46 lines
1.1 KiB
Go
46 lines
1.1 KiB
Go
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package typeset
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import "golang.org/x/image/font"
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import "golang.org/x/image/math/fixed"
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func measure (tokens []token, face font.Face) {
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var lastRune rune
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for index, token := range tokens {
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var x fixed.Int26_6
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for index, runl := range token.runes {
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advance, ok := face.GlyphAdvance(runl.run)
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if !ok { advance = tofuAdvance(face) }
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advance += face.Kern(lastRune, runl.run)
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runl.x = x
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x += advance
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lastRune = runl.run
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token.runes[index] = runl
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}
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token.width = x
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tokens[index] = token
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}
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}
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const tofuStandinRune = 'M'
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const fallbackTofuAdvance = 16
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const fallbackTofuWidth = 14
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const fallbackTofuAscend = 16
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func tofuAdvance (face font.Face) fixed.Int26_6 {
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if advance, ok := face.GlyphAdvance(tofuStandinRune); ok {
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return advance
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} else {
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return fallbackTofuAdvance
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}
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}
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func tofuBounds (face font.Face) (fixed.Rectangle26_6, fixed.Int26_6) {
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if bounds, advance, ok := face.GlyphBounds(tofuStandinRune); ok {
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return bounds, advance
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} else {
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return fixed.R(0, -fallbackTofuAscend, fallbackTofuWidth, 0),
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fallbackTofuAdvance
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}
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}
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