Implemented some shape drawing functions to debug character positioning

backends/x/x.go

@@ -222,6 +222,12 @@ func (backend *Backend) drawRune (x, y int, character rune) {
 	_, mask, maskPoint, _, _ := backend.font.face.Glyph (
 		fixed.Point26_6 { },
 		character)
+	strokeRectangle (
+		&image.Uniform {
+			C: backend.config.Color(stone.ColorForeground),
+		},
+		backend.canvas,
+		backend.boundsOfCell(x, y))
 	draw.DrawMask (
 		backend.canvas,
 		backend.boundsOfCell(x, y),
@@ -352,6 +358,44 @@ func findAndLoadFont (name string, size float64) (face font.Face) {
 	return
 }
 
+func fillRectangle (
+	source      image.Image,
+	destination draw.Image,
+	bounds      image.Rectangle,
+) {
+	for y := bounds.Min.Y; y < bounds.Max.Y; y ++ {
+	for x := bounds.Min.X; x < bounds.Max.X; x ++ {
+		destination.Set(x, y, source.At(x, y))
+	}}
+}
+
+func strokeRectangle (
+	source      image.Image,
+	destination draw.Image,
+	bounds      image.Rectangle,
+) {
+	x := 0
+	y := bounds.Min.Y
+	for x = bounds.Min.X; x < bounds.Max.X; x ++ {
+		destination.Set(x, y, source.At(x, y))
+	}
+
+	y = bounds.Max.Y - 1
+	for x = bounds.Min.X; x < bounds.Max.X; x ++ {
+		destination.Set(x, y, source.At(x, y))
+	}
+
+	x = bounds.Min.X
+	for y = bounds.Min.Y; y < bounds.Max.Y; y ++ {
+		destination.Set(x, y, source.At(x, y))
+	}
+
+	x = bounds.Max.X - 1
+	for y = bounds.Min.Y; y < bounds.Max.Y; y ++ {
+		destination.Set(x, y, source.At(x, y))
+	}
+}
+
 // init registers this backend when the program starts.
 func init () {
 	stone.RegisterBackend(factory)