Crate denise_render 

Denise’s software rasteriser.

Rectangles, rounded rectangles, circles, arcs, stars, lines, image blitting, rectangular clipping and source-over alpha blending, straight into a denise::Frame. No GPU, no path builder, no allocator: this crate needs neither std nor alloc, and every operation writes through a borrowed slice the caller already owns.

let mut canvas = Canvas::new(frame);
for region in damage {
    // Everything inside this borrow is confined to `region`.
    let mut c = canvas.with_clip(*region);
    c.clear(Color::from_rgb888(0x1E1E2E));
    c.fill_rounded_rect(Rect::new(40, 40, 200, 64), 12, Color::rgba(255, 255, 255, 32));
    c.draw_line(Point::new(40, 120), Point::new(240, 121), Color::WHITE);
    // A 70% progress ring. Angles are binary turns: 0 is twelve o'clock,
    // clockwise positive, no radians and no floats anywhere.
    c.stroke_arc(Point::new(300, 90), 40, 8, 0, 70 * denise_render::TURN / 100, Color::WHITE);
}

No floating point

The rasteriser is integer throughout, including anti-aliasing coverage. That avoids a libm dependency on no_std targets and keeps output bit-identical between x86 and ARM, so the reference tests mean the same thing on a developer’s desktop and on the Pi.

No unsafe

Deliberately, for now. Bounds checks are hoisted by working through row slices rather than indexing pixel by pixel. If the benches ever show that costing real time, that is the evidence needed to justify unchecked access — not before.

Re-exports

pub use canvas::Canvas;

pub use font::BitmapFont;

Modules

blend

Pixel arithmetic.

blit

Drawing somebody else’s pixels: the positioned, blended blit.

canvas

The drawing target: a borrowed frame plus a clip rectangle.

coverage

Compositing 8-bit coverage masks.

font

The built-in bitmap font.

icon

Shapes a widget can draw when the font has no glyph for them.

painter

Canvas wearing the painting contract.

Structs

ClipToken

Proof that a clip was narrowed, and the only way to widen one back.

Clipped

A painter with a narrowed clip, which it restores when dropped.

Mask

A borrowed 8-bit coverage mask: 0 transparent, 255 fully covered.

Paint

A colour prepared for drawing.

Pen

The pen widgets draw with: a &mut dyn Painter wearing the ergonomics the trait cannot have.

PixelView

A read-only view of somebody else’s pixels, for Canvas::copy_from.

Constants

MAX_ICON_VERTICES

The most vertices one shape of an Icon may have.

TURN

One full revolution, in the angle unit every arc call takes.

Traits

Painter

A clipped drawing target.

PainterExt

The part of the painting API that cannot be object-safe.