Implemented highlight and underline styles

backends/x/draw.go

@@ -53,7 +53,12 @@ func (backend *Backend) drawCells (forceRedraw bool) (areas []image.Rectangle) {
 		if forceRedraw && content < 32 { continue }
 
 		areas = append(areas, backend.boundsOfCell(x, y))
-		backend.drawRune(x, y, content, cell.Color(), !forceRedraw)
+		backend.drawRune (
+			x, y,
+			content,
+			cell.Color(),
+			cell.Style(),
+			!forceRedraw)
 	}}
 
 	if backend.drawBufferBounds && forceRedraw {
@@ -74,24 +79,35 @@ func (backend *Backend) drawRune (
 	x, y int,
 	character rune,
 	runeColor stone.Color,
+	runeStyle stone.Style,
 	drawBackground bool,
 ) {
 	// TODO: cache these draws as non-transparent buffers with the
 	// application background color as the background. that way, we won't
 	// need to redraw the characters *or* composite them.
 
-	if drawBackground {
+	var background xgraphics.BGRA
+	var foreground xgraphics.BGRA
+	highlight := runeStyle & stone.StyleHighlight > 0
+
+	if highlight {
+		background = backend.colors[runeColor]
+		foreground = backend.colors[stone.ColorBackground]
+	} else {
+		background = backend.colors[stone.ColorBackground]
+		foreground = backend.colors[runeColor]
+	}
+
+	if drawBackground || highlight {
 		fillRectangle (
-			&image.Uniform {
+			&image.Uniform { C: background },
-				C: backend.config.Color(stone.ColorBackground),
-			},
 			backend.canvas,
 			backend.boundsOfCell(x, y))
 	}
 
-	if character < 32 { return }
-
 	origin := backend.originOfCell(x, y + 1)
+
+	if character >= 32 {
 		destinationRectangle, mask, maskPoint, _, ok := backend.font.face.Glyph (
 			fixed.Point26_6 {
 				X: fixed.I(origin.X),
@@ -101,9 +117,7 @@ func (backend *Backend) drawRune (
 
 		if !ok {
 			strokeRectangle (
-			&image.Uniform {
+				&image.Uniform { C: foreground },
-				C: backend.config.Color(stone.ColorForeground),
-			},
 				backend.canvas,
 				backend.boundsOfCell(x, y))
 			return
@@ -111,9 +125,7 @@ func (backend *Backend) drawRune (
 
 		if backend.drawCellBounds {
 			strokeRectangle (
-			&image.Uniform {
+				&image.Uniform { C: foreground },
-				C: backend.config.Color(stone.ColorForeground),
-			},
 				backend.canvas,
 				backend.boundsOfCell(x, y))
 		}
@@ -123,11 +135,23 @@ func (backend *Backend) drawRune (
 		if isAlpha {
 			backend.sprayRuneMaskAlpha (
 				alphaMask, destinationRectangle,
-			maskPoint, backend.colors[runeColor])
+				maskPoint, foreground, background)
 		} else {
 			backend.sprayRuneMask (
 				mask, destinationRectangle,
-			maskPoint, backend.colors[runeColor])
+				maskPoint, foreground, background)
+		}
+	}
+
+	// underline
+	if runeStyle & stone.StyleUnderline > 0 {
+		maxX := origin.X + backend.metrics.cellWidth
+		y :=
+			origin.Y -
+			backend.metrics.descent
+		for x := origin.X; x < maxX; x ++ {
+			backend.canvas.SetBGRA(x, y, foreground)
+		}
 	}
 }
 
@@ -136,6 +160,7 @@ func (backend *Backend) sprayRuneMask (
 	bounds     image.Rectangle,
 	maskPoint  image.Point,
 	fill       xgraphics.BGRA,
+	background xgraphics.BGRA,
 ) {
 	maxX := bounds.Max.X - bounds.Min.X
 	maxY := bounds.Max.Y - bounds.Min.Y
@@ -148,7 +173,7 @@ func (backend *Backend) sprayRuneMask (
 			x + bounds.Min.X,
 			y + bounds.Min.Y - backend.metrics.descent,
 			xgraphics.BlendBGRA (
-				backend.colors[stone.ColorBackground],
+				background,
 				xgraphics.BGRA {
 					R: fill.R,
 					G: fill.G,
@@ -163,6 +188,7 @@ func (backend *Backend) sprayRuneMaskAlpha (
 	bounds     image.Rectangle,
 	maskPoint  image.Point,
 	fill       xgraphics.BGRA,
+	background xgraphics.BGRA,
 ) {
 	maxX := bounds.Max.X - bounds.Min.X
 	maxY := bounds.Max.Y - bounds.Min.Y
@@ -174,7 +200,7 @@ func (backend *Backend) sprayRuneMaskAlpha (
 			x + bounds.Min.X,
 			y + bounds.Min.Y - backend.metrics.descent,
 			xgraphics.BlendBGRA (
-				backend.colors[stone.ColorBackground],
+				background,
 				xgraphics.BGRA {
 					R: fill.R,
 					G: fill.G,

buffer.go

@@ -21,11 +21,11 @@ const (
 type Style uint8
 
 const (
-	StyleNormal     Style = iota
+	StyleNormal     Style = 0
-	StyleBold       Style = iota >> 1
+	StyleBold       Style = 1
-	StyleItalic
+	StyleItalic     Style = 2
-	StyleUnderline
+	StyleUnderline  Style = 4
-	StyleHighlight
+	StyleHighlight  Style = 8
 	StyleBoldItalic Style = StyleBold | StyleItalic
 )