Add fill support to rectangles

[nagieeb0]

Rectangles currently always emit re followed by S, so shapes can only be outlined:

20 20 60 60 re
S

That rules out anything built from solid colour — table header backgrounds, status badges, bar charts, and QR codes. A QR drawn as stroked outlines is unscannable, which is what led me here: I needed ZATCA (Saudi VAT) QR codes on invoices.

Changes

Path.Rectangle gains :fill:

Path.rectangle(path, lower_left: {10, 10}, dimensions: {40, 20}, fill: {0, 0.5, 1})
#=> q / 0 0.5 1 rg / 10 10 40 20 re / f / Q

rg sets the non-stroking colour, f paints the interior. Adding stroke: true emits B instead, filling and stroking in one operation so the two stay aligned:

Path.rectangle(path,
  lower_left: {10, 10}, dimensions: {40, 20},
  fill: {1, 1, 0}, colour: {0, 0, 0}, stroke: true, line_width: 2
)
#=> q / 1 1 0 rg / 0 0 0 RG / 2 w / 10 10 40 20 re / B / Q

stroke is an explicit flag rather than inferred from :colour, since :colour already defaults to black and there would be no way to tell "fill only" from "fill and outline in black".

Default behaviour is unchanged — without :fill, rectangles stroke exactly as before, and there is a test asserting that.

Verification

Four new tests in drawing_test.exs covering fill-only, fill+stroke, the unchanged stroke-only path, and many filled rectangles composing (the QR / bar-chart shape). test/drawing_test.exs is green: 12 tests, 0 failures.

The wider suite shows 21 failures both with and without this change on my machine — I am outside the Nix shell and substituted Google Fonts builds of Libre Bodoni/Franklin, whose metrics differ from the pinned ones. No new failures are introduced.

Happy to add Path.Line fill or a general close-and-fill in a follow-up if you would like the shape of it to be different.

🤖 Generated with Claude Code