Struct webrender_api::ImageDescriptor

pub struct ImageDescriptor {
    pub format: ImageFormat,
    pub size: DeviceIntSize,
    pub stride: Option<i32>,
    pub offset: i32,
    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: DeviceIntSize

Width and length of the image data, in pixels.

stride: Option<i32>

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: i32

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: i32,
    height: i32,
    format: ImageFormat,
    is_opaque: bool,
    allow_mipmaps: bool
) -> Self

Mints a new ImageDescriptor.

pub fn compute_stride(&self) -> i32

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

pub fn compute_total_size(&self) -> i32

Computes the total size of the image, in bytes.

pub fn full_rect(&self) -> DeviceIntRect

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

Trait Implementations

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 Copy for ImageDescriptor

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 !=.

impl Debug for ImageDescriptor

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

Formats the value using the given formatter.

impl Serialize for ImageDescriptor

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

Serialize this value into the given Serde serializer.

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

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

Deserialize this value from the given Serde deserializer.

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