Struct Strip 

pub struct Strip {
    pub x: u16,
    pub y: u16,
    packed_alpha_idx_fill_gap: u32,
}

A strip.

Fields

x: u16

The x coordinate of the strip, in user coordinates.

y: u16

The y coordinate of the strip, in user coordinates.

packed_alpha_idx_fill_gap: u32

Packed alpha index and fill gap flag.

Bit layout (u32):

• bit 31: fill_gap (See Strip::fill_gap()).
• bits 0..=30: alpha_idx (See Strip::alpha_idx()).

Implementations

impl Strip

const FILL_GAP_MASK: u32

The bit mask for fill_gap packed into packed_alpha_idx_fill_gap.

pub fn new(x: u16, y: u16, alpha_idx: u32, fill_gap: bool) -> Self

Creates a new strip.

pub fn sentinel(y: u16, alpha_idx: u32) -> Self

Creates a sentinel strip.

pub fn is_sentinel(&self) -> bool

Return whether the strip is a sentinel strip.

pub fn strip_y(&self) -> u16

Return the y coordinate of the strip, in strip units.

pub fn width_to(&self, next: &Self) -> u16

Returns the horizontal pixel width of this strip.

IMPORTANT: This assumes that the next is actually the next adjacent strip to self, otherwise this method will return a garbage value!

pub fn alpha_idx(&self) -> u32

Returns the alpha index.

pub fn set_alpha_idx(&mut self, alpha_idx: u32)

Sets the alpha index.

Note that the largest value that can be stored in the alpha index is u32::MAX << 1, as the highest bit is reserved for fill_gap.

pub fn fill_gap(&self) -> bool

Returns whether the gap that lies between this strip and the previous in the same row should be filled.

pub fn set_fill_gap(&mut self, fill: bool)

Sets whether the gap that lies between this strip and the previous in the same row should be filled.

fn emit_culled_background<F>( start: u16, end: u16, viewport_width: u16, strips: &mut Vec<Self>, alphas: &mut Vec<u8>, windings: &CulledWindings, should_fill: F, )

where F: FnMut(i32) -> bool,

When early culling is active, geometry fully to the left of the viewport creates no tiles. However, if that geometry has a non-zero winding (e.g. a large shape surrounding the viewport), then we must output strips for those fills.

We reconstruct this “background” fill using row_windings (the winding at x=0) to emit solid strips for: 1. All rows vertically above the first visible tile. 2. ‘Captive’ rows between two tile-containing rows. 3. All rows vertically below the last visible tile.

Trait Implementations

impl Clone for Strip

fn clone(&self) -> Strip

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Strip

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

Formats the value using the given formatter.

impl PartialEq for Strip

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Strip

impl Eq for Strip

impl StructuralPartialEq for Strip