Struct CanvasBuffer 

pub struct CanvasBuffer {
    pub addr: *mut u8,
    pub width: usize,
    pub height: usize,
    pub pitch: usize,
    pub bpp: u16,
    pub back_buffer: Option<Vec<u32>>,
    pub draw_to_back: bool,
    pub dirty: DirtyRectSet,
    pub track_dirty: bool,
    pub present_pending: bool,
    pub last_present_tick: u64,
    pub ops: FramebufferOps,
}

A raw framebuffer canvas with optional double buffering.

Encapsulates the HW framebuffer pointer, optional back-buffer (always 32bpp), dirty-region tracking, SIMD-accelerated pixel ops, and a present() that flushes dirty regions to the real hardware.

Used by both the VGA text-mode writer (VgaWriter) and the raw hardware video driver (hardware::video::Framebuffer), eliminating the duplicated present() / dirty-tracking logic between them.

Fields

addr: *mut u8

Pointer to the start of the HW framebuffer (HHDM-mapped virtual).

width: usize

Width in pixels.

height: usize

Height in pixels.

pitch: usize

Bytes per row (stride / pitch).

bpp: u16

Bits per pixel (24 or 32).

back_buffer: Option<Vec<u32>>

Optional back-buffer (always 32bpp / u32 per pixel).

draw_to_back: bool

If true, draw operations write to back_buffer instead of HW.

dirty: DirtyRectSet

Set of dirty rectangles pending a present().

track_dirty: bool

If true, dirty rectangles are tracked.

present_pending: bool

Whether a present() has been requested.

last_present_tick: u64

Tick of the last present() (for rate-limiting).

ops: FramebufferOps

SIMD-accelerated pixel ops (fill, blit, blend, convert).

Implementations

impl CanvasBuffer

pub fn enable_back_buffer(&mut self) -> bool

Enable double-buffering by allocating and syncing a back-buffer.

pub fn disable_back_buffer(&mut self, do_present: bool)

Disable double-buffering, optionally presenting first.

pub fn pixel_offset(&self, x: usize, y: usize) -> Option<usize>

Byte offset in HW memory for pixel (x, y).

pub fn read_hw_pixel(&self, x: usize, y: usize) -> u32

Read a packed pixel directly from HW memory.

pub fn write_hw_pixel(&mut self, x: usize, y: usize, color: u32)

Write a packed pixel to HW memory.

pub fn read_pixel(&self, x: usize, y: usize) -> u32

Read pixel (x, y) : from back-buffer if available, else HW.

pub fn write_pixel(&mut self, x: usize, y: usize, color: u32)

Write pixel (x, y) : to back-buffer if available, else HW.

pub fn fill_rect(&mut self, x: usize, y: usize, w: usize, h: usize, color: u32)

Fill a rectangle with a packed colour.

pub fn present(&mut self)

Flush dirty back-buffer regions to the hardware framebuffer.

Uses SIMD-accelerated ops.blit when the back-buffer’s row stride matches the frame-buffer’s stride, falling back to row-by-row copies.

pub fn request_present(&mut self)

Request a present (throttled).

pub fn present_if_due(&mut self, force: bool, now: u64)

Present if a request is pending and the throttle delay has elapsed.

Trait Implementations

impl Send for CanvasBuffer