Struct RowPtrCache 

pub struct RowPtrCache { /* private fields */ }

Row pointer cache that pre-computes pointers for O(1) row access.

Port of C++ agg::row_ptr_cache<int8u>.

Implementations

impl RowPtrCache

pub fn new() -> Self

Create an empty (unattached) row pointer cache.

pub unsafe fn new_with_buf( buf: *mut u8, width: u32, height: u32, stride: i32, ) -> Self

Create and attach to a buffer.

Safety

buf must point to a valid buffer of at least height * stride.abs() bytes. The buffer must remain valid for the lifetime of this cache.

pub unsafe fn attach( &mut self, buf: *mut u8, width: u32, height: u32, stride: i32, )

Attach to a buffer, building the row pointer cache.

Safety

Same requirements as new_with_buf.

pub fn buf(&self) -> *mut u8

Raw buffer pointer.

pub fn width(&self) -> u32

pub fn height(&self) -> u32

pub fn stride(&self) -> i32

pub fn stride_abs(&self) -> u32

pub unsafe fn row_ptr(&self, y: i32) -> *mut u8

Get a raw mutable pointer to a row (O(1) via cached pointers).

Safety

y must be in [0, height).

pub fn row_slice(&self, y: u32) -> &[u8]

Get a safe immutable slice for row y.

pub fn row_slice_mut(&mut self, y: u32) -> &mut [u8]

Get a safe mutable slice for row y.

pub fn row(&self, y: u32) -> RowData<'_>

Get row data (x1, x2 range + pointer).

pub fn copy_from<T: RenderingBufferAccess>(&mut self, src: &T)

Copy pixel data from another buffer.

pub fn clear(&mut self, value: u8)

Fill every byte in the buffer with value.

Trait Implementations

impl Default for RowPtrCache

fn default() -> Self

Returns the “default value” for a type.

impl RenderingBufferAccess for RowPtrCache

fn width(&self) -> u32

fn height(&self) -> u32

fn stride_abs(&self) -> u32

unsafe fn row_ptr_const(&self, y: i32) -> *const u8

Safety