Struct webrender::api::ImageDescriptor

pub struct ImageDescriptor {
    pub format: ImageFormat,
    pub size: TypedSize2D<u32, DevicePixel>,
    pub stride: Option<u32>,
    pub offset: u32,
    pub is_opaque: bool,
    pub allow_mipmaps: bool,
}

Metadata (but not storage) describing an image In WebRender.

Fields

format: ImageFormat

Format of the image data.

size: TypedSize2D<u32, DevicePixel>

Width and length of the image data, in pixels.

stride: Option<u32>

The number of bytes from the start of one row to the next. If non-None, compute_stride will return this value, otherwise it returns width * bpp. Different source of images have different alignment constraints for rows, so the stride isn't always equal to width * bpp.

offset: u32

Offset in bytes of the first pixel of this image in its backing buffer. This is used for tiling, wherein WebRender extracts chunks of input images in order to cache, manipulate, and render them individually. This offset tells the texture upload machinery where to find the bytes to upload for this tile. Non-tiled images generally set this to zero.

is_opaque: bool

Whether this image is opaque, or has an alpha channel. Avoiding blending for opaque surfaces is an important optimization.

allow_mipmaps: bool

Whether to allow the driver to automatically generate mipmaps. If images are already downscaled appropriately, mipmap generation can be wasted work, and cause performance problems on some cards/drivers.

See https://github.com/servo/webrender/pull/2555/

Methods

impl ImageDescriptor

pub fn new(     width: u32,     height: u32,     format: ImageFormat,     is_opaque: bool,     allow_mipmaps: bool ) -> ImageDescriptor

Mints a new ImageDescriptor.

pub fn compute_stride(&self) -> u32

Returns the stride, either via an explicit stride stashed on the object or by the default computation.

pub fn compute_total_size(&self) -> u32

Computes the total size of the image, in bytes.

pub fn full_rect(&self) -> TypedRect<u32, DevicePixel>

Computes the bounding rectangle for the image, rooted at (0, 0).

Trait Implementations

impl Copy for ImageDescriptor

impl Clone for ImageDescriptor

fn clone(&self) -> ImageDescriptor

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Serialize for ImageDescriptor

fn serialize<__S>(     &self,     __serializer: __S ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error> where     __S: Serializer,

Serialize this value into the given Serde serializer.

impl Debug for ImageDescriptor

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ImageDescriptor

fn deserialize<__D>(     __deserializer: __D ) -> Result<ImageDescriptor, <__D as Deserializer<'de>>::Error> where     __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

fn deserialize_in_place<__D>(     __deserializer: __D,     __place: &mut ImageDescriptor ) -> Result<(), <__D as Deserializer<'de>>::Error> where     __D: Deserializer<'de>,

impl PartialEq<ImageDescriptor> for ImageDescriptor

fn eq(&self, other: &ImageDescriptor) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &ImageDescriptor) -> bool

This method tests for !=.