mirror of
https://git.sr.ht/~eliasnaur/gio
synced 2026-07-01 07:35:40 +00:00
Chris Waldon
b7d126e24c
This commit restructures the entire text shaping stack to enable lines of shaped text to
have non-homogeneous properties like which font face they belong to and which direction
a segment of text is going.
The text package now provides a concrete type text.Shaper which can be used to convert
strings into sequences of renderable text.Glyphs. At a high level, the API is used
like this:
// Prepare some fonts.
var collection []text.FontFace
// Make a shaper with those fonts loaded.
shaper := text.NewShaper(collection)
// Shape a string.
shaper.LayoutString(text.Parameters{
PxPerEm: fixed.I(12),
}, 0, 100, system.Locale{}, "Hello")
// Iterate the glyphs from that string.
for glyph, ok := shaper.NextGlyph(); ok; glyph, ok = shaper.NextGlyph() {
// Convert the glyph data into a path. In real uses, convert batches of glyphs
// rather than single glyphs to reduce the number of individual paths and offsets
// required to display your text.
shape := shaper.Shape([]text.Glyph{glyph})
// Offset the glyph to the position it declares within its fields. This will
// automatically handle correct bidirectional text glyph positioning.
offset := op.Offset(image.Pt(glyph.X.Floor(), int(glyph.Y))).Push(gtx.Ops)
// Create a clip area from the shape of the glyph.
area := clip.Outline{Path: shape}.Push(gtx.Ops)
// Paint whatever the current color is within the glyph's shape.
paint.PaintOp{}.Add(gtx.Ops)
area.Pop()
offset.Pop()
}
This API will transparently handle both font fallback (choosing appropriate fonts
from those loaded when the primary font doesn't contain a required glyph) and
bidirectional text (mixed left-to-right and right-to-left text). Glyphs are
iterated in order of the input runes, not their visual order, but proper use
of the provided offsets will ensure that text always displays correctly.
Thanks to Elias Naur for suggesting this glyph iterator strategy. It let us cut
through a lot of accumulated complexity from trying to match our old text APIs,
meaning that this change actually is a net negative change in lines of code.
This commit consumes the upstream github.com/go-text/typesetting/shaping API
now that my prior work is merged there, removing the need for the font/opentype/internal
package entirely.
As part of my efforts, I fuzzed both the low-level text shaping stack and the
editor widget extensively. I've committed regression tests found that way into
the appropriate testdata files to ensure the fuzzer re-checks them.
Fixes: https://todo.sr.ht/~eliasnaur/gio/425
Fixes: https://todo.sr.ht/~eliasnaur/gio/211
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
34 lines
3.2 KiB
Plaintext
34 lines
3.2 KiB
Plaintext
eliasnaur.com/font v0.0.0-20220124212145-832bb8fc08c3 h1:djFprmHZgrSepsHAIRMp5UJn3PzsoTg9drI+BDmif5Q=
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eliasnaur.com/font v0.0.0-20220124212145-832bb8fc08c3/go.mod h1:OYVuxibdk9OSLX8vAqydtRPP87PyTFcT9uH3MlEGBQA=
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gioui.org/cpu v0.0.0-20210808092351-bfe733dd3334/go.mod h1:A8M0Cn5o+vY5LTMlnRoK3O5kG+rH0kWfJjeKd9QpBmQ=
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gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2 h1:AGDDxsJE1RpcXTAxPG2B4jrwVUJGFDjINIPi1jtO6pc=
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gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2/go.mod h1:A8M0Cn5o+vY5LTMlnRoK3O5kG+rH0kWfJjeKd9QpBmQ=
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gioui.org/shader v1.0.6 h1:cvZmU+eODFR2545X+/8XucgZdTtEjR3QWW6W65b0q5Y=
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gioui.org/shader v1.0.6/go.mod h1:mWdiME581d/kV7/iEhLmUgUK5iZ09XR5XpduXzbePVM=
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github.com/benoitkugler/pstokenizer v1.0.0/go.mod h1:l1G2Voirz0q/jj0TQfabNxVsa8HZXh/VMxFSRALWTiE=
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github.com/benoitkugler/textlayout v0.2.0 h1:I+s1LuIKckIJgDbsGF1iUNEZ24HZ8mMfb2LsMJU+Uko=
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github.com/benoitkugler/textlayout v0.2.0/go.mod h1:o+1hFV+JSHBC9qNLIuwVoLedERU7sBPgEFcuSgfvi/w=
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github.com/benoitkugler/textlayout-testdata v0.1.1 h1:AvFxBxpfrQd8v55qH59mZOJOQjtD6K2SFe9/HvnIbJk=
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github.com/benoitkugler/textlayout-testdata v0.1.1/go.mod h1:i/qZl09BbUOtd7Bu/W1CAubRwTWrEXWq6JwMkw8wYxo=
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github.com/go-text/typesetting v0.0.0-20221111143014-22bec069817d h1:aAOmUgKRf9Rg2OsWezNWgsEjEtCIcFReQgXH81LrldI=
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github.com/go-text/typesetting v0.0.0-20221111143014-22bec069817d/go.mod h1:RO32JTaCKQV+XI9psTihlQhZsQJp0R4BIkJvHQGsuVo=
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golang.org/x/exp v0.0.0-20221012211006-4de253d81b95 h1:sBdrWpxhGDdTAYNqbgBLAR+ULAPPhfgncLr1X0lyWtg=
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golang.org/x/exp v0.0.0-20221012211006-4de253d81b95/go.mod h1:cyybsKvd6eL0RnXn6p/Grxp8F5bW7iYuBgsNCOHpMYE=
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golang.org/x/exp/shiny v0.0.0-20220827204233-334a2380cb91 h1:ryT6Nf0R83ZgD8WnFFdfI8wCeyqgdXWN4+CkFVNPAT0=
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golang.org/x/exp/shiny v0.0.0-20220827204233-334a2380cb91/go.mod h1:VjAR7z0ngyATZTELrBSkxOOHhhlnVUxDye4mcjx5h/8=
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golang.org/x/image v0.0.0-20210504121937-7319ad40d33e/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
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golang.org/x/image v0.0.0-20210628002857-a66eb6448b8d/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
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golang.org/x/image v0.0.0-20220722155232-062f8c9fd539 h1:/eM0PCrQI2xd471rI+snWuu251/+/jpBpZqir2mPdnU=
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golang.org/x/image v0.0.0-20220722155232-062f8c9fd539/go.mod h1:doUCurBvlfPMKfmIpRIywoHmhN3VyhnoFDbvIEWF4hY=
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golang.org/x/net v0.0.0-20210510120150-4163338589ed/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
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golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
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golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
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golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64 h1:UiNENfZ8gDvpiWw7IpOMQ27spWmThO1RwwdQVbJahJM=
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golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
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golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
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golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
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golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
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golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
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golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
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golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
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