Rendro.Path (Rendro v1.0.0) (stable)

Declarative vector-graphics block element for Rendro documents.

A %Rendro.Path{} is an inert authored value — a list of drawing operations (ops) with optional fill and stroke styling. It is placed in a document as a block element (via Rendro.path/2) and rendered through the standard build → compose → measure → paginate → render pipeline.

Coordinate model

All coordinates are block-relative, author top-left, Y-down — the same convention used by Rendro.Text, Rendro.Image, and Rendro.Table. The writer performs the single PDF Y-flip internally. Do not pre-flip coordinates.

Op vocabulary

The ops list accepts the following tagged tuple operations:

{:move, x, y} — Move to (x, y) without drawing (m PDF operator).
{:line, x, y} — Draw a straight line to (x, y) (l).
{:curve, x1, y1, x2, y2, x3, y3} — Draw a cubic Bézier curve with two control points (x1,y1), (x2,y2) and endpoint (x3,y3) (c).
{:rect, x, y, w, h} — Draw a rectangle at (x, y) with dimensions w × h (re).
{:rounded_rect, x, y, w, h, radius} — Draw a rectangle with rounded corners of the given radius. Decomposed deterministically into move/line/curve ops using the 0.5522847498 kappa approximation.
:close — Close the current subpath (h).

Stroke and fill

stroke and fill each accept:

nil (default) — no stroke / no fill.
{r, g, b} tuple (integers, 0–255) — bare color, using PDF default line width 1.0, butt caps, miter join, solid dash.
A map with any of: color: {r,g,b}, width: float(), dash: nil | [on, off], cap: :butt | :round | :square, join: :miter | :round | :bevel.

Paint-op selection is deterministic: {nil, nil} → n; {nil, fill} → f; {stroke, nil} → S; {stroke, fill} → B.

Example

Rendro.path([
  {:rect, 10, 10, 100, 50}
], stroke: {0, 0, 0}, width: 200, height: 70)

Summary

Types

color()

fill_style()

op()

stroke_style()

t()

Types

color()

@type color() :: {non_neg_integer(), non_neg_integer(), non_neg_integer()}

fill_style()

@type fill_style() :: nil | color() | %{optional(:color) => color()}

op()

@type op() ::
  {:move, number(), number()}
  | {:line, number(), number()}
  | {:curve, number(), number(), number(), number(), number(), number()}
  | {:rect, number(), number(), number(), number()}
  | {:rounded_rect, number(), number(), number(), number(), number()}
  | :close

stroke_style()

@type stroke_style() ::
  nil
  | color()
  | %{
      optional(:color) => color(),
      optional(:width) => number(),
      optional(:dash) => nil | [number()],
      optional(:cap) => :butt | :round | :square,
      optional(:join) => :miter | :round | :bevel
    }

t()

@type t() :: %Rendro.Path{fill: fill_style(), ops: [op()], stroke: stroke_style()}