erm/app/darktile/gui/render/ligatures.go

46 lines
975 B
Go

package render
import (
"image/color"
"github.com/hajimehoshi/ebiten/v2/text"
imagefont "golang.org/x/image/font"
)
var ligatures = map[string]rune{
":=": '≔',
"===": '≡',
"!=": '≠',
"!==": '≢',
"<=": '≤',
">=": '≥',
"=>": '⇒',
"->": '→',
"<-": '←',
"<>": '≷',
}
func (r *Render) handleLigatures(sx uint16, sy uint16, face imagefont.Face, colour color.Color) (length int) {
var candidate string
for x := sx; x <= sx+2; x++ {
cell := r.buffer.GetCell(x, sy)
if cell == nil || cell.Rune().Rune == 0 {
break
}
candidate += string(cell.Rune().Rune)
}
for len(candidate) > 1 {
if ru, ok := ligatures[candidate]; ok {
// draw ligature
ligX := (int(sx) * r.font.CellSize.X) + (((len(candidate) - 1) * r.font.CellSize.X) / 2)
text.Draw(r.frame, string(ru), face, ligX, (int(sy)*r.font.CellSize.Y)+r.font.DotDepth, colour)
return len(candidate)
}
candidate = candidate[:len(candidate)-1]
}
return 0
}