README
¶
gfx — pure-Go 2D graphics foundation
github.com/go-gfx/gfx is a pure-Go, CGO=0 2D graphics foundation: the shared
substrate that sits below the fleet's image-processing and rendering libraries.
It is not an image-processing library (that is go-images, the scikit-image analogue) and not a widget toolkit (that is go-widgets). It is the common layer both stand on: pixel buffers, colour science, high-quality resampling, image codecs, and vector rasterization — each usable on its own, with no third-party dependencies.
Packages
| Package | Purpose |
|---|---|
geometry |
points, rectangles, affine transforms |
color |
full colour science: HSV/HSL/HWB, XYZ/Lab/LCh/Luv/OKLab/OKLCH, Y′CbCr, CMYK, D65↔D50 Bradford, ΔE (76/94/2000/OK), separable + non-separable blends, premultiplied alpha |
raster |
shared pixel-buffer / pixel-format substrate |
resample |
high-quality resizing: box/area, bicubic (Catmull-Rom), Lanczos |
codec |
image decoders/encoders: png, jpeg, webp, ico, icns, gif, tiff |
vector |
paths, anti-aliased fill/stroke rasterizer (round joins & caps, non-zero / even-odd), linear/radial gradients, source-over compositing |
iso |
isometric projection (project / unproject / depth-sort) and shaded pixel primitives — cube, brick, pyramid, slope, line, side — composited into a depth-ordered scene (the pure-Go obelisk.js) |
Consumers
- go-images — image processing/analysis, built on
raster/color/resample. - go-widgets/painter — tri-backend renderer, built on
vector/raster/color. - go-webengine — HTML/CSS → image, built on
resample/codec/vector. - go-widgets/desktop — icon & thumbnail rendering.
Status
Landed: geometry (float64 point / axis-aligned rect / 2-D affine matrix —
translate, scale, rotate, shear, compose, invert, transform point & rect),
raster (pixel substrate), color (a complete colour-science layer: premultiplied
alpha; the sRGB and generic-gamma transfer functions; the cylindrical sRGB models
HSV/HSL/HWB; the CIE hub XYZ with D65 and D50 white points and Bradford
D65↔D50 adaptation; CIE L*a*b*/LCh, L*u*v*/LCh(uv), Ottosson OKLab/OKLCH;
Y′CbCr BT.601/709 and naive CMYK; the ΔE colour-difference metrics ΔE76, ΔE94,
CIEDE2000 and ΔE-OK; the W3C separable and non-separable blend modes; and a
second, scikit-image-byte-compatible sRGB↔XYZ↔Lab regime so go-images can share
one colour library — all numerically checked against the colour-science oracle
and the published CIE / W3C / Sharma reference values), resample (nearest, bilinear, box/area, bicubic, Lanczos — each with
a premultiplied-alpha variant), and vector (2-D path builder +
anti-aliased scanline fill/stroke rasterizer, extracted verbatim from
go-widgets/painter and proven pixel-identical to it, now with linear/radial
gradients and source-over compositing of any paint through a coverage grid).
Colour-science and blend results match the published CIE / W3C reference values.
Pure-Go, CGO=0, 100% covered, six-arch CI, numeric parity with Pillow. See
docs/perf.md.
License
BSD-3-Clause — see LICENSE. Copyright the go-gfx authors.
Documentation
¶
Overview ¶
Package gfx is the module root for the go-gfx pure-Go 2D graphics foundation.
The functionality lives in subpackages (geometry, color, raster, resample, codec, vector). This file exists only to document the module and give it a root package; import the subpackage you need.
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
|
Package codec is go-gfx's unified image-decoding registry: one Decode entry point that sniffs a byte slice's container format and dispatches to the appropriate REFERENCE decoder, returning the shared raster.Image substrate the rest of go-gfx consumes.
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Package codec is go-gfx's unified image-decoding registry: one Decode entry point that sniffs a byte slice's container format and dispatches to the appropriate REFERENCE decoder, returning the shared raster.Image substrate the rest of go-gfx consumes. |
|
Package color holds go-gfx's colour helpers.
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Package color holds go-gfx's colour helpers. |
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Package geometry is go-gfx's floating-point 2-D geometry substrate: a Point, an axis-aligned Rect, and a 2-D affine Matrix (translate / scale / rotate / shear, composed, inverted, and applied to points and rectangles).
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Package geometry is go-gfx's floating-point 2-D geometry substrate: a Point, an axis-aligned Rect, and a 2-D affine Matrix (translate / scale / rotate / shear, composed, inverted, and applied to points and rectangles). |
|
Package iso is go-gfx's isometric projection and primitive-drawing layer: the pure-Go equivalent of obelisk.js.
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Package iso is go-gfx's isometric projection and primitive-drawing layer: the pure-Go equivalent of obelisk.js. |
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Package raster is the shared pixel-buffer substrate of go-gfx: a densely packed 8-bit RGBA image the higher layers (resample, color, and the fleet's image-processing and rendering libraries) read and write.
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Package raster is the shared pixel-buffer substrate of go-gfx: a densely packed 8-bit RGBA image the higher layers (resample, color, and the fleet's image-processing and rendering libraries) read and write. |
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Package resample resizes RGBA images with a choice of separable filters: nearest-neighbour, bilinear, box/area, bicubic (Catmull-Rom) and Lanczos (a=3).
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Package resample resizes RGBA images with a choice of separable filters: nearest-neighbour, bilinear, box/area, bicubic (Catmull-Rom) and Lanczos (a=3). |
|
Package vector is go-gfx's pure-Go 2-D vector rasterizer: it turns arbitrary outlines (move / line / quadratic / cubic / close) into per-pixel coverage, with an anti-aliased scanline accumulator and a round-join / round-cap stroker.
|
Package vector is go-gfx's pure-Go 2-D vector rasterizer: it turns arbitrary outlines (move / line / quadratic / cubic / close) into per-pixel coverage, with an anti-aliased scanline accumulator and a round-join / round-cap stroker. |