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API Reference

API Reference

The importable package is named canvas. This page groups its public modules by task; each link opens generated documentation containing the complete signatures, parameters, return values, and errors. See the full package reference for the module tree.

Start here

  • buffer — Canvas, pixel access, drawing state, transforms, clipping, batches, and supersampled regions.
  • color — Color and ColorSpace.
  • geometry — Point, FPoint, Transform2D, and Matrix2D.
  • vector.draw_target — the shared DrawTarget interface implemented by all three backends.

Most public entry points are also re-exported from the package root:

from canvas import Canvas, Color, Path, fill_circle_aa, write_png

Shapes

  • shapes.lines — lines, polylines, polygon outlines, dashes, caps, and joins.
  • shapes.rects — rectangle outlines and solid, gradient, radial-gradient, or pattern fills.
  • shapes.circles — circle outlines and fills, including batched equal-radius markers with fill_circles_aa.
  • shapes.ellipses — ellipse outlines and fills.
  • shapes.arcs — arcs, wedges, and ring sectors.
  • shapes.polygon_fill — polygon fills.
  • shapes.mesh — fill_mesh and fill_mesh_shaded: adjacent faces drawn as one seam-free shape, flat or with a color per vertex.

Hard-edged primitives have plain names such as draw_line; anti-aliased variants end in _aa.

Paths and paint

  • path — construct, query, transform, fill, and stroke multi-subpath Path values.
  • fill_rule — EVEN_ODD and NONZERO interior rules.
  • gradient — linear, radial, and conic gradients.
  • pattern — raster tiles, hatches, and edge extension.
  • named_colors — CSS named-color constants.

Text

  • text.render — draw, stroke, measure, prepare, and place text on paths.
  • text.font_cache — caller-owned cache for font resolution, parsed faces, and glyph masks. Construction is cheap; font discovery occurs on the first lookup.
  • text.font_discovery — resolve a family, slant, weight, or codepoint to an installed font.
  • text.text_align — left, center, and right alignment.
  • text.glyph_outline — glyph paths and metrics.
  • text.ttf — low-level TrueType/OpenType parsing.
  • text.bidi — bidirectional layout primitives.

Use measure_text for a single line’s TextMetrics, including advance. Use measure_text_block for an anchor-relative multiline ink bounding box. When the same text must be measured and drawn, prepare_text, measure_layout, and draw_layout share one prepared TextLayout.

Compositing and effects

  • compose — place, transform, filter, mask, and composite one canvas onto another.
  • blend — Porter-Duff composite operators and separable or non-separable blend modes.
  • mask — create and apply 8-bit coverage masks.
  • blur — Gaussian-like blur and drop shadows.
  • resize — integer downsampling and general resizing.

Image I/O

  • io.png — read PNG and write 8-bit, non-interlaced PNG; PngLevel selects encoding effort.
  • io.bmp — read and write uncompressed BMP.
  • io.jpeg — read baseline and progressive JPEG.
  • io.deflate — raw DEFLATE streams used by PNG.

SVG and PDF

  • vector.svg — SvgCanvas, SVG text, and write_svg.
  • vector.pdf — PdfCanvas, embedded text and images, multiple pages, and write_pdf.
  • vector.pdf_font — PDF font subsetting internals.

Canvas, SvgCanvas, and PdfCanvas share the DrawTarget primitives, bulk markers, meshes, draw_image, rectangle clips, batches, annotated groups, transforms, and blend and color-space state. Text, path clips, and some paint operations remain backend-specific; consult each backend’s generated reference for its supported surface.

Internal modules

aa_area, aa_crossing, shapes.dash, text.cff, text.joining, and workers are implementation modules rather than package-root APIs. They remain visible in the full package reference for contributors.