obj:`~gi.repository.Gdk.DmabufTextureBuilder.build`. .. versionadded:: 4.14 :param width: The texture's width or 0 to unset Properties ---------- .. rst-class:: interim-class .. class:: DmabufTextureBuilder :no-index: .. attribute:: props.color_state :type: ~gi.repository.Gdk.ColorState The type of the None singleton. .. versionadded:: 4.16 .. attribute:: props.display :type: ~gi.repository.Gdk.Display The type of the None singleton. .. versionadded:: 4.14 .. attribute:: props.fourcc :type: int The type of the None singleton. .. versionadded:: 4.14 .. attribute:: props.height :type: int The type of the None singleton. .. versionadded:: 4.14 .. attribute:: props.modifier :type: int The type of the None singleton. .. versionadded:: 4.14 .. attribute:: props.n_planes :type: int The type of the None singleton. .. versionadded:: 4.14 .. attribute:: props.premultiplied :type: bool The type of the None singleton. .. versionadded:: 4.14 .. attribute:: props.update_region :type: ~gi.repository.cairo.Region The type of the None singleton. .. versionadded:: 4.14 .. attribute:: props.update_texture :type: ~gi.repository.Gdk.Texture The type of the None singleton. .. versionadded:: 4.14 .. attribute:: props.width :type: int The type of the None singleton. .. versionadded:: 4.14